import { NextResponse } from "next/server";
import { PrismaClient } from "@prisma/client";

import { verifyAccessToken } from "@/features/auth/authCrypto";

// /api/reports/leads
// - 로그인한 사용자의 FormSubmission(리드) 목록을 기간/프로젝트 필터에 맞게 조회해,
//   최신순으로 정렬된 리드 리스트와 총 개수를 반환한다.

const prisma = new PrismaClient();

type RangeParam = "7d" | "30d" | "all";

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;
}

export async function GET(request: Request) {
  try {
    const url = new URL(request.url);
    const range = (url.searchParams.get("range") as RangeParam | null) ?? "all";
    const projectIdFilter = url.searchParams.get("projectId");
    const fromParam = url.searchParams.get("from");
    const toParam = url.searchParams.get("to");

    if (range !== "7d" && range !== "30d" && range !== "all") {
      return NextResponse.json({ message: "Invalid range parameter" }, { status: 400 });
    }

    const cookieHeader = request.headers.get("cookie");
    const token = extractTokenFromCookieHeader(cookieHeader);

    if (!token) {
      return NextResponse.json({ message: "인증 정보가 없습니다." }, { status: 401 });
    }

    const payload = await verifyAccessToken(token);
    if (!payload) {
      return NextResponse.json({ message: "유효하지 않은 토큰입니다." }, { status: 401 });
    }

    const userId = payload.sub;

    const [projects, submissions] = await Promise.all([
      prisma.project.findMany({
        where: { userId },
        select: {
          id: true,
          title: true,
          slug: true,
        },
      }),
      prisma.formSubmission.findMany({
        where: { userId },
        select: {
          id: true,
          projectId: true,
          projectSlug: true,
          createdAt: true,
          payloadJson: true,
        },
      }),
    ]);

    let fromDate: Date | null = null;
    let toDate: Date | null = null;

    if (fromParam || toParam) {
      if (fromParam) {
        const parsedFrom = new Date(`${fromParam}T00:00:00.000Z`);
        if (Number.isNaN(parsedFrom.getTime())) {
          return NextResponse.json({ message: "Invalid from parameter" }, { status: 400 });
        }
        fromDate = parsedFrom;
      }
      if (toParam) {
        const parsedTo = new Date(`${toParam}T23:59:59.999Z`);
        if (Number.isNaN(parsedTo.getTime())) {
          return NextResponse.json({ message: "Invalid to parameter" }, { status: 400 });
        }
        toDate = parsedTo;
      }
    } else {
      const now = new Date();
      if (range === "7d") {
        fromDate = new Date(now.getTime() - 7 * 24 * 60 * 60 * 1000);
      } else if (range === "30d") {
        fromDate = new Date(now.getTime() - 30 * 24 * 60 * 60 * 1000);
      }
    }

    // 1단계: 기간/프로젝트 필터 적용
    const filtered = submissions.filter((s) => {
      const createdAt = s.createdAt instanceof Date ? s.createdAt : new Date(s.createdAt as any);

      if (fromDate && createdAt < fromDate) {
        return false;
      }

      if (toDate && createdAt > toDate) {
        return false;
      }

      if (projectIdFilter && s.projectId !== projectIdFilter) {
        return false;
      }

      return true;
    });

    // 2단계: 최신순 정렬 (createdAt desc)
    filtered.sort((a, b) => {
      const aDate = a.createdAt instanceof Date ? a.createdAt : new Date(a.createdAt as any);
      const bDate = b.createdAt instanceof Date ? b.createdAt : new Date(b.createdAt as any);
      return bDate.getTime() - aDate.getTime();
    });

    const projectById = new Map<
      string,
      {
        title: string;
        slug: string;
      }
    >();

    for (const p of projects) {
      projectById.set(p.id, { title: p.title, slug: p.slug });
    }

    const items = filtered.map((s) => {
      const createdAt = s.createdAt instanceof Date ? s.createdAt : new Date(s.createdAt as any);
      const projectMeta = s.projectId ? projectById.get(s.projectId) : null;

      return {
        id: s.id,
        projectId: s.projectId ?? null,
        projectSlug: s.projectSlug,
        projectTitle: projectMeta?.title ?? null,
        createdAt: createdAt.toISOString(),
        payload: (s as any).payloadJson ?? {},
      };
    });

    const body = {
      total: items.length,
      items,
    };

    return NextResponse.json(body, { status: 200 });
  } catch (error: any) {
    return NextResponse.json(
      {
        message: "리드 리포트를 불러오는 중 오류가 발생했습니다.",
        error: error?.message,
      },
      { status: 500 },
    );
  }
}