import { NextRequest, NextResponse } from "next/server";

import {
    AUTH_USER_ID,
    CLAIM_NAME,
    PORT,
    PROXY_HOST,
    SERVER_API_URL,
    SITE_ID,
    ST_SERVICE_URL,
} from "./src/shared/config";

const serverApiUrl = process.env.SERVER_API_URL;

const stServiceUrl = ST_SERVICE_URL;

const linkBackendApiHost =
    process.env.NEXT_PUBLIC_LINK_BACKEND_API_HOST ?? "http://localhost:8080";

// CSP 헤더 설정 함수 (img-src만)
function addSecurityHeaders(response: NextResponse): NextResponse {
    response.headers.set(
        "Content-Security-Policy",
        "img-src 'self' data: https: blob:;",
    );
    return response;
}

export function middleware(req: NextRequest) {
    const pathname = req.nextUrl.pathname;
    const searchParams = req.nextUrl.searchParams;

    const logMessages: string[] = [
        `[Middleware Request] ${new Date().toISOString()}`,
        `[Environment]\n  Mode: ${process.env.NODE_ENV}\n  Port: ${PORT}\n  Proxy Host: ${PROXY_HOST}\n  Server API URL: ${SERVER_API_URL}\n  Site ID: ${SITE_ID}\n  ST Service URL: ${stServiceUrl}`,
        `[Request]\n  Original Pathname: ${pathname}`,
    ];

    // ST Service 처리 (dc의 /server/dc-service 패턴과 동일)
    if (
        pathname.startsWith("/server/st-management-service") ||
        pathname.startsWith("/server/st-input-service")
    ) {
        const requestHeaders = new Headers(req.headers);
        const token = req.cookies.get(CLAIM_NAME)?.value;
        const userId = req.cookies.get(AUTH_USER_ID)?.value;

        const queryParams = searchParams.toString();
        const newUrl = `${stServiceUrl}${pathname.replace("/server", "")}${
            queryParams ? `?${queryParams}` : ""
        }`;

        if (token) requestHeaders.set(CLAIM_NAME, token);
        if (userId) requestHeaders.set(AUTH_USER_ID, userId);

        logMessages.push(`  Token Debug: ${token ? "EXISTS" : "MISSING"}`);
        logMessages.push(`  UserId Debug: ${userId ? "EXISTS" : "MISSING"}`);
        logMessages.push(`  ST Service Rewritten URL: ${newUrl}`);
        logMessages.push("\n--------------------------------\n");
        console.log(logMessages.join("\n"));

        const response = NextResponse.rewrite(new URL(newUrl), {
            headers: requestHeaders,
        });
        return addSecurityHeaders(response);
    }

    // 일반 Server API 처리 (ST 서비스 제외)
    if (
        pathname.startsWith("/server") &&
        !pathname.startsWith("/server/st-management-service") &&
        !pathname.startsWith("/server/st-input-service")
    ) {
        const requestHeaders = new Headers(req.headers);
        const token = req.cookies.get(CLAIM_NAME)?.value;
        const userId = req.cookies.get(AUTH_USER_ID)?.value;

        const queryParams = searchParams.toString();
        const newUrl = `${serverApiUrl}${pathname.replace("/server", "")}${
            queryParams ? `?${queryParams}` : ""
        }`;

        if (token) requestHeaders.set(CLAIM_NAME, token);
        if (userId) requestHeaders.set(AUTH_USER_ID, userId);

        logMessages.push(`  Rewritten URL: ${newUrl}`);
        logMessages.push("\n--------------------------------\n");
        console.log(logMessages.join("\n"));

        const response = NextResponse.rewrite(new URL(newUrl), {
            headers: requestHeaders,
        });
        return addSecurityHeaders(response);
    }

    if (pathname.startsWith("/attach-service")) {
        const requestHeaders = new Headers(req.headers);
        const token = req.cookies.get(CLAIM_NAME)?.value;
        const userId = req.cookies.get(AUTH_USER_ID)?.value;
        const newUrl = `${serverApiUrl}${pathname}`;

        if (token) requestHeaders.set(CLAIM_NAME, token);
        if (userId) requestHeaders.set(AUTH_USER_ID, userId);

        logMessages.push(`  Rewritten URL: ${newUrl}`);
        logMessages.push("\n--------------------------------\n");
        console.log(logMessages.join("\n"));

        const response = NextResponse.rewrite(new URL(newUrl), {
            headers: requestHeaders,
        });
        return addSecurityHeaders(response);
    }

    if (pathname.startsWith("/api/link")) {
        const requestHeaders = new Headers(req.headers);
        const token = req.cookies.get(CLAIM_NAME)?.value;
        const userId = req.cookies.get(AUTH_USER_ID)?.value;

        // /api/link 경로를 제거하고 백엔드 API 경로로 변환
        const apiPath = pathname.replace("/api/link", "");
        const queryParams = searchParams.toString();
        const newUrl = `${linkBackendApiHost}${apiPath}${
            queryParams ? `?${queryParams}` : ""
        }`;

        if (token) requestHeaders.set(CLAIM_NAME, token);
        if (userId) requestHeaders.set(AUTH_USER_ID, userId);

        logMessages.push(`  Link API Rewritten URL: ${newUrl}`);
        logMessages.push("\n--------------------------------\n");
        console.log(logMessages.join("\n"));

        const response = NextResponse.rewrite(new URL(newUrl), {
            headers: requestHeaders,
        });
        return addSecurityHeaders(response);
    }

    if (pathname === "/") {
        const response = NextResponse.redirect(new URL("/statistics", req.url));
        return addSecurityHeaders(response);
    }

    logMessages.push("\n--------------------------------\n");
    console.log(logMessages.join("\n"));

    const response = NextResponse.next();
    return addSecurityHeaders(response);
}

export const config = {
    matcher: [
        "/server/:path*",
        "/attach-service/:path*",
        "/api/link/:path*",
        "/",
    ],
};