#include "login.hpp"    
#include "crow/http_response.h"
#include "databasepool.h"
#include "SessionHandler.hpp"
#include <optional>

namespace login
{

SessionHandler sessionHandler;

std::string getSessionId(const crow::request& req) {
    auto cookie_header = req.get_header_value("Cookie");
    std::string prefix = "session_id=";
    auto pos = cookie_header.find(prefix);
    if (pos == std::string::npos) 
        return "";
    return cookie_header.substr(pos + prefix.size(), Session::SESSION_ID_SIZE);
}

static crow::response redirectToLogin(){
    crow::response res(302); // 302 = temporary redirect
    res.set_header("Location", "/");
    return res;
}

std::optional<crow::response> isLoggedIn(const crow::request& req) {
    std::string sessionId = getSessionId(req);
    if (sessionId.empty()) 
        return std::move(redirectToLogin());
    
    auto userId = sessionHandler.isSessionValid(sessionId);
    if(!userId.has_value())
        return std::move(redirectToLogin());

    return {};
}

std::optional<std::string> loginUser(const std::string& username, const std::string& password)
{
    auto user = getVerifiedUser(username, password);
    if (user) {
        return sessionHandler.createSession(user->id);
    }
    return {};
}

void initLogin(crow::App<CORS>& app)
{

   createUser("lukas", "Trollar4928");

    CROW_ROUTE(app, "/login").methods("POST"_method)
    ([](const crow::request& req) {
        nlohmann::json body = nlohmann::json::parse(req.body);   // parse JSON from HTTP body
        if (body.empty())
            return crow::response(400, "Invalid JSON");

        auto usenameIt = body.find("username");
        auto passwordIt = body.find("password");
        if(usenameIt == body.end() || passwordIt == body.end())
            return crow::response(400, "No username or password in body");

        const std::string& username = *usenameIt;
        const std::string& password = *passwordIt;

        // Validate credentials
        auto sessionId = loginUser(username, password); 
        if(!sessionId.has_value())
            return crow::response(401, "Invalid credentials");

        // Set cookie
        crow::response res;
        res.code = 200;
        res.set_header(
            "Set-Cookie",
            "session_id=" + sessionId.value() +
            "; HttpOnly; Path=/; SameSite=Strict"
            // add "; Secure" when using HTTPS
        );
        res.set_header("Access-Control-Allow-Credentials", "true");
        res.set_header("Access-Control-Allow-Origin", "http://localhost:5173"); 

        res.body = "Logged in";
        return res;
    });
}
}