import {
  Api,
  GlobalSettings,
  type GlobalSettingsUpdate,
  mergeSettings,
  type SecretPurpose,
  type SettingsKey,
} from "@umt/contracts";
import { ApiException } from "../../http/errors.ts";
import type { ModuleApp, ServerContext } from "../types.ts";
import { audit, endpoint } from "./endpoint.ts";
import { type CachedSettingsReader, SETTINGS_CHANGED_EVENT } from "./provided.ts";

// GET/PATCH /settings:按分组部分更新 → mergeSettings → GlobalSettings 整体校验 → 逐组 upsert;
// TMDB 密钥(metadata.tmdbApiKey)与网页搜索 Key(agent.webSearch.apiKey)只写,存为 secret,设置里只留 secret 引用(Agent 上游密钥在 pi_upstream,
// 旧 pi.apiKey 已弃用,PATCH 里会被 schema 丢弃);变更经 SSE 总线广播 settings.changed,
// 各进程的 ctx.settings 缓存随之失效。自动化总开关 automation.enabled / 只读对账 automation.readOnlyReconcile 也走这里。

const isCached = (s: unknown): s is CachedSettingsReader =>
  typeof (s as CachedSettingsReader)?.invalidate === "function";

export function registerSettingsRoutes(app: ModuleApp, ctx: ServerContext) {
  endpoint(app, { ...Api.settings.get, tags: ["settings"] }, async () => {
    if (isCached(ctx.settings)) return await ctx.settings.fresh();
    return await ctx.settings.all();
  });

  endpoint(app, { ...Api.settings.update, tags: ["settings"] }, async ({ body, actor }) => {
    const patch = body as GlobalSettingsUpdate;
    const current = isCached(ctx.settings) ? await ctx.settings.fresh() : await ctx.settings.all();
    const merged = mergeSettings(current, patch);
    // 只写密钥:存 secret,设置里只留 secret 引用
    const slots = secretSlots(patch);
    for (const sl of slots) if (sl.plaintext === null) sl.set(merged, null);
    const parsed = GlobalSettings.safeParse(merged);
    if (!parsed.success) {
      const msg = parsed.error.issues.map((i) => `${i.path.join(".")}: ${i.message}`).join("; ");
      throw new ApiException("validation_failed", msg);
    }
    const next = parsed.data;
    const created: string[] = [];
    const dropped: string[] = [];
    for (const sl of slots) {
      const oldRef = sl.get(current);
      if (sl.plaintext === null) {
        if (oldRef) dropped.push(oldRef);
      } else if (oldRef) {
        await ctx.secrets.replace(oldRef, sl.plaintext);
        sl.set(next, oldRef);
      } else {
        const ref = await ctx.secrets.create({ purpose: sl.purpose, plaintext: sl.plaintext, label: sl.label });
        created.push(ref);
        sl.set(next, ref);
      }
    }
    const keys = (Object.keys(patch) as SettingsKey[]).filter((k) => patch[k] !== undefined);
    try {
      await ctx.db.transaction().execute(async (trx) => {
        for (const key of keys) {
          await trx
            .insertInto("settings")
            .values({ key, value: JSON.stringify(next[key]), updated_at: new Date() })
            .onConflict((oc) =>
              oc.column("key").doUpdateSet({ value: JSON.stringify(next[key]), updated_at: new Date() }),
            )
            .execute();
        }
      });
    } catch (err) {
      for (const ref of created) await ctx.secrets.remove(ref).catch(() => {});
      throw err;
    }
    for (const ref of dropped) await ctx.secrets.remove(ref).catch(() => {});
    if (isCached(ctx.settings)) ctx.settings.invalidate();
    void ctx.events.publish(SETTINGS_CHANGED_EVENT, { keys });
    // 审计里不留明文密钥
    const logged: Record<string, unknown> = { ...patch };
    if (patch.metadata && "tmdbApiKey" in patch.metadata)
      logged.metadata = { ...patch.metadata, tmdbApiKey: patch.metadata.tmdbApiKey === null ? "(cleared)" : "(set)" };
    const ws = patch.agent?.webSearch;
    if (ws && "apiKey" in ws)
      logged.agent = { ...patch.agent, webSearch: { ...ws, apiKey: ws.apiKey === null ? "(cleared)" : "(set)" } };
    await audit(ctx, actor, "settings.update", { type: "settings", id: keys.join(",") }, { patch: logged });
    return next;
  });
}

interface SecretSlot {
  plaintext: string | null;
  purpose: SecretPurpose;
  label: string;
  get(s: GlobalSettings): string | null;
  set(s: GlobalSettings, ref: string | null): void;
}

/** PATCH 里出现的只写密钥字段(undefined = 不改;null = 清除;字符串 = 设置) */
function secretSlots(patch: GlobalSettingsUpdate): SecretSlot[] {
  const out: SecretSlot[] = [];
  const tmdb = patch.metadata?.tmdbApiKey;
  if (tmdb !== undefined)
    out.push({
      plaintext: tmdb,
      purpose: "metadata_api_key",
      label: "tmdb",
      get: (s) => s.metadata.tmdbApiKeySecretRef,
      set: (s, ref) => {
        s.metadata.tmdbApiKeySecretRef = ref;
      },
    });
  const ws = patch.agent?.webSearch?.apiKey;
  if (ws !== undefined)
    out.push({
      plaintext: ws,
      purpose: "other",
      label: "websearch",
      get: (s) => s.agent.webSearch?.apiKeySecretRef ?? null,
      set: (s, ref) => {
        s.agent.webSearch.apiKeySecretRef = ref;
      },
    });
  return out;
}