use clap::{Parser, Subcommand};
use colored::*;
use serde::Deserialize;

use traveltext::types::*;
use traveltext::{iceportal::*, travelynx::*};

#[derive(Parser)]
struct Cli {
    #[clap(subcommand)]
    command: Command,
    /// print requests that couldn't be parsed to help debugging
    #[clap(long)]
    debug: bool,
    #[clap(default_value = "https://travelynx.de")]
    baseurl: String,
    /// API token to use in requests
    token: Option<String>,
}

#[derive(Subcommand)]
enum Command {
    /// Get current travelynx status
    Status,
    /// Check in to a train using travelynx
    Checkin {
        from: String,
        to: String,
        // TODO: make this optional and guess which train if not given
        #[clap(flatten)]
        train: TrainRef,
    },
    /// (If already checked in) change the trip's destination
    Destination {
        to: String
    },
    Arewethereyet,
    /// If iceportal.de is available, ask it which train we're in and
    /// check in
    Autocheckin,
    /// Undo the last checkin (if any).
    Undo,
    /// Query iceportal.de (for testing)
    ICEPortal,
}

#[derive(Deserialize)]
struct Config {
    token_status: String,
    token_travel: String,
}

fn main() -> Result<(), ureq::Error> {
    let cli = Cli::parse();

    let traveltext = format!(
        "{}{}el{}{}",
        "tr".cyan(),
        "av".bright_magenta(),
        "te".bright_magenta(),
        "xt".cyan()
    );

    let configpath = {
        let mut path = dirs::config_dir().unwrap();
        path.push("traveltext.toml");
        path
    };

    let config: Config = match std::fs::read_to_string(&configpath) {
        Ok(text) => match toml::from_str(&text) {
            Ok(config) => config,
            Err(err) => exit_err(
                &err.to_string(),
                &format!(
                    "failed parsing config file {}",
                    configpath.to_string_lossy()
                ),
            ),
        },
        Err(err) => exit_err(
            &err.to_string(),
            &format!("failed reading config at: {}", configpath.to_string_lossy()),
        ),
    };

    match cli.command {
        Command::Status => {
            let status: Status = exiting_get_request(
                &format!("{}/api/v1/status/{}", cli.baseurl, config.token_status),
                cli.debug,
            );

            println!("{}: {}", traveltext, status);
        }
        Command::Arewethereyet => {
            let status: Status = exiting_get_request(
                &format!("{}/api/v1/status/{}", cli.baseurl, config.token_status),
                cli.debug,
            );

            match status.to_station {
                None => println!("{}: Fahrt ins {}", traveltext, "Blaue".blue()),
                Some(to) => {
                    let now = chrono::Utc::now();
                    let duration = to.real_arrival().map(|dt| *dt - now);
                    match duration {
                        Some (d) => println!(
                            "{}: we'll be there in {} minutes",
                            traveltext,
                            d.num_minutes()
                        ),
                        None => println!("{}: I have no idea", traveltext)
                    }
                }
            }
        },
        Command::Checkin { from, to, train } => {
            let resp: Response = exiting_post_request(
                &format!("{}/api/v1/travel", cli.baseurl),
                Action::CheckIn {
                    train,
                    from_station: from,
                    to_station: Some(to),
                    comment: None,
                    token: format!("{}", config.token_travel),
                },
                cli.debug,
            );

            println!("{}: {}", traveltext, resp);
        },
        Command::Destination { to } => {
            let resp: Response = exiting_post_request(
                &format!("{}/api/v1/travel", cli.baseurl),
                Action::CheckOut {
                    to_station: to,
                    force: false,
                    token: config.token_travel,
                    comment: None
                },
                cli.debug
            );
            println!("{}: {}", traveltext, resp);
        }
        Command::Undo => {
            let resp: Response = exiting_post_request(
                &format!("{}/api/v1/travel", cli.baseurl),
                Action::Undo {
                    token: config.token_travel.to_owned(),
                },
                cli.debug,
            );

            println!("{}: {}", traveltext, resp);
        }
        Command::Autocheckin => {
            let iceportal: TripInfo =
                exiting_get_request("https://iceportal.de/api1/rs/tripInfo/trip", cli.debug);

            let last_stop = iceportal.guess_last_station().unwrap();
            let train = iceportal.get_train_ref();
            println!(
                "{}: guessing you got onto {} {} in {}, checking in …",
                traveltext, train._type, train.no, last_stop
            );
            let resp: Response = exiting_post_request(
                &format!("{}/api/v1/travel", cli.baseurl),
                Action::CheckIn {
                    train,
                    from_station: last_stop,
                    to_station: None,
                    comment: None,
                    token: format!("{}", config.token_travel),
                },
                cli.debug,
            );

            // eprintln!("{:?}", resp);
            println!("{}: {}", traveltext, resp);
        }
        Command::ICEPortal => {
            match get_request::<TripInfo>("https://iceportal.de/api1/rs/tripInfo/trip") {
                Ok(resp) => {
                    println!("{}: Currently in {}\n", traveltext, resp.get_train_ref().to_string().green());
                    println!("guessing last stop was: {:?}\n", resp.guess_last_station());
                    println!("Stops:\n{}", resp.trip())
                }
                Err(err) => {
                    if cli.debug {
                        eprintln!("{:?}", err);
                    }
                    println!("either this tool or the iceportal broke or you're not actually on an ICE\n\
                              (get a response but couldn't parse it)");
                }
            }
        }
    }
    Ok(())
}

fn get_request<R>(uri: &str) -> Result<R, (serde_json::Error, String)>
where
    R: serde::de::DeserializeOwned,
{
    let resp: String = ureq::get(uri)
        .call()
        .unwrap_or_else(|err| exit_err(&err.to_string(), "get request failed"))
        .into_string()
        .unwrap_or_else(|err| exit_err(&err.to_string(), "get request response failed"));

    match serde_json::from_str::<R>(&resp) {
        Ok(obj) => Ok(obj),
        Err(err) => Err((err, resp)),
    }
}

fn exiting_get_request<R: serde::de::DeserializeOwned>(uri: &str, debug: bool) -> R {
    match get_request(uri) {
        Ok(obj) => obj,
        Err((err, resp)) => {
            if debug {
                eprintln!("DEBUG: {}", resp);
            }
            exit_err(&err.to_string(), "parsing response failed")
        }
    }
}

fn exiting_post_request<R, P>(uri: &str, payload: P, debug: bool) -> R
where
    P: serde::Serialize,
    R: serde::de::DeserializeOwned,
{
    let resp: String = ureq::post(uri)
        .send_json(payload)
        .unwrap_or_else(|err| exit_err(&err.to_string(), "post request failed"))
        .into_string()
        .unwrap_or_else(|err| exit_err(&err.to_string(), "post request response failed"));

    match serde_json::from_str::<R>(&resp) {
        Ok(obj) => obj,
        Err(err) => {
            if debug {
                eprintln!("DEBUG: {}", resp);
            }
            exit_err(&err.to_string(), "parsing response failed")
        }
    }
}

fn exit_err(msg: &str, scope: &str) -> ! {
    eprintln!("{}: {}", scope, msg);
    std::process::exit(1)
}