use std::io::stdout;
use std::io::Result;
use std::time::Instant;

use crossterm::{
    event::{self, KeyCode, KeyEventKind},
    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
    ExecutableCommand,
};
use ratatui::prelude::*;
use ratatui::widgets::block::{Position, Title};
use ratatui::widgets::{Block, BorderType, Borders, Wrap};
use ratatui::{
    prelude::{CrosstermBackend, Terminal},
    widgets::Paragraph,
};
use whoami::realname;

use crate::game::{Game, GameState};
use crate::level_widget::LevelWidget;
use crate::player::Player;
use crate::position::HasPosition;

mod artifacts;
mod game;
mod level;
mod level_generator;
mod level_widget;
mod monster;
mod player;
mod position;

/// length of a game frame in ms
pub const FRAME_LENGTH: u64 = 100;

//
fn main() -> Result<()> {
    let mut game = Game::new(Player::new(realname().as_str(), 30));

    stdout().execute(EnterAlternateScreen)?;
    enable_raw_mode()?;
    let mut terminal = Terminal::new(CrosstermBackend::new(stdout()))?;
    terminal.clear()?;

    let start_time = Instant::now();
    let mut ticks = 0;
    loop {
        terminal.draw(|frame| {
            let mut area = frame.area();
            frame.render_widget(
                Block::default().style(Style::default().bg(Color::Green)),
                area,
            );

            // don't draw stuff except an info box if the terminal is too small (less than 80x25)
            // to prevent the read drawing code from crashing the game.
            if area.width < 80 || area.height < 25 {
                let block = Block::default()
                    .title("Info")
                    .borders(Borders::ALL)
                    .border_style(Style::default().fg(Color::White))
                    .border_type(BorderType::Rounded)
                    .style(Style::default().bg(Color::Black));
                let paragraph = Paragraph::new("Terminal needs to be at leas 80x25!")
                    .block(block)
                    .wrap(Wrap { trim: true });
                frame.render_widget(paragraph, area);
                return;
            }

            if area.width > 80 {
                area.x = (area.width - 80) / 2;
                area.width = 80;
            }
            if area.height > 25 {
                area.y = (area.height - 25) / 2;
                area.height = 25;
            }

            let map_area = Rect {
                x: area.x,
                y: area.y,
                width: level::LEVEL_WIDTH as u16,
                height: level::LEVEL_HEIGHT as u16,
            };
            frame.render_stateful_widget(LevelWidget {}, map_area, &mut game);

            let stats_area = Rect {
                x: area.x + 50,
                y: area.y,
                width: 30,
                height: 15,
            };
            let block = Block::default()
                .title(
                    Title::from(format!(" {} ", game.get_player().get_name()))
                        .alignment(Alignment::Center)
                        .position(Position::Top),
                )
                .borders(Borders::TOP)
                .border_style(Style::default().fg(Color::White))
                .border_type(BorderType::Rounded)
                .style(Style::default().bg(Color::Blue));
            frame.render_widget(
                Paragraph::new(format!(
                    "Health: {}/{}\nExp: {}\nGold: {}\nLevel: {}\nInventory: {}",
                    game.get_player().get_life(),
                    game.get_player().get_max_life(),
                    game.get_player().get_experience(),
                    game.get_player().get_gold(),
                    game.get_player().get_immutable_position().get_level() + 1,
                    game.get_player().inventory_size(),
                ))
                .block(block)
                .wrap(Wrap { trim: true }),
                stats_area,
            );
            let messages_area = Rect {
                x: area.x + 50,
                y: area.y + 15,
                width: 30,
                height: 10,
            };
            // Display the latest messages from the game to the user
            let block = Block::default()
                .title(
                    Title::from(" messages ")
                        .alignment(Alignment::Center)
                        .position(Position::Top),
                )
                .borders(Borders::TOP)
                .border_style(Style::default().fg(Color::White))
                .border_type(BorderType::Rounded)
                .style(Style::default().bg(Color::Blue));

            let paragraph1 = if game.messages.is_empty() {
                "".to_string()
            } else {
                format!("> {}", game.messages.join("\n> "))
            };
            frame.render_widget(
                Paragraph::new(paragraph1)
                    .block(block)
                    .wrap(Wrap { trim: true }),
                messages_area,
            );
        })?;
        if event::poll(std::time::Duration::from_millis(FRAME_LENGTH))? {
            if let event::Event::Key(key) = event::read()? {
                if key.kind == KeyEventKind::Press {
                    match key.code {
                        KeyCode::Char('v') => {
                            game.messages.insert(
                                0,
                                format!("You are playing version '{}'.", env!("GIT_HASH"))
                                    .to_string(),
                            );
                        }
                        KeyCode::Char('p') => {
                            let gained_health = game.get_mutable_player().consume_inventory();
                            if gained_health > 0 {
                                game.messages.insert(
                                    0,
                                    format!(
                                        "used a potion from inventory and gained {} health.",
                                        gained_health
                                    )
                                    .to_string(),
                                );
                            }
                        }
                        KeyCode::Char('q') => {
                            break;
                        }
                        KeyCode::Left | KeyCode::Down | KeyCode::Right | KeyCode::Up => {
                            let new_pos = match key.code {
                                KeyCode::Left => game.move_player(-1, 0),
                                KeyCode::Right => game.move_player(1, 0),
                                KeyCode::Up => game.move_player(0, -1),
                                KeyCode::Down => game.move_player(0, 1),
                                _ => (0, 0),
                            };
                            if !game.player_fights_monster() {
                                // player attacked monster but did not kill it
                                game.move_player(new_pos.0, new_pos.1);
                            }
                            game.player_collects_artifact();
                        }
                        _ => {}
                    }
                }
            }
        }
        game.update_level(ticks);
        if game.get_game_state() != GameState::Running {
            break;
        }
        ticks += 1;
    }
    let playtime = start_time.elapsed();
    loop {
        let _ = terminal.draw(|frame| {
            let mut area = frame.area();
            let w = area.width / 2;
            let h = area.height / 2;
            area.x += w - 20;
            area.y += h - 10;
            area.width = 40;
            area.height = 20;
            let block = Block::default()
                .title(
                    Title::from(" Game ended ")
                        .alignment(Alignment::Center)
                        .position(Position::Top),
                )
                .title(Title::from("Press `q` to quit!").position(Position::Bottom))
                .borders(Borders::ALL)
                .border_style(Style::default().fg(Color::White))
                .border_type(BorderType::Rounded)
                .style(Style::default().bg(Color::Black));
            let mut text = match game.get_game_state() {
                GameState::Running => {
                    "Quitting is for cowards! You'll better try again!".to_string()
                }
                GameState::Lost => {
                    "Sorry, you died in the dungeon. Better luck next time!".to_string()
                }
                GameState::Won => {
                    "Congratulation! You mastered your way through the dungeon and won the game."
                        .to_string()
                }
            };
            text += format!(
                "\nYou gained {} experience.",
                game.get_player().get_experience()
            )
            .as_str();
            text += format!("\nYou collected {} gold.", game.get_player().get_gold()).as_str();
            text += format!("\nYou played {} seconds.", playtime.as_secs()).as_str();
            let paragraph = Paragraph::new(text).block(block).wrap(Wrap { trim: true });
            frame.render_widget(paragraph, area);
        });
        if event::poll(std::time::Duration::from_millis(16))? {
            if let event::Event::Key(key) = event::read()? {
                if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('q') {
                    break;
                }
            }
        }
    }
    stdout().execute(LeaveAlternateScreen)?;
    disable_raw_mode()?;
    Ok(())
}