import { useCallback, useEffect, useMemo, useState } from 'react'
import { Navigate } from 'react-router-dom'
import {
  ClipboardList,
  Play,
  Plus,
  RotateCcw,
  Search,
  Square,
  Trash2,
} from 'lucide-react'
import { Breadcrumbs, Pagination, useLocale } from '@meshkee/dashboard-ui'
import { EmptyTableRow } from '../components/EmptyState'
import { PageTitle } from '../components/PageTitle'
import { RollCallTasksModal } from '../components/RollCallTasksModal'
import { Tooltip } from '../components/Tooltip'
import { useAuth } from '../context/AuthContext'
import { useToast } from '../context/ToastContext'
import { useT } from '../i18n/useT'
import { ApiError, isAbortError } from '../lib/api'
import { getActiveBusinessId } from '../lib/businessContext'
import {
  createRollCall,
  listRollCalls,
  removeRollCall,
  updateRollCall,
  type RollCall,
  type RollCallSummary,
  type RollCallsListResponse,
} from '../services/rollCallService'
import { canAccessRollCall } from '../utils/rollCallAccess'
import pageStyles from '../components/PageContent.module.css'
import styles from './RollCallPage.module.css'

const PAGE_SIZE = 24
const COLUMN_COUNT = 5
const ACTIVE_KEY = 'meshkee_roll_call_active_id'

function todayIso() {
  const now = new Date()
  const y = now.getFullYear()
  const m = String(now.getMonth() + 1).padStart(2, '0')
  const d = String(now.getDate()).padStart(2, '0')
  return `${y}-${m}-${d}`
}

function nowTimeHhMm() {
  const now = new Date()
  return `${String(now.getHours()).padStart(2, '0')}:${String(now.getMinutes()).padStart(2, '0')}`
}

function timeToMinutes(value: string) {
  const [h, m] = value.split(':').map(Number)
  return h * 60 + m
}

function minutesSinceStart(startTime: string, now = new Date()) {
  const start = timeToMinutes(startTime)
  const current = now.getHours() * 60 + now.getMinutes()
  if (current >= start) return current - start
  return 24 * 60 - start + current
}

function formatDuration(
  minutes: number,
  t: (
    key:
      | 'rollCall.duration.minutesOnly'
      | 'rollCall.duration.hoursOnly'
      | 'rollCall.duration.hoursMinutes',
    vars?: Record<string, string | number>,
  ) => string,
) {
  const hours = Math.floor(minutes / 60)
  const mins = minutes % 60
  if (hours === 0) return t('rollCall.duration.minutesOnly', { minutes: mins })
  if (mins === 0) return t('rollCall.duration.hoursOnly', { hours })
  return t('rollCall.duration.hoursMinutes', { hours, minutes: mins })
}

function formatDateLabel(value: string, locale: string) {
  const date = new Date(`${value}T00:00:00`)
  if (Number.isNaN(date.getTime())) return value
  return new Intl.DateTimeFormat(locale === 'fa' ? 'fa-IR' : 'en-GB', {
    year: 'numeric',
    month: 'short',
    day: 'numeric',
  }).format(date)
}

function readActiveId() {
  return localStorage.getItem(ACTIVE_KEY)
}

function writeActiveId(id: string | null) {
  if (id) localStorage.setItem(ACTIVE_KEY, id)
  else localStorage.removeItem(ACTIVE_KEY)
}

export function RollCallPage() {
  const t = useT()
  const { locale } = useLocale()
  const { showToast } = useToast()
  const { user } = useAuth()
  const activeBusinessId = getActiveBusinessId()
  const allowed = canAccessRollCall(user, activeBusinessId)

  const [data, setData] = useState<RollCallsListResponse | null>(null)
  const [loading, setLoading] = useState(false)
  const [starting, setStarting] = useState(false)
  const [stoppingId, setStoppingId] = useState<string | null>(null)
  const [error, setError] = useState('')
  const [page, setPage] = useState(1)
  const [draftDateFrom, setDraftDateFrom] = useState('')
  const [draftDateTo, setDraftDateTo] = useState('')
  const [appliedDateFrom, setAppliedDateFrom] = useState('')
  const [appliedDateTo, setAppliedDateTo] = useState('')
  const [tasksModalOpen, setTasksModalOpen] = useState(false)
  const [tasksTarget, setTasksTarget] = useState<RollCall | null>(null)
  const [removingId, setRemovingId] = useState<string | null>(null)
  const [activeId, setActiveId] = useState<string | null>(() => readActiveId())
  const [nowTick, setNowTick] = useState(() => Date.now())

  const load = useCallback(
    async (signal?: AbortSignal) => {
      setLoading(true)
      setError('')
      try {
        const response = await listRollCalls(
          {
            page,
            pageSize: PAGE_SIZE,
            ...(appliedDateFrom ? { dateFrom: appliedDateFrom } : {}),
            ...(appliedDateTo ? { dateTo: appliedDateTo } : {}),
          },
          signal,
        )
        if (signal?.aborted) return
        setData(response)
      } catch (err) {
        if (isAbortError(err) || signal?.aborted) return
        setError(err instanceof ApiError ? err.message : t('rollCall.error.load'))
      } finally {
        if (!signal?.aborted) setLoading(false)
      }
    },
    [page, appliedDateFrom, appliedDateTo, t],
  )

  useEffect(() => {
    if (!allowed) return
    const controller = new AbortController()
    void load(controller.signal)
    return () => controller.abort()
  }, [allowed, load])

  useEffect(() => {
    if (!activeId) return
    const timer = window.setInterval(() => setNowTick(Date.now()), 15_000)
    return () => window.clearInterval(timer)
  }, [activeId])

  const totalPages = useMemo(() => {
    const total = data?.total ?? 0
    return Math.max(1, Math.ceil(total / PAGE_SIZE))
  }, [data?.total])

  const summary: RollCallSummary = data?.summary ?? {
    totalDays: 0,
    totalWorkingMinutes: 0,
    totalTasks: 0,
  }

  const hasActiveSession = Boolean(activeId)
  const activeItem = data?.items.find((item) => item.id === activeId) ?? null

  if (!allowed) {
    return <Navigate to="/" replace />
  }

  function applyFilters() {
    setAppliedDateFrom(draftDateFrom)
    setAppliedDateTo(draftDateTo)
    setPage(1)
  }

  function clearFilters() {
    setDraftDateFrom('')
    setDraftDateTo('')
    setAppliedDateFrom('')
    setAppliedDateTo('')
    setPage(1)
  }

  function upsertItem(saved: RollCall) {
    setData((prev) => {
      if (!prev) return prev
      const index = prev.items.findIndex((item) => item.id === saved.id)
      if (index >= 0) {
        const items = [...prev.items]
        items[index] = saved
        return { ...prev, items }
      }
      return {
        ...prev,
        items: [saved, ...prev.items],
        total: prev.total + 1,
      }
    })
  }

  function openTasks(item: RollCall) {
    setTasksTarget(item)
    setTasksModalOpen(true)
  }

  async function handleStart() {
    if (hasActiveSession) {
      showToast(t('rollCall.error.alreadyRunning'), 'info')
      return
    }

    setStarting(true)
    setError('')
    const workDate = todayIso()
    const startTime = nowTimeHhMm()

    try {
      const existingToday = data?.items.find((item) => item.workDate === workDate)
      if (existingToday) {
        writeActiveId(existingToday.id)
        setActiveId(existingToday.id)
        showToast(t('rollCall.toast.resumed'), 'success')
        return
      }

      const result = await createRollCall({
        workDate,
        startTime,
        endTime: startTime,
        tasks: [],
      })
      writeActiveId(result.rollCall.id)
      setActiveId(result.rollCall.id)
      upsertItem(result.rollCall)
      showToast(t('rollCall.toast.started'), 'success')
      void load()
    } catch (err) {
      const message =
        err instanceof ApiError ? err.message : t('rollCall.error.start')
      setError(message)
      showToast(message, 'error')
    } finally {
      setStarting(false)
    }
  }

  async function handleStop(item: Pick<RollCall, 'id'>) {
    setStoppingId(item.id)
    setError('')
    try {
      const result = await updateRollCall(item.id, { endTime: nowTimeHhMm() })
      writeActiveId(null)
      setActiveId(null)
      upsertItem(result.rollCall)
      showToast(t('rollCall.toast.stopped'), 'success')
      void load()
    } catch (err) {
      const message =
        err instanceof ApiError ? err.message : t('rollCall.error.stop')
      setError(message)
      showToast(message, 'error')
    } finally {
      setStoppingId(null)
    }
  }

  async function handleRemove(item: RollCall) {
    setRemovingId(item.id)
    setError('')
    try {
      await removeRollCall(item.id)
      if (activeId === item.id) {
        writeActiveId(null)
        setActiveId(null)
      }
      showToast(t('rollCall.toast.removed'), 'success')
      void load()
    } catch (err) {
      const message =
        err instanceof ApiError ? err.message : t('rollCall.error.remove')
      setError(message)
      showToast(message, 'error')
    } finally {
      setRemovingId(null)
    }
  }

  function spentMinutes(item: RollCall) {
    void nowTick
    if (activeId === item.id) return minutesSinceStart(item.startTime)
    return item.workingMinutes
  }

  return (
    <main className={pageStyles.content}>
      <Breadcrumbs
        items={[{ label: t('nav.home'), href: '/' }, { label: t('rollCall.title') }]}
      />

      <div className={pageStyles.pageHeader}>
        <div>
          <PageTitle en="ROLL CALL">{t('rollCall.title')}</PageTitle>
          <p className={pageStyles.pageSubtitle}>{t('rollCall.subtitle')}</p>
        </div>
      </div>

      <div className={styles.filtersPanel}>
        <form
          className={styles.filtersGrid}
          onSubmit={(e) => {
            e.preventDefault()
            applyFilters()
          }}
        >
          <div className={styles.filtersInputs}>
            <div className={styles.field}>
              <input
                type="date"
                value={draftDateFrom}
                onChange={(e) => setDraftDateFrom(e.target.value)}
                aria-label={t('rollCall.filter.dateFrom')}
                title={t('rollCall.filter.dateFrom')}
              />
            </div>
            <div className={styles.field}>
              <input
                type="date"
                value={draftDateTo}
                onChange={(e) => setDraftDateTo(e.target.value)}
                aria-label={t('rollCall.filter.dateTo')}
                title={t('rollCall.filter.dateTo')}
              />
            </div>
          </div>
          <div className={styles.filterActions}>
            <button
              type="submit"
              className={`${styles.iconActionBtn} ${styles.iconActionBtnPrimary}`}
              disabled={loading}
              aria-label={t('rollCall.search')}
              title={t('rollCall.search')}
            >
              <Search size={18} />
            </button>
            <button
              type="button"
              className={`${styles.iconActionBtn} ${styles.iconActionBtnGhost}`}
              onClick={clearFilters}
              disabled={loading}
              aria-label={t('rollCall.clearFilters')}
              title={t('rollCall.clearFilters')}
            >
              <RotateCcw size={18} />
            </button>
          </div>
        </form>
      </div>

      <div className={styles.summaryRow}>
        <div className={styles.summaryItem}>
          <span className={styles.summaryLabel}>{t('rollCall.summary.days')}</span>
          <span className={styles.summaryValue}>{summary.totalDays}</span>
        </div>
        <div className={styles.summaryItem}>
          <span className={styles.summaryLabel}>{t('rollCall.summary.hours')}</span>
          <span className={styles.summaryValue}>
            {formatDuration(summary.totalWorkingMinutes, t)}
          </span>
        </div>
        <div className={styles.summaryItem}>
          <span className={styles.summaryLabel}>{t('rollCall.summary.tasks')}</span>
          <span className={styles.summaryValue}>{summary.totalTasks}</span>
        </div>
      </div>

      <div className={styles.tablePanel}>
        <div className={styles.tableWrap}>
          <div className={styles.tableHeader}>
            <div className={styles.tableHeaderTitle}>{t('rollCall.listTitle')}</div>
          </div>

          {error && <div className={styles.errorBanner}>{error}</div>}

          <table className={styles.table} dir={locale === 'fa' ? 'rtl' : 'ltr'}>
            <thead>
              <tr>
                <th className={styles.th}>{t('rollCall.col.date')}</th>
                <th className={styles.th}>{t('rollCall.col.start')}</th>
                <th className={styles.th}>{t('rollCall.col.minutes')}</th>
                <th className={styles.th}>{t('rollCall.col.tasks')}</th>
                <th className={`${styles.th} ${styles.thActions}`}>
                  {t('rollCall.col.actions')}
                </th>
              </tr>
            </thead>
            <tbody>
              {loading && (
                <tr>
                  <td className={styles.td} colSpan={COLUMN_COUNT}>
                    {t('rollCall.loading')}
                  </td>
                </tr>
              )}

              {!loading && data?.items.length === 0 && (
                <EmptyTableRow colSpan={COLUMN_COUNT} message={t('rollCall.empty')} />
              )}

              {!loading &&
                data?.items.map((item) => {
                  const running = activeId === item.id
                  const minutes = spentMinutes(item)
                  return (
                    <tr key={item.id} className={running ? styles.activeRow : undefined}>
                      <td className={styles.td}>
                        {formatDateLabel(item.workDate, locale)}
                        {running && (
                          <span className={styles.runningBadge}>{t('rollCall.running')}</span>
                        )}
                      </td>
                      <td className={styles.td}>{item.startTime}</td>
                      <td className={styles.td}>
                        <span className={styles.minutesValue}>{minutes}</span>
                        <span className={styles.minutesUnit}>
                          {t('rollCall.minutesUnit')}
                        </span>
                      </td>
                      <td className={styles.td}>
                        <div className={styles.tasksCell}>
                          <button
                            type="button"
                            className={styles.tasksToggle}
                            onClick={() => openTasks(item)}
                            aria-label={t('rollCall.col.tasks')}
                            title={t('rollCall.col.tasks')}
                          >
                            <ClipboardList size={16} />
                            <span>
                              {t('rollCall.tasksDone', {
                                count: item.taskCount.toLocaleString(
                                  locale === 'fa' ? 'fa-IR' : 'en-US',
                                ),
                              })}
                            </span>
                          </button>
                          <Tooltip label={t('rollCall.addTask')}>
                            <button
                              type="button"
                              className={styles.addTaskBtn}
                              onClick={() => openTasks(item)}
                              aria-label={t('rollCall.addTask')}
                            >
                              <Plus size={18} strokeWidth={2.5} />
                            </button>
                          </Tooltip>
                        </div>
                      </td>
                      <td className={`${styles.td} ${styles.tdActions}`}>
                        <div className={styles.rowActions}>
                          {running && (
                            <Tooltip label={t('rollCall.stop')}>
                              <button
                                type="button"
                                className={`${styles.iconBtn} ${styles.stopIconBtn}`}
                                onClick={() => void handleStop(item)}
                                disabled={stoppingId === item.id}
                                aria-label={t('rollCall.stop')}
                              >
                                <Square size={15} />
                              </button>
                            </Tooltip>
                          )}
                          <Tooltip label={t('rollCall.remove')}>
                            <button
                              type="button"
                              className={styles.iconBtn}
                              onClick={() => void handleRemove(item)}
                              disabled={removingId === item.id}
                              aria-label={t('rollCall.remove')}
                            >
                              <Trash2 size={16} />
                            </button>
                          </Tooltip>
                        </div>
                      </td>
                    </tr>
                  )
                })}
            </tbody>
          </table>

          {data && data.total > PAGE_SIZE && (
            <div className={styles.pagination}>
              <Pagination
                currentPage={page}
                totalPages={totalPages}
                onPageChange={setPage}
                disabled={loading}
                variant="inline"
              />
            </div>
          )}
        </div>
      </div>

      {hasActiveSession && activeId ? (
        <button
          type="button"
          className={`${styles.startFab} ${styles.stopFab}`}
          onClick={() => void handleStop(activeItem ?? { id: activeId })}
          disabled={stoppingId === activeId}
          aria-label={t('rollCall.stop')}
          title={t('rollCall.stop')}
        >
          <Square size={18} />
          <span>{t('rollCall.stop')}</span>
        </button>
      ) : (
        <button
          type="button"
          className={styles.startFab}
          onClick={() => void handleStart()}
          disabled={starting}
          aria-label={t('rollCall.start')}
          title={t('rollCall.start')}
        >
          <Play size={20} />
          <span>{t('rollCall.start')}</span>
        </button>
      )}

      <RollCallTasksModal
        open={tasksModalOpen}
        rollCall={tasksTarget}
        onClose={() => {
          setTasksModalOpen(false)
          setTasksTarget(null)
        }}
        onSaved={(saved) => {
          upsertItem(saved)
          void load()
        }}
      />
    </main>
  )
}