import { NextResponse } from "next/server";
import { auth } from "@/app/(auth)/auth";
import {
  getFlowBoardDraftByUserId,
  upsertFlowBoardDraftByUserId,
} from "@/lib/db/queries";
import type { FlowBoardSnapshotData } from "@/lib/db/schema";

export const runtime = "nodejs";

function isRecord(value: unknown): value is Record<string, unknown> {
  return typeof value === "object" && value !== null && !Array.isArray(value);
}

function normalizeRecord(value: unknown): Record<string, unknown> | null {
  return isRecord(value) ? value : null;
}

function normalizeFlowBoardSnapshot(value: unknown): FlowBoardSnapshotData {
  const raw = isRecord(value) ? value : {};
  const updatedAt =
    typeof raw.updatedAt === "string" && raw.updatedAt.trim()
      ? raw.updatedAt
      : new Date().toISOString();

  return {
    children: Array.isArray(raw.children)
      ? raw.children.filter(isRecord)
      : [],
    viewport: normalizeRecord(raw.viewport),
    theme: normalizeRecord(raw.theme),
    updatedAt,
  };
}

export async function GET() {
  const session = await auth();
  if (!session?.user?.id) {
    return NextResponse.json(
      { success: false, error: "未登录" },
      { status: 401 }
    );
  }

  const draft = await getFlowBoardDraftByUserId({
    userId: session.user.id,
  });

  return NextResponse.json({
    success: true,
    data: {
      snapshot: draft?.snapshot ?? { children: [] },
      updatedAt: draft?.updatedAt?.toISOString() ?? null,
    },
  });
}

export async function PUT(request: Request) {
  const session = await auth();
  if (!session?.user?.id) {
    return NextResponse.json(
      { success: false, error: "未登录" },
      { status: 401 }
    );
  }

  const body = (await request.json().catch(() => ({}))) as {
    snapshot?: unknown;
  };
  const snapshot = normalizeFlowBoardSnapshot(body.snapshot ?? body);
  const savedDraft = await upsertFlowBoardDraftByUserId({
    userId: session.user.id,
    snapshot,
  });

  if (!savedDraft) {
    return NextResponse.json(
      { success: false, error: "保存流程白板失败" },
      { status: 500 }
    );
  }

  return NextResponse.json({
    success: true,
    data: {
      snapshot: savedDraft.snapshot,
      updatedAt: savedDraft.updatedAt?.toISOString() ?? snapshot.updatedAt,
    },
  });
}