mod util;
mod command;
mod config;
mod api_types;
mod log;
mod cache;
mod net;
#[macro_use] mod common;

use crate::util::event::{Event, Events};
use crate::command::Command;
use crate::cache::Cache;
use std::{env, fs, error::Error, io};
use std::sync::Mutex;
use clap::{App as Clap, Arg, ArgMatches};
use termion::{event::Key, raw::IntoRawMode, screen::AlternateScreen};
use tui::{
    backend::TermionBackend,
    layout::{Constraint, Direction, Layout},
    style::{Color, Modifier, Style},
    text::{Span, Spans, Text},
    widgets::{Wrap, Block, Borders, Paragraph},
    Terminal,
};
use unicode_width::UnicodeWidthStr;

enum InputMode {
    Normal,
    Editing,
}

/// App holds the state of the application
struct App {
    /// Current value of the input box
    input: String,
    /// Current input mode
    input_mode: InputMode,
    /// History of recorded messages
    messages: Vec<Command>,
}

impl App {
    fn new() -> App {
        let init_commands = vec![
            Command::Text("! /chan | /channel <u64> - Switches text context to that channel".into()),
            Command::Text("! /serv | /server <hostname> - Must include port if its not default to 80/443".into()),
            Command::Text("! /lh - List hosts in config (-H flag does this on startup)".into()),
            Command::Text("! /help - Shows the help menu".into()),
            Command::Text("! Commands: available".into()),
        ];
        App {
            input: String::new(),
            input_mode: InputMode::Normal,
            messages: init_commands,
        }
    }
}

fn get_args() -> ArgMatches<'static> {
    Clap::new("Freechat TUI")
        .version("v69.420")
        .author("Author: shockrah")
        .about("Description: A terminal based program for interacting with freechat servers")
        .arg(Arg::with_name("config")
            .short("c")
            .long("config")
            .value_name("CONFIG")
            .help("Specify path of config to use")
            .takes_value(true))
        .arg(Arg::with_name("no_border")
             .short("n")
             .long("no-border")
             .takes_value(false)
             .help("Removes border from messages box "))
        .arg(Arg::with_name("no_login")
             .short("l")
             .long("no-login")
             .help("Don't automatically login on startup")).get_matches()
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    // parameter things first
    let args = get_args();

    let (config_path, config): (String, config::ConfigFile) = if let Some(path) = args.value_of("config") {
        match fs::read_to_string(path) {
            Ok(data) => (path.into(), serde_json::from_str(&data).unwrap()),
            Err(e) => panic!("Unable to parse config file @{}: {}", path, e)
        }
    } else {
        let home = env::var("HOME").unwrap();
        let path = format!("{}/.config/freechat/config.json", home);
        match fs::read_to_string(&path) {
            Ok(data) => (path.into(), serde_json::from_str(&data).unwrap()),
            Err(e) => panic!("Unable to parse config file @{}: {}", path, e)
        }
    };
    let border_opt = args.is_present("no_border");

    // Terminal initialization
    let stdout = io::stdout().into_raw_mode()?;
    let stdout = AlternateScreen::from(stdout);
    let backend = TermionBackend::new(stdout);
    let mut terminal = Terminal::new(backend)?;

    // Setup event handlers
    let mut events = Events::new();

    // Create default app state
    let mut app = App::new();
    let cache: Mutex<Cache> = Mutex::new(Cache::from(&config));

    loop {
        // Draw UI
        terminal.draw(|f| {
            let chunks = Layout::default()
                .direction(Direction::Vertical)
                .margin(2)
                .constraints(
                    [
                        Constraint::Length(1), // Info line
                        Constraint::Length(3), // Text box (w/ borders
                        Constraint::Min(1), // the rest of it
                    ]
                    .as_ref(),
                )
                .split(f.size());

            let (msg, style) = match app.input_mode {
                InputMode::Normal => (
                    vec![
                        bold!("I"),
                        normal!(" for insert mode"),
                    ],
                    Style::default()
                ),
                InputMode::Editing => (
                    vec![ bold!("/help for commands") ],
                    Style::default(),
                ),
            };
            let mut text = Text::from(Spans::from(msg));
            text.patch_style(style);
            let help_message = Paragraph::new(text);
            f.render_widget(help_message, chunks[0]);

            let input = Paragraph::new(app.input.as_ref())
                .style(match app.input_mode {
                    InputMode::Normal => Style::default(),
                    InputMode::Editing => Style::default().fg(Color::Yellow),
                })
                .block(Block::default().borders(Borders::ALL));
            f.render_widget(input, chunks[1]);

            let mut lines: Vec<Spans> = Vec::new();
            let msgs = &app.messages;
            for cmd in msgs.iter().rev() {
                &lines.push(cmd.styled());
            }

            let list = if border_opt {
                Paragraph::new(lines)
                    .wrap(Wrap { trim: false })
                    .block(Block::default()
                    .title("Messages"))
            } else {
                Paragraph::new(lines)
                    .wrap(Wrap { trim: false })
                    .block(Block::default()
                       .title("Messages")
                       .borders(Borders::ALL))
            };

            f.render_widget(list, chunks[2]);

            match app.input_mode {
                InputMode::Normal =>
                    // Hide the cursor. `Frame` does this by default, so we don't need to do anything here
                    {}

                InputMode::Editing => {
                    // Make the cursor visible and ask tui-rs to put it at the specified coordinates after rendering
                    f.set_cursor(
                        // Put cursor past the end of the input text
                        chunks[1].x + app.input.width() as u16 + 1,
                        // Move one line down, from the border to the input line
                        chunks[1].y + 1,
                    )
                }
            }
        })?;

        // Handle input
        if let Event::Input(input) = events.next()? {
            match app.input_mode {
                InputMode::Normal => match input {
                    Key::Char('i') | Key::Char('/') => {
                        app.input_mode = InputMode::Editing;
                        // only add the slash on slash command start
                        if Key::Char('/') == input { app.input.push('/'); }
                        events.disable_exit_key();
                    }
                    Key::Char('q') => {
                        // save the config as is then quit out
                        match config.save(config_path) {
                            Ok(_) => println!(":^)"),
                            Err(e) => eprintln!("Couldn't save config state: {}", e)
                        };
                        break;
                    }
                    _ => {}
                },
                InputMode::Editing => match input {
                    Key::Char('\n') => {
                        let raw: String = app.input.drain(..).collect();
                        let trimmed = raw.trim();

                        // TODO: flattten me mommy
                        if trimmed.len() != 0 {
                            let cmd = Command::from(trimmed);
                            app.messages.push(match cmd {
                                // only for networked commands do we need to touch cache
                                Command::Channel(id) => {
                                    cache.lock().unwrap().switch_channel(id).await
                                },
                                Command::Server(url_portion) => {
                                    if let Some((id, secret, url)) = config.find_login_data(&url_portion) {
                                        match net::login(&url, id, &secret).await {
                                            Ok(jwt) => if cache.lock().unwrap().set_jwt(&url, &jwt) {
                                                cache.lock().unwrap().set_active(&url);
                                                Command::Text("[Tell shock to make this ux not suck btw] /lc to fetch/update channels".into())
                                            } else {
                                                Command::Failure("Token could not be set".into())
                                            },
                                            Err(_) => Command::Failure(format!("Unable to login to {}", url))
                                        }
                                    } else {
                                        Command::Failure("No server found".into())
                                    }
                                },
                                Command::Message(msg) => cache.lock().unwrap().send_message(&msg).await,
                                Command::ListHost => cache.lock().unwrap().list_hosts(),
                                Command::ListChannel => {
                                    let session_params = cache.lock().unwrap().session();
                                    if let Some((url, id, jwt)) = session_params {
                                        match net::list_channels(&url , id, &jwt).await {
                                            Ok(channels) => {
                                                cache.lock().unwrap().add_channels(&url, channels.as_slice());
                                                Command::Text(format!("{:?}", channels))
                                            },
                                            Err(_) => Command::Text("Coulnd't fetch channels".into())
                                        }
                                    } else {
                                        Command::Text("adf".into())
                                    }
                                },
                                _ => cmd
                            });
                        }
                    }
                    Key::Char(c) => {
                        app.input.push(c);
                    }
                    Key::Backspace => {
                        app.input.pop();
                    }
                    Key::Ctrl('c') | Key::Esc => {
                        app.input_mode = InputMode::Normal;
                        events.enable_exit_key();
                    }
                    _ => {}
                },
            }
        }
    }
    Ok(())
}