"use client"

import { useCallback, useEffect, useRef, useState } from "react"
import { PageHeader } from "@/components/page-header"
import { backups as mockBackups, servers as mockServers, type Backup, type Server } from "@/lib/data"
import { createFilterQuery } from "@/components/reui/filters/filters-query"
import type { FilterQuery } from "@/components/reui/filters/filters-types"
import type { BackupScheduleSettingsDto, BackupStorageSettingsDto } from "@mmapp/contracts/backups"
import { KpiStatGrid } from "@/components/reui-kit/kpi-stat-grid"
import { Alert, AlertAction, AlertDescription, AlertTitle } from "@/components/reui/alert"
import { Button } from "@/components/ui/button"
import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs"
import {
  CloudIcon,
  ClockIcon,
  HardDriveIcon,
  PlusIcon,
  RefreshCwIcon,
} from "lucide-react"
import { useDataSource } from "@/lib/data-source"
import { serverListSchema } from "@mmapp/contracts/servers"
import { can } from "@/lib/auth"
import { userApiError } from "@/shared/api/users"
import { toFrontendServer } from "@/entities/server/model/mappers"
import {
  createBackupsAsync,
  deleteBackup,
  getBackupJob,
  getBackupScheduleSettings,
  getBackupStorageSettings,
  listBackups,
  putBackupScheduleSettings,
  putBackupStorageSettings,
  restoreBackup,
  syncBackupsFromStorage,
  testBackupStorage,
  type BackupItem,
} from "@/shared/api/backups"
import { requestJson, requestBlob } from "@/shared/api/http-client"
import { toast } from "sonner"
import { BackupsHistory } from "@/components/backups/backups-history"
import {
  BackupsSettings,
  WEEK_DAYS,
  defaultSchedule,
  defaultStorageForm,
  type BackupScheduleForm,
  type BackupStorageForm,
} from "@/components/backups/backups-settings"
import { BackupCreateSheet } from "@/components/backups/backup-create-sheet"
import { BackupDeleteDialog, BackupRestoreDialog } from "@/components/backups/backup-confirm-dialogs"

type PageTab = "history" | "settings"
type KindFilter = "all" | "auto" | "manual"

type Resource = "backups" | "servers" | "schedule" | "storage"
type ResourceState = { known: boolean; error: string | null; receivedAt: string | null }
const unknownResource = (): ResourceState => ({ known: false, error: null, receivedAt: null })

export default function BackupsPage() {
  const { mode, backendUrl, prefsHydrated } = useDataSource()
  if (!prefsHydrated) return <p role="status" className="p-5">Загрузка настроек источника…</p>
  return <BackupsContent key={mode + ":" + backendUrl} />
}
function BackupsContent() {
  const { mode, backendUrl } = useDataSource()
  const isLive = mode === "live"
  const canRead = can("mm:backups:read")
  const canWrite = isLive && can("mm:backups:write")
  const canReadServers = can("mm:servers:read")
  const [resources, setResources] = useState<Record<Resource, ResourceState>>(() => ({ backups: unknownResource(), servers: unknownResource(), schedule: unknownResource(), storage: unknownResource() }))
  const reader = useRef<AbortController | null>(null)
  const revision = useRef(0)
  const alive = useRef(true)
  const scheduleDirty = useRef(false)
  const storageDirty = useRef(false)
  const known = (resource: Resource) => !isLive || resources[resource].known
  const current = (resource: Resource) => known(resource) && !resources[resource].error
  const [tab, setTab] = useState<PageTab>("history")
  const [backupList, setBackupList] = useState<Backup[]>(isLive ? [] : mockBackups)
  const [kindFilter, setKindFilter] = useState<KindFilter>("all")
  const [search, setSearch] = useState("")
  const [advancedFilters, setAdvancedFilters] = useState<FilterQuery>(() => createFilterQuery())
  const [liveServers, setLiveServers] = useState<Server[]>(isLive ? [] : mockServers)
  const canCreate = canWrite && canReadServers && liveServers.length > 0 && current("servers") && current("storage")
  const [loading, setLoading] = useState(false)
  const [opBusy, setOpBusy] = useState(false)
  const [opError, setOpError] = useState<string | null>(null)
  const [backupJobId, setBackupJobId] = useState<string | null>(null)
  const [scheduleSaveBusy, setScheduleSaveBusy] = useState(false)
  const [testBusy, setTestBusy] = useState(false)
  const [syncBusy, setSyncBusy] = useState(false)
  const [schedule, setSchedule] = useState<BackupScheduleForm>(defaultSchedule)
  const [storage, setStorage] = useState<BackupStorageForm>(defaultStorageForm)
  const [savedSchedule, setSavedSchedule] = useState<BackupScheduleSettingsDto | null>(null)
  const [savedStorage, setSavedStorage] = useState<BackupStorageSettingsDto | null>(null)
  const [scheduleLastError, setScheduleLastError] = useState<string | null>(null)
  const [selectedServers, setSelectedServers] = useState<Set<string>>(new Set())
  const [manualOpen, setManualOpen] = useState(false)
  const [manualStep, setManualStep] = useState(1)
  const [manualServers, setManualServers] = useState<Set<string>>(new Set())
  const [manualNotes, setManualNotes] = useState("")
  const [deleteTarget, setDeleteTarget] = useState<Backup | null>(null)
  const [restoreTarget, setRestoreTarget] = useState<Backup | null>(null)

  const setSched = <K extends keyof BackupScheduleForm>(k: K, v: BackupScheduleForm[K]) => { scheduleDirty.current = true; setSchedule(s => ({ ...s, [k]: v })) }
  const setStore = <K extends keyof BackupStorageForm>(k: K, v: BackupStorageForm[K]) => { storageDirty.current = true; setStorage(s => ({ ...s, [k]: v })) }

  const mapApiBackupToUi = useCallback((b: BackupItem): Backup => {
    const kb = Math.round(b.sizeBytes / 1024)
    return {
      id: b.id,
      server: b.serverName,
      serverId: b.serverId == null ? null : String(b.serverId),
      filename: b.filename,
      size: b.sizeBytes < 1024 ? `${b.sizeBytes} Б` : `${kb} КБ`,
      sizeBytes: b.sizeBytes,
      created: new Date(b.createdAt).toLocaleString("ru-RU"),
      kind: b.kind,
      notes: b.notes ?? "",
      storage: b.storage,
      uploadError: b.uploadError ?? undefined,
    }
  }, [])

  const loadLive = useCallback(async () => {
    if (!isLive || !canRead || !alive.current) return
    reader.current?.abort()
    const abort = new AbortController(), version = ++revision.current
    reader.current = abort
    const signal = AbortSignal.any([abort.signal, AbortSignal.timeout(30_000)])
    const active = () => alive.current && !abort.signal.aborted && revision.current === version
    const success = (resource: Resource) => { if (active()) setResources(prev => ({ ...prev, [resource]: { known: true, error: null, receivedAt: new Date().toISOString() } })) }
    const failure = (resource: Resource, error: unknown) => { if (active()) setResources(prev => ({ ...prev, [resource]: { ...prev[resource], error: userApiError(error) } })) }
    setLoading(true)
    await Promise.allSettled([
      listBackups(backendUrl, { signal }).then(rows => { if (!active()) return; setBackupList(rows.map(mapApiBackupToUi)); success("backups") }).catch(error => failure("backups", error)),
      canReadServers ? requestJson<unknown>(backendUrl, "/api/servers", { signal }).then(payload => {
        const rows = serverListSchema.parse(payload)
        if (!active()) return
        setLiveServers(rows.map(toFrontendServer)); success("servers")
      }).catch(error => failure("servers", error)) : Promise.resolve(),
      getBackupScheduleSettings(backendUrl, { signal }).then(row => {
        if (!active()) return
        if (!scheduleDirty.current) { setSchedule(row); setSelectedServers(new Set(row.serverIds)) }
        setSavedSchedule(row); setScheduleLastError(row.lastError ?? null); success("schedule")
      }).catch(error => failure("schedule", error)),
      getBackupStorageSettings(backendUrl, { signal }).then(row => {
        if (!active()) return
        setSavedStorage(row)
        if (!storageDirty.current) setStorage(prev => ({ ...prev, ...row, s3SecretAccessKey: "" }))
        success("storage")
      }).catch(error => failure("storage", error)),
    ])
    if (active()) setLoading(false)
  }, [backendUrl, isLive, canRead, canReadServers, mapApiBackupToUi])
  useEffect(() => {
    alive.current = true
    queueMicrotask(() => { if (alive.current) void loadLive() })
    return () => { alive.current = false; reader.current?.abort() }
  }, [loadLive])

  async function handleSave() {
    if (!canWrite || !current("schedule") || !current("storage") || scheduleSaveBusy) return
    setScheduleSaveBusy(true)
    setOpError(null)
    try {
      const confirmedSchedule = await putBackupScheduleSettings(backendUrl, {
        enabled: schedule.enabled,
        frequency: schedule.frequency,
        hour: schedule.hour,
        minute: schedule.minute,
        weekDay: schedule.weekDay,
        monthDay: schedule.monthDay,
        keepCount: schedule.keepCount,
        format: "rsc",
        serverIds: [...selectedServers],
      })
      setSavedSchedule(confirmedSchedule)
      const saved = await putBackupStorageSettings(backendUrl, {
        provider: storage.provider,
        s3Endpoint: storage.s3Endpoint,
        s3Region: storage.s3Region,
        s3Bucket: storage.s3Bucket,
        s3Prefix: storage.s3Prefix,
        s3AccessKeyId: storage.s3AccessKeyId,
        s3SecretAccessKey: storage.s3SecretAccessKey || undefined,
        s3ForcePathStyle: storage.s3ForcePathStyle,
        keepLocalCopy: storage.keepLocalCopy,
      })
      setSavedStorage(saved)
      setStorage((prev) => ({ ...prev, s3SecretAccessKey: "" }))
      toast.success("Настройки сохранены")
    } catch (e) {
      setOpError(e instanceof Error ? e.message : "Ошибка сохранения настроек")
    } finally {
      setScheduleSaveBusy(false)
    }
  }

  async function handleTestStorage() {
    if (!canWrite || !current("storage")) return
    setTestBusy(true)
    try {
      await putBackupStorageSettings(backendUrl, {
        provider: storage.provider,
        s3Endpoint: storage.s3Endpoint,
        s3Region: storage.s3Region,
        s3Bucket: storage.s3Bucket,
        s3Prefix: storage.s3Prefix,
        s3AccessKeyId: storage.s3AccessKeyId,
        s3SecretAccessKey: storage.s3SecretAccessKey || undefined,
        s3ForcePathStyle: storage.s3ForcePathStyle,
        keepLocalCopy: storage.keepLocalCopy,
      })
      const result = await testBackupStorage(backendUrl)
      setSavedStorage(result)
      toast.success("S3 доступен")
    } catch (e) {
      toast.error(e instanceof Error ? e.message : "Ошибка проверки S3")
      try {
        setSavedStorage(await getBackupStorageSettings(backendUrl))
      } catch {
        /* ignore */
      }
    } finally {
      setTestBusy(false)
    }
  }

  async function handleSyncStorage() {
    if (!canWrite || !current("storage")) return
    setSyncBusy(true)
    try {
      const result = await syncBackupsFromStorage(backendUrl)
      toast.success(`Импортировано: ${result.imported}, пропущено: ${result.skipped}`)
      await loadLive()
    } catch (e) {
      toast.error(e instanceof Error ? e.message : "Ошибка синхронизации")
    } finally {
      setSyncBusy(false)
    }
  }

  async function handleManualBackup() {
    if (!canCreate || manualServers.size === 0 || opBusy) return
    setOpError(null)
    try {
      const res = await createBackupsAsync(backendUrl, {
        serverIds: [...manualServers],
        notes: manualNotes || undefined,
      })
      setBackupJobId(res.jobId)
      setManualOpen(false)
      setManualServers(new Set())
      setManualNotes("")
      setTab("history")
    } catch (e) {
      setOpError(e instanceof Error ? e.message : "Ошибка создания бэкапа")
    }
  }

  useEffect(() => {
    if (!backupJobId) return
    toast.info("Бэкап выполняется в фоне...")
    let cancelled = false
    const timer = setInterval(() => {
      void (async () => {
        try {
          const job = await getBackupJob(backendUrl, backupJobId)
          if (cancelled) return
          if (job.status === "done") {
            clearInterval(timer)
            setBackupJobId(null)
            if (job.failures.length > 0) {
              setOpError(`Часть бэкапов не создалась: ${job.failures.map((f) => `${f.serverId}: ${f.error}`).join("; ")}`)
            } else {
              toast.success("Бэкап успешно завершён")
            }
            await loadLive()
          } else if (job.status === "failed") {
            clearInterval(timer)
            setBackupJobId(null)
            setOpError(job.failures.map((f) => `${f.serverId}: ${f.error}`).join("; ") || "Ошибка фоновой задачи бэкапа")
            await loadLive()
          }
        } catch (e) {
          clearInterval(timer)
          setBackupJobId(null)
          setOpError(e instanceof Error ? e.message : "Ошибка опроса задачи бэкапа")
        }
      })()
    }, 1200)
    return () => {
      cancelled = true
      clearInterval(timer)
    }
  }, [backendUrl, backupJobId, loadLive])

  useEffect(() => {
    if (opError) toast.error(opError)
  }, [opError])

  async function handleDelete() {
    if (!canWrite || !deleteTarget) return
    setOpBusy(true)
    setOpError(null)
    try {
      await deleteBackup(backendUrl, deleteTarget.id)
      setDeleteTarget(null)
      await loadLive()
    } catch (e) {
      setOpError(e instanceof Error ? e.message : "Ошибка удаления бэкапа")
    } finally {
      setOpBusy(false)
    }
  }

  async function handleRestore() {
    if (!canWrite || !restoreTarget) return
    setOpBusy(true)
    setOpError(null)
    try {
      await restoreBackup(backendUrl, restoreTarget.id)
      toast.success(`Конфигурация восстановлена на ${restoreTarget.server}`)
      setRestoreTarget(null)
    } catch (e) {
      setOpError(e instanceof Error ? e.message : "Ошибка восстановления")
    } finally {
      setOpBusy(false)
    }
  }

  async function handleDownload(id: string, fallbackFilename: string) {
    if (!isLive || !canRead) return
    const res = await requestBlob(backendUrl, `/api/backups/${id}/download`)
    const blob = await res.blob()
    const url = URL.createObjectURL(blob)
    const a = document.createElement("a")
    a.href = url
    a.download = fallbackFilename
    a.click()
    URL.revokeObjectURL(url)
  }

  const autoCount = backupList.filter((b) => b.kind === "auto").length
  const manualCount = backupList.filter((b) => b.kind === "manual").length
  const s3Count = backupList.filter((b) => b.storage === "s3" || b.storage === "both").length

  const schedSummary = (() => {
    const confirmed = isLive ? savedSchedule : defaultSchedule
    if (!confirmed) return "Расписание пока неизвестно"
    if (!confirmed.enabled) return "Расписание отключено"
    const time = String(confirmed.hour).padStart(2, "0") + ":" + String(confirmed.minute).padStart(2, "0")
    if (confirmed.frequency === "daily") return "Каждый день в " + time
    if (confirmed.frequency === "weekly") return "Каждую неделю (" + WEEK_DAYS[confirmed.weekDay] + ") в " + time
    return confirmed.monthDay + "-го числа каждого месяца в " + time
  })()
  const confirmedStorage = isLive ? savedStorage : defaultStorageForm
  const destinationLabel = !confirmedStorage ? "Хранилище пока неизвестно" : confirmedStorage.provider === "s3"
    ? (confirmedStorage.keepLocalCopy ? "локально и в S3" : "в S3")
    : "локально (storage/backups)"

  const statusDetail = [
    backupJobId ? null : `${destinationLabel} · ${known("servers") ? liveServers.length + " серверов в каталоге" : "Серверы пока неизвестны"}`,
    scheduleLastError,
    savedStorage?.lastTestError,
  ].filter(Boolean).join(" · ")

  const alertVariant = backupJobId
    ? "info"
    : opError || scheduleLastError || savedStorage?.lastTestError
      ? "warning"
      : "default"

  function openCreate(all: boolean) {
    if (!canCreate) return
    setManualServers(all ? new Set(liveServers.map((s) => s.id)) : new Set())
    setManualNotes("")
    setManualStep(1)
    setManualOpen(true)
  }

  return (
    <div className="flex flex-col h-full">
      <PageHeader
        crumbs={[{ label: "Управление" }, { label: "Бэкапы" }]}
        actions={
          <>
            <Button
              type="button"
              variant="outline"
              size="sm"
              onClick={() => openCreate(true)}
              disabled={!canCreate || loading}
            >
              <RefreshCwIcon className="size-4" />
              Снять со всех
            </Button>
            <Button
              type="button"
              size="sm"
              onClick={() => openCreate(false)}
              disabled={!canCreate || loading}
            >
              <PlusIcon className="size-4" />
              Новый бэкап
            </Button>
          </>
        }
      />

      <div className="flex-1 overflow-y-auto p-6">
        <div className="flex flex-col gap-5">
          {!isLive && <p role="status" className="text-sm text-muted-foreground">Демонстрационные данные. Операции и сохранение недоступны.</p>}
          {!canRead && <p role="status">Нет права mm:backups:read</p>}
          {isLive && !canReadServers && <p role="status">Каталог устройств недоступен без mm:servers:read.</p>}
          {isLive && canRead && <div className="flex items-center gap-3 text-sm text-muted-foreground">
            <Button type="button" variant="outline" size="sm" onClick={() => void loadLive()} disabled={loading}>Обновить</Button>
            <span role="status">{loading ? "Обновление данных…" : resources.backups.receivedAt ? "Получено: " + new Date(resources.backups.receivedAt).toLocaleString("ru-RU") : "Резервные копии пока неизвестны"}</span>
          </div>}
          {isLive && (Object.keys(resources) as Resource[]).filter(resource => resources[resource].error).map(resource => <Alert key={resource} variant="warning" aria-label={"Данные резервных копий: " + resource}>
            <AlertTitle>{resources[resource].known ? "Последние данные сохранены" : "Данные пока неизвестны"}</AlertTitle>
            <AlertDescription>{({ backups: "История", servers: "Серверы", schedule: "Расписание", storage: "Хранилище" })[resource]}: {resources[resource].error}</AlertDescription>
          </Alert>)}

          <KpiStatGrid
            aria-label="Сводка бэкапов"
            items={[
              {
                id: "all",
                label: "Всего бэкапов",
                value: known("backups") ? backupList.length : "—",
                icon: <HardDriveIcon className="size-4" />,
                iconClassName: "text-muted-foreground",
              },
              {
                id: "auto",
                label: "Авто",
                value: known("backups") ? autoCount : "—",
                icon: <ClockIcon className="size-4" />,
                iconClassName: "text-info",
              },
              {
                id: "manual",
                label: "Вручную",
                value: known("backups") ? manualCount : "—",
                icon: <PlusIcon className="size-4" />,
                iconClassName: "text-muted-foreground",
              },
              {
                id: "s3",
                label: "В S3",
                value: known("backups") ? s3Count : "—",
                icon: <CloudIcon className="size-4" />,
                iconClassName: "text-primary",
              },
            ]}
          />

          <Alert variant={alertVariant}>
            <ClockIcon />
            <AlertTitle>
              {backupJobId ? "Задача выполняется" : schedSummary}
            </AlertTitle>
            <AlertDescription>
              {backupJobId
                ? "Снимок конфигурации снимается в фоне. Список обновится после завершения."
                : statusDetail}
            </AlertDescription>
            <AlertAction>
              <Button type="button" variant="ghost" size="xs" onClick={() => setTab("settings")}>
                Настройки
              </Button>
            </AlertAction>
          </Alert>

          <Tabs
            value={tab}
            onValueChange={(v) => setTab(String(v) as PageTab)}
            className="gap-5"
          >
            <TabsList variant="line" className="w-fit">
              <TabsTrigger value="history">История бэкапов</TabsTrigger>
              <TabsTrigger value="settings">Настройки</TabsTrigger>
            </TabsList>
            <TabsContent value="history" className="flex flex-col gap-5">
              {!canRead ? <p role="status">История недоступна без права чтения</p> : !known("backups") ? <p role="status">{resources.backups.error ? "История резервных копий пока неизвестна" : "Загрузка резервных копий…"}</p> : <BackupsHistory
                backups={backupList}
                kindFilter={kindFilter}
                onKindFilterChange={setKindFilter}
                search={search}
                onSearchChange={setSearch}
                filters={advancedFilters}
                onFiltersChange={setAdvancedFilters}
                onDownload={handleDownload}
                onRestore={setRestoreTarget}
                onDelete={setDeleteTarget}
                onCreate={() => openCreate(false)}
                canCreate={canCreate}
                canWrite={canWrite}
                canDownload={isLive && canRead}
              />}
            </TabsContent>
            <TabsContent value="settings">
              {(!known("schedule") || !known("storage")) ? <p role="status">Настройки резервных копий пока неизвестны</p> : <fieldset disabled={!canWrite || !current("schedule") || !current("storage")} className="min-w-0">
              <BackupsSettings
                schedule={schedule}
                onScheduleChange={setSched}
                storage={storage}
                onStorageChange={setStore}
                savedStorage={savedStorage}
                servers={liveServers}
                selectedServers={selectedServers}
                onToggleServer={(id) => {
                  scheduleDirty.current = true
                  setSelectedServers((prev) => {
                    const next = new Set(prev)
                    if (next.has(id)) next.delete(id)
                    else next.add(id)
                    return next
                  })
                }}
                onSelectAll={() => { scheduleDirty.current = true; setSelectedServers(new Set(liveServers.map(s => s.id))) }}
                onClearServers={() => { scheduleDirty.current = true; setSelectedServers(new Set()) }}
                onSave={handleSave}
                onTest={handleTestStorage}
                onSync={handleSyncStorage}
                saveBusy={scheduleSaveBusy}
                testBusy={testBusy}
                syncBusy={syncBusy}
              />
              </fieldset>}
            </TabsContent>
          </Tabs>
        </div>
      </div>

      <BackupCreateSheet
        open={manualOpen}
        onOpenChange={setManualOpen}
        step={manualStep}
        onStepChange={setManualStep}
        servers={liveServers}
        selected={manualServers}
        onToggle={(id) => {
          setManualServers((prev) => {
            const next = new Set(prev)
            if (next.has(id)) next.delete(id)
            else next.add(id)
            return next
          })
        }}
        onSelectAll={() => setManualServers(new Set(liveServers.map((s) => s.id)))}
        onClear={() => setManualServers(new Set())}
        notes={manualNotes}
        onNotesChange={setManualNotes}
        destinationLabel={destinationLabel}
        busy={backupJobId !== null}
        onSubmit={handleManualBackup}
      />

      <BackupDeleteDialog
        backup={deleteTarget}
        busy={opBusy}
        onConfirm={() => void handleDelete()}
        onCancel={() => setDeleteTarget(null)}
      />
      <BackupRestoreDialog
        backup={restoreTarget}
        busy={opBusy}
        onConfirm={() => void handleRestore()}
        onCancel={() => setRestoreTarget(null)}
      />
    </div>
  )
}