/*
 * Copyright (C) 2024 Jonni Liljamo <jonni@liljamo.com>
 *
 * This file is licensed under GPL-3.0-or-later, see NOTICE and LICENSE for
 * more information.
 */

use clap::Parser;
use emerwen_protocol::{
    emerwen_protocol_server::{EmerwenProtocol, EmerwenProtocolServer},
    target::{MethodGet, MethodPing},
    SetTargetStateRequest, Target, TargetsResponse,
};
use tonic::{transport::Server, Request, Response, Status};
use tracing::{debug, info, level_filters::LevelFilter};
use tracing_subscriber::{prelude::*, EnvFilter};

#[derive(Parser)]
#[command(version)]
struct Args {
    /// Enable debug logging
    #[arg(long)]
    debug: bool,
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let args = Args::parse();

    tracing_subscriber::registry()
        .with(
            tracing_subscriber::fmt::layer()
                .with_file(args.debug)
                .with_line_number(args.debug)
                .with_level(true),
        )
        .with(
            EnvFilter::builder()
                .with_default_directive(if args.debug {
                    LevelFilter::DEBUG.into()
                } else {
                    LevelFilter::INFO.into()
                })
                .from_env_lossy(),
        )
        .init();

    let addr = "127.0.0.1:8000";

    info!(message = "Starting emerwen master...", %addr);
    debug!("Hello, debug!");

    let workers = vec![Worker {
        id: 0,
        auth_token: "avain_perkele".into(),
        targets: vec![
            Target {
                id: 0,
                addr: "127.0.0.1".into(),
                interval: 2000,
                method: Some(MethodPing {}.into()),
            },
            Target {
                id: 1,
                addr: "https://liljamo.com/".into(),
                interval: 2000,
                method: Some(
                    MethodGet {
                        ok_codes: vec![200],
                    }
                    .into(),
                ),
            },
            Target {
                id: 2,
                addr: "10.1.2.30".into(),
                interval: 2000,
                method: Some(MethodPing {}.into()),
            },
        ],
    }];

    let server = MasterServer::new(workers);

    Server::builder()
        .add_service(EmerwenProtocolServer::with_interceptor(
            server,
            move |req: Request<()>| {
                match req.metadata().get("authorization") {
                    Some(_token) => {
                        // TODO: check
                        Ok(req)
                    }
                    None => Err(Status::unauthenticated("invalid auth")),
                }
            },
        ))
        .serve(addr.parse()?)
        .await?;

    Ok(())
}

struct MasterServer {
    workers: Vec<Worker>,
}

impl MasterServer {
    fn new(workers: Vec<Worker>) -> MasterServer {
        MasterServer { workers }
    }
}

#[tonic::async_trait]
impl EmerwenProtocol for MasterServer {
    async fn get_targets(&self, request: Request<()>) -> Result<Response<TargetsResponse>, Status> {
        let token = match request.metadata().get("authorization") {
            Some(value) => match value.to_str() {
                Ok(bearer_token) => bearer_token.trim_start_matches("Bearer "),
                Err(_) => {
                    return Err(Status::invalid_argument(
                        "couldn't read bearer auth to string",
                    ))
                }
            },
            None => {
                return Err(Status::unauthenticated(
                    "request had no authorization, when it should",
                ))
            }
        };

        let targets = match self
            .workers
            .iter()
            .find(|worker| *worker.auth_token == *token)
        {
            Some(worker) => worker.targets.clone(),
            None => {
                return Err(Status::invalid_argument(
                    "no worker exists with the auth token",
                ))
            }
        };

        Ok(Response::new(TargetsResponse { targets }))
    }

    async fn set_target_state(
        &self,
        request: Request<SetTargetStateRequest>,
    ) -> Result<Response<()>, Status> {
        info!("{:?}", request.into_inner());

        Ok(Response::new(()))
    }
}

struct Worker {
    pub id: u32,
    pub auth_token: String,
    pub targets: Vec<Target>,
}