"use client"

import { useMemo, useRef, useState, type ComponentProps } from "react"
import { HistoryIcon, LoaderCircleIcon, RotateCcwIcon } from "lucide-react"
import {
  Sheet,
  SheetContent,
  SheetDescription,
  SheetHeader,
  SheetTitle,
} from "@/components/ui/sheet"
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogMedia,
  AlertDialogTitle,
} from "@/components/ui/alert-dialog"
import { Button } from "@/components/ui/button"
import { Badge } from "@/components/reui/badge"
import { Frame, FramePanel } from "@/components/reui/frame"
import {
  Timeline,
  TimelineContent,
  TimelineDate,
  TimelineHeader,
  TimelineIndicator,
  TimelineItem,
  TimelineSeparator,
  TimelineTitle,
} from "@/components/reui/timeline"
import { EmptyState } from "@/components/empty-state"
import { Alert, AlertDescription, AlertTitle } from "@/components/reui/alert"
import { TriangleAlertIcon } from "lucide-react"
import type { ConfigRevisionDto } from "@/lib/config-revisions"

const SOURCE_LABEL: Record<ConfigRevisionDto["source"], string> = {
  apply: "Изменение",
  rollback: "Откат",
  observed: "С роутера",
  copy: "Копирование",
}

const SOURCE_BADGE: Record<ConfigRevisionDto["source"], ComponentProps<typeof Badge>["variant"]> = {
  apply: "primary-light",
  rollback: "warning-light",
  observed: "secondary",
  copy: "success-light",
}

function formatWhen(iso: string): string {
  const d = new Date(iso)
  if (Number.isNaN(d.getTime())) return iso
  return d.toLocaleString("ru-RU", { dateStyle: "short", timeStyle: "short" })
}

export function ConfigHistorySheet({
  open,
  onOpenChange,
  title,
  itemLabel,
  revisions,
  loading,
  loadError,
  onRetry,
  restoring,
  onRestore,
  restoreDisabled = true,
}: {
  open: boolean
  onOpenChange: (open: boolean) => void
  title: string
  itemLabel: string
  revisions: ConfigRevisionDto[]
  loading: boolean
  loadError?: string | null
  onRetry?: () => void
  restoring: boolean
  restoreDisabled: boolean
  onRestore: (id: string) => Promise<void> | void
}) {
  const [pending, setPending] = useState<ConfigRevisionDto | null>(null)
  const restoreLock = useRef(false)
  const [submitting, setSubmitting] = useState(false)
  const [restoreError, setRestoreError] = useState<string | null>(null)
  const busy = restoring || submitting
  async function confirmRestore() {
    if (!pending || restoreLock.current || restoring || restoreDisabled) return
    restoreLock.current = true
    setSubmitting(true)
    setRestoreError(null)
    try {
      await onRestore(pending.id)
      setPending(null)
    } catch (error) {
      setRestoreError(error instanceof Error ? error.message : "Не удалось восстановить версию")
    } finally {
      restoreLock.current = false
      setSubmitting(false)
    }
  }
  const newestFirst = useMemo(() => revisions, [revisions])

  return (
    <>
      <Sheet open={open} onOpenChange={v => {
        if (restoreLock.current || restoring) return
        if (!v) {
          setPending(null)
          setRestoreError(null)
        }
        onOpenChange(v)
      }}>
        <SheetContent showCloseButton={!busy} side="right" className="w-full sm:max-w-md flex flex-col gap-0 p-0">
          <SheetHeader className="px-6 pt-6 pb-4 border-b shrink-0">
            <SheetTitle>{title}</SheetTitle>
            <SheetDescription>
              Снапшоты managed-объектов. Откат применяет выбранную версию на CHR.
            </SheetDescription>
          </SheetHeader>
          <div className="flex-1 min-h-0 overflow-y-auto px-6 py-5">
            {restoreDisabled && !busy && <p role="status" className="px-4 text-sm text-muted-foreground">Откат недоступен. Проверьте права на изменение и состояние выбранного устройства.</p>}
          {loading ? (
              <div role="status" className="flex items-center justify-center gap-2 py-16 text-sm text-muted-foreground">
                <LoaderCircleIcon className="size-4 animate-spin" />
                Загрузка истории…
              </div>
            ) : loadError ? (
              <div className="flex flex-col gap-3">
                <p role="alert" className="text-sm text-destructive">Не удалось загрузить историю: {loadError}</p>
                {onRetry && <Button type="button" variant="outline" disabled={busy} onClick={onRetry}>Повторить загрузку</Button>}
              </div>
            ) : newestFirst.length === 0 ? (
              <EmptyState
                icon={<HistoryIcon className="size-4" />}
                title="Истории пока нет"
                description="Снапшот появится после первого чтения или изменения на роутере"
                className="py-12"
              />
            ) : (
              <Frame>
                <FramePanel>
                  <Timeline value={newestFirst.length} className="px-1">
                    {newestFirst.map((rev, idx) => (
                      <TimelineItem key={rev.id} step={newestFirst.length - idx}>
                        <TimelineHeader>
                          <TimelineDate dateTime={rev.createdAt}>{formatWhen(rev.createdAt)}</TimelineDate>
                          <TimelineTitle className="flex items-center gap-2 flex-wrap">
                            <Badge variant={SOURCE_BADGE[rev.source]} size="sm">
                              {SOURCE_LABEL[rev.source]}
                            </Badge>
                            <span className="text-muted-foreground font-normal tabular-nums">
                              {rev.itemCount} {itemLabel}
                            </span>
                          </TimelineTitle>
                        </TimelineHeader>
                        <TimelineIndicator />
                        <TimelineSeparator />
                        <TimelineContent>
                          <Button
                            type="button"
                            variant="outline"
                            size="sm"
                            disabled={busy || restoreDisabled}
                            onClick={() => { setRestoreError(null); setPending(rev) }}
                          >
                            <RotateCcwIcon className="size-3.5" />
                            Откатить
                          </Button>
                        </TimelineContent>
                      </TimelineItem>
                    ))}
                  </Timeline>
                </FramePanel>
              </Frame>
            )}
          </div>
        </SheetContent>
      </Sheet>

      <AlertDialog open={Boolean(pending)} onOpenChange={(v) => { if (!v && !restoreLock.current && !restoring) { setPending(null); setRestoreError(null) } }}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogMedia className="bg-warning/10 text-warning">
              <TriangleAlertIcon />
            </AlertDialogMedia>
            <AlertDialogTitle>Откатить на эту версию?</AlertDialogTitle>
            <AlertDialogDescription className="flex flex-col gap-3">
              <span>
                На CHR будут применены {pending?.itemCount ?? 0} {itemLabel} от{" "}
                {pending ? formatWhen(pending.createdAt) : ""}.
              </span>
            </AlertDialogDescription>
            <Alert variant="warning">
              <TriangleAlertIcon />
              <AlertTitle>Изменятся только объекты MikrotikManager</AlertTitle>
              <AlertDescription>
                Чужие правила и маршруты на роутере не удаляются.
              </AlertDescription>
            </Alert>
          </AlertDialogHeader>
          {busy && <p role="status" className="text-sm text-muted-foreground">Ожидание результата восстановления…</p>}
          {restoreError && <p role="alert" className="text-sm text-destructive">{restoreError}</p>}
          <AlertDialogFooter>
            <AlertDialogCancel disabled={busy} onClick={() => setPending(null)}>Отмена</AlertDialogCancel>
            <AlertDialogAction
              disabled={busy || restoreDisabled || !pending}
              type="button"
              onClick={() => void confirmRestore()}
            >
              {busy ? <LoaderCircleIcon className="size-4 animate-spin" /> : null}
              Откатить
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>
    </>
  )
}