import { internal } from "../_generated/api";
import { nowIso } from "./time";
import type { MutationCtx } from "../_generated/server";

type JobStatus = "queued" | "running" | "succeeded" | "failed";

async function upsertJob(
  ctx: MutationCtx,
  args: {
    id: string;
    userId: string;
    type: string;
    payload: unknown;
    debounceMs?: number;
  },
): Promise<{ id: string; status: JobStatus }> {
  const debounceMs = Math.max(0, Math.floor(args.debounceMs ?? 1200));
  const ts = nowIso();

  const existing = await ctx.db
    .query("jobs")
    .withIndex("by_job_id", (q) => q.eq("id", args.id))
    .first();

  if (existing) {
    if (existing.user_id !== args.userId) {
      // 说明：避免不同用户复用同一 job id 导致“互相覆盖”。
      return { id: args.id, status: existing.status as JobStatus };
    }

    const status = String(existing.status) as JobStatus;
    if (status === "running" || status === "queued") {
      await ctx.db.patch(existing._id, { updated_at: ts });
      // 说明：start 内部会检查状态，重复 schedule 不会造成重复执行。
      await ctx.scheduler.runAfter(debounceMs, internal.jobs.start, { id: args.id });
      return { id: args.id, status };
    }

    await ctx.db.patch(existing._id, {
      type: args.type,
      status: "queued",
      payload: args.payload,
      result: null,
      error: null,
      updated_at: ts,
      started_at: null,
      finished_at: null,
    });
    await ctx.scheduler.runAfter(debounceMs, internal.jobs.start, { id: args.id });
    return { id: args.id, status: "queued" };
  }

  await ctx.db.insert("jobs", {
    id: args.id,
    user_id: args.userId,
    type: args.type,
    status: "queued",
    payload: args.payload,
    result: null,
    error: null,
    created_at: ts,
    updated_at: ts,
    started_at: null,
    finished_at: null,
  });
  await ctx.scheduler.runAfter(debounceMs, internal.jobs.start, { id: args.id });
  return { id: args.id, status: "queued" };
}

export function ingestDocumentJobId(documentId: string): string {
  return `ingest:document:${documentId}`;
}

export function ingestMindmapJobId(docId: string, mindmapId: string): string {
  return `ingest:mindmap:${docId}:${mindmapId}`;
}

export function ingestMediaAssetJobId(assetId: string): string {
  return `ingest:media:${assetId}`;
}

export async function enqueueIngestDocumentJob(
  ctx: MutationCtx,
  args: { userId: string; documentId: string; debounceMs?: number },
): Promise<{ id: string }> {
  const id = ingestDocumentJobId(args.documentId);
  await upsertJob(ctx, {
    id,
    userId: args.userId,
    type: "ingest.rag_index_document",
    payload: { documentId: args.documentId },
    debounceMs: args.debounceMs,
  });
  return { id };
}

export async function enqueueIngestMindmapJob(
  ctx: MutationCtx,
  args: { userId: string; docId: string; mindmapId: string; debounceMs?: number },
): Promise<{ id: string }> {
  const id = ingestMindmapJobId(args.docId, args.mindmapId);
  await upsertJob(ctx, {
    id,
    userId: args.userId,
    type: "ingest.rag_index_mindmap",
    payload: { docId: args.docId, mindmapId: args.mindmapId },
    debounceMs: args.debounceMs,
  });
  return { id };
}

export async function enqueueIngestMediaAssetJob(
  ctx: MutationCtx,
  args: { userId: string; assetId: string; debounceMs?: number },
): Promise<{ id: string }> {
  const id = ingestMediaAssetJobId(args.assetId);
  await upsertJob(ctx, {
    id,
    userId: args.userId,
    type: "ingest.rag_index_media_asset",
    payload: { assetId: args.assetId },
    debounceMs: args.debounceMs,
  });
  return { id };
}