// src/main.rs
use std::{fs, time::Duration};
use reqwest::header::{HeaderMap, HeaderValue, AUTHORIZATION};
use serde::{Serialize, Deserialize};
use std::process::Command;
use std::sync::{Arc};
use axum::{routing::post, routing::get, routing::delete, Json, Router, http::Method, extract::State, http::{Request, StatusCode},middleware::Next,response::Response,};
use tokio::task;
use tokio::time::{self, interval};
use tokio::sync::Mutex as AsyncMutex;
use clap::{Parser, Subcommand};
use reqwest;
use chrono::{DateTime, Utc};
use tower_http::cors::{Any, AllowOrigin, CorsLayer};
use inquire::{Text, Password};
use rand::{thread_rng, RngCore};
use base64::{engine::general_purpose, Engine as _};
use axum::extract::ConnectInfo;
use std::net::SocketAddr;

#[derive(Deserialize)]
struct DeleteRequest {
    service_id: i32,
}

#[derive(Parser)]
#[command(name = "nodecli")]
#[command(about = "CLI to config node", long_about = None)]
struct Cli {
    #[command(subcommand)]
    command: Option<Commands>,
}

#[derive(Subcommand, Debug)]
enum Commands {
    Config,
    Start,
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct StatusRecord {
    pub timestamp: DateTime<Utc>,
    pub status: u8,
}

impl Default for StatusRecord {
    fn default() -> Self {
        StatusRecord {
            timestamp: Utc::now(),
            status: 0,
        }
    }
}

#[derive(Debug, Serialize, Deserialize, Clone)]
struct ProcessConfig {
    #[serde(default)]
    id: i32,
    name: String,
    command: String,
}

#[derive(Debug, Serialize, Deserialize)]
struct ConfigData {
    server_url : String,
    node_name : String,
    node_url : String,
    api_key : String,
}

#[derive(Debug, Serialize, Deserialize)]
struct FileData {
    node_id: i32,
    processes: Vec<ProcessConfig>,
}

static PROCESSES_FILE: &str = "processes.json";
static CONFIG_FILE: &str = "config.json";

async fn list_processes(state: axum::extract::State<AppState>) -> Json<Vec<ProcessConfig>> {
    let guard = state.processes.lock().await;
    Json(guard.clone())
}

#[derive(Clone)]
struct AppState {
    server_url : Arc<AsyncMutex<String>>,
    node_name : Arc<AsyncMutex<String>>,
    node_url : Arc<AsyncMutex<String>>,
    api_key : Arc<AsyncMutex<String>>,
    node_id: Arc<AsyncMutex<i32>>,
    processes: Arc<AsyncMutex<Vec<ProcessConfig>>>,
    current_api_key: Arc<AsyncMutex<ApiKey>>,
}

#[derive(Serialize)]
struct RegistrationRequest {
    id: i32,
    name: String,
    address: String,
}

#[derive(Serialize)]
struct RegistrationServiceRequest {
    node_id: i32,
    service: ProcessConfig,
}

#[derive(Deserialize)]
struct RegisterResponse {
    id: i32,
}

#[derive(Serialize)]
struct ServiceUpdateRequest {
    service_id: i32,
    service_status: StatusRecord,
}

#[derive(Serialize)]
struct UpdateRequest {
    node_id: String,
    #[serde(default)]
    services: Vec<ServiceUpdateRequest>,
}

#[derive(Clone)]
struct ApiKey {
    key: Arc<AsyncMutex<Option<String>>>,
    timestamp_end: Arc<AsyncMutex<DateTime<Utc>>>
}

fn generate_secure_api_key() -> String {
    let mut key_bytes = [0u8; 32];
    thread_rng().fill_bytes(&mut key_bytes);
    general_purpose::URL_SAFE_NO_PAD.encode(key_bytes)
}

async fn run_api_key_creation(
    ConnectInfo(addr): ConnectInfo<SocketAddr>,
    state: axum::extract::State<AppState>,
) -> Result<String, StatusCode> {
    if !addr.ip().is_loopback() {
        println!("Error access denied");
        return Err(StatusCode::FORBIDDEN); 
    }

    {
        let mut current_api_key= state.current_api_key.lock().await;

        let mut key_guard = current_api_key.key.lock().await;
        *key_guard = Some(generate_secure_api_key());

        let mut time_guard = current_api_key.timestamp_end.lock().await;
        *time_guard = Utc::now() + chrono::Duration::minutes(30);

        if let Some(ref k) = *key_guard {
            println!("Api enabled for 30min. Key: {}", k);
            Ok(k.to_string())
        } else {
            println!("No key generated.");
            return Err(StatusCode::FORBIDDEN);
        }
    }
}

fn run_config_wizard() {
    println!("--- NodeCLI Configuration ---");

    let serveur_url = Text::new("The url of the server :" )
        .with_placeholder("ex: http://<addess>:<port>")
        .prompt();

    let node_name = Text::new("The name of this node : ")
        .with_placeholder("ex: http://<addess>:<port>")
        .prompt();

    let node_url = Text::new("url of this node : ")
        .with_placeholder("ex: http://<addess>:<port>")
        .prompt();

    let api_key = Password::new("The API key of the node:")
        .with_display_mode(inquire::PasswordDisplayMode::Masked)
        .prompt();

    match (serveur_url, node_name, node_url, api_key) {
        (Ok(s), Ok(n), Ok(nu), Ok(a)) => {
            println!("\n✅ Configuration saved !");
            println!("Server url : {}", s);
            println!("Node name: {}", n);
            println!("Node name: {}", nu);
            println!("API key : **** (longueur: {})", a.len());

            save_config_to_disk(&ConfigData{ server_url: s, node_name: n, node_url : nu, api_key: a })
        }
        _ => println!("\n❌ Configuration canceled."),
    }
}

async fn add_process(
    state: axum::extract::State<AppState>,
    Json(payload): Json<ProcessConfig>,
) -> Json<String> {
    let mut vec_guard= state.processes.lock().await.clone();
    let id_guard = state.node_id.lock().await.clone();
    let server_url = state.server_url.lock().await.clone();
    let api_key = state.api_key.lock().await.clone();

    let mut new_process = payload.clone();

    let client = reqwest::Client::new();
    let request_payload = RegistrationServiceRequest {
        node_id: id_guard.clone(),
        service: new_process.clone(),
    };

    let mut headers = HeaderMap::new();

    headers.insert(
        "X-Node-API-Key", 
        HeaderValue::from_str(&*api_key).expect("Invalid API Key format")
    );
    
    match client
        .post(format!("{}/api/registerService", server_url))
        .headers(headers)
        .json(&request_payload)
        .send()
        .await
    {
        Ok(response) => {
            if response.status().is_success() {
                match response.json::<RegisterResponse>().await {
                    Ok(data) => {
                        new_process.id = data.id;
                        vec_guard.push(new_process.clone());
                        save_processes_to_disk(&FileData { node_id: data.id, processes: vec_guard.clone() });

                        return Json(format!("✅ Enregistrement réussi. ID du service attribué : {}", data.id));
                    }
                    Err(_) => { return Json(format!("Process error on json received")); },
                }
            } else {
                return Json(format!("⚠️ Échec de l'enregistrement, statut: {}", response.status())); 
            }
        }
        Err(e) => {
            return Json(format!("❌ Impossible de joindre le serveur Go : {}. Nouvelle tentative dans 5s...", e)); 
        }
    }
}

async fn delete_service(
    state: axum::extract::State<AppState>,
    Json(payload): Json<DeleteRequest>,
) -> impl axum::response::IntoResponse {

    let mut guard = state.processes.lock().await.clone();
    let id_guard= state.node_id.lock().await.clone();
    let service_id = payload.service_id;

    let index_to_remove = guard.iter().position(|service| {
        service.id == service_id
    });



    match index_to_remove {
        Some(index) => {
            let removed_service = guard.remove(index);
            
            println!("Service supprimé avec succès: {}", removed_service.name);

            save_processes_to_disk(&FileData { node_id: id_guard.clone(), processes: guard.clone() });

            return axum::http::StatusCode::NO_CONTENT;
        }
        None => {
            println!("Erreur: Service ID {} non trouvé.", service_id);

            return axum::http::StatusCode::NOT_FOUND;
        }
    }
}

async fn register_with_server(state: AppState) {

    let mut id_guard: tokio::sync::MutexGuard<'_, i32> = state.node_id.lock().await;
    let guard = state.processes.lock().await;
    let server_url: tokio::sync::MutexGuard<'_, String> = state.server_url.lock().await;
    let node_url: tokio::sync::MutexGuard<'_, String> = state.node_url.lock().await;
    let node_name: tokio::sync::MutexGuard<'_, String> = state.node_name.lock().await;
    let api_key: tokio::sync::MutexGuard<'_, String> = state.api_key.lock().await;

    let address_full = format!( "{}", node_url );

    eprintln!("full ip is {}", address_full);

    let client = reqwest::Client::new();
    let payload = RegistrationRequest {
        id: id_guard.clone(),
        name: node_name.to_string(),
        address: address_full,
    };

    let mut headers = HeaderMap::new();
    headers.insert(
        "X-Node-API-Key", 
        HeaderValue::from_str(&*api_key).expect("Invalid API Key format")
    );

    loop {
        match client
            .post(format!("{}/api/register", server_url))
            .headers(headers.clone())
            .json(&payload)
            .send()
            .await
        {
            Ok(response) => {
                if response.status().is_success() {
                    match response.json::<RegisterResponse>().await {
                        Ok(data) => {
                            println!("✅ Enregistrement réussi. ID du node attribué : {}", data.id);
                            *id_guard = data.id;

                            save_processes_to_disk(&FileData { node_id: data.id, processes: guard.clone() });
                        }
                        Err(_) => eprintln!("⚠️ Réponse réussie mais format JSON invalide"),
                    }
                    break;
                } else {
                    eprintln!("⚠️ Échec de l'enregistrement, statut: {}", response.status());
                }
            }
            Err(e) => {
                eprintln!("❌ Impossible de joindre le serveur Go : {}. Nouvelle tentative dans 5s...", e);
            }
        }
        time::sleep(Duration::from_secs(5)).await;
    }

}

fn save_config_to_disk(data: &ConfigData) {
    let json = serde_json::to_string_pretty(&data).unwrap();
    fs::write(CONFIG_FILE, json).unwrap();
}

fn initialize_config_file() {

    if !std::path::Path::new(CONFIG_FILE).exists() {
        println!("No {} found, creating an empty one...", CONFIG_FILE);
        std::fs::write(CONFIG_FILE.to_string(), "[]").expect("Failed to create config.json");
    }
    else
    {
        println!("{} found", CONFIG_FILE);
    }
}

fn load_config_from_disk() -> ConfigData{
    if let Ok(content) = fs::read_to_string(CONFIG_FILE) {
        if let Ok(parsed) = serde_json::from_str::<ConfigData>(&content) {
            return parsed;
        }
    }
    ConfigData{ server_url: "".to_string(), node_name: "".to_string(), node_url : "".to_string(), api_key:"".to_string() }
}

fn save_processes_to_disk(data: &FileData) {
    let json = serde_json::to_string_pretty(&data).unwrap();
    fs::write(PROCESSES_FILE, json).unwrap();
}

fn initialize_processes_file() {

    if !std::path::Path::new(PROCESSES_FILE).exists() {
        println!("No processes.json found, creating an empty one...");
        std::fs::write(PROCESSES_FILE, "[]").expect("Failed to create processes.json");
    }
    else
    {
        println!("{} found", PROCESSES_FILE);
    }
}

fn load_processes_from_disk() -> FileData{
    if let Ok(content) = fs::read_to_string(PROCESSES_FILE) {
        if let Ok(parsed) = serde_json::from_str::<FileData>(&content) {
            return parsed;
        }
    }
    FileData{ node_id: 0, processes: vec![] }
}

fn check_process_running(cmd: &str) -> bool {
    let output_result = Command::new("sh").arg("-c").arg(cmd).output();

    match output_result {
        Ok(output) => {
            if !output.status.success() {
                let stdout_str = match str::from_utf8(&output.stderr) {
                    Ok(s) => s,
                    Err(_) => "",
                };

                println!("error: {}",stdout_str.to_string());

                return false;
            }

            let stdout_str = match str::from_utf8(&output.stdout) {
                Ok(s) => s.trim(),
                Err(_) => {
                    return false;
                }
            };

            println!("result: {}",stdout_str.to_string());

            if stdout_str == "1" {
                return true;
            } else if stdout_str == "0" {
                return false;
            } else {
                return false;
            }
        }
        Err(_) => {
            return false;
        }
    }
}

async fn start_monitor(state: AppState) {

    println!("Monitoring started");

    let mut interval = interval(Duration::from_mins(1) );
    interval.tick().await;

    let node_name= state.node_name.lock().await.clone();
    let server_url= state.server_url.lock().await.clone();
    let api_key= state.api_key.lock().await.clone();

    let mut headers = HeaderMap::new();
    headers.insert(
        "X-Node-API-Key", 
        HeaderValue::from_str(&api_key).unwrap()
    );

    loop {
        {
            interval.tick().await;

            let mut update_request = UpdateRequest{ node_id: node_name.to_string(), services: Vec::new() };

            let mut guard = state.processes.lock().await;
            println!("--- Checking processes ---");
            for p in guard.iter_mut() {
                let running = check_process_running(&p.command);
                println!("{} => {}", p.name, if running { "RUNNING" } else { "STOPPED" });
                
                let mut status = StatusRecord{ status: 0, timestamp: Utc::now() };
                if running == true {
                    status.status = 1;
                }

                update_request.services.push(ServiceUpdateRequest{ service_id: p.id.clone(), service_status: status.clone() });
            }

            if update_request.services.len() > 0 {
                let client = reqwest::Client::new();
                let payload = update_request;

                match client
                    .post(format!("{}/api/updateServiceStatus", server_url ))
                    .headers(headers.clone())
                    .json(&payload)
                    .send()
                    .await
                {
                    Ok(response) => {
                        if response.status().is_success() {
                            println!("✅ Update success");
                        } else {
                            eprintln!("⚠️ Update failed {}", response.status());
                        }
                    }
                    Err(e) => {
                        eprintln!("❌ Error : {}", e);
                    }
                }
            }
        }
    }
}

async fn api_key_auth(
    State(state): State<ApiKey>,
    req: axum::http::Request<axum::body::Body>,
    next: Next,
) -> Result<Response, StatusCode> {

    let auth_header = req.headers()
        .get("X-Node-API-Key")
        .and_then(|val| val.to_str().ok());

    let (valid_key, timestamp_end) = {
        let key_guard = state.key.lock().await;
        let time_guard = state.timestamp_end.lock().await;
        (key_guard.clone(), *time_guard)
    };

    match valid_key.clone() {
        Some(valeur) => println!("La clé est : {}", valeur),
        None => println!("Il n'y a pas de clé !"),
    }

    match auth_header.clone() {
        Some(s) => println!("Checking api key : {}", s), // s est un &str
        None => println!("Empty API key"),
    }

    match (auth_header, valid_key) {
        (Some(sent_key), Some(stored_key)) 
            if sent_key == stored_key && chrono::Utc::now() < timestamp_end => 
        {
            // Tout est bon, on passe à la suite (la fonction add_process)
            println!("api key valid");
            Ok(next.run(req).await)
        }
        _ => {
            println!("Error api key not valid");
            Err(StatusCode::UNAUTHORIZED)
        }
    }
}

#[tokio::main]
async fn main() {
    initialize_processes_file();
    initialize_config_file();

    let initial_process = load_processes_from_disk();

    println!("initial node_id: {}", initial_process.node_id);

    let initial_config = load_config_from_disk();

    println!("server url: {}", initial_config.server_url);

    let cli = Cli::parse();

    if let Some(Commands::Config) = &cli.command {
        run_config_wizard(); 
        println!("Configuration terminée. Relancez sans argument pour démarrer le service.");
        return; 
    }

    let api_key_state = ApiKey {
        key: Arc::new(AsyncMutex::new(None)),
        
        timestamp_end: Arc::new(AsyncMutex::new(Utc::now())),
    };

    let mut state = AppState {
        server_url: Arc::new(AsyncMutex::new(initial_config.server_url)),
        node_name: Arc::new(AsyncMutex::new(initial_config.node_name)), 
        node_url: Arc::new(AsyncMutex::new(initial_config.node_url)),
        api_key: Arc::new(AsyncMutex::new(initial_config.api_key)),
        node_id: Arc::new(AsyncMutex::new(initial_process.node_id)),
        processes: Arc::new(AsyncMutex::new(initial_process.processes)),
        current_api_key : Arc::new(AsyncMutex::new(api_key_state.clone())),
    };

    if let Some(Commands::Start) = &cli.command {
        let client = reqwest::Client::new();
        match client.post("http://localhost:8081/internal/generate-key").send().await {
            Ok(response) => {
                if let Ok(key) = response.text().await {
                    println!("🔑 Clé générée avec succès : {}", key);
                }
            },
            Err(_) => {
                println!("❌ Erreur : Impossible de joindre le service Node.");
                println!("Vérifiez que 'nodecli start' est bien en cours d'exécution.");
            }
        }
        return;
    }

    let state_register = state.clone();
    tokio::task::spawn(async move {
        tokio::time::sleep(tokio::time::Duration::from_millis(100)).await; 
        
        register_with_server(state_register).await;
    });

    let state_monitor = state.clone();
    task::spawn(async move {
        start_monitor(state_monitor).await;
    });

    let state_for_cors = state.clone();

    let cors = CorsLayer::new()
        .allow_origin(AllowOrigin::predicate(move |origin: &axum::http::HeaderValue, _parts: &axum::http::request::Parts| {
            // Lecture du state de manière synchrone pour le CORS
            let server_url = futures::executor::block_on(async {
                state_for_cors.server_url.lock().await.clone()
            });

            // Comparaison (on vérifie si l'origine correspond à notre URL de config)
            origin.as_bytes() == server_url.as_bytes()
        }))
        .allow_methods([Method::GET, Method::POST, Method::DELETE, Method::OPTIONS])
        .allow_headers(Any);

    let app = Router::new()
    .route(
            "/add", 
            post(add_process).route_layer(axum::middleware::from_fn_with_state(api_key_state, api_key_auth))
        )
    .route("/list", get(list_processes))
    .route("/services", delete(delete_service))  
    .route("/internal/generate-key", post(run_api_key_creation))  
    .with_state(state)
    .layer(cors);

    let listener = tokio::net::TcpListener::bind("0.0.0.0:8081").await.unwrap();

    println!("Node service running on port 8081");

    axum::serve(
        listener, 
        app.into_make_service_with_connect_info::<SocketAddr>()
    )
    .await
    .unwrap();

}