import type {
  FileIdentifyCandidate,
  FilesScrapeItem,
  FilesScrapeNeedsChoice,
  FilesScrapeRequest,
  FilesScrapeResult,
  ScrapeMatch,
} from "@umt/contracts";
import type { Principal } from "../../http/auth.ts";
import {
  entityScrapeMatch,
  loadScrapeRecords,
  queueScrape,
  scrapeSettings,
  waitScrapeRecords,
} from "../acquisition-organize/services/scrape.ts";
import { actorOfP, FilesError, type FmDeps, resolveIn } from "./common.ts";
import { candidateKey, identifyCore } from "./identify.ts";
import { audit } from "./ledger.ts";
import { kindOfName } from "./list.ts";
import { entitiesUnder } from "./records.ts";

// SCR-2 文件管理「刮削」(照 MP 文件管理的刮削):任意目录 / 视频文件 → 识别作品 → 就地写 NFO 与图片。
// 识别顺序:请求指定(选定的候选)> 目录里已登记文件所属的唯一作品 > 按路径识别(本地召回 + TMDB,resolveIdentity
// 能自动确认且各视频一致时自动用)。认不准的项进 needsChoice(前 5 候选),选定后带 mediaEntityId / external 再提交。
// 未登记也能刮削(直接用 TMDB 字段);addToLibrary 时顺手把 TMDB 条目加入媒体库。
// 每项一条刮削记录,排 scrapeMedia;请求内最多等 transferWaitMs,没刮完的 pending=true,前端按 id 轮询。

const RECOGNIZE_TIMEOUT_MS = 15_000;

type Actor = { type: string; id: string | null };
const actorOf = (p: Principal | undefined): Actor => ({
  type: p?.kind === "api_key" ? "api_key" : "user",
  id: p?.id ?? null,
});

/** 路径识别:各视频都能自动确认且是同一作品时返回它;否则返回候选(按出现次数与等级合并,前 5) */
async function recognize(
  d: FmDeps,
  principal: Principal | undefined,
  it: FilesScrapeItem,
): Promise<{ pick: FileIdentifyCandidate | null; choice: Omit<FilesScrapeNeedsChoice, "root" | "path"> }> {
  const r = await identifyCore(
    d,
    { items: [{ root: it.root, path: it.path }], minSizeBytes: 0 },
    { mode: "remote", actorId: actorOfP(principal), signal: AbortSignal.timeout(RECOGNIZE_TIMEOUT_MS) },
  );
  const items = r.result.items;
  const picks = items.map((i) => r.autoPicks.get(`${i.root}\u0000${i.path}`) ?? null);
  const agreed = picks.length > 0 && picks.every((p) => p && p === picks[0]) ? picks[0] : null;
  const LV = { high: 3, medium: 2, low: 1 } as const;
  const merged = new Map<string, { c: FileIdentifyCandidate; n: number }>();
  for (const i of items)
    for (const c of i.candidates) {
      const k = candidateKey(c);
      const cur = merged.get(k);
      if (!cur) merged.set(k, { c, n: 1 });
      else {
        cur.n += 1;
        if (LV[c.level] > LV[cur.c.level]) cur.c = { ...c, posterUrl: c.posterUrl ?? cur.c.posterUrl };
      }
    }
  const ranked = [...merged.values()].sort((a, b) => b.n - a.n || LV[b.c.level] - LV[a.c.level]).map((x) => x.c);
  const pick = agreed ? (ranked.find((c) => candidateKey(c) === agreed) ?? null) : null;
  const first = items[0]?.parsed;
  return {
    pick,
    choice: {
      title: first?.title ?? null,
      candidates: ranked.slice(0, 5),
      warnings: [...new Set(items.flatMap((i) => i.warnings))].slice(0, 5),
    },
  };
}

/** TMDB 条目 → 识别结果:已有本地作品(已接受的 TMDB 映射)就用它;addToLibrary 时建作品 */
async function externalMatch(
  d: FmDeps,
  ext: { externalId: string; kind: "movie" | "tv"; title?: string; year?: number | null },
  source: ScrapeMatch["source"],
  addToLibrary: boolean,
  actor: Actor,
  entities: FilesScrapeResult["entities"],
): Promise<ScrapeMatch> {
  const local = await d.ctx.db
    .selectFrom("external_identity")
    .select(["media_entity_id"])
    .where("provider", "=", "tmdb")
    .where("entity_type", "=", ext.kind)
    .where("external_id", "=", ext.externalId)
    .where("status", "=", "accepted")
    .where("content_unit_id", "is", null)
    .executeTakeFirst();
  let entityId = local?.media_entity_id ?? null;
  if (!entityId && addToLibrary) {
    entityId = await d.ao.ports.entityFromTmdb({ type: ext.kind, id: ext.externalId }, actor);
    const e = await d.ctx.db.selectFrom("media_entity").select(["title"]).where("id", "=", entityId).executeTakeFirst();
    entities.push({ mediaEntityId: entityId, title: e?.title ?? ext.title ?? ext.externalId, created: true });
  }
  if (entityId) {
    const m = await entityScrapeMatch(d.ao, entityId, source);
    if (m) return { ...m, provider: "tmdb", externalId: ext.externalId };
  }
  return {
    mediaEntityId: null,
    provider: "tmdb",
    externalId: ext.externalId,
    kind: ext.kind,
    title: ext.title ?? `TMDB ${ext.externalId}`,
    year: ext.year ?? null,
    source,
  };
}

export async function scrapeFiles(
  d: FmDeps,
  principal: Principal | undefined,
  body: FilesScrapeRequest,
): Promise<FilesScrapeResult> {
  const db = d.ctx.db;
  const actor = actorOf(principal);
  const mode = body.mode ?? (await scrapeSettings(d.ao)).scrapeMode;
  const recordIds: string[] = [];
  const needsChoice: FilesScrapeResult["needsChoice"] = [];
  const skipped: FilesScrapeResult["skipped"] = [];
  const entities: FilesScrapeResult["entities"] = [];
  for (const it of body.items) {
    if (it.mediaEntityId && it.external) throw new FilesError("bad_request", "mediaEntityId 与 external 只能给一个");
    const r = await resolveIn(d, it.root, it.path);
    const ref = { root: it.root, path: r.rel };
    if (r.def.kind === "library" && !r.def.modifiable) {
      skipped.push({ ...ref, reason: "scrape_root_read_only" });
      continue;
    }
    const isDir = !!r.lst?.isDirectory();
    if (!isDir && !(r.lst?.isFile() && kindOfName(r.abs) === "video")) {
      skipped.push({ ...ref, reason: "scrape_not_video" });
      continue;
    }
    let match: ScrapeMatch | null = null;
    if (it.mediaEntityId) {
      match = await entityScrapeMatch(d.ao, it.mediaEntityId, "chosen");
      if (!match) throw new FilesError("not_found", `作品不存在：${it.mediaEntityId}`);
    } else if (it.external) {
      match = await externalMatch(d, it.external, "chosen", body.addToLibrary, actor, entities);
    } else {
      // 目录里的文件已登记到唯一作品:直接用(重新刮削已入库的)
      const owners = r.def.libraryRootId ? await entitiesUnder(db, r.def.libraryRootId, r.rel, isDir) : [];
      if (owners.length === 1) match = await entityScrapeMatch(d.ao, owners[0]!, "library");
      if (!match) {
        let rec: Awaited<ReturnType<typeof recognize>>;
        try {
          rec = await recognize(d, principal, { ...it, path: r.rel });
        } catch (e) {
          if (e instanceof FilesError && e.reason === "bad_request") {
            skipped.push({ ...ref, reason: "scrape_no_videos" });
            continue;
          }
          throw e;
        }
        const c = rec.pick;
        if (c?.mediaEntityId) match = await entityScrapeMatch(d.ao, c.mediaEntityId, "auto");
        else if (c && c.provider === "tmdb" && c.externalId)
          match = await externalMatch(
            d,
            { externalId: c.externalId, kind: c.kind === "movie" ? "movie" : "tv", title: c.title, year: c.year },
            "auto",
            body.addToLibrary,
            actor,
            entities,
          );
        if (!match) {
          needsChoice.push({ ...ref, ...rec.choice });
          continue;
        }
      }
    }
    const q = await queueScrape(d.ao, {
      rootId: r.def.id,
      rootPath: r.def.hostPath,
      libraryRootId: r.def.libraryRootId,
      path: r.rel,
      match,
      mode,
      trigger: "manual",
      actor,
    });
    recordIds.push(q.recordId);
  }
  const records = recordIds.length ? await waitScrapeRecords(d.ao, recordIds, d.options.transferWaitMs) : [];
  await audit(d, principal, "scrape", {
    items: body.items.map((i) => `${i.root}:${i.path}`).slice(0, 100),
    mode,
    recordIds,
    needsChoice: needsChoice.map((n) => `${n.root}:${n.path}`),
    skipped,
  });
  return {
    records,
    needsChoice,
    skipped,
    pending: records.some((r) => r.status === "queued" || r.status === "running"),
    entities,
  };
}

export async function scrapeRecords(d: FmDeps, idsParam: string) {
  const ids = [...new Set(idsParam.split(",").map((s) => s.trim()))].filter((s) => /^[0-9a-f-]{36}$/i.test(s));
  if (!ids.length || ids.length > 100) throw new FilesError("bad_request", "ids 需要 1–100 个刮削记录 id");
  return { records: await loadScrapeRecords(d.ao, ids) };
}