import { getWorkRule, listAttendanceBetween, listLogItemsBetween, listProjects, listWeeklyNotesBetween } from '../db/repo'
import { type LogItem } from '../db/schema'
import { getLogCategories } from '../db/categories'
import { todayStr } from '../lib/date'
import { computeDay } from './attendance'

export interface ReportRange {
  start: string
  end: string
  label: string
}

export interface CategoryStat {
  key: string
  label: string
  count: number
  percent: number
}

export interface ProjectStat {
  name: string
  count: number
}

export interface ReportData {
  range: ReportRange
  attendDays: number
  totalHours: string
  makeupCount: number
  leaveCount: number
  itemCount: number
  categoryStats: CategoryStat[]
  projectStats: ProjectStat[]
  locationStats: { name: string; count: number }[]
  milestones: { date: string; content: string }[]
  followups: { date: string; content: string; remark: string }[]
  takeaways: { date: string; text: string }[]
  weekNotes: { weekStart: string; highlights: string; challenges: string; plan_next: string }[]
}

export async function buildReport(start: string, end: string, label: string): Promise<ReportData> {
  const t = todayStr()
  const results = await Promise.all([
    getWorkRule(),
    listAttendanceBetween(start, end),
    listLogItemsBetween(start, end),
    listProjects(true),
    listWeeklyNotesBetween(start, end),
    getLogCategories()
  ])
  const rule = results[0]
  const atts = results[1]
  const items = results[2]
  const projects = results[3]
  const notes = results[4]
  const logCats: string[] = results[5] as string[]

  let attendDays = 0
  let workedMin = 0
  let makeupCount = 0
  for (const a of atts) {
    if (a.clock_in_at || a.kind === 'makeup') attendDays++
    if (a.kind === 'makeup') makeupCount++
    const info = computeDay(a, a.date, rule, a.date === t)
    workedMin += info.workedMinutes ?? 0
  }

  const lcount = new Map<string, number>()
  for (const a of atts) {
    if (!(a.clock_in_at || a.kind === 'makeup')) continue
    const name = a.location || '未记录'
    lcount.set(name, (lcount.get(name) || 0) + 1)
  }
  const locationStats = Array.from(lcount.entries())
    .map(pair => ({ name: pair[0], count: pair[1] }))
    .sort((a, b) => b.count - a.count)

  const total = items.length || 1
  const catCount2 = new Map<string, number>()
  for (const it of items) catCount2.set(it.category, (catCount2.get(it.category) || 0) + 1)
  const catSet2 = new Set(logCats)
  for (const k of catCount2.keys()) if (!catSet2.has(k)) logCats.push(k)
  const categoryStats: CategoryStat[] = logCats
    .map(label => {
      const count = catCount2.get(label) || 0
      return { key: label, label, count, percent: Math.round((count / total) * 100) }
    })
    .filter(c => c.count > 0)
    .sort((a, b) => b.count - a.count)

  const pname = new Map<number, string>(projects.map(p => [p.id as number, p.name]))
  const pcount = new Map<string, number>()
  for (const it of items) {
    const name = it.project_id ? (pname.get(it.project_id) || '已删除项目') : '无项目'
    pcount.set(name, (pcount.get(name) || 0) + 1)
  }
  const projectStats: ProjectStat[] = Array.from(pcount.entries())
    .map(pair => ({ name: pair[0], count: pair[1] }))
    .sort((a, b) => b.count - a.count)

  const milestones = items.filter(i => i.is_milestone === 1).map(i => ({ date: i.date, content: i.content }))
  const followups = items.filter(i => i.needs_followup === 1).map(i => ({ date: i.date, content: i.content, remark: i.remark || '' }))
  const takeaways = items.filter(i => !!i.takeaway).map(i => ({ date: i.date, text: i.takeaway as string }))
  const weekNotes = notes.map(n => ({
    weekStart: n.week_start,
    highlights: n.highlights || '',
    challenges: n.challenges || '',
    plan_next: n.plan_next || ''
  }))

  return {
    range: { start, end, label },
    attendDays,
    totalHours: (workedMin / 60).toFixed(1),
    makeupCount,
    leaveCount: atts.filter(a => a.kind === 'leave').length,
    itemCount: items.length,
    categoryStats,
    projectStats,
    locationStats,
    milestones,
    followups,
    takeaways,
    weekNotes
  }
}

export function reportToMarkdown(d: ReportData): string {
  const out: string[] = []
  out.push('# 实习工作总结（' + d.range.start + ' ~ ' + d.range.end + '）')
  out.push('')
  out.push('## 一、考勤概况')
  out.push('')
  out.push('出勤 ' + d.attendDays + ' 天，累计工时 ' + d.totalHours + ' 小时，补卡 ' + d.makeupCount + ' 次' + (d.leaveCount ? '，请假 ' + d.leaveCount + ' 天' : ''))
  const locParts = d.locationStats.filter(l => l.name !== '未记录')
  if (locParts.length) {
    out.push('其中：' + locParts.map(l => l.name + ' ' + l.count + ' 天').join('，'))
  }
  out.push('')
  out.push('## 二、工作内容分布')
  out.push('')
  out.push(d.categoryStats.length
    ? d.categoryStats.map(c => c.label + ' ' + c.percent + '%（' + c.count + ' 条）').join('，')
    : '（无记录）')
  out.push('')
  out.push('## 三、项目投入')
  out.push('')
  out.push(d.projectStats.length
    ? d.projectStats.map(p => p.name + ' ' + p.count + ' 条').join('，')
    : '（无记录）')
  out.push('')
  out.push('## 四、主要成果')
  out.push('')
  if (d.milestones.length) {
    d.milestones.forEach((m, i) => out.push((i + 1) + '. 【成果】' + m.content + '（' + m.date + '）'))
  } else {
    out.push('（无）')
  }
  out.push('')
  out.push('## 五、待跟进事项')
  out.push('')
  if (d.followups.length) {
    d.followups.forEach(f => out.push('- 【待跟进】' + f.content + (f.remark ? '（' + f.date + ' 备注：' + f.remark + '）' : '（' + f.date + '）')))
  } else {
    out.push('（无）')
  }
  out.push('')
  out.push('## 六、学习与成长')
  out.push('')
  if (d.takeaways.length) {
    d.takeaways.forEach(tk => out.push('- ' + tk.text + '（' + tk.date + '）'))
  } else {
    out.push('（无）')
  }
  for (const w of d.weekNotes) {
    out.push('')
    out.push('### 周记（' + w.weekStart + ' 起）')
    out.push('')
    out.push('- 本周亮点：' + (w.highlights || '（无）'))
    out.push('- 踩的坑：' + (w.challenges || '（无）'))
    out.push('- 下周计划：' + (w.plan_next || '（无）'))
  }
  out.push('')
  return out.join('\n')
}