#include <crow.h>
#include <fstream>
#include <sstream>
#include <cstdlib>
#include <string>
#include <array>
#include <format>
#include <optional>

using namespace std;

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

bool is_service_active(string_view service_name) {
    const string cmd = format("systemctl is-active --quiet {}", service_name);
    return system(cmd.c_str()) == 0;
}

bool is_service_enabled(string_view service_name) {
    const string cmd = format("systemctl is-enabled --quiet {}", service_name);
    return system(cmd.c_str()) == 0;
}

void toggle_service(string_view serviceName){
    string_view toggle = is_service_active(serviceName) ? "stop" : "start";
    const string cmd = format("systemctl {} {}", toggle, serviceName);
    system(cmd.c_str());
}

string_view get_button_class(bool isActive) {
    return isActive ? "active-button" : "inactive-button";
}

optional<string> get_body_name(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;
}

string create_htmx_button(string_view endpoint, string_view serviceName, string_view text) {
    return format( 
        "<td>\
            <button\
                hx-post=\"{}\"\
                hx-vals='{{\"name\":\"{}\"}}'\
                hx-target=\"closest tr\"\
                hx-swap=\"outerHTML\">\
                {} \
            </button> \
        </td>", endpoint, serviceName, text);
}

string create_htmx_table_row(string_view serviceName){
    const bool isRunning = is_service_active(serviceName);
    const bool isEnabled = is_service_active(serviceName);

    const auto running = isRunning ? "Running" : "Stopped";
    const auto enabled = isEnabled ? "Enabled" : "Disabled";

    // create status indicators 
    string html = format(
        "<tr>\
            <td>{}</td>\
            <td class='{}'>{}</td>\
            <td class='{}'>{}</td>", 
            serviceName, get_button_class(isRunning), running, get_button_class(isEnabled), enabled);

    // create buttons 
    html += create_htmx_button("/toggle-service", serviceName, isRunning ? "Stop" : "Start");
    html += create_htmx_button("/enable-service", serviceName, isEnabled ? "Disable" : "Enable"); 
    html += create_htmx_button("/restart-service", serviceName, "Restart"); 
    return html;
}

const array<string, 1>& get_service_names() {
    static const array<string, 1> arr = {
        "cups.service"
    }; 
    return arr;
}

int main() {
    crow::SimpleApp app;

    CROW_ROUTE(app, "/")([] {
        return crow::response(load_file("templates/index.html"));
    });

    CROW_ROUTE(app, "/static/<string>")([](const std::string& file) {
        return crow::response(load_file("static/" + file));
    });

    CROW_ROUTE(app, "/status")([] {
        auto names = get_service_names();

        // define the table header 
        string html = "<table><tr>\
                        <th>Service</th>\
                        <th>Status</th>\
                        <th>State</th>\
                    </tr>";

        // display each service as an entry
        for (auto& serviceName : names) {
            html += create_htmx_table_row(serviceName);
        }
        html += " </tr></table>";
        return crow::response{html};
    });

    CROW_ROUTE(app, "/toggle-service").methods(crow::HTTPMethod::Post)([](const crow::request& req) {
        auto body = get_body_name(req.body);
        if (!body.has_value())
            return crow::response(400);
    
        const string& serviceName = body.value();
    
        toggle_service(serviceName);  

        const string html = create_htmx_table_row(serviceName);
        return crow::response{html};
    });    

    app.port(8080).multithreaded().run();
}