import { type CacheHitStats, cacheRegionLabel } from "@umt/contracts";
import { useState } from "react";
import { toast } from "sonner";
import {
  useCacheRegions,
  useClearCacheRegion,
  useClearImageCache,
  useClearTmdbCache,
  useImageCache,
  useTmdbCache,
} from "~/api/cache.ts";
import { ConfirmDialog } from "~/components/console/confirm-dialog.tsx";
import { type DataColumn, DataTable } from "~/components/console/data-table.tsx";
import { Button } from "~/components/ui/button.tsx";
import { errorMessage } from "~/lib/api.ts";
import { formatRelative } from "~/lib/labels.ts";
import { formatBytes } from "~/lib/utils.ts";
import { num } from "./resource-section.tsx";
import { SettingsBlock } from "./settings-block.tsx";
import { type CardSpec, n, SettingsCard, SettingsGate } from "./settings-card.tsx";

// 缓存分区:通用缓存(kv_cache)按区统计与清空 + 图片缓存(磁盘)同表展示;TMDB 缓存条数上限、图片缓存开关、各类有效期。
// 清空只删缓存,下次用到时重新请求;不会删作品、资源或文件。

/** 图片缓存在磁盘上,不在 kv_cache 里;表里用这个保留名占一行 */
const IMAGES_ROW = "images";

export type CacheRow = {
  region: string;
  label: string;
  entries: number;
  expired: number;
  bytes: number;
  lastWriteAt: string | null;
  /** 统一元数据缓存的区才有:最近 7 天命中统计 */
  hits?: CacheHitStats | undefined;
};

/** 区名 → 行:有中文名的用中文名,没有的原样显示 region */
export function cacheRow(r: Omit<CacheRow, "label">): CacheRow {
  return { ...r, label: cacheRegionLabel(r.region) ?? r.region };
}

/** 命中率文字:没有统计的区显示「—」,有统计没读取显示「暂无读取」 */
export function hitRateText(h: CacheHitStats | undefined): string {
  if (!h) return "—";
  if (h.hitRate === null) return "暂无读取";
  return `${Math.round(h.hitRate * 1000) / 10}%`;
}

/** 命中明细:内存 / 数据库 / 旧值 / 未命中,有失败与后台刷新时附上 */
export function hitDetailText(h: CacheHitStats): string {
  const parts = [`内存 ${h.l1Hits}`, `数据库 ${h.l2Hits}`];
  if (h.staleHits) parts.push(`旧值 ${h.staleHits}`);
  parts.push(`未命中 ${h.misses}`);
  if (h.failures) parts.push(`回源失败 ${h.failures}`);
  if (h.refreshes) parts.push(`后台刷新 ${h.refreshes}`);
  return parts.join(" · ");
}

function CacheRegionsBlock() {
  const regions = useCacheRegions();
  const images = useImageCache();
  const clearRegion = useClearCacheRegion();
  const clearImages = useClearImageCache();
  const [target, setTarget] = useState<CacheRow | null>(null);

  const rows: CacheRow[] | undefined = regions.data
    ? [
        ...regions.data.items.map(cacheRow),
        ...(images.data
          ? [
              cacheRow({
                region: IMAGES_ROW,
                entries: images.data.files,
                expired: 0,
                bytes: images.data.usedBytes,
                lastWriteAt: null,
              }),
            ]
          : []),
      ]
    : undefined;

  const columns: DataColumn<CacheRow>[] = [
    {
      key: "label",
      header: "缓存",
      cell: (r) => (
        <div className="min-w-0">
          <p className="font-medium">{r.label}</p>
          {r.label !== r.region ? <p className="font-mono text-meta text-muted-foreground">{r.region}</p> : null}
        </div>
      ),
    },
    {
      key: "entries",
      header: "条数",
      align: "right",
      cell: (r) => (
        <div className="tabular-nums">
          {r.entries}
          {r.expired > 0 ? <p className="text-meta text-muted-foreground">另有 {r.expired} 条已过期</p> : null}
        </div>
      ),
    },
    {
      key: "hitRate",
      header: "命中率",
      align: "right",
      cell: (r) => (
        <div className="tabular-nums">
          {hitRateText(r.hits)}
          {r.hits && r.hits.hitRate !== null ? (
            <p className="text-meta text-muted-foreground">{hitDetailText(r.hits)}</p>
          ) : null}
        </div>
      ),
    },
    {
      key: "bytes",
      header: "占用",
      align: "right",
      cell: (r) => <span className="tabular-nums">{formatBytes(r.bytes, 1)}</span>,
    },
    {
      key: "last",
      header: "最近写入",
      hideBelow: "md",
      cell: (r) => <span className="text-muted-foreground">{formatRelative(r.lastWriteAt)}</span>,
    },
    {
      key: "actions",
      header: <span className="sr-only">操作</span>,
      align: "right",
      cell: (r) => (
        <Button
          type="button"
          variant="ghost"
          size="sm"
          className="hover:text-destructive"
          disabled={r.entries + r.expired === 0}
          onClick={() => setTarget(r)}
        >
          清空
        </Button>
      ),
    },
  ];

  return (
    <SettingsBlock
      section="cache"
      anchor="regions"
      title="缓存区"
      description="清空后下次用到时重新请求，不影响作品、资源和文件。已过期的条目由定时任务清理。命中率按最近 7 天、三个进程合计。"
      plain
    >
      <DataTable<CacheRow>
        rows={rows}
        rowKey={(r) => r.region}
        loading={regions.isPending}
        error={regions.error}
        onRetry={() => regions.refetch()}
        empty={{ title: "还没有缓存", description: "用到 TMDB、豆瓣、站点详情等数据后会出现在这里。" }}
        columns={columns}
      />
      <ConfirmDialog
        open={!!target}
        onOpenChange={(o) => !o && setTarget(null)}
        title={`清空「${target?.label ?? ""}」？`}
        description={`删除 ${target ? target.entries + target.expired : 0} 条缓存，之后用到时重新请求。`}
        confirmLabel="清空"
        destructive
        onConfirm={async () => {
          if (!target) return;
          try {
            const r =
              target.region === IMAGES_ROW
                ? await clearImages.mutateAsync()
                : await clearRegion.mutateAsync(target.region);
            toast.success(`已清空「${target.label}」，删除 ${r.deleted} 条`);
            setTarget(null);
          } catch (err) {
            toast.error(errorMessage(err, "清空失败"));
            throw err;
          }
        }}
      />
    </SettingsBlock>
  );
}

// TMDB 缓存(对照 MP:CONF.tmdb 条数;有效期在下面「缓存有效期」)
export const TMDB_CACHE_CARD: CardSpec = {
  anchor: "tmdb-cache",
  title: "TMDB 缓存",
  description: "请求响应与识别结果存在数据库里，三个进程共用。超过条数上限时删最久未用的条目。",
  fields: [{ name: "cache.tmdbMaxSize", label: "条数上限", kind: "number", hint: "请求缓存和识别缓存各自计数" }],
  fromSettings: (s) => ({ "cache.tmdbMaxSize": n(s.cache.tmdbMaxSize) }),
  toPatch: (v) => ({ cache: { tmdbMaxSize: num(v["cache.tmdbMaxSize"]) } }),
  extra: () => <TmdbCacheStatus />,
};

function TmdbCacheStatus() {
  const q = useTmdbCache();
  const clear = useClearTmdbCache();
  const c = q.data?.counts;
  return (
    <div className="mb-2 flex flex-wrap items-center gap-2 text-meta text-muted-foreground">
      <span className="tabular-nums">
        {c ? `识别 ${c.recognize} 条 · 请求 ${c.request} 条 · 上限各 ${q.data?.maxSize} 条` : "读取中…"}
      </span>
      <ConfirmDialog
        trigger={
          <Button type="button" variant="ghost" size="xs" className="hover:text-destructive">
            清空
          </Button>
        }
        title="清空 TMDB 缓存？"
        description="请求响应和识别结果一起删除，之后用到时重新请求 TMDB。"
        confirmLabel="清空"
        destructive
        onConfirm={async () => {
          try {
            const r = await clear.mutateAsync();
            toast.success(`已清空 ${r.deleted} 条 TMDB 缓存`);
          } catch (err) {
            toast.error(errorMessage(err, "清空失败"));
            throw err;
          }
        }}
      />
    </div>
  );
}

// 图片代理与缓存(对照 MP GLOBAL_IMAGE_CACHE / GLOBAL_IMAGE_CACHE_DAYS);用量与清空在上面的缓存区表里
export const IMAGES_CARD: CardSpec = {
  anchor: "images",
  title: "图片缓存",
  description: "海报经服务端从 TMDB 取回。开启缓存后保存到数据目录，下次直接读取；容量上限在「系统 → 存储预算」。",
  fields: [
    { name: "cache.globalImageCache", label: "缓存图片", kind: "switch" },
    { name: "cache.globalImageCacheDays", label: "保留天数", kind: "number", hint: "超过天数的图片每天清理一次" },
  ],
  fromSettings: (s) => ({
    "cache.globalImageCache": s.cache.globalImageCache,
    "cache.globalImageCacheDays": n(s.cache.globalImageCacheDays),
  }),
  toPatch: (v) => ({
    cache: {
      globalImageCache: v["cache.globalImageCache"] === true,
      globalImageCacheDays: num(v["cache.globalImageCacheDays"]),
    },
  }),
};

const TTL_KEYS = [
  "tmdbSearchDays",
  "tmdbDetailDays",
  "tmdbMissDays",
  "imageDays",
  "metaSearchDays",
  "metaDetailDays",
  "siteDetailDays",
  "webSearchDays",
] as const;
const ttlField = (k: string, label: string, hint?: string) => ({
  name: `storage.cacheTtl.${k}`,
  label,
  kind: "number" as const,
  hint,
});
export const TTL_CARD: CardSpec = {
  anchor: "ttl",
  title: "缓存有效期",
  description: "单位天。过期后先用旧值、后台刷新；关注中的作品命中详情缓存时自动续期，不会因条数上限被清掉。",
  fields: [
    ttlField("tmdbSearchDays", "TMDB 搜索与识别结果"),
    ttlField("tmdbDetailDays", "TMDB 详情"),
    ttlField("tmdbMissDays", "TMDB 空结果", "搜索无结果、未识别时的负缓存"),
    ttlField("imageDays", "TMDB 人物与图片"),
    ttlField("metaSearchDays", "豆瓣 / Bangumi 搜索"),
    ttlField("metaDetailDays", "豆瓣 / Bangumi 条目"),
    ttlField("siteDetailDays", "站点详情页内容"),
    ttlField("webSearchDays", "网页搜索结果"),
  ],
  fromSettings: (s) => Object.fromEntries(TTL_KEYS.map((k) => [`storage.cacheTtl.${k}`, n(s.storage.cacheTtl[k])])),
  toPatch: (v) => ({
    storage: { cacheTtl: Object.fromEntries(TTL_KEYS.map((k) => [k, num(v[`storage.cacheTtl.${k}`])])) },
  }),
};

export function CacheSection() {
  return (
    <div className="grid grid-cols-1 gap-8">
      <CacheRegionsBlock />
      <SettingsGate>
        {(s) => (
          <>
            <SettingsCard section="cache" spec={TMDB_CACHE_CARD} settings={s} />
            <SettingsCard section="cache" spec={IMAGES_CARD} settings={s} />
            <SettingsCard section="cache" spec={TTL_CARD} settings={s} />
          </>
        )}
      </SettingsGate>
    </div>
  );
}