#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include "utils.hpp"
#include "crow/http_response.h"
#include <algorithm>
#include <fstream>
#include <sstream>

using namespace std;

namespace utils {

map<string, string> parseBody(const string& body)
{
    size_t pos = 0;
    size_t start = 0;
    map<string, string> data;

    while (true)
    {
        pos = body.find('=', start);
        const string key = body.substr(start, pos - start);

        size_t nextPos = body.find('&', pos + 1);
        string value = body.substr(pos + 1, nextPos - (pos + 1));
        data[key] = value;

        if (nextPos == std::string::npos)
        {
            break;
        }
        start = nextPos + 1;
    }
    return data;
}

optional<string> getBodyName(const string& body) {
    const auto pos = body.find('=');
    if (pos == std::string::npos) return {};

    const string key = body.substr(0, pos);
    string value = body.substr(pos + 1);

    if (key != "name") return {};

    return value;
}

expected<bool, string> isLocalPortOpen(uint16_t portno) {
    const char *hostname = "localhost";
 
    int sockfd;
    bool ret;
    struct sockaddr_in serv_addr;
    struct hostent *server;
 
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        close(sockfd);
        return unexpected("ERROR opening socket");
    }
 
    server = gethostbyname(hostname);
 
    if (server == NULL) {
        close(sockfd);
        return unexpected("ERROR, no such host");
    }
 
    bzero((char *) &serv_addr, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    bcopy((char *)server->h_addr,
         (char *)&serv_addr.sin_addr.s_addr,
         server->h_length);
 
    serv_addr.sin_port = htons(portno);
    if (connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0) {
        ret = false;
    } else {
        ret = true;
    }
 
    close(sockfd);
    return ret;
}

string to_id_format(const string& s){
    string new_s = s;

   // transform(new_s.begin(), new_s.end(), new_s.begin(),
   // [](unsigned char c){ return std::tolower(c); });

    replace( new_s.begin(), new_s.end(), ' ',  '-'); 

    return new_s;
}

string loadFile(const string& path) {
    ifstream f(path);
    stringstream buffer;
    buffer << f.rdbuf();
    return buffer.str();
}

std::filesystem::path getDataDir(){
    return std::getenv("XDG_DATA_HOME") 
    ? std::filesystem::path(std::getenv("XDG_DATA_HOME")) / APPLICATION_NAME 
    : std::filesystem::path(std::getenv("HOME")) / ".local" / "share" / APPLICATION_NAME;
}

std::string urlDecode(const std::string& str) {
    std::ostringstream decoded;
    for (size_t i = 0; i < str.length(); ++i) {
        if (str[i] == '%' && i + 2 < str.length()) {
            std::istringstream hex_stream(str.substr(i + 1, 2));
            int hex = 0;
            if (hex_stream >> std::hex >> hex) {
                decoded << static_cast<char>(hex);
                i += 2;
            } else {
                decoded << '%'; // malformed encoding, keep as-is
            }
        } else if (str[i] == '+') {
            decoded << ' '; // '+' is often used for spaces in form-encoding
        } else {
            decoded << str[i];
        }
    }
    return decoded.str();
}

string currentTime(){
    auto now = std::chrono::system_clock::now();
    std::time_t t = std::chrono::system_clock::to_time_t(now);
    std::stringstream ss;
    ss << std::put_time(std::gmtime(&t), "%Y-%m-%d %H:%M:%S");
    return ss.str();
}

std::string read_file(const std::string& path) {
    std::ifstream file(path, std::ios::binary);
    if (!file) {
        throw std::runtime_error("Cannot open file: " + path);
    }
    std::ostringstream ss;
    ss << file.rdbuf();
    return ss.str();
}

// Simple MIME type detection
std::string get_mime_type(const std::string& path) {
    if (path.ends_with(".html")) return "text/html";
    if (path.ends_with(".js")) return "text/javascript";
    if (path.ends_with(".css")) return "text/css";
    if (path.ends_with(".json")) return "application/json";
    if (path.ends_with(".svg")) return "image/svg+xml";
    if (path.ends_with(".png")) return "image/png";
    if (path.ends_with(".jpg") || path.ends_with(".jpeg")) return "image/jpeg";
    if (path.ends_with(".woff")) return "font/woff";
    if (path.ends_with(".woff2")) return "font/woff2";
    if (path.ends_with(".pdf")) return "application/pdf";
    return "application/octet-stream";
}

crow::response getFile(const filesystem::path& file_path){
    // If file exists, serve it
    if (filesystem::exists(file_path)) {
        auto data = read_file(file_path);
        auto mime = get_mime_type(file_path.string());
        return crow::response(200, mime.c_str(), data);
    }

    // SPA fallback: serve root index.html for unknown routes
    filesystem::path fallback = build_dir / "index.html";
    auto data = read_file(fallback);
    return crow::response(404, "text/html", data);
}

std::expected<nlohmann::json, std::string> parseJson(const std::string& input) {
    try {
        return nlohmann::json::parse(input);
    }
    catch (const nlohmann::json::exception& e) {
        return std::unexpected(e.what());
    }
}
}