import { NextResponse, type NextRequest } from "next/server";
import { requireApiAdmin } from "@/lib/api-auth";
import { createUserRecord, getUserByUsername } from "@/lib/db";
import { hashPassword, toPublicUser } from "@/lib/auth";
import { getQuotaSnapshotForUser } from "@/lib/quota";
import { jsonError, normalizeError } from "@/lib/http";

export const runtime = "nodejs";

export async function POST(request: NextRequest) {
  try {
    requireApiAdmin(request);

    const body = (await request.json()) as {
      username?: unknown;
      password?: unknown;
      role?: unknown;
      monthlyQuota?: unknown;
    };
    const username = String(body?.username ?? "")
      .trim()
      .toLowerCase();
    const password = String(body?.password ?? "");
    const role = body?.role === "admin" ? "admin" : "user";
    const monthlyQuota =
      typeof body?.monthlyQuota === "number" ||
      typeof body?.monthlyQuota === "string"
        ? body.monthlyQuota
        : undefined;

    if (!username) {
      return jsonError("用户名不能为空。", 400);
    }

    if (password.length < 8) {
      return jsonError("密码至少需要 8 个字符。", 400);
    }

    if (getUserByUsername(username)) {
      return jsonError("该用户名已存在。", 409);
    }

    const publicUser = toPublicUser(
      createUserRecord({
        username,
        passwordHash: hashPassword(password),
        role,
        monthlyQuota: role === "admin" ? null : monthlyQuota,
      }),
    );

    if (!publicUser) {
      return jsonError("创建用户失败。", 500);
    }

    const quota = getQuotaSnapshotForUser(publicUser);

    return NextResponse.json({
      ok: true,
      user: {
        ...publicUser,
        usedThisPeriod: quota.used,
        remaining: quota.remaining,
        limit: quota.limit,
        isUnlimited: quota.isUnlimited,
      },
    });
  } catch (error) {
    const normalizedError = normalizeError(error, "创建用户失败。");
    return jsonError(normalizedError.message, normalizedError.statusCode);
  }
}