#include "relayconf.h"

#include <algorithm>
#include <cstdlib>
#include <fstream>
#include <sstream>
#include <string>

namespace wg {

static std::string trim(const std::string &s) {
    const char *ws = " \t\r\n";
    size_t start = s.find_first_not_of(ws);
    if (start == std::string::npos) return {};
    size_t end = s.find_last_not_of(ws);
    return s.substr(start, end - start + 1);
}

bool parseRelayConf(const std::string &path, RelayConf &conf, std::string &errOut) {
    std::ifstream file(path);
    if (!file.is_open()) {
        errOut = "Cannot open relay.conf: " + path;
        return false;
    }

    std::string line;
    int lineNum = 0;

    while (std::getline(file, line)) {
        ++lineNum;
        std::string trimmed = trim(line);

        // Skip blank lines and comments
        if (trimmed.empty() || trimmed[0] == '#') continue;

        size_t eq = trimmed.find('=');
        if (eq == std::string::npos) {
            errOut = "relay.conf line " + std::to_string(lineNum) + ": missing '='";
            return false;
        }

        std::string key   = trim(trimmed.substr(0, eq));
        std::string value = trim(trimmed.substr(eq + 1));

        if (key == "server_address")    conf.server_address    = value;
        else if (key == "private_key")  conf.private_key       = value;
        else if (key == "server_public_key") conf.server_public_key = value;
        else if (key == "relay_token")  conf.relay_token       = value;
        else if (key == "relay_host")   conf.relay_host        = value;
        else if (key == "server_port") {
            try { conf.server_port = std::stoi(value); }
            catch (...) {
                errOut = "relay.conf line " + std::to_string(lineNum) + ": invalid server_port";
                return false;
            }
        }
        else if (key == "relay_port") {
            try { conf.relay_port = std::stoi(value); }
            catch (...) {
                errOut = "relay.conf line " + std::to_string(lineNum) + ": invalid relay_port";
                return false;
            }
        }
        // Unknown keys are silently ignored for forward compatibility
    }

    // Validate required fields
    if (conf.server_address.empty()) { errOut = "relay.conf: missing server_address"; return false; }
    if (conf.private_key.empty())    { errOut = "relay.conf: missing private_key";    return false; }
    if (conf.server_public_key.empty()) { errOut = "relay.conf: missing server_public_key"; return false; }
    if (conf.relay_token.empty())    { errOut = "relay.conf: missing relay_token";    return false; }

    // Default relay_host from server_address if not set
    if (conf.relay_host.empty()) {
        conf.relay_host = "https://" + conf.server_address;
    }

    return true;
}

std::string defaultRelayConfPath() {
#ifdef _WIN32
    const char *pd = std::getenv("PROGRAMDATA");
    std::string base = pd ? pd : "C:\\ProgramData";
    return base + "\\Artemis\\relay.conf";
#else
    return "/etc/artemis/relay.conf";
#endif
}

} // namespace wg