// 数据层：dev-bridge 与 seed 共用
// v2：多端同步地基 —— uuid v7 / 软删除墓碑 / HLC / 变更日志（自建服务方案）
import { DatabaseSync } from 'node:sqlite';
import fs from 'node:fs';
import path from 'node:path';
import crypto from 'node:crypto';
import { fileURLToPath } from 'node:url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
export const DATA_DIR = process.env.DATA_DIR || path.join(__dirname, '..', '.data');
export const ATT_DIR = path.join(DATA_DIR, 'attachments');
export const DB_PATH = path.join(DATA_DIR, 'footprints.db');

function getMeta(d, key) {
  const r = d.prepare('SELECT value FROM sync_state WHERE key=?').get(key);
  return r ? r.value : null;
}

function setMeta(d, key, value) {
  d.prepare("INSERT INTO sync_state (key, value) VALUES (?,?) ON CONFLICT(key) DO UPDATE SET value=excluded.value")
    .run(key, String(value));
}

function getDeviceId(d) {
  let id = getMeta(d, 'device_id');
  if (!id) {
    id = crypto.randomBytes(6).toString('hex');
    setMeta(d, 'device_id', id);
  }
  return id;
}

// UUID v7（RFC 9562）：48bit 毫秒时间戳 + 随机位，时间有序，索引友好
export function uuidv7() {
  const ts = Date.now();
  const b = Buffer.alloc(16);
  b.writeUIntBE(ts % 281474976710656, 0, 6);
  crypto.randomBytes(10).copy(b, 6);
  b[6] = (b[6] & 0x0f) | 0x70;   // version 7
  b[8] = (b[8] & 0x3f) | 0x80;   // variant 10
  const h = b.toString('hex');
  return h.slice(0, 8) + '-' + h.slice(8, 12) + '-' + h.slice(12, 16) + '-' + h.slice(16, 20) + '-' + h.slice(20, 32);
}

// 混合逻辑时钟：毫秒:计数:设备 —— 时钟回拨免疫，同设备单调，跨设备可比较
export function hlcNext(d) {
  const ms = Date.now();
  const lastMs = Number(getMeta(d, 'hlc_ms') || 0);
  const lastCnt = Number(getMeta(d, 'hlc_counter') || 0);
  let newMs, newCnt;
  if (ms > lastMs) { newMs = ms; newCnt = 0; }
  else { newMs = lastMs; newCnt = lastCnt + 1; }
  setMeta(d, 'hlc_ms', String(newMs));
  setMeta(d, 'hlc_counter', String(newCnt));
  return newMs + ':' + newCnt + ':' + getDeviceId(d);
}

function touchOplog(d, table, rowUuid, op, hlc) {
  d.prepare('INSERT INTO sync_oplog (table_name, row_uuid, op, hlc) VALUES (?,?,?,?)')
    .run(table, rowUuid, op, hlc);
}

function withTx(d, fn) {
  d.exec('BEGIN');
  try { const r = fn(); d.exec('COMMIT'); return r; }
  catch (e) { d.exec('ROLLBACK'); throw e; }
}

function getUuid(d, table, id) {
  const r = d.prepare('SELECT uuid FROM ' + table + ' WHERE id=?').get(id);
  return r ? r.uuid : null;
}

export function buildSearchText(title, description, result, tags, extras) {
  const extraFlat = Object.entries(extras || {}).map(([k, v]) => {
    if (v == null) return '';
    if (typeof v === 'object') return Object.values(v).filter(Boolean).join(' ');
    return String(v);
  }).filter(Boolean);
  return [title, description || '', result || '', (tags || []).join(' '), ...extraFlat]
    .filter(Boolean).join('\n');
}

// ---------- Wire 协议（各端互通：uuid 引用 FK，LWW 仲裁） ----------

function parseHlc(h) {
  const m = /^([0-9]+):([0-9]+):(.+)$/.exec(String(h || ''));
  return m ? { ms: Number(m[1]), cnt: Number(m[2]), dev: m[3] } : null;
}

function hlcNewer(a, b) {
  if (a.ms !== b.ms) return a.ms > b.ms;
  if (a.cnt !== b.cnt) return a.cnt > b.cnt;
  return a.dev > b.dev;
}

// 表 → [列, FK引用目标表]
const WIRE_TABLES = {
  footprint: { fks: { type_id: 'footprint_type', parent_id: 'footprint' } },
  footprint_type: { fks: {} },
  taxonomy: { fks: {} },
  dimension: { fks: {} },
  grade_band: { fks: {} },
  metric_def: { fks: {} },
  semester: { fks: {} },
  course_grade: { fks: { semester_id: 'semester' } },
  saved_view: { fks: {} },
  attachment: { fks: { owner_id: 'footprint' } },
  footprint_dimension: { fks: { footprint_id: 'footprint', dimension_id: 'dimension' } }
};

// 老库迁移：补列 + 回填 uuid/hlc/origin（幂等）
const SYNC_TABLES = ['footprint', 'footprint_type', 'taxonomy', 'dimension', 'attachment',
  'semester', 'course_grade', 'metric_def', 'saved_view', 'grade_band'];

const SYNC_COLS = [['uuid', 'TEXT'], ['deleted_at', 'TEXT'], ['origin', 'TEXT'], ['hlc', 'TEXT']];

function preMigrateColumns(d) {
  const addCols = (t, cols) => {
    const exists = d.prepare("SELECT 1 FROM sqlite_master WHERE type='table' AND name=?").get(t);
    if (!exists) return; // 全新库：表由 schema.sql 创建，自带同步列
    const have = new Set(d.prepare('PRAGMA table_info(' + t + ')').all().map(c => c.name));
    for (const [name, ddl] of cols) {
      if (!have.has(name)) d.exec('ALTER TABLE ' + t + ' ADD COLUMN ' + name + ' ' + ddl);
    }
  };
  for (const t of SYNC_TABLES) addCols(t, SYNC_COLS);
  addCols('attachment', [['sha256', 'TEXT'], ['thumb_rel_path', 'TEXT']]);
}

export function migrateSync(d) {
  const addCols = (t, cols) => {
    const have = new Set(d.prepare('PRAGMA table_info(' + t + ')').all().map(c => c.name));
    for (const [name, ddl] of cols) {
      if (!have.has(name)) d.exec('ALTER TABLE ' + t + ' ADD COLUMN ' + name + ' ' + ddl);
    }
  };
  for (const t of SYNC_TABLES) {
    addCols(t, [['uuid', 'TEXT'], ['deleted_at', 'TEXT'], ['origin', 'TEXT'], ['hlc', 'TEXT']]);
  }
  addCols('attachment', [['sha256', 'TEXT']]);
  for (const t of SYNC_TABLES) {
    const rows = d.prepare('SELECT id FROM ' + t + ' WHERE uuid IS NULL').all();
    for (const row of rows) {
      d.prepare('UPDATE ' + t + ' SET uuid=?, hlc=?, origin=? WHERE id=?')
        .run(uuidv7(), hlcNext(d), 'migrate', row.id);
    }
  }
}

function softDelete(d, table, id) {
  const uuid = getUuid(d, table, id);
  if (!uuid) return;
  const h = hlcNext(d);
  d.prepare('UPDATE ' + table + " SET deleted_at=datetime('now','localtime'), hlc=? WHERE id=?").run(h, id);
  touchOplog(d, table, uuid, 'delete', h);
}

// ---------- 全局固定内置 uuid（各端一致；Rust 端 ensure_builtin 使用同一映射） ----------
export const BUILTIN_UUID = {
  '类型:学业': '018f0000-0000-7000-8000-000000000001',
  '类型:竞赛': '018f0000-0000-7000-8000-000000000002',
  '类型:科研': '018f0000-0000-7000-8000-000000000003',
  '类型:实习实践': '018f0000-0000-7000-8000-000000000004',
  '类型:学生工作': '018f0000-0000-7000-8000-000000000005',
  '类型:志愿公益': '018f0000-0000-7000-8000-000000000006',
  '类型:文体活动': '018f0000-0000-7000-8000-000000000007',
  '类型:证书技能': '018f0000-0000-7000-8000-000000000008',
  '类型:荣誉惩处': '018f0000-0000-7000-8000-000000000009',
  '级别:国际级': '018f0000-0000-7000-8000-000000000011',
  '级别:国家级': '018f0000-0000-7000-8000-000000000012',
  '级别:省市级': '018f0000-0000-7000-8000-000000000013',
  '级别:区县级': '018f0000-0000-7000-8000-000000000014',
  '级别:校级': '018f0000-0000-7000-8000-000000000015',
  '级别:院级': '018f0000-0000-7000-8000-000000000016',
  '角色:主导': '018f0000-0000-7000-8000-000000000017',
  '角色:核心': '018f0000-0000-7000-8000-000000000018',
  '角色:参加': '018f0000-0000-7000-8000-000000000019',
  '维度:学业深造': '018f0000-0000-7000-8000-000000000021',
  '维度:职业发展': '018f0000-0000-7000-8000-000000000022',
  '维度:综合素养': '018f0000-0000-7000-8000-000000000023',
  '维度:兴趣生活': '018f0000-0000-7000-8000-000000000024',
  '梯度:优秀': '018f0000-0000-7000-8000-000000000031',
  '梯度:良好': '018f0000-0000-7000-8000-000000000032',
  '梯度:中等': '018f0000-0000-7000-8000-000000000033',
  '梯度:及格': '018f0000-0000-7000-8000-000000000034',
  '梯度:不及格': '018f0000-0000-7000-8000-000000000035',
  '指标:volunteer_hours': '018f0000-0000-7000-8000-000000000041'
};

// 内置 uuid 按名称对齐（存量库与新库统一；origin=builtin）
function alignBuiltinUuids(db) {
  const fix = (table, key) => {
    const uuid = BUILTIN_UUID[key];
    if (!uuid) return;
    db.prepare('UPDATE ' + table + ' SET uuid=? WHERE name=? AND uuid<>?').run(uuid, key.split(':')[1], uuid);
  };
  for (const key of Object.keys(BUILTIN_UUID)) {
    const [kind, name] = key.split(':');
    const uuid = BUILTIN_UUID[key];
    if (kind === '类型') db.prepare('UPDATE footprint_type SET uuid=? WHERE name=? AND uuid<>?').run(uuid, name, uuid);
    else if (kind === '级别') db.prepare("UPDATE taxonomy SET uuid=? WHERE kind='level' AND value=? AND uuid<>?").run(uuid, name, uuid);
    else if (kind === '角色') db.prepare("UPDATE taxonomy SET uuid=? WHERE kind='role' AND value=? AND uuid<>?").run(uuid, name, uuid);
    else if (kind === '维度') db.prepare('UPDATE dimension SET uuid=? WHERE name=? AND uuid<>?').run(uuid, name, uuid);
    else if (kind === '梯度') db.prepare('UPDATE grade_band SET uuid=? WHERE label=? AND uuid<>?').run(uuid, name, uuid);
    else if (kind === '指标') db.prepare('UPDATE metric_def SET uuid=? WHERE key=? AND uuid<>?').run(uuid, name, uuid);
  }
}

const BUILTIN_TYPES = [
  ['学业', 'graduation-cap', '#3056d3', 10, JSON.stringify([
    { key: 'semester_label', label: '学期', widget: 'text', placeholder: '如：2024-2025-1' }
  ])],
  ['竞赛', 'trophy', '#7c3aed', 20, JSON.stringify([
    { key: 'my_work', label: '我的分工', widget: 'textarea', required: true },
    { key: 'deliverable', label: '最终产品', widget: 'text', placeholder: '作品 / 论文 / 系统名称' },
    { key: 'team_members', label: '队伍成员', widget: 'text' }
  ])],
  ['科研', 'flask-conical', '#0891b2', 30, JSON.stringify([
    { key: 'authors', label: '作者排序', widget: 'text', placeholder: '如：第 2 作者' },
    { key: 'outcome', label: '成果形式', widget: 'select', options: ['论文', '专利', '软件著作权', '研究报告'] }
  ])],
  ['实习实践', 'briefcase', '#0f766e', 40, JSON.stringify([
    { key: 'position', label: '岗位', widget: 'text' },
    { key: 'mentor', label: '带教人', widget: 'text' }
  ])],
  ['学生工作', 'network', '#d97706', 50, JSON.stringify([
    { key: 'duties', label: '职责', widget: 'textarea' },
    { key: 'term', label: '任期', widget: 'text', placeholder: '2024.09 - 2025.06' }
  ])],
  ['志愿公益', 'heart-handshake', '#16a34a', 60, JSON.stringify([
    { key: 'hours', label: '志愿时长', widget: 'number', unit: '小时', metric: 'volunteer_hours' },
    { key: 'contact', label: '组织负责人', widget: 'text' }
  ])],
  ['文体活动', 'palette', '#db2777', 70, JSON.stringify([
    { key: 'participation', label: '参与形式', widget: 'text', placeholder: '如：方阵队员 / 主唱' }
  ])],
  ['证书技能', 'file-badge', '#64748b', 80, JSON.stringify([
    { key: 'cert_no', label: '证书编号', widget: 'text' },
    { key: 'score', label: '成绩', widget: 'text', placeholder: '如：580 / 良好' }
  ])],
  ['荣誉惩处', 'award', '#b45309', 90, JSON.stringify([
    { key: 'issued_by', label: '授予 / 决定单位', widget: 'text' }
  ])]
];

const BUILTIN_LEVELS = [
  ['国际级', '#7c3aed', 10], ['国家级', '#dc2626', 20], ['省市级', '#ea580c', 30],
  ['区县级', '#2563eb', 40], ['校级', '#16a34a', 50], ['院级', '#0891b2', 60]
];

const BUILTIN_ROLES = [
  ['主导', '#3056d3', 10], ['核心', '#0891b2', 20], ['参加', '#64748b', 30]
];

const BUILTIN_DIMENSIONS = [
  ['学业深造', '#3056d3', 10], ['职业发展', '#0891b2', 20],
  ['综合素养', '#16a34a', 30], ['兴趣生活', '#db2777', 40]
];

function ensureBuiltin(db) {
  const seed = (table, cols, rows) => {
    if (db.prepare('SELECT COUNT(*) AS c FROM ' + table + ' WHERE deleted_at IS NULL').get().c > 0) return;
    const ins = db.prepare('INSERT INTO ' + table + ' (' + cols.join(',') + ') VALUES (' + cols.map(() => '?').join(',') + ')');
    for (const row of rows) {
      const [uuidKey, ...rest] = row;
      ins.run(...rest, BUILTIN_UUID[uuidKey], '0:0:builtin', 'builtin');
    }
  };

  const tpl = (o) => JSON.stringify(o);
  seed('footprint_type', ['name', 'icon', 'color', 'sort', 'form_template', 'is_builtin', 'uuid', 'hlc', 'origin'], [
    ['类型:学业', '学业', 'graduation-cap', '#3056d3', 10, tpl([{ key: 'semester_label', label: '学期', widget: 'text' }]), 1],
    ['类型:竞赛', '竞赛', 'trophy', '#7c3aed', 20, tpl([{ key: 'my_work', label: '我的分工', widget: 'textarea', required: true }, { key: 'deliverable', label: '最终产品', widget: 'text' }, { key: 'team_members', label: '队伍成员', widget: 'text' }]), 1],
    ['类型:科研', '科研', 'flask-conical', '#0891b2', 30, tpl([{ key: 'authors', label: '作者排序', widget: 'text' }, { key: 'outcome', label: '成果形式', widget: 'select', options: ['论文', '专利', '软件著作权', '研究报告'] }]), 1],
    ['类型:实习实践', '实习实践', 'briefcase', '#0f766e', 40, tpl([{ key: 'position', label: '岗位', widget: 'text' }, { key: 'mentor', label: '带教人', widget: 'text' }]), 1],
    ['类型:学生工作', '学生工作', 'network', '#d97706', 50, tpl([{ key: 'duties', label: '职责', widget: 'textarea' }, { key: 'term', label: '任期', widget: 'text' }]), 1],
    ['类型:志愿公益', '志愿公益', 'heart-handshake', '#16a34a', 60, tpl([{ key: 'hours', label: '志愿时长', widget: 'number', unit: '小时', metric: 'volunteer_hours' }, { key: 'contact', label: '组织负责人', widget: 'text' }]), 1],
    ['类型:文体活动', '文体活动', 'palette', '#db2777', 70, tpl([{ key: 'participation', label: '参与形式', widget: 'text' }]), 1],
    ['类型:证书技能', '证书技能', 'file-badge', '#64748b', 80, tpl([{ key: 'cert_no', label: '证书编号', widget: 'text' }, { key: 'score', label: '成绩', widget: 'text' }]), 1],
    ['类型:荣誉惩处', '荣誉惩处', 'award', '#b45309', 90, tpl([{ key: 'issued_by', label: '授予 / 决定单位', widget: 'text' }]), 1]
  ]);

  seed('taxonomy', ['kind', 'value', 'color', 'sort', 'is_builtin', 'uuid', 'hlc', 'origin'], [
    ['级别:国际级', 'level', '国际级', '#7c3aed', 10, 1],
    ['级别:国家级', 'level', '国家级', '#dc2626', 20, 1],
    ['级别:省市级', 'level', '省市级', '#ea580c', 30, 1],
    ['级别:区县级', 'level', '区县级', '#2563eb', 40, 1],
    ['级别:校级', 'level', '校级', '#16a34a', 50, 1],
    ['级别:院级', 'level', '院级', '#0891b2', 60, 1],
    ['角色:主导', 'role', '主导', '#3056d3', 10, 1],
    ['角色:核心', 'role', '核心', '#0891b2', 20, 1],
    ['角色:参加', 'role', '参加', '#64748b', 30, 1]
  ]);  // 注意：seed 行参数顺序见 sort 列映射

  // taxonomy 的 seed 行参数顺序与列序不同，单独处理（kind,value,color,sort）
  if (db.prepare('SELECT COUNT(*) AS c FROM taxonomy WHERE deleted_at IS NULL').get().c === 0) {
    const ins2 = db.prepare('INSERT INTO taxonomy (kind, value, color, sort, is_builtin, uuid, hlc, origin) VALUES (?,?,?,?,1,?,?,?)');
    for (const [uuidKey, kind, value, color, sort] of [
      ['级别:国际级', 'level', '国际级', '#7c3aed', 10],
      ['级别:国家级', 'level', '国家级', '#dc2626', 20],
      ['级别:省市级', 'level', '省市级', '#ea580c', 30],
      ['级别:区县级', 'level', '区县级', '#2563eb', 40],
      ['级别:校级', 'level', '校级', '#16a34a', 50],
      ['级别:院级', 'level', '院级', '#0891b2', 60],
      ['角色:主导', 'role', '主导', '#3056d3', 10],
      ['角色:核心', 'role', '核心', '#0891b2', 20],
      ['角色:参加', 'role', '参加', '#64748b', 30]
    ]) ins2.run(kind, value, color, sort, BUILTIN_UUID[uuidKey], '0:0:builtin', 'builtin');
  }

  seed('dimension', ['name', 'color', 'sort', 'uuid', 'hlc', 'origin'], [
    ['维度:学业深造', '学业深造', '#3056d3', 10],
    ['维度:职业发展', '职业发展', '#0891b2', 20],
    ['维度:综合素养', '综合素养', '#16a34a', 30],
    ['维度:兴趣生活', '兴趣生活', '#db2777', 40]
  ]);

  seed('grade_band', ['label', 'color', 'min', 'max', 'sort', 'uuid', 'hlc', 'origin'], [
    ['梯度:优秀', '优秀', '#16803c', 90, 100, 10],
    ['梯度:良好', '良好', '#0891b2', 80, 90, 20],
    ['梯度:中等', '中等', '#d97706', 70, 80, 30],
    ['梯度:及格', '及格', '#ea580c', 60, 70, 40],
    ['梯度:不及格', '不及格', '#dc2626', 0, 60, 50]
  ]);

  seed('metric_def', ['key', 'label', 'unit', 'agg', 'section', 'uuid', 'hlc', 'origin'], [
    ['指标:volunteer_hours', 'volunteer_hours', '志愿时长', '小时', 'sum', '志愿服务']
  ]);
}

function openDb(dbPath) {
  fs.mkdirSync(path.join(path.dirname(dbPath), 'attachments'), { recursive: true });
  const d = new DatabaseSync(dbPath);
  d.exec('PRAGMA foreign_keys = ON;');
  preMigrateColumns(d);
  d.exec(fs.readFileSync(path.join(__dirname, '..', 'schema.sql'), 'utf8'));
  migrateSync(d);
  ensureBuiltin(d);
  alignBuiltinUuids(d);
  return d;
}

// 按数据库路径创建一套应用命令（多用户/服务器模式：每个用户一个独立档案库）

// ---------- 演示数据（demo 账号播种 / 本地 seed 共用） ----------
// 行格式: [类型, 标题, 角色, 级别, 获奖等级, 主办方, 开始, 结束, 状态, 描述, 结果, 标签, 维度, extras, metrics]
export const DEMO_ROWS = [
  ['竞赛', '2025 全国大学生数学建模竞赛', '主导', '国家级', '省市级二等奖', '中国工业与应用数学学会', '2025-09-05', '2025-09-08', 'finished',
   '担任队长，负责模型建立与论文主笔；协调三人分工与时间安排', '重庆赛区二等奖', ['建模', '团队协作'], ['学业深造'],
   { my_work: '模型建立与论文主笔', deliverable: '参赛论文《基于优化模型的共享单车调度研究》', team_members: '张三、李四、王五' }, {}],
  ['竞赛', '第十六届蓝桥杯程序设计大赛', '参加', '省市级', '省市级二等奖', '工业和信息化部人才交流中心', '2025-04-12', '2025-06-20', 'finished',
   '备战算法与数据结构，完成省赛', '重庆赛区 C/C++ B 组二等奖', ['算法'], ['职业发展', '学业深造'],
   { my_work: '独立参赛', deliverable: '省赛获奖证书' }, {}],
  ['竞赛', '全国大学生信息安全竞赛', '核心', '国家级', null, '教育部高等学校网络空间安全专业教学指导委员会', '2025-05-01', '2025-08-15', 'submitted',
   '负责 Web 漏洞挖掘与利用脚本编写，参与作品报告撰写', '已提交作品，等待国赛评审', ['安全', 'CTF'], ['职业发展'],
   { my_work: 'Web 漏洞挖掘与利用脚本编写', deliverable: '参赛作品与报告' }, {}],
  ['志愿公益', '校图书馆迎新志愿服务', '参加', '校级', null, '校图书馆', '2025-09-01', '2025-09-05', 'finished',
   '新生入馆引导与借阅咨询，共服务 5 天', '获馆方感谢信', ['志愿'], ['综合素养'],
   { hours: 24, contact: '李老师' }, { volunteer_hours: 24 }],
  ['志愿公益', '社区敬老院慰问活动', '参加', '区县级', null, '所在社区居委会', '2025-03-15', '2025-03-15', 'finished',
   '陪伴老人、协助整理活动室', '', ['志愿', '公益'], ['综合素养'],
   { hours: 6 }, { volunteer_hours: 6 }],
  ['学生工作', '院学生会宣传部干事', '参加', '院级', null, '院学生会', '2024-09-01', '2025-06-30', 'finished',
   '负责活动推文撰写与排版，全年产出推文 20 篇', '获优秀干事', ['宣传'], ['综合素养'],
   { duties: '推文撰写与排版、活动现场摄影', term: '2024.09 - 2025.06' }, {}],
  ['学生工作', '院学生会宣传部副部长', '主导', '院级', null, '院学生会', '2025-09-01', null, 'ongoing',
   '统筹部门工作，管理 8 名干事，主导院级活动宣传方案', '', ['管理'], ['综合素养', '职业发展'],
   { duties: '部门统筹、活动宣传方案设计', term: '2025.09 - 至今' }, {}],
  ['荣誉惩处', '校级二等奖学金', '参加', '校级', null, '重庆城市科技学院', '2025-10-15', '2025-10-15', 'finished',
   '2024-2025 学年综合测评前列', '二等奖学金', ['奖学金'], ['学业深造'],
   { issued_by: '重庆城市科技学院' }, {}],
  ['荣誉惩处', '优秀共青团员', '参加', '校级', null, '校团委', '2025-05-04', '2025-05-04', 'finished',
   '五四表彰', '优秀共青团员', ['表彰'], ['综合素养'],
   { issued_by: '共青团重庆城市科技学院委员会' }, {}],
  ['证书技能', '大学英语六级', '参加', '国家级', null, '教育部教育考试院', '2025-06-14', '2025-08-20', 'finished',
   '笔试 528 分', 'CET-6 528 分', ['英语'], ['学业深造', '职业发展'],
   { cert_no: '510001251200123', score: '528' }, {}],
  ['证书技能', '计算机技术与软件专业技术资格（中级）', '参加', '国家级', null, '工业和信息化部', '2025-11-08', null, 'ongoing',
   '备考软件设计师', '', ['软考'], ['职业发展'],
   { score: '' }, {}],
  ['学业', '2024-2025 学年秋季学期', '参加', null, null, null, '2024-09-01', '2025-01-15', 'finished',
   '学期绩点 3.72，专业排名 12/156', '', ['绩点'], ['学业深造'],
   { semester_label: '2024-2025-1' }, {}],
  ['学业', '2024-2025 学年春季学期', '参加', null, null, null, '2025-02-24', '2025-07-05', 'finished',
   '学期绩点 3.85，专业排名 9/156', '', ['绩点'], ['学业深造'],
   { semester_label: '2024-2025-2' }, {}],
  ['文体活动', '校运动会开幕式方阵', '参加', '校级', null, '校体育运动委员会', '2025-04-18', '2025-04-20', 'finished',
   '学院方阵队员，参与排练与开幕式表演', '', ['文体'], ['兴趣生活'],
   { participation: '方阵队员' }, {}],
  ['科研', '大学生创新创业训练计划项目', '主导', '校级', null, '校创新创业学院', '2025-03-01', null, 'ongoing',
   '主持校级大创项目「基于流量特征的入侵检测研究」，带 2 名成员', '中期检查通过', ['科研', '安全'], ['学业深造', '职业发展'],
   { authors: '主持人', outcome: '研究报告' }, {}],
  ['实习实践', '某安全公司渗透测试实习生', '参加', null, null, '某网络安全科技有限公司', '2025-07-01', '2025-08-25', 'finished',
   '参与企业授权渗透测试项目 3 个，编写测试报告', '获实习优秀评价', ['实习', '安全'], ['职业发展'],
   { position: '渗透测试实习生', mentor: '陈工' }, {}]
];
// 学期: { term, gpa, rank, total, courses: [课程名, 学分, 分数, 绩点][] }
export const DEMO_SEMESTERS = [
  { term: '2023-2024-1', gpa: 3.42, rank: 38, total: 156, courses: [
    ['高等数学（上）', 5, 78, 3.0], ['大学英语（一）', 3, 85, 3.7], ['程序设计基础', 4, 91, 4.0],
    ['思想道德与法治', 2, 88, 3.9], ['体育（一）', 1, 82, 3.5]
  ]},
  { term: '2023-2024-2', gpa: 3.61, rank: 29, total: 156, courses: [
    ['高等数学（下）', 5, 84, 3.7], ['线性代数', 3, 76, 2.9], ['数据结构', 4, 90, 4.0],
    ['大学英语（二）', 3, 87, 3.8], ['中国近现代史纲要', 2, 84, 3.5], ['体育（二）', 1, 86, 3.8]
  ]},
  { term: '2024-2025-1', gpa: 3.78, rank: 18, total: 156, courses: [
    ['概率论与数理统计', 3, 88, 3.9], ['操作系统', 4, 92, 4.0], ['计算机网络', 4, 86, 3.8],
    ['数据库原理', 3, 94, 4.0], ['马克思主义基本原理', 2, 81, 3.3]
  ]},
  { term: '2024-2025-2', gpa: 3.85, rank: 12, total: 156, courses: [
    ['软件工程', 3, 90, 4.0], ['信息安全导论', 3, 95, 4.0], ['密码学基础', 3, 89, 3.9],
    ['Web 应用开发', 2, 96, 4.0], ['数字逻辑', 3, 79, 3.1], ['体育（四）', 1, 90, 4.0]
  ]}
];

export function createAppCommands(dbPath) {
  const db = openDb(dbPath);
  const DATA_DIR = path.dirname(dbPath); // 工厂内遮蔽顶层默认值：附件按用户目录
  function getDb() {
    return db;
  }


// ---------- 同步基础设施 ----------


const SORTS = {
  date_desc: "COALESCE(NULLIF(fp.start_date,''), substr(fp.created_at,1,10)) DESC, fp.id DESC",
  date_asc: "COALESCE(NULLIF(fp.start_date,''), substr(fp.created_at,1,10)) ASC, fp.id ASC",
  updated_desc: 'fp.updated_at DESC, fp.id DESC',
  weight_desc: "fp.weight DESC, COALESCE(NULLIF(fp.start_date,''), substr(fp.created_at,1,10)) DESC"
};

function buildWhere(query) {
  const conds = [];
  const params = [];
  const joins = [];
  if (query.q) {
    // 中文检索策略：长度>=3 的词走 FTS5 trigram（子串匹配），更短的词回退 LIKE
    const ftsTerms = [];
    for (const raw of String(query.q).trim().split(/\s+/).filter(Boolean)) {
      const clean = raw.replace(/["\\]/g, ' ');
      if (!clean.trim()) continue;
      if ([...clean].length >= 3) {
        ftsTerms.push('"' + clean + '"');
      } else {
        conds.push('fp.search_text LIKE ?');
        params.push('%' + clean + '%');
      }
    }
    if (ftsTerms.length) {
      joins.push('JOIN footprint_fts ON footprint_fts.rowid = fp.id');
      conds.push('footprint_fts MATCH ?');
      params.push(ftsTerms.join(' AND '));
    }
  }
  if (query.types?.length) {
    conds.push('fp.type_id IN (' + query.types.map(() => '?').join(',') + ')');
    params.push(...query.types);
  }
  if (query.levels?.length) {
    conds.push('fp.level IN (' + query.levels.map(() => '?').join(',') + ')');
    params.push(...query.levels);
  }
  if (query.roles?.length) {
    conds.push('fp.role IN (' + query.roles.map(() => '?').join(',') + ')');
    params.push(...query.roles);
  }
  if (query.statuses?.length) {
    conds.push('fp.status IN (' + query.statuses.map(() => '?').join(',') + ')');
    params.push(...query.statuses);
  }
  if (query.dims?.length) {
    conds.push('fp.id IN (SELECT footprint_id FROM footprint_dimension WHERE dimension_id IN ('
      + query.dims.map(() => '?').join(',') + '))');
    params.push(...query.dims);
  }
  if (query.year) {
    conds.push("strftime('%Y', COALESCE(NULLIF(fp.start_date,''), substr(fp.created_at,1,10))) = ?");
    params.push(String(query.year));
  }
  if (query.polarity) {
    conds.push('fp.polarity = ?');
    params.push(query.polarity);
  }
  if (query.has_attachment) {
    conds.push("EXISTS (SELECT 1 FROM attachment a WHERE a.owner_type='footprint' AND a.owner_id=fp.id AND a.deleted_at IS NULL)");
  }
  if (query.tag) {
    conds.push('fp.tags LIKE ?');
    params.push('%"' + query.tag + '"%');
  }
  return { joins, conds, params };
}

const BASE_SELECT = `SELECT fp.*, ft.name AS type_name, ft.color AS type_color, ft.icon AS type_icon,
  (SELECT COUNT(*) FROM attachment a WHERE a.owner_type='footprint' AND a.owner_id=fp.id AND a.deleted_at IS NULL) AS attachment_count,
  (SELECT GROUP_CONCAT(dimension_id) FROM footprint_dimension fd WHERE fd.footprint_id=fp.id) AS dim_ids
  FROM footprint fp JOIN footprint_type ft ON ft.id = fp.type_id`;

function mapRow(r) {
  let metrics = {}, extras = {}, tags = [];
  try { metrics = JSON.parse(r.metrics || '{}'); } catch {}
  try { extras = JSON.parse(r.extras || '{}'); } catch {}
  try { tags = JSON.parse(r.tags || '[]'); } catch {}
  return {
    ...r,
    metrics, extras, tags,
    dimensions: r.dim_ids ? String(r.dim_ids).split(',').map(Number) : [],
    dim_ids: undefined
  };
}

function listFootprints(d, query) {
  const page = Math.max(1, query.page || 1);
  const pageSize = Math.min(2000, Math.max(1, query.page_size || 20));
  const { joins, conds, params } = buildWhere(query);
  const base = ' WHERE fp.deleted_at IS NULL';
  const where = conds.length ? base + ' AND ' + conds.join(' AND ') : base;
  const order = SORTS[query.sort] || SORTS.date_desc;

  const total = d.prepare(
    'SELECT COUNT(*) AS c FROM footprint fp ' + joins.join(' ') + where
  ).get(...params).c;

  const rows = d.prepare(
    BASE_SELECT + ' ' + joins.join(' ') + where + ' ORDER BY ' + order +
    ' LIMIT ' + pageSize + ' OFFSET ' + (page - 1) * pageSize
  ).all(...params).map(mapRow);

  return { items: rows, total, page, page_size: pageSize };
}

// ---------- 命令处理 ----------
  function handleCommand(cmd, payload) {
  const d = getDb();

  switch (cmd) {
    case 'app_info': {
      const pending = d.prepare('SELECT COUNT(*) AS c FROM sync_oplog WHERE synced_at IS NULL').get().c;
      return {
        app_name: 'Footprints 足迹',
        version: '0.2.0',
        db_path: DB_PATH,
        attachment_dir: ATT_DIR,
        schema_ok: true,
        device_id: getDeviceId(d),
        pending_ops: pending,
        last_sync_at: getMeta(d, 'last_sync_at')
      };
    }

    case 'sync_status':
      return {
        mode: 'local',
        device_id: getDeviceId(d),
        pending_ops: d.prepare('SELECT COUNT(*) AS c FROM sync_oplog WHERE synced_at IS NULL').get().c,
        last_sync_at: getMeta(d, 'last_sync_at')
      };

    case 'type_list': {
      const items = d.prepare(`
        SELECT t.*, (SELECT COUNT(*) FROM footprint f WHERE f.type_id = t.id AND f.deleted_at IS NULL) AS usage_count
        FROM footprint_type t WHERE t.deleted_at IS NULL ORDER BY t.sort, t.id`).all()
        .map(t => ({ ...t, form_template: JSON.parse(t.form_template || '[]'), is_builtin: !!t.is_builtin, closed: !!t.closed }));
      return { items };
    }

    case 'type_upsert': {
      const p = payload;
      const tpl = JSON.stringify(p.form_template || []);
      let id = p.id;
      if (id) {
        withTx(d, () => {
          const h = hlcNext(d);
          d.prepare('UPDATE footprint_type SET name=?, icon=?, color=?, sort=?, form_template=?, closed=?, hlc=? WHERE id=?')
            .run(p.name, p.icon, p.color, p.sort, tpl, p.closed ? 1 : 0, h, id);
          touchOplog(d, 'footprint_type', getUuid(d, 'footprint_type', id), 'upsert', h);
        });
      } else {
        withTx(d, () => {
          const h = hlcNext(d);
          const uuid = uuidv7();
          id = Number(d.prepare(
            'INSERT INTO footprint_type (name, icon, color, sort, form_template, closed, uuid, hlc, origin) VALUES (?,?,?,?,?,?,?,?,?)')
            .run(p.name, p.icon, p.color, p.sort, tpl, p.closed ? 1 : 0, uuid, h, getDeviceId(d)).lastInsertRowid);
          touchOplog(d, 'footprint_type', uuid, 'upsert', h);
        });
      }
      return { item: { id } };
    }

    case 'type_delete': {
      const used = d.prepare('SELECT COUNT(*) AS c FROM footprint WHERE type_id=? AND deleted_at IS NULL').get(payload.id).c;
      if (used > 0) throw new Error('该类型下仍有 ' + used + ' 条记录，请先迁移后再删除');
      const row = d.prepare('SELECT uuid, is_builtin FROM footprint_type WHERE id=?').get(payload.id);
      if (!row) return { ok: true };
      if (row.is_builtin) throw new Error('内置类型不可删除');
      withTx(d, () => softDelete(d, 'footprint_type', payload.id));
      return { ok: true };
    }

    case 'taxonomy_list': {
      const sql = payload.kind
        ? "SELECT * FROM taxonomy WHERE kind=? AND deleted_at IS NULL ORDER BY sort, id"
        : "SELECT * FROM taxonomy WHERE deleted_at IS NULL ORDER BY kind, sort, id";
      const rows = payload.kind ? d.prepare(sql).all(payload.kind) : d.prepare(sql).all();
      return { items: rows.map(r => ({ ...r, is_builtin: !!r.is_builtin })) };
    }

    case 'taxonomy_upsert': {
      const p = payload;
      let id = p.id;
      if (id) {
        withTx(d, () => {
          const h = hlcNext(d);
          d.prepare('UPDATE taxonomy SET kind=?, value=?, color=?, sort=?, hlc=? WHERE id=?')
            .run(p.kind, p.value, p.color ?? null, p.sort ?? 100, h, id);
          touchOplog(d, 'taxonomy', getUuid(d, 'taxonomy', id), 'upsert', h);
        });
      } else {
        withTx(d, () => {
          const h = hlcNext(d);
          const uuid = uuidv7();
          id = Number(d.prepare('INSERT INTO taxonomy (kind, value, color, sort, uuid, hlc, origin) VALUES (?,?,?,?,?,?,?)')
            .run(p.kind, p.value, p.color ?? null, p.sort ?? 100, uuid, h, getDeviceId(d)).lastInsertRowid);
          touchOplog(d, 'taxonomy', uuid, 'upsert', h);
        });
      }
      return { item: { id } };
    }

    case 'taxonomy_delete': {
      const row = d.prepare('SELECT is_builtin FROM taxonomy WHERE id=?').get(payload.id);
      if (!row) return { ok: true };
      if (row.is_builtin) throw new Error('内置条目不可删除');
      withTx(d, () => softDelete(d, 'taxonomy', payload.id));
      return { ok: true };
    }

    case 'dimension_list':
      return { items: d.prepare('SELECT * FROM dimension WHERE deleted_at IS NULL ORDER BY sort, id').all() };

    case 'dimension_upsert': {
      const p = payload;
      let id = p.id;
      if (id) {
        withTx(d, () => {
          const h = hlcNext(d);
          d.prepare('UPDATE dimension SET name=?, color=?, sort=?, hlc=? WHERE id=?')
            .run(p.name, p.color ?? null, p.sort ?? 100, h, id);
          touchOplog(d, 'dimension', getUuid(d, 'dimension', id), 'upsert', h);
        });
      } else {
        withTx(d, () => {
          const h = hlcNext(d);
          const uuid = uuidv7();
          id = Number(d.prepare('INSERT INTO dimension (name, color, sort, uuid, hlc, origin) VALUES (?,?,?,?,?,?)')
            .run(p.name, p.color ?? null, p.sort ?? 100, uuid, h, getDeviceId(d)).lastInsertRowid);
          touchOplog(d, 'dimension', uuid, 'upsert', h);
        });
      }
      return { item: { id } };
    }

    case 'dimension_delete': {
      withTx(d, () => softDelete(d, 'dimension', payload.id));
      return { ok: true };
    }

    case 'footprint_list':
      return listFootprints(d, payload.query || {});

    case 'footprint_get': {
      const row = d.prepare(BASE_SELECT + ' AND fp.id=?').get(payload.id);
      if (!row) throw new Error('记录不存在');
      const attachments = d.prepare(
        "SELECT * FROM attachment WHERE owner_type='footprint' AND owner_id=? AND deleted_at IS NULL ORDER BY id"
      ).all(payload.id);
      return { item: { ...mapRow(row), attachments } };
    }

    case 'footprint_upsert': {
      const it = payload.item;
      if (!it.type_id) throw new Error('缺少记录类型');
      if (!it.title || !it.title.trim()) throw new Error('缺少标题');
      const search = buildSearchText(it.title.trim(), it.description, it.result, it.tags, it.extras);
      const metrics = JSON.stringify(it.metrics || {});
      const extras = JSON.stringify(it.extras || {});
      const tags = JSON.stringify(it.tags || []);
      const nowLocal = "datetime('now','localtime')";
      let id = it.id;

      withTx(d, () => {
        if (id) {
          const h = hlcNext(d);
          d.prepare(`UPDATE footprint SET type_id=?, title=?, role=?, level=?, polarity=?, award_grade=?, rank=?,
            organizer=?, start_date=?, end_date=?, status=?, description=?, result=?, metrics=?, extras=?,
            group_id=?, parent_id=?, tags=?, weight=?, search_text=?, hlc=?, updated_at=${nowLocal} WHERE id=?`)
            .run(it.type_id, it.title.trim(), it.role ?? null, it.level ?? null, it.polarity || 'positive',
              it.award_grade ?? null, it.rank ?? null, it.organizer ?? null, it.start_date ?? null, it.end_date ?? null,
              it.status || 'draft', it.description ?? '', it.result ?? '', metrics, extras,
              it.group_id ?? null, it.parent_id ?? null, tags, it.weight ?? 3, search, h, id);
          touchOplog(d, 'footprint', getUuid(d, 'footprint', id), 'upsert', h);
        } else {
          const h = hlcNext(d);
          const uuid = uuidv7();
          id = Number(d.prepare(`INSERT INTO footprint (type_id, title, role, level, polarity, award_grade, rank,
            organizer, start_date, end_date, status, description, result, metrics, extras, group_id, parent_id,
            tags, weight, search_text, uuid, hlc, origin) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)`)
            .run(it.type_id, it.title.trim(), it.role ?? null, it.level ?? null, it.polarity || 'positive',
              it.award_grade ?? null, it.rank ?? null, it.organizer ?? null, it.start_date ?? null, it.end_date ?? null,
              it.status || 'draft', it.description ?? '', it.result ?? '', metrics, extras,
              it.group_id ?? null, it.parent_id ?? null, tags, it.weight ?? 3, search, uuid, h, getDeviceId(d)).lastInsertRowid);
          touchOplog(d, 'footprint', uuid, 'upsert', h);
        }
        if (Array.isArray(it.dimension_ids)) {
          d.prepare('DELETE FROM footprint_dimension WHERE footprint_id=?').run(id);
          const ins = d.prepare('INSERT OR IGNORE INTO footprint_dimension (footprint_id, dimension_id) VALUES (?,?)');
          for (const dim of it.dimension_ids) ins.run(id, dim);
        }
      });
      return { id };
    }

    case 'footprint_delete': {
      const row = d.prepare('SELECT uuid FROM footprint WHERE id=?').get(payload.id);
      if (!row) return { ok: true };
      withTx(d, () => {
        // FTS 内容表需同步移除：先物理删除 FTS 行，墓碑保留在主表
        d.prepare("INSERT INTO footprint_fts(footprint_fts, rowid, search_text) SELECT 'delete', id, search_text FROM footprint WHERE id=?")
          .run(payload.id);
        softDelete(d, 'footprint', payload.id);
        // 级联清理附件：墓碑（同步到其他端）+ 磁盘原图/缩略图
        const atts = d.prepare("SELECT * FROM attachment WHERE owner_type='footprint' AND owner_id=? AND deleted_at IS NULL").all(payload.id);
        for (const a of atts) {
          softDelete(d, 'attachment', a.id);
          for (const rel of [a.rel_path, a.thumb_rel_path]) {
            if (rel) { try { fs.unlinkSync(path.join(DATA_DIR, rel)); } catch {} }
          }
        }
      });
      return { ok: true };
    }

    case 'timeline': {
      const res = listFootprints(d, { ...(payload.query || {}), page_size: 2000, sort: 'date_desc' });
      const groups = [];
      const byYear = new Map();
      for (const row of res.items) {
        const date = (row.start_date && row.start_date.slice(0, 10)) || row.created_at.slice(0, 10);
        const year = Number(date.slice(0, 4));
        const month = Number(date.slice(5, 7));
        if (!byYear.has(year)) {
          const g = { year, count: 0, months: [] };
          byYear.set(year, g);
          groups.push(g);
        }
        const g = byYear.get(year);
        g.count++;
        let m = g.months.find(x => x.month === month);
        if (!m) { m = { month, items: [] }; g.months.push(m); }
        m.items.push(row);
      }
      groups.sort((a, b) => b.year - a.year);
      for (const g of groups) g.months.sort((a, b) => a.month - b.month);
      return { groups, total: res.total };
    }

    case 'stats_overview': {
      const year = payload.year || null;
      const yearCond = year
        ? " AND strftime('%Y', COALESCE(NULLIF(fp.start_date,''), substr(fp.created_at,1,10))) = '" + String(year).replace(/[^0-9]/g, '') + "'"
        : '';
      const yearCondRaw = year
        ? " AND strftime('%Y', COALESCE(NULLIF(start_date,''), substr(created_at,1,10))) = '" + String(year).replace(/[^0-9]/g, '') + "'"
        : '';
      const DEL = 'fp.deleted_at IS NULL';
      const DEL_RAW = 'deleted_at IS NULL';

      const total = d.prepare('SELECT COUNT(*) AS c FROM footprint fp WHERE ' + DEL + yearCond).get().c;
      const curYear = year || new Date().getFullYear();
      const totalThisYear = d.prepare(
        "SELECT COUNT(*) AS c FROM footprint fp WHERE strftime('%Y', COALESCE(NULLIF(fp.start_date,''), substr(fp.created_at,1,10))) = ?"
      ).get(String(curYear)).c;
      const attTotal = d.prepare(
        "SELECT COUNT(*) AS c FROM attachment a JOIN footprint fp ON fp.id = a.owner_id AND a.owner_type='footprint' WHERE a.deleted_at IS NULL AND " + DEL + yearCond
      ).get().c;

      const byType = d.prepare(`SELECT ft.name AS label, ft.color, COUNT(*) AS count
        FROM footprint fp JOIN footprint_type ft ON ft.id=fp.type_id WHERE ${DEL}${yearCond}
        GROUP BY fp.type_id ORDER BY count DESC`).all();
      const byLevel = d.prepare(`SELECT COALESCE(fp.level,'未设置') AS label, COUNT(*) AS count
        FROM footprint fp WHERE ${DEL}${yearCond} GROUP BY fp.level ORDER BY count DESC`).all();
      const byRole = d.prepare(`SELECT COALESCE(fp.role,'未设置') AS label, COUNT(*) AS count
        FROM footprint fp WHERE ${DEL}${yearCond} GROUP BY fp.role ORDER BY count DESC`).all();
      const byStatus = d.prepare(`SELECT fp.status AS label, COUNT(*) AS count
        FROM footprint fp WHERE ${DEL}${yearCond} GROUP BY fp.status`).all();

      const monthlyRows = d.prepare(`SELECT substr(COALESCE(NULLIF(start_date,''), substr(created_at,1,10)),1,7) AS ym, COUNT(*) AS count
        FROM footprint WHERE ${DEL_RAW}${yearCondRaw} GROUP BY ym ORDER BY ym`).all();
      const monthlyMap = new Map(monthlyRows.map(r => [r.ym, r.count]));
      const monthly = [];
      const now = new Date();
      for (let i = 11; i >= 0; i--) {
        const dt = new Date(now.getFullYear(), now.getMonth() - i, 1);
        const ym = dt.getFullYear() + '-' + String(dt.getMonth() + 1).padStart(2, '0');
        monthly.push({ ym, count: monthlyMap.get(ym) ?? 0 });
      }

      const metrics = [];
      for (const m of d.prepare('SELECT * FROM metric_def WHERE deleted_at IS NULL').all()) {
        const path = '$."' + m.key + '"';
        let value = 0;
        if (m.agg === 'sum') {
          const r = d.prepare(`SELECT SUM(CAST(json_extract(fp.metrics, ?) AS REAL)) AS v
            FROM footprint fp WHERE json_extract(fp.metrics, ?) IS NOT NULL AND ${DEL}${yearCond}`).get(path, path);
          value = r.v ?? 0;
        } else if (m.agg === 'count') {
          value = d.prepare(`SELECT COUNT(*) AS c FROM footprint fp WHERE json_extract(fp.metrics, ?) IS NOT NULL AND ${DEL}${yearCond}`).get(path).c;
        } else if (m.agg === 'distinct') {
          value = d.prepare(`SELECT COUNT(DISTINCT json_extract(fp.metrics, ?)) AS c FROM footprint fp WHERE json_extract(fp.metrics, ?) IS NOT NULL AND ${DEL}${yearCond}`).get(path, path).c;
        }
        metrics.push({ key: m.key, label: m.label, unit: m.unit, agg: m.agg, value });
      }

      const years = d.prepare(`SELECT DISTINCT CAST(strftime('%Y', COALESCE(NULLIF(start_date,''), substr(created_at,1,10))) AS INTEGER) AS y
        FROM footprint WHERE ${DEL_RAW} ORDER BY y DESC`).all().map(r => r.y);

      return {
        total, total_this_year: totalThisYear, attachment_total: attTotal,
        by_type: byType, by_level: byLevel, by_role: byRole, by_status: byStatus,
        monthly, metrics, years
      };
    }

    case 'metric_list':
      return { items: d.prepare('SELECT * FROM metric_def WHERE deleted_at IS NULL ORDER BY id').all() };

    case 'metric_upsert': {
      const p = payload;
      const exist = d.prepare('SELECT id, uuid FROM metric_def WHERE key=? AND deleted_at IS NULL').get(p.key);
      withTx(d, () => {
        if (exist) {
          const h = hlcNext(d);
          d.prepare('UPDATE metric_def SET label=?, unit=?, agg=?, section=?, hlc=? WHERE id=?')
            .run(p.label, p.unit ?? null, p.agg || 'sum', p.section ?? null, h, exist.id);
          touchOplog(d, 'metric_def', exist.uuid, 'upsert', h);
        } else {
          const h = hlcNext(d);
          const uuid = uuidv7();
          d.prepare('INSERT INTO metric_def (key, label, unit, agg, section, uuid, hlc, origin) VALUES (?,?,?,?,?,?,?,?)')
            .run(p.key, p.label, p.unit ?? null, p.agg || 'sum', p.section ?? null, uuid, h, getDeviceId(d));
          touchOplog(d, 'metric_def', uuid, 'upsert', h);
        }
      });
      return { item: p };
    }

    case 'metric_delete': {
      const row = d.prepare('SELECT id FROM metric_def WHERE key=?').get(payload.key);
      if (row) withTx(d, () => softDelete(d, 'metric_def', row.id));
      return { ok: true };
    }

    // ---------- 学年学科成绩 ----------
    case 'grades_overview': {
      const DEL = 'deleted_at IS NULL';
      const bands = d.prepare('SELECT * FROM grade_band WHERE ' + DEL + ' ORDER BY sort, id').all();
      const bandOf = (score) => {
        if (score == null) return null;
        let hit = bands.find(b => score >= b.min && score < b.max);
        if (!hit) hit = bands.find(b => score >= b.min && score <= b.max);
        return hit ? { id: hit.id, label: hit.label, color: hit.color } : null;
      };
      const semesters = d.prepare('SELECT * FROM semester WHERE ' + DEL + ' ORDER BY term DESC').all();
      const activeSemIds = new Set(semesters.map(s => s.id));
      const courses = d.prepare('SELECT * FROM course_grade WHERE ' + DEL + ' ORDER BY id').all()
        .filter(c => activeSemIds.has(c.semester_id));
      for (const s of semesters) {
        s.courses = courses.filter(c => c.semester_id === s.id).map(c => ({ ...c, band: bandOf(c.score) }));
        const scored = s.courses.filter(c => c.score != null);
        const creditsAll = s.courses.reduce((a, c) => a + (c.credit || 0), 0);
        const creditsScored = scored.reduce((a, c) => a + (c.credit || 0), 0);
        s.stats = {
          credits: Math.round(creditsAll * 10) / 10,
          courses: s.courses.length,
          avg: creditsScored > 0 ? Math.round(scored.reduce((a, c) => a + c.score * c.credit, 0) / creditsScored * 100) / 100 : null
        };
      }
      const allScored = courses.filter(c => c.score != null);
      const creditsAll = allScored.reduce((a, c) => a + (c.credit || 0), 0);
      const overallAvg = creditsAll > 0
        ? Math.round(allScored.reduce((a, c) => a + c.score * c.credit, 0) / creditsAll * 100) / 100
        : null;
      const tierDist = bands.map(b => ({
        label: b.label, color: b.color,
        count: allScored.filter(c => { const x = bandOf(c.score); return x && x.id === b.id; }).length
      }));
      const gpaTrend = [...semesters]
        .filter(s => s.gpa != null)
        .sort((a, b) => a.term.localeCompare(b.term))
        .map(s => ({ term: s.term, gpa: s.gpa, avg: s.stats.avg }));
      return {
        semesters,
        bands,
        overall: {
          avg: overallAvg,
          credits: Math.round(courses.reduce((a, c) => a + (c.credit || 0), 0) * 10) / 10,
          courses: courses.length,
          gpa_trend: gpaTrend,
          tier_dist: tierDist
        }
      };
    }

    case 'semester_upsert': {
      const p = payload;
      if (!p.term || !String(p.term).trim()) throw new Error('缺少学期名称');
      const term = String(p.term).trim();
      let id = p.id;
      withTx(d, () => {
        if (id) {
          const dup = d.prepare('SELECT id FROM semester WHERE term=? AND deleted_at IS NULL AND id != ?').get(term, id);
          if (dup) throw new Error('学期已存在：' + term);
          const h = hlcNext(d);
          d.prepare('UPDATE semester SET term=?, gpa=?, rank=?, total_students=?, hlc=? WHERE id=?')
            .run(term, p.gpa ?? null, p.rank ?? null, p.total_students ?? null, h, id);
          touchOplog(d, 'semester', getUuid(d, 'semester', id), 'upsert', h);
        } else {
          const dup = d.prepare('SELECT 1 FROM semester WHERE term=? AND deleted_at IS NULL').get(term);
          if (dup) throw new Error('学期已存在：' + term);
          const h = hlcNext(d);
          const uuid = uuidv7();
          id = Number(d.prepare('INSERT INTO semester (term, gpa, rank, total_students, uuid, hlc, origin) VALUES (?,?,?,?,?,?,?)')
            .run(term, p.gpa ?? null, p.rank ?? null, p.total_students ?? null, uuid, h, getDeviceId(d)).lastInsertRowid);
          touchOplog(d, 'semester', uuid, 'upsert', h);
        }
      });
      return { item: { id } };
    }

    case 'semester_delete': {
      withTx(d, () => {
        softDelete(d, 'semester', payload.id);
        // 级联墓碑该学期下全部课程，避免孤儿课程污染总览
        const courses = d.prepare('SELECT id FROM course_grade WHERE semester_id=? AND deleted_at IS NULL').all(payload.id);
        for (const c of courses) softDelete(d, 'course_grade', c.id);
      });
      return { ok: true };
    }

    case 'course_upsert': {
      const p = payload;
      if (!p.semester_id) throw new Error('缺少学期');
      if (!p.course_name || !String(p.course_name).trim()) throw new Error('缺少课程名');
      if (p.score != null && (p.score < 0 || p.score > 100)) throw new Error('分数需在 0-100 之间');
      if (p.grade_point != null && p.grade_point < 0) throw new Error('绩点不能为负');
      const name = String(p.course_name).trim();
      let id = p.id;
      withTx(d, () => {
        if (id) {
          const h = hlcNext(d);
          d.prepare('UPDATE course_grade SET semester_id=?, course_name=?, credit=?, score=?, grade_point=?, hlc=? WHERE id=?')
            .run(p.semester_id, name, p.credit ?? 0, p.score ?? null, p.grade_point ?? null, h, id);
          touchOplog(d, 'course_grade', getUuid(d, 'course_grade', id), 'upsert', h);
        } else {
          const h = hlcNext(d);
          const uuid = uuidv7();
          id = Number(d.prepare('INSERT INTO course_grade (semester_id, course_name, credit, score, grade_point, uuid, hlc, origin) VALUES (?,?,?,?,?,?,?,?)')
            .run(p.semester_id, name, p.credit ?? 0, p.score ?? null, p.grade_point ?? null, uuid, h, getDeviceId(d)).lastInsertRowid);
          touchOplog(d, 'course_grade', uuid, 'upsert', h);
        }
      });
      return { item: { id } };
    }

    case 'course_delete': {
      withTx(d, () => softDelete(d, 'course_grade', payload.id));
      return { ok: true };
    }

    case 'band_upsert': {
      const p = payload;
      if (!p.label || !String(p.label).trim()) throw new Error('缺少等级名称');
      if (p.min == null || p.max == null || p.min >= p.max) throw new Error('分数区间不合法（需 min < max）');
      const label = String(p.label).trim();
      let id = p.id;
      withTx(d, () => {
        if (id) {
          const h = hlcNext(d);
          d.prepare('UPDATE grade_band SET label=?, color=?, min=?, max=?, sort=?, hlc=? WHERE id=?')
            .run(label, p.color ?? '#64748b', p.min, p.max, p.sort ?? 100, h, id);
          touchOplog(d, 'grade_band', getUuid(d, 'grade_band', id), 'upsert', h);
        } else {
          const h = hlcNext(d);
          const uuid = uuidv7();
          id = Number(d.prepare('INSERT INTO grade_band (label, color, min, max, sort, uuid, hlc, origin) VALUES (?,?,?,?,?,?,?,?)')
            .run(label, p.color ?? '#64748b', p.min, p.max, p.sort ?? 100, uuid, h, getDeviceId(d)).lastInsertRowid);
          touchOplog(d, 'grade_band', uuid, 'upsert', h);
        }
      });
      return { item: { id } };
    }

    case 'band_delete': {
      withTx(d, () => softDelete(d, 'grade_band', payload.id));
      return { ok: true };
    }

    case 'attachment_add': {
      const p = payload;
      const buf = Buffer.from(p.data_b64 || '', 'base64');
      const sha = crypto.createHash('sha256').update(buf).digest('hex');
      const safe = p.file_name.replace(/[\\/:*?"<>|]/g, '_');
      const rel = path.join('attachments', String(p.owner_id), crypto.randomUUID() + '_' + safe);
      const abs = path.join(DATA_DIR, rel);
      fs.mkdirSync(path.dirname(abs), { recursive: true });
      fs.writeFileSync(abs, buf);
      // 服务端缩略图（上传时由客户端 canvas 生成 480px WebP；无则 NULL，读取时回退原图）
      let thumbRel = null;
      if (p.thumb_b64) {
        const tb = Buffer.from(p.thumb_b64, 'base64');
        if (tb.length) {
          thumbRel = path.join('attachments', String(p.owner_id), crypto.randomUUID() + '_thumb.webp');
          const tAbs = path.join(DATA_DIR, thumbRel);
          fs.mkdirSync(path.dirname(tAbs), { recursive: true });
          fs.writeFileSync(tAbs, tb);
          thumbRel = thumbRel.split(path.sep).join('/');
        }
      }
      const uuid = uuidv7();
      let item = null;
      withTx(d, () => {
        const h = hlcNext(d);
        const r = d.prepare(
          "INSERT INTO attachment (owner_type, owner_id, kind, file_name, mime, size, rel_path, thumb_rel_path, sha256, uuid, hlc, origin) VALUES ('footprint',?,?,?,?,?,?,?,?,?,?,?)"
        ).run(p.owner_id, null, p.file_name, p.mime ?? null, buf.length, rel.split(path.sep).join('/'), thumbRel, sha, uuid, h, getDeviceId(d));
        item = d.prepare('SELECT * FROM attachment WHERE id=?').get(Number(r.lastInsertRowid));
        touchOplog(d, 'attachment', uuid, 'upsert', h);
      });
      return { item };
    }

    case 'attachment_list':
      return {
        items: d.prepare(
          "SELECT * FROM attachment WHERE owner_type='footprint' AND owner_id=? AND deleted_at IS NULL ORDER BY id"
        ).all(payload.owner_id)
      };

    case 'attachment_delete': {
      const row = d.prepare('SELECT * FROM attachment WHERE id=?').get(payload.id);
      if (row) {
        withTx(d, () => softDelete(d, 'attachment', payload.id));
        const abs = path.join(DATA_DIR, row.rel_path);
        try { fs.unlinkSync(abs); } catch {}
        if (row.thumb_rel_path) { try { fs.unlinkSync(path.join(DATA_DIR, row.thumb_rel_path)); } catch {} }
      }
      return { ok: true };
    }

    case 'attachment_read': {
      const row = d.prepare('SELECT * FROM attachment WHERE id=?').get(payload.id);
      if (!row) throw new Error('附件不存在');
      const data = fs.readFileSync(path.join(DATA_DIR, row.rel_path));
      return { data_b64: data.toString('base64'), mime: row.mime, file_name: row.file_name };
    }

    case 'attachment_thumb': {
      // 缩略图读取：有服务端缩略图用之（20KB 级 WebP），老附件回退原图
      const row = d.prepare('SELECT * FROM attachment WHERE id=?').get(payload.id);
      if (!row) throw new Error('附件不存在');
      const rel = row.thumb_rel_path || row.rel_path;
      const data = fs.readFileSync(path.join(DATA_DIR, rel));
      return { data_b64: data.toString('base64'), mime: row.thumb_rel_path ? 'image/webp' : row.mime, file_name: row.file_name };
    }

    case 'view_list':
      return { items: d.prepare('SELECT * FROM saved_view WHERE deleted_at IS NULL ORDER BY id').all().map(v => ({
        ...v, filter: JSON.parse(v.filter || '{}'), sort: JSON.parse(v.sort || '{}'), is_default: !!v.is_default
      })) };

    case 'view_upsert': {
      const p = payload;
      let id = p.id;
      withTx(d, () => {
        if (id) {
          const h = hlcNext(d);
          d.prepare("UPDATE saved_view SET name=?, filter=?, sort=?, is_default=?, hlc=?, updated_at=datetime('now','localtime') WHERE id=?")
            .run(p.name, JSON.stringify(p.filter || {}), JSON.stringify(p.sort || {}), p.is_default ? 1 : 0, h, id);
          touchOplog(d, 'saved_view', getUuid(d, 'saved_view', id), 'upsert', h);
        } else {
          const h = hlcNext(d);
          const uuid = uuidv7();
          id = Number(d.prepare('INSERT INTO saved_view (name, filter, sort, is_default, uuid, hlc, origin) VALUES (?,?,?,?,?,?,?)')
            .run(p.name, JSON.stringify(p.filter || {}), JSON.stringify(p.sort || {}), p.is_default ? 1 : 0, uuid, h, getDeviceId(d)).lastInsertRowid);
          touchOplog(d, 'saved_view', uuid, 'upsert', h);
        }
      });
      return { item: { id } };
    }

    case 'view_delete': {
      const row = d.prepare('SELECT id FROM saved_view WHERE id=?').get(payload.id);
      if (row) withTx(d, () => softDelete(d, 'saved_view', row.id));
      return { ok: true };
    }

    case 'demo_seed': {
      // 演示数据播种（仅当档案库为空时；走真实命令层，附带同步元数据与 oplog）
      const fpCnt = d.prepare('SELECT COUNT(*) AS c FROM footprint WHERE deleted_at IS NULL').get().c;
      const semCnt = d.prepare('SELECT COUNT(*) AS c FROM semester WHERE deleted_at IS NULL').get().c;
      if (fpCnt > 0 || semCnt > 0) return { seeded: false, footprints: fpCnt, semesters: semCnt };
      const typeIds = Object.fromEntries(d.prepare('SELECT id, name FROM footprint_type').all().map((r) => [r.name, r.id]));
      const dimIds = Object.fromEntries(d.prepare('SELECT id, name FROM dimension').all().map((r) => [r.name, r.id]));
      let n = 0;
      for (const [t, title, role, level, grade, organizer, start, end, status, desc, result, tags, dimNames, extras, metrics] of DEMO_ROWS) {
        const typeId = typeIds[t];
        if (!typeId) continue;
        handleCommand('footprint_upsert', { item: {
          type_id: typeId, title, role, level, award_grade: grade, organizer,
          start_date: start, end_date: end, status, description: desc, result,
          tags, metrics, extras,
          dimension_ids: (dimNames || []).map((nm) => dimIds[nm]).filter(Boolean),
        }});
        n++;
      }
      let sems = 0;
      for (const s of DEMO_SEMESTERS) {
        const r = handleCommand('semester_upsert', { term: s.term, gpa: s.gpa, rank: s.rank, total_students: s.total });
        const sid = r.item.id;
        for (const [name, credit, score, gp] of s.courses) {
          handleCommand('course_upsert', { semester_id: sid, course_name: name, credit, score, grade_point: gp });
        }
        sems++;
      }
      return { seeded: true, footprints: n, semesters: sems };
    }
    case 'sync_apply_wire':
      return applyWireBatch(payload.changes || []);

    case 'sync_pull_wire':
      return pullWire(payload.cursor, payload.limit);

    default:
      throw new Error('未知命令：' + cmd);
  }
}

// 工厂闭合
    // ---------- Wire 协议：出站序列化 / 入站应用 ----------

  const SKIP_COLS = ['id', 'uuid', 'hlc', 'origin', 'created_at', 'updated_at', 'search_text'];

  function uuidOf(table, id) {
    if (id == null) return null;
    const r = db.prepare('SELECT uuid FROM ' + table + ' WHERE id=?').get(id);
    return r ? r.uuid : null;
  }

  function idOfUuid(table, uuid, mayCreate) {
    if (uuid == null) return null;
    const r = db.prepare('SELECT id FROM ' + table + ' WHERE uuid=?').get(uuid);
    if (r) return r.id;
    if (!mayCreate) return null;
    const h2 = hlcNext(db);
    if (table === 'footprint_type') {
      const rr = db.prepare("INSERT INTO footprint_type (name, icon, color, sort, form_template, is_builtin, uuid, hlc, origin) VALUES (?,?,?,?,?,0,?,?,?)")
        .run('同步类型 ' + uuid.slice(0, 8), 'tag', '#64748b', 500, '[]', uuid, h2, 'sync');
      return Number(rr.lastInsertRowid);
    }
    if (table === 'dimension') {
      const rr = db.prepare("INSERT INTO dimension (name, color, sort, uuid, hlc, origin) VALUES (?,?,?,?,?,?)")
        .run('同步维度 ' + uuid.slice(0, 8), '#64748b', 500, uuid, h2, 'sync');
      return Number(rr.lastInsertRowid);
    }
    if (table === 'grade_band') {
      const rr = db.prepare("INSERT INTO grade_band (label, color, min, max, sort, uuid, hlc, origin) VALUES (?,?,?,?,?,?,?,?)")
        .run('同步梯度 ' + uuid.slice(0, 8), '#64748b', 60, 70, 500, uuid, h2, 'sync');
      return Number(rr.lastInsertRowid);
    }
    if (table === 'metric_def') {
      const rr = db.prepare("INSERT INTO metric_def (key, label, unit, agg, section, uuid, hlc, origin) VALUES (?,?,?,?,?,?,?,?)")
        .run('sync_' + uuid.slice(0, 8), '同步指标 ' + uuid.slice(0, 8), null, 'sum', null, uuid, h2, 'sync');
      return Number(rr.lastInsertRowid);
    }
    if (table === 'taxonomy') {
      const rr = db.prepare("INSERT INTO taxonomy (kind, value, color, sort, uuid, hlc, origin) VALUES (?,?,?,0,?,?,?,?)")
        .run('level', '同步条目 ' + uuid.slice(0, 8), '#64748b', uuid, h2, 'sync');
      return Number(rr.lastInsertRowid);
    }
    return null;
  }

  function serializeRowOf(table) {
    const spec = WIRE_TABLES[table];
    return (row) => {
      const out = { uuid: row.uuid, hlc: row.hlc, deleted_at: row.deleted_at || null };
      for (const k of Object.keys(row)) {
        if (SKIP_COLS.includes(k)) continue;
        if (spec.fks[k] !== undefined) { out[k.replace('_id', '_uuid')] = uuidOf(spec.fks[k], row[k]); continue; }
        out[k] = row[k];
      }
      return out;
    };
  }

  function softDeleteById(table, id) {
    db.prepare('UPDATE ' + table + " SET deleted_at=datetime('now','localtime') WHERE id=?").run(id);
  }

  function applyWire(change) {
    const spec = WIRE_TABLES[change.table];
    if (!spec) return { accepted: 0, stale: 0, invalid: 1 };
    const rowUuid = String(change.row_uuid || '');
    const incoming = parseHlc(change.hlc);
    if (!incoming || (change.op !== 'upsert' && change.op !== 'delete')) return { accepted: 0, stale: 0, invalid: 1 };
    const existing = db.prepare('SELECT id, hlc FROM ' + change.table + ' WHERE uuid=?').get(rowUuid);
    if (existing) {
      const e = parseHlc(existing.hlc);
      if (e && !hlcNewer(incoming, e)) return { accepted: 0, stale: 1, invalid: 0 };
    }
    let res;
    try {
      res = withTx(db, () => {
      if (change.op === 'delete') {
        if (existing) softDeleteById(change.table, existing.id);
        touchOplog(db, change.table, rowUuid, 'delete', change.hlc);
        return 1;
      }
      const data = change.data || {};
      const fv = {};
      for (const fk of Object.keys(spec.fks)) {
        const uuidVal = data[fk.replace('_id', '_uuid')];
        fv[fk] = idOfUuid(spec.fks[fk], uuidVal, true);
      }
      const cols = [];
      const vals = [];
      for (const k of Object.keys(data)) {
        if (['uuid', 'hlc', 'deleted_at'].includes(k)) continue;
        if (k.endsWith('_uuid') && spec.fks[k.replace('_uuid', '_id')] !== undefined) continue;
        cols.push(k);
        vals.push(data[k]);
      }
      for (const fk of Object.keys(fv)) { cols.push(fk); vals.push(fv[fk]); }
      cols.push('uuid', 'hlc', 'origin');
      vals.push(rowUuid, change.hlc, 'sync');
      if (change.table === 'footprint') {
        cols.push('search_text');
        vals.push(buildSearchText(String(data.title || ''), String(data.description || ''), String(data.result || ''), data.tags || [], data.extras || {}));
      }
      if (existing) {
        const setSql = cols.map(c => c + '=?').join(', ');
        db.prepare('UPDATE ' + change.table + ' SET ' + setSql + ' WHERE id=?').run(...vals, existing.id);
      } else {
        db.prepare('INSERT INTO ' + change.table + ' (' + cols.join(',') + ') VALUES (' + cols.map(() => '?').join(',') + ')').run(...vals);
      }
      touchOplog(db, change.table, rowUuid, 'upsert', change.hlc);
      return 1;
    });
    } catch (ex) {
      throw ex;
    }
    return res === 1 ? { accepted: 1, stale: 0, invalid: 0 } : { accepted: 0, stale: 0, invalid: 0 };
  }

  function applyWireBatch(changes) {
    let accepted = 0; let stale = 0; let invalid = 0;
    for (const ch of (changes || [])) {
      const r = applyWire(ch);
      accepted += r.accepted; stale += r.stale; invalid += r.invalid;
    }
    return { accepted, stale, invalid };
  }

  function pullWire(cursorRaw, limitRaw) {
    const cursor = Math.max(0, Number(cursorRaw) || 0);
    const limit = Math.min(500, Math.max(1, Number(limitRaw) || 200));
    const opRows = db.prepare('SELECT id, table_name, row_uuid, op, hlc FROM sync_oplog WHERE id>? ORDER BY id LIMIT ?').all(cursor, limit);
    const changes = [];
    for (const op of opRows) {
      if (!WIRE_TABLES[op.table_name]) continue;
      if (op.op === 'delete') {
        changes.push({ seq: op.id, table: op.table_name, row_uuid: op.row_uuid, op: 'delete', hlc: op.hlc, data: null });
        continue;
      }
      const row = db.prepare('SELECT * FROM ' + op.table_name + ' WHERE uuid=?').get(op.row_uuid);
      if (!row) continue;
      changes.push({ seq: op.id, table: op.table_name, row_uuid: op.row_uuid, op: 'upsert', hlc: op.hlc, data: serializeRowOf(op.table_name)(row) });
    }
    const maxSeq = db.prepare('SELECT COALESCE(MAX(id),0) AS m FROM sync_oplog').get().m;
    const hasMore = opRows.length === limit;
    return {
      changes,
      cursor: hasMore && opRows.length ? opRows[opRows.length - 1].id : Math.max(cursor, maxSeq),
      has_more: hasMore
    };
  }

  return { handleCommand, getDb, pullWire, applyWireBatch };
}

// ---------- 默认单例（开发桥接 / seed 兼容） ----------
let defaultCommands = null;
function getDefault() {
  if (!defaultCommands) defaultCommands = createAppCommands(DB_PATH);
  return defaultCommands;
}

export function getDb() {
  return getDefault().getDb();
}

export function handleCommand(cmd, payload) {
  return getDefault().handleCommand(cmd, payload);
}