import { NextResponse } from "next/server";
import { PrismaClient } from "@prisma/client";
import { verifyAccessToken } from "@/features/auth/authCrypto";
import { cachePublicProject, parseProjectContentJson } from "@/features/projects/publicCache";

const prisma = new PrismaClient();

interface AuthUser {
  id: string;
  email: string;
  tokenVersion: number;
}

function extractTokenFromCookieHeader(cookieHeader: string | null): string | null {
  if (!cookieHeader) return null;

  const parts = cookieHeader.split(";");
  for (const part of parts) {
    const trimmed = part.trim();
    if (trimmed.startsWith("pb_access=")) {
      const value = trimmed.substring("pb_access=".length);
      return decodeURIComponent(value);
    }
  }
  return null;
}

async function getAuthUserFromRequest(request: Request): Promise<AuthUser | null> {
  const cookieHeader = request.headers.get("cookie");
  const token = extractTokenFromCookieHeader(cookieHeader);
  if (!token) return null;

  const payload = await verifyAccessToken(token);
  if (!payload) return null;

  return {
    id: payload.sub,
    email: payload.email,
    tokenVersion: payload.tokenVersion,
  };
}

export async function GET(request: Request) {
  const authUser = await getAuthUserFromRequest(request);
  if (!authUser) {
    return NextResponse.json({ message: "프로젝트 목록을 조회하려면 로그인이 필요합니다." }, { status: 401 });
  }

  try {
    const projects = await prisma.project.findMany({
      where: { userId: authUser.id },
      orderBy: { createdAt: "desc" },
      take: 50,
      select: {
        id: true,
        title: true,
        slug: true,
        status: true,
        createdAt: true,
        updatedAt: true,
      },
    });

    if (projects.length === 0) {
      return NextResponse.json(
        projects.map((p) => ({
          ...p,
          todaySubmissions: 0,
          totalSubmissions: 0,
        })),
        { status: 200 },
      );
    }

    const projectIds = projects.map((p) => p.id);

    const submissions = await prisma.formSubmission.findMany({
      where: {
        userId: authUser.id,
        projectId: { in: projectIds },
      },
      select: {
        id: true,
        projectId: true,
        createdAt: true,
      },
    });

    const now = new Date();
    const startOfToday = new Date(now);
    startOfToday.setHours(0, 0, 0, 0);

    const statsByProjectId = new Map<
      string,
      {
        todaySubmissions: number;
        totalSubmissions: number;
      }
    >();

    for (const project of projects) {
      statsByProjectId.set(project.id, { todaySubmissions: 0, totalSubmissions: 0 });
    }

    for (const submission of submissions) {
      const projectId = submission.projectId;
      if (!projectId) continue;

      const stat = statsByProjectId.get(projectId);
      if (!stat) continue;

      stat.totalSubmissions += 1;

      const createdAt =
        submission.createdAt instanceof Date
          ? submission.createdAt
          : new Date((submission.createdAt as unknown as string) ?? "");

      if (createdAt >= startOfToday) {
        stat.todaySubmissions += 1;
      }
    }

    const result = projects.map((project) => {
      const stat = statsByProjectId.get(project.id) ?? {
        todaySubmissions: 0,
        totalSubmissions: 0,
      };

      return {
        ...project,
        todaySubmissions: stat.todaySubmissions,
        totalSubmissions: stat.totalSubmissions,
      };
    });

    return NextResponse.json(result, { status: 200 });
  } catch (error: any) {
    return NextResponse.json(
      { message: "프로젝트 목록을 가져오는 중 오류가 발생했습니다.", error: error?.message },
      { status: 500 },
    );
  }
}

export async function POST(request: Request) {
  const authUser = await getAuthUserFromRequest(request);
  if (!authUser) {
    return NextResponse.json({ message: "프로젝트를 저장하려면 로그인이 필요합니다." }, { status: 401 });
  }

  const body = await request.json();
  const { title, slug, contentJson } = body;

  if (!title || !slug || typeof title !== "string" || typeof slug !== "string") {
    return NextResponse.json({ message: "title과 slug는 필수입니다." }, { status: 400 });
  }

  try {
    const existing = await prisma.project.findUnique({
      where: { slug },
    });

    if (existing && existing.userId && existing.userId !== authUser.id) {
      return NextResponse.json(
        { message: "이미 다른 사용자가 사용 중인 프로젝트 주소입니다." },
        { status: 409 },
      );
    }

    const project = await prisma.project.upsert({
      where: { slug },
      update: {
        title,
        contentJson,
      },
      create: {
        title,
        slug,
        contentJson,
        userId: authUser.id,
      },
    });

    // 퍼블릭 슬러그 페이지(/p/[slug])가 DB 조회 없이도 최신 스냅샷을 바로 렌더링할 수 있도록
    // 메모리 기반 캐시에 프로젝트 스냅샷을 저장해 둔다.
    const { blocks, projectConfig } = parseProjectContentJson((project as any).contentJson);

    try {
      cachePublicProject({
        slug: project.slug,
        title: project.title,
        status: (project as any).status ?? "DRAFT",
        blocks,
        projectConfig,
      });
    } catch {
      // 캐시 저장 실패는 퍼블릭 렌더링에만 영향을 주므로, API 응답 자체는 정상적으로 계속 진행한다.
    }

    return NextResponse.json(project, { status: 201 });
  } catch (error: any) {
    return NextResponse.json(
      { message: "프로젝트 생성 중 오류가 발생했습니다.", error: error?.message },
      { status: 500 },
    );
  }
}