import { NextResponse } from "next/server";
import { prisma } from "@/lib/db";
import { authErrorResponse } from "@/lib/auth/api";
import { requireSessionUser } from "@/lib/auth/session";
import { recoverStaleBackgroundJobs } from "@/lib/jobs/runner";

export async function GET(request: Request) {
  try {
    const user = await requireSessionUser();
    const { searchParams } = new URL(request.url);
    const activeOnly = searchParams.get("active") === "1";
    const topicId = searchParams.get("topicId");
    const limit = Math.min(parseInt(searchParams.get("limit") ?? "10", 10), 30);

    const userAccounts = await prisma.account.findMany({
      where: { userId: user.id },
      select: { id: true },
    });
    const accountIds = userAccounts.map((account) => account.id);
    if (accountIds.length === 0) {
      return NextResponse.json({ jobs: [] });
    }

    if (activeOnly) {
      await recoverStaleBackgroundJobs();
    }

    const baseWhere = {
      accountId: { in: accountIds },
      ...(topicId ? { topicId } : {}),
    };
    const jobs = activeOnly
      ? await prisma.backgroundJob.findMany({
          where: { ...baseWhere, status: { in: ["pending", "running"] } },
          orderBy: { createdAt: "desc" },
        })
      : await Promise.all([
          prisma.backgroundJob.findMany({
            where: { ...baseWhere, status: { in: ["pending", "running"] } },
            orderBy: { createdAt: "desc" },
          }),
          prisma.backgroundJob.findMany({
            where: baseWhere,
            orderBy: { createdAt: "desc" },
            take: limit,
          }),
        ]).then(([active, recent]) => {
          const merged = new Map([...active, ...recent].map((job) => [job.id, job]));
          return [...merged.values()].sort(
            (a, b) => b.createdAt.getTime() - a.createdAt.getTime()
          );
        });

    return NextResponse.json({ jobs });
  } catch (error) {
    const authRes = authErrorResponse(error);
    if (authRes) return authRes;
    console.error("[jobs GET]", error);
    return NextResponse.json(
      { error: error instanceof Error ? error.message : "載入任務失敗", jobs: [] },
      { status: 500 }
    );
  }
}