#include "kappa/system/activate.hpp"

#include <filesystem>
#include <format>
#include <fstream>

namespace kappa::system {

ActivateResult write_hostname(const std::string& hostname,
                              std::string_view prefix) {
    if (hostname.empty()) {
        return {false, "hostname is empty"};
    }

    std::filesystem::path path = std::filesystem::path(prefix) / "etc/hostname";
    std::error_code ec;
    std::filesystem::create_directories(path.parent_path(), ec);
    if (ec) {
        return {false, std::format("cannot create {}: {}", path.parent_path().string(), ec.message())};
    }

    std::ofstream out(path);
    if (!out) {
        return {false, std::format("cannot write {}", path.string())};
    }
    out << hostname << "\n";
    return {true, {}};
}

ActivateResult write_timezone(const std::string& timezone,
                              std::string_view prefix) {
    if (timezone.empty()) {
        return {false, "timezone is empty"};
    }

    // /etc/localtime is a symlink to /usr/share/zoneinfo/{timezone}
    std::filesystem::path localtime = std::filesystem::path(prefix) / "etc/localtime";
    std::filesystem::path zoneinfo  = std::filesystem::path(prefix) / "usr/share/zoneinfo" / timezone;

    std::error_code ec;
    if (!std::filesystem::exists(zoneinfo, ec)) {
        return {false, std::format("timezone data not found: {}", zoneinfo.string())};
    }

    std::filesystem::create_directories(localtime.parent_path(), ec);
    // Remove existing symlink/file if present
    std::filesystem::remove(localtime, ec);
    std::filesystem::create_symlink(zoneinfo, localtime, ec);
    if (ec) {
        return {false, std::format("cannot create symlink {}: {}", localtime.string(), ec.message())};
    }
    return {true, {}};
}

} // namespace kappa::system