use axum::{Json, Router, extract::State, routing::get};
use clap::Parser;
use native_tls::TlsConnector;
use printstats::*;
use reqwest::Client;
use rumqttc::{AsyncClient, Event, MqttOptions, Packet, QoS, Transport};
use std::collections::HashMap;
use std::fs;
use std::process;
use std::sync::Arc;
use std::sync::RwLock;
use std::time::Duration;
use tracing::{debug, error, info, warn};

type StateMap = Arc<RwLock<HashMap<String, PrinterState>>>;

#[derive(Parser, Debug)]
#[command(about = "Print statistics scraper")]
struct Args {
    /// Path to the configuration file
    #[arg(long, default_value = "config.toml")]
    config: String,

    /// Address to bind the HTTP server to
    #[arg(long, default_value = "0.0.0.0:3000")]
    bind: String,
}

#[tokio::main]
async fn main() {
    tracing_subscriber::fmt::init();

    let args = Args::parse();
    let content = fs::read_to_string(&args.config).unwrap_or_else(|e| {
        error!(path = %args.config, error = %e, "Failed to read config file");
        process::exit(1);
    });
    let config = Config::load(&content).unwrap_or_else(|e| {
        error!(path = %args.config, error = %e, "Failed to parse config file");
        process::exit(1);
    });
    let state: StateMap = Arc::new(RwLock::new(HashMap::new()));
    for printer in config.printers {
        let state = state.clone();
        match printer {
            Printer::Prusa {
                name,
                host,
                api_key,
            } => {
                info!(name, host, "Found Prusa");
                tokio::spawn(async move {
                    match tokio::spawn(poll_prusa(name.clone(), host, api_key, state)).await {
                        Ok(()) => warn!(name, "Prusa polling task exited unexpectedly"),
                        Err(e) => error!(name, error = ?e, "Prusa polling task panicked"),
                    }
                });
            }
            Printer::Bambu {
                name,
                host,
                serial_number,
                access_code,
            } => {
                info!(name, host, "Found Bambu");
                tokio::spawn(async move {
                    match tokio::spawn(poll_bambu(
                        name.clone(),
                        host,
                        serial_number,
                        access_code,
                        state,
                    ))
                    .await
                    {
                        Ok(()) => warn!(name, "Bambu polling task exited unexpectedly"),
                        Err(e) => error!(name, error = ?e, "Bambu polling task panicked"),
                    }
                });
            }
        }
    }

    let app = Router::new().route("/", get(root)).with_state(state);

    let listener = tokio::net::TcpListener::bind(&args.bind)
        .await
        .unwrap_or_else(|e| {
            error!(addr = %args.bind, error = %e, "Failed to bind to address");
            process::exit(1);
        });
    info!(addr = %args.bind, "Listening");
    axum::serve(listener, app).await.unwrap_or_else(|e| {
        error!(error = %e, "HTTP server error");
        process::exit(1);
    });
}

async fn fetch_prusa(
    client: &Client,
    name: &str,
    host: &str,
    api_key: &str,
    state: &StateMap,
) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    let response = client
        .get(format!("http://{}/api/v1/status", host))
        .header("X-Api-Key", api_key)
        .send()
        .await?
        .json::<PrusaStatus>()
        .await?;
    let mut lock = state.write().unwrap();
    lock.entry(name.to_owned())
        .or_default()
        .update_from(&response);
    Ok(())
}

async fn poll_prusa(name: String, host: String, api_key: String, state: StateMap) {
    let client = Client::builder()
        .timeout(Duration::from_secs(10))
        .build()
        .unwrap_or_else(|e| {
            error!(name, error = %e, "Failed to build HTTP client");
            process::exit(1);
        });
    loop {
        if let Err(e) = fetch_prusa(&client, &name, &host, &api_key, &state).await {
            error!(name, error = %e, "Error polling Prusa printer");
        }
        tokio::time::sleep(Duration::from_secs(5)).await;
    }
}

async fn poll_bambu(
    name: String,
    host: String,
    serial_number: String,
    access_code: String,
    state: StateMap,
) {
    let mut mqttoptions = MqttOptions::new(&name, &host, 8883);
    mqttoptions.set_keep_alive(Duration::from_secs(5));
    mqttoptions.set_credentials("bblp", &access_code);

    // Bambu printers use TLS with a self-signed certificate
    let connector = match TlsConnector::builder()
        .danger_accept_invalid_certs(true)
        .build()
    {
        Ok(c) => c,
        Err(e) => {
            error!(name, error = %e, "Failed to build TLS connector");
            process::exit(1);
        }
    };
    mqttoptions.set_transport(Transport::tls_with_config(connector.into()));

    let (client, mut eventloop) = AsyncClient::new(mqttoptions, 10);

    loop {
        // eventloop.poll() yields back to Tokio when there's no data
        match eventloop.poll().await {
            Ok(Event::Incoming(Packet::ConnAck(_))) => {
                if let Err(e) = client
                    .subscribe(format!("device/{}/report", serial_number), QoS::AtMostOnce)
                    .await
                {
                    error!(name, error = %e, "Failed to subscribe to Bambu MQTT topic");
                }
                // Send a request to push all values to us; otherwise we'll have to wait for the values to come in incremental updates.
                if let Err(e) = client
                    .publish(
                        format!("device/{}/request", serial_number),
                        QoS::AtMostOnce,
                        false,
                        serde_json::json!({
                            "pushing": {
                                "sequence_id": "0",
                                "command": "pushall",
                                "version": 1,
                                "push_target": 1
                            }
                        })
                        .to_string(),
                    )
                    .await
                {
                    error!(name, error = %e, "Failed to send pushall to Bambu printer");
                }
            }
            Ok(Event::Incoming(Packet::Publish(p))) => {
                debug!(payload = ?p.payload, "Received Bambu payload");
                match serde_json::from_slice::<BambuStatus>(&p.payload) {
                    Ok(msg) => {
                        let mut lock = state.write().unwrap();
                        lock.entry(name.clone()).or_default().update_from(&msg);
                        debug!(name, "Updated state");
                    }
                    Err(e) => error!(error = %e, "Failed to deserialize BambuStatus"),
                }
            }
            Ok(_) => {}
            Err(e) => {
                error!(error = ?e, "MQTT error");
                tokio::time::sleep(Duration::from_secs(5)).await; // Simple retry
            }
        }
    }
}

async fn root(State(state): State<StateMap>) -> Json<HashMap<String, PrinterState>> {
    Json(state.read().unwrap().clone())
}