use std::collections::HashSet;
use bevy::{
    input::gamepad::{Gamepad, GamepadAxisType, GamepadButtonType, GamepadEvent, GamepadEventType},
    prelude::*,
};

#[derive(Clone, Debug, PartialEq, Eq, Hash)]
pub enum Source {
    KeyboardRight,
    KeyboardLeft,
    Gamepad(Gamepad),
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum Key {
    Up,
    Down,
    Left,
    Right,
    Jump,
}

const KEYBOARD_KEYS: &[(KeyCode, Source, Key)] = &[
    (KeyCode::Up, Source::KeyboardRight, Key::Up),
    (KeyCode::Down, Source::KeyboardRight, Key::Down),
    (KeyCode::Left, Source::KeyboardRight, Key::Left),
    (KeyCode::Right, Source::KeyboardRight, Key::Right),
    (KeyCode::Return, Source::KeyboardRight, Key::Jump),
    (KeyCode::W, Source::KeyboardLeft, Key::Up),
    (KeyCode::S, Source::KeyboardLeft, Key::Down),
    (KeyCode::A, Source::KeyboardLeft, Key::Left),
    (KeyCode::D, Source::KeyboardLeft, Key::Right),
    (KeyCode::Space, Source::KeyboardLeft, Key::Jump),
];

const GAMEPAD_KEYS: &[(GamepadButtonType, Key)] = &[
    (GamepadButtonType::DPadUp, Key::Up),
    (GamepadButtonType::DPadDown, Key::Down),
    (GamepadButtonType::DPadLeft, Key::Left),
    (GamepadButtonType::DPadRight, Key::Right),
    (GamepadButtonType::South, Key::Jump),
];

#[derive(Default)]
pub struct InputState(pub HashSet<(Source, Key)>);

pub fn setup(mut commands: Commands) {
    commands.insert_resource(InputState::default());
}

pub fn handle(
    keyboard: Res<Input<KeyCode>>,
    mut gamepad_event: EventReader<GamepadEvent>,
    mut state: ResMut<InputState>,
) {
    // handle keyboard
    for (key_code, source, key) in KEYBOARD_KEYS {
        if keyboard.pressed(*key_code) {
            state.0.insert((source.clone(), *key));
        } else {
            state.0.remove(&(source.clone(), *key));
        }
    }

    // handle gamepads
    for event in gamepad_event.iter() {
        match event {
            GamepadEvent(gamepad, GamepadEventType::ButtonChanged(button, value)) => {
                if let Some((_, key)) = GAMEPAD_KEYS.iter().find(|(button_, _)| {
                    button == button_
                }) {
                    if *value > 0.01 {
                        state.0.insert((Source::Gamepad(*gamepad), *key));
                    } else {
                        state.0.remove(&(Source::Gamepad(*gamepad), *key));
                    }
                }
            }
            GamepadEvent(gamepad, GamepadEventType::AxisChanged(GamepadAxisType::DPadX, value)) |
            GamepadEvent(gamepad, GamepadEventType::AxisChanged(GamepadAxisType::LeftStickX, value)) => {
                if *value < -0.01 {
                    state.0.insert((Source::Gamepad(*gamepad), Key::Left));
                    state.0.remove(&(Source::Gamepad(*gamepad), Key::Right));
                } else if *value > 0.01 {
                    state.0.insert((Source::Gamepad(*gamepad), Key::Right));
                    state.0.remove(&(Source::Gamepad(*gamepad), Key::Left));
                } else {
                    state.0.remove(&(Source::Gamepad(*gamepad), Key::Left));
                    state.0.remove(&(Source::Gamepad(*gamepad), Key::Right));
                }
            }
            GamepadEvent(gamepad, GamepadEventType::AxisChanged(GamepadAxisType::DPadY, value)) |
            GamepadEvent(gamepad, GamepadEventType::AxisChanged(GamepadAxisType::LeftStickY, value)) => {
                if *value < -0.01 {
                    state.0.insert((Source::Gamepad(*gamepad), Key::Down));
                    state.0.remove(&(Source::Gamepad(*gamepad), Key::Up));
                } else if *value > 0.01 {
                    state.0.insert((Source::Gamepad(*gamepad), Key::Up));
                    state.0.remove(&(Source::Gamepad(*gamepad), Key::Down));
                } else {
                    state.0.remove(&(Source::Gamepad(*gamepad), Key::Up));
                    state.0.remove(&(Source::Gamepad(*gamepad), Key::Down));
                }
            }
            _ => {}
        }
    }
}