#![feature(let_chains)]

use clap::Parser;
use futures::StreamExt;
use std::path::PathBuf;

mod config;

#[derive(clap::Parser, Debug, Clone)]
#[clap(author, version, about, long_about = None)]
struct Args {
    #[command(subcommand)]
    command: Commands,
    #[clap(long, default_value = "/etc/charge-controller-supervisor/config.json")]
    config: PathBuf,
}

#[derive(clap::Subcommand, Debug, Clone)]
enum Commands {
    /// Run charge controller server
    Watch,
    /// Print the default config file
    GenerateConfig,
}

mod controller;
mod gauges;
mod pl;
mod tristar;

mod web;

pub const CHARGE_CONTROLLER_LABEL: &str = "charge_controller";
pub const PL_LABEL: &str = "pl_device";
pub const TRISTAR_LABEL: &str = "tristar_device";

#[tokio::main]
async fn main() {
    env_logger::builder()
        .format_module_path(false)
        .format_timestamp(
            if std::env::var("LOG_TIMESTAMP").is_ok_and(|v| v == "false") {
                None
            } else {
                Some(env_logger::TimestampPrecision::Seconds)
            },
        )
        .init();

    if let Err(e) = run().await {
        log::error!("{e:?}");
        std::process::exit(1);
    }
}

async fn run() -> eyre::Result<()> {
    let args = Args::parse();

    match args.command {
        Commands::Watch => watch(args).await,
        Commands::GenerateConfig => {
            let config = config::ConfigStorage::default();
            let json = serde_json::to_string_pretty(&config)?;
            println!("{json}");
            Ok(())
        }
    }
}

async fn watch(args: Args) -> eyre::Result<()> {
    let _w = config::init_config(&args.config);
    let (map, follow_voltage_tx, mut controller_tasks) = {
        let config = config::access_config().await;
        if config
            .charge_controllers
            .iter()
            .any(|cc| cc.follow_primary && cc.name == config.primary_charge_controller)
        {
            return Err(eyre::eyre!(
                "primary charge controller is set to follow primary!"
            ));
        }

        let mut controllers = Vec::new();
        let mut map = std::collections::HashMap::new();
        let mut follow_voltage_tx = Vec::new();

        for config in &config.charge_controllers {
            let n = config.name.clone();
            match controller::Controller::new(config.clone()) {
                Ok((v, voltage_tx)) => {
                    map.insert(n, v.get_data_ptr());
                    controllers.push(v);
                    if let Some(voltage_tx) = voltage_tx {
                        follow_voltage_tx.push(voltage_tx);
                    }
                }
                Err(e) => log::error!("couldn't connect to {}: {e:?}", n),
            }
        }

        let follow_voltage_tx = controller::MultiTx(follow_voltage_tx);

        if let Some(primary) = controllers
            .iter_mut()
            .find(|c| c.name() == config.primary_charge_controller)
        {
            primary.set_tx_to_secondary(follow_voltage_tx.clone());
        }

        let controller_tasks = futures::stream::FuturesUnordered::new();
        for controller in controllers {
            controller_tasks.push(run_loop(controller));
        }

        (map, follow_voltage_tx, controller_tasks)
    };

    let server = web::rocket(web::ServerState::new(
        &config::access_config().await.primary_charge_controller,
        map,
        follow_voltage_tx,
    ));
    let server_task = tokio::task::spawn(server.launch());

    tokio::select! {
        v = controller_tasks.next() => {
            match v {
                Some(Err(e)) => {
                    log::error!("{e:?}");
                }
                _ => {
                    log::error!("no controller tasks left???");
                }
            }
        }
        v = server_task => {
            if let Err(e)=v {
                log::error!("server exited: {e:#?}");
                std::process::exit(1);
            } else {
                std::process::exit(0);
            }
        }
    }

    std::process::exit(1)
}

async fn run_loop(mut controller: controller::Controller) -> eyre::Result<()> {
    let mut timeout = tokio::time::interval(controller.timeout_interval());

    loop {
        if let Some(rx) = controller.get_rx() {
            tokio::select! {
                _ = timeout.tick() => {
                    do_refresh(&mut controller).await;
                }
                Some(command) = rx.recv() => {
                    if let Err(e) = controller.process_command(command).await {
                        log::error!("controller {} failed to process command: {e}", controller.name());
                    }
                }
            }
        } else {
            timeout.tick().await;
            do_refresh(&mut controller).await;
        }
    }
}

async fn do_refresh(controller: &mut controller::Controller) {
    if let Err(e) = controller.refresh().await {
        log::warn!("error reading controller {}: {e:?}", controller.name());
    }
}