// 打卡 · 日历与打卡合并视图 (V0.2.1 界面调整, 设计文档 §11.5)
//   - 上: 月历 (月份切换 + 回到今天), 去掉「昨天/今天/明天」分段
//   - 下: 当日打卡项, 按 每天 / 每周 / 每月 分组 (去掉「每年」分组)
//   - 卡片紧凑化: 内边距 8px, 环形 42px/环宽 5, 间距 7px
//   - 撤销 / 编辑 / 归档 收进「⋯」底部面板
//   - 未来日期只读, 按钮灰显「计划」
import { useCallback, useEffect, useMemo, useState } from 'react'
import {
  Button, Dialog, DotLoading, Empty, Input, Popup, Selector, Stepper, Toast,
} from 'antd-mobile'
import RingProgress, { Celebrate } from '../../components/RingProgress.jsx'
import { checkinApi } from '../../api/checkin.js'
import useRefreshOnVisible from '../../hooks/useRefreshOnVisible.js'
import {
  toDateStr, addDays, addMonths, monthGrid, weekdayLabels, dayLabel, fmtMonth,
} from './date.js'

// 分组顺序: 每天 → 每周 → 每月 (去掉每年)
const GROUP_ORDER = ['day', 'week', 'month']
const GROUP_LABEL = { day: '每天', week: '每周', month: '每月' }

const PERIOD_OPTIONS = [
  { label: '每天', value: 'day' },
  { label: '每周', value: 'week' },
  { label: '每月', value: 'month' },
  { label: '每年', value: 'year' },
]

const COLORS = ['#1677ff', '#00b578', '#ff8f1f', '#ff3141', '#a855f7', '#14b8a6', '#f43f9e']
const EMPTY_FORM = { id: null, name: '', period: 'day', target: 1, color: COLORS[0], note: '' }

export default function MergedView({ date, onDateChange }) {
  const today = toDateStr()
  const [month, setMonth] = useState(() => date.slice(0, 7))
  const [cal, setCal] = useState(null)       // 月历数据 { days, rate }
  const [detail, setDetail] = useState(null) // 选中日详情 { today, date, items, summary, isFuture }
  const [err, setErr] = useState('')
  const [bursts, setBursts] = useState({})
  const [sheetItem, setSheetItem] = useState(null) // 「⋯」面板对应的打卡项
  const [form, setForm] = useState(EMPTY_FORM)
  const [showForm, setShowForm] = useState(false)

  // ---------- 数据加载 ----------
  const loadCal = useCallback((silent) => {
    if (!silent) setErr('')
    checkinApi.calendar(month)
      .then(setCal)
      .catch((e) => { if (!silent) setErr(e.message) })
  }, [month])

  const loadDetail = useCallback((silent) => {
    if (!silent) setErr('')
    checkinApi.habits(date)
      .then(setDetail)
      .catch((e) => { if (!silent) setErr(e.message) })
  }, [date])

  useEffect(() => { loadCal(false) }, [loadCal])
  useEffect(() => { setDetail(null); loadDetail(false) }, [loadDetail])
  useRefreshOnVisible(() => { loadCal(true); loadDetail(true) })

  // 切换日期时若跨月, 同步月份
  useEffect(() => {
    const m = date.slice(0, 7)
    setMonth((cur) => (cur === m ? cur : m))
  }, [date])

  const days = useMemo(() => monthGrid(month), [month])
  const byDate = useMemo(() => {
    const map = new Map()
    ;(cal?.days || []).forEach((d) => map.set(d.date, d))
    return map
  }, [cal])

  const items = detail?.items || []
  const isFuture = !!detail?.isFuture

  // 按周期分组: 每天 → 每周 → 每月. "每年" 不在合并视图中展示, 但若存在
  // 历史 year 项则归入"每月"之外的单列, 避免数据凭空消失.
  const groups = useMemo(() => {
    const bucket = new Map()
    for (const it of items) {
      const key = GROUP_ORDER.includes(it.period) ? it.period : 'other'
      if (!bucket.has(key)) bucket.set(key, [])
      bucket.get(key).push(it)
    }
    // 组内排序: 未完成在前, 已完成在后 (沿用 F-CK-16 默认口径)
    for (const arr of bucket.values()) {
      arr.sort((a, b) => Number(a.completed) - Number(b.completed) || a.id - b.id)
    }
    const order = [...GROUP_ORDER, 'other']
    return order.filter((k) => bucket.has(k)).map((k) => ({
      key: k,
      label: GROUP_LABEL[k] || '其它周期',
      items: bucket.get(k),
    }))
  }, [items])

  const summary = detail?.summary || { total: 0, done: 0 }
  const fireBurst = (id) => setBursts((m) => ({ ...m, [id]: (m[id] || 0) + 1 }))

  // ---------- 打卡 / 撤销 (乐观更新) ----------
  async function doCheck(item) {
    if (!item.canCheck || isFuture) return
    const before = detail
    setDetail((d) => ({
      ...d,
      items: d.items.map((x) => {
        if (x.id !== item.id) return x
        const done = x.done + 1
        const countOnDate = (x.countOnDate || 0) + 1
        return {
          ...x,
          done,
          remaining: Math.max(0, x.target - done),
          percent: Math.min(1, done / x.target),
          completed: done >= x.target,
          over: Math.max(0, done - x.target),
          countOnDate,
          dayDone: countOnDate >= x.expectedPerDay,
        }
      }),
    }))
    try {
      const res = await checkinApi.check(item.id, date)
      const fresh = await checkinApi.habits(date)
      setDetail(fresh)
      if (res.item?.completed) fireBurst(item.id)
      loadCal(true)
    } catch (e) {
      setDetail(before)
      Toast.show({ content: e.message || '打卡失败' })
    }
  }

  async function doUncheck(item) {
    const before = detail
    setDetail((d) => ({
      ...d,
      items: d.items.map((x) => {
        if (x.id !== item.id) return x
        const done = Math.max(0, x.done - 1)
        const countOnDate = Math.max(0, (x.countOnDate || 0) - 1)
        return {
          ...x,
          done,
          remaining: Math.max(0, x.target - done),
          percent: Math.min(1, done / x.target),
          completed: done >= x.target,
          over: Math.max(0, done - x.target),
          countOnDate,
          dayDone: countOnDate >= x.expectedPerDay,
        }
      }),
    }))
    try {
      await checkinApi.uncheck(item.id, date)
      const fresh = await checkinApi.habits(date)
      setDetail(fresh)
      loadCal(true)
    } catch (e) {
      setDetail(before)
      Toast.show({ content: e.message || '撤销失败' })
    }
  }

  // ---------- 新建 / 编辑 / 归档 ----------
  function openCreate() {
    setForm(EMPTY_FORM)
    setShowForm(true)
  }

  function openEdit(item) {
    setSheetItem(null)
    setForm({ id: item.id, name: item.name, period: item.period, target: item.target, color: item.color, note: item.note })
    setShowForm(true)
  }

  async function submitForm() {
    const name = String(form.name || '').trim()
    if (!name) return Toast.show({ content: '请填写名称' })
    if (name.length > 20) return Toast.show({ content: '名称不能超过 20 个字' })
    const payload = { name, period: form.period, target: Number(form.target) || 1, color: form.color, note: form.note }
    try {
      if (form.id) await checkinApi.updateHabit(form.id, payload)
      else await checkinApi.createHabit(payload)
      setShowForm(false)
      setForm(EMPTY_FORM)
      loadDetail(true)
      loadCal(true)
    } catch (e) {
      Toast.show({ content: e.message || '保存失败' })
    }
  }

  async function doArchive(item) {
    setSheetItem(null)
    const ok = await Dialog.confirm({
      content: `归档「${item.name}」？归档后不再出现在待办，历史记录保留。`,
      confirmText: '归档',
      cancelText: '取消',
    })
    if (!ok) return
    try {
      await checkinApi.deleteHabit(item.id)
      Toast.show({ content: '已归档' })
      loadDetail(true)
      loadCal(true)
    } catch (e) {
      Toast.show({ content: e.message || '操作失败' })
    }
  }

  // ---------- 渲染 ----------
  return (
    <div className="mv-view">
      {/* 月历 */}
      <div className="mv-cal">
        <div className="mv-month">
          <span className="arrow" onClick={() => setMonth((m) => addMonths(m, -1))}>‹</span>
          <b>{fmtMonth(month)}</b>
          <span className="arrow" onClick={() => setMonth((m) => addMonths(m, 1))}>›</span>
          <span className="today" onClick={() => onDateChange(today)}>回到今天</span>
        </div>

        <div className="mv-grid mv-wd">
          {weekdayLabels().map((w) => <span key={w}>{w}</span>)}
        </div>
        <div className="mv-grid">
          {days.map((d) => {
            const info = byDate.get(d)
            const inMonth = d.slice(0, 7) === month
            const status = info?.status || 'empty'
            return (
              <div
                key={d}
                className={
                  'mv-day' + (inMonth ? '' : ' out') + (d === date ? ' sel' : '') +
                  (info?.isToday ? ' today' : '') + (info?.isFuture ? ' future' : '')
                }
                onClick={() => onDateChange(d)}
              >
                <span>{Number(d.slice(8, 10))}</span>
                {inMonth && status !== 'empty' && <i className={status} />}
              </div>
            )
          })}
        </div>

        {cal && (
          <div className="mv-rate">
            <span>本月完成率</span>
            <b>{Math.round((cal.rate || 0) * 100)}%</b>
          </div>
        )}
      </div>

      {err && <div className="error-banner">{err}<span className="retry-link" onClick={() => { loadCal(false); loadDetail(false) }}>重试</span></div>}

      {/* 当日栏: 右侧放「+ 新建」, 替代原来无实际作用的「点环即打卡」提示 */}
      <div className="mv-daybar">
        {dayLabel(date, detail?.today || today)}
        {isFuture
          ? <span className="badge">计划（不可打卡）</span>
          : <span className="badge">已完成 {summary.done} / {summary.total}</span>}
        <Button
          className="mv-new-btn"
          size="mini"
          color="primary"
          onClick={openCreate}
        >
          + 新建
        </Button>
      </div>

      {detail === null && !err && <div className="monitor-loading"><DotLoading /> 加载中...</div>}

      {detail !== null && items.length === 0 && (
        <div className="checkin-empty">
          <Empty description="当天没有打卡项" />
          <Button color="primary" size="small" onClick={openCreate}>创建第一个打卡项</Button>
        </div>
      )}

      {/* 分组列表 */}
      <div className="mv-groups">
        {groups.map((g) => (
          <div key={g.key}>
            <div className="mv-ghead">{g.label}<span className="cnt">{g.items.length} 项</span></div>
            {g.items.map((item) => (
              <div key={item.id} className={'mv-card' + (item.completed ? ' done' : '')}>
                <RingProgress
                  size={42}
                  stroke={5}
                  percent={item.percent}
                  done={item.done}
                  target={item.target}
                  over={item.over}
                  completed={item.completed}
                  color={item.color}
                  onClick={() => doCheck(item)}
                />
                <div className="mv-main">
                  <div className="mv-name">{item.name}</div>
                  <div className="mv-meta">
                    {item.periodLabel} {item.target} 次 · 当日 {item.countOnDate || 0}/{item.expectedPerDay}
                    {item.streak > 0 && <span className="st">连续 {item.streak}</span>}
                  </div>
                </div>
                {isFuture ? (
                  <div className="mv-btn grey">计划</div>
                ) : (
                  <div
                    className={'mv-btn' + (item.completed ? ' grey' : '')}
                    onClick={() => doCheck(item)}
                  >
                    {item.completed ? '再打一次' : '打卡'}
                  </div>
                )}
                <div className="mv-more" onClick={() => setSheetItem(item)}>⋯</div>
                <Celebrate fire={bursts[item.id] || 0} color={item.color} />
              </div>
            ))}
          </div>
        ))}
      </div>

      {/* 「⋯」操作面板: 撤销 / 编辑 / 归档 */}
      <Popup
        visible={!!sheetItem}
        onMaskClick={() => setSheetItem(null)}
        bodyStyle={{ borderTopLeftRadius: 12, borderTopRightRadius: 12, paddingBottom: 16 }}
      >
        {sheetItem && (
          <div className="mv-sheet">
            <div className="sheet-title">{sheetItem.name}</div>
            <div
              className={'mv-sheet-row' + (sheetItem.done > 0 ? '' : ' disabled')}
              onClick={() => { if (sheetItem.done > 0) { doUncheck(sheetItem); setSheetItem(null) } }}
            >
              <span>撤销上次打卡</span>
              <span className="k">今日 {sheetItem.countOnDate || 0} 次</span>
            </div>
            <div className="mv-sheet-row" onClick={() => openEdit(sheetItem)}>
              <span>编辑打卡项</span>
              <span className="k">名称 / 周期 / 目标</span>
            </div>
            <div className="mv-sheet-row danger" onClick={() => doArchive(sheetItem)}>
              <span>归档</span>
              <span className="k">历史记录保留</span>
            </div>
          </div>
        )}
      </Popup>

      {/* 新建 / 编辑表单 */}
      <Popup
        visible={showForm}
        onMaskClick={() => setShowForm(false)}
        bodyStyle={{ borderTopLeftRadius: 12, borderTopRightRadius: 12, paddingBottom: 16 }}
      >
        <div className="form-popup">
          <div className="form-title">{form.id ? '编辑打卡项' : '新建打卡项'}</div>
          <div className="form-field">
            <label>名称</label>
            <Input
              placeholder="例如：喝水 / 健身 / 读书"
              value={form.name}
              maxLength={20}
              onChange={(v) => setForm((f) => ({ ...f, name: v }))}
            />
          </div>
          <div className="form-field">
            <label>周期</label>
            <Selector
              options={PERIOD_OPTIONS}
              value={[form.period]}
              onChange={(v) => setForm((f) => ({ ...f, period: v[0] }))}
            />
          </div>
          <div className="form-field">
            <label>目标次数（周期内）</label>
            <Stepper min={1} max={999} value={form.target} onChange={(v) => setForm((f) => ({ ...f, target: v }))} />
          </div>
          <div className="form-field">
            <label>颜色</label>
            <div className="color-row">
              {COLORS.map((c) => (
                <span
                  key={c}
                  className={'color-dot' + (form.color === c ? ' active' : '')}
                  style={{ background: c }}
                  onClick={() => setForm((f) => ({ ...f, color: c }))}
                />
              ))}
            </div>
          </div>
          <div className="form-field">
            <label>备注（可选）</label>
            <Input
              placeholder="补充说明"
              value={form.note}
              onChange={(v) => setForm((f) => ({ ...f, note: v }))}
            />
          </div>
          <div className="form-actions">
            <Button block color="primary" onClick={submitForm}>保存</Button>
            <Button block fill="outline" onClick={() => setShowForm(false)} style={{ marginTop: 8 }}>取消</Button>
          </div>
        </div>
      </Popup>
    </div>
  )
}