// SDL2-2.30.10/include/SDL_events.h

/* Joystick events */
SDL_JOYAXISMOTION  = 0x600, /**< Joystick axis motion */
SDL_JOYBALLMOTION,          /**< Joystick trackball motion */
SDL_JOYHATMOTION,           /**< Joystick hat position change */
SDL_JOYBUTTONDOWN,          /**< Joystick button pressed */
SDL_JOYBUTTONUP,            /**< Joystick button released */
SDL_JOYDEVICEADDED,         /**< A new joystick has been inserted into the system */
SDL_JOYDEVICEREMOVED,       /**< An opened joystick has been removed */
SDL_JOYBATTERYUPDATED,      /**< Joystick battery level change */

初始化SDL → 监听事件 → 一般事件 进行响应处理
              ↓
        设备添加/移除事件
              ↓
        设备 添加/移除 集合

/*
 * 解析GUID 获取VID和PID
 *
 * GUID: 030017173807000021a2000000000000
 * VID: 0738
 * PID: A221
 * 返回值: (VID, PID) 大写
 */
pub fn parse_guid(guid_str: &str) -> (String, String) {
    let vid = format!("{}{}", &guid_str[10..12], &guid_str[8..10]);
    let pid = format!("{}{}", &guid_str[18..20], &guid_str[16..18]);

    (vid.to_uppercase(), pid.to_uppercase())
}

#[cfg(test)]
mod test {

    #[test]
    fn test_parse_guid() {
        let guid = super::parse_guid("03003187380700002122000000000000");
        assert_eq!(guid, ("0738".to_string(), "2221".to_string()));
    }
}

use sdl2::joystick::{Guid, Joystick};
use sdl2::JoystickSubsystem;

mod utils;

pub struct JoyDevice {
    pub id: u32,
    pub name: String,
    pub guid: Guid,
    pub joystick: Joystick,
}

impl JoyDevice {
    pub fn new(joystick: Joystick) -> Self {
        Self {
            id: joystick.instance_id(),
            name: joystick.name(),
            guid: joystick.guid(),
            joystick,
        }
    }
}

// 读取游戏设备
fn read_joy_device(ins_id: u32, js: &JoystickSubsystem) -> JoyDevice {
    if let Ok(joystick) = js.open(ins_id) {
        JoyDevice::new(joystick)
    } else {
        panic!("Failed to open joystick ID {}", ins_id);
    }
}

// 设备GUID
const GUIDS: &[&str] = &[
    "03003187380700002122000000000000", // 摇杆
    "030017173807000021a2000000000000", // 油门
];

fn main() -> Result<(), String> {
    let sdl_context = sdl2::init()?;

    let joystick_subsystem = sdl_context.joystick()?;

    // 存储所有的游戏设备
    let mut joysticks: Vec<JoyDevice> = Vec::new();

    let mut event_pump = sdl_context.event_pump()?;

    for event in event_pump.wait_iter() {
        use sdl2::event::Event;

        match event {
            Event::JoyAxisMotion {
                which,
                axis_idx,
                value,
                ..
            } => {
                println!("Device {}: Axis {} moved to {}", which, axis_idx, value);
            }
            Event::JoyButtonDown {
                which, button_idx, ..
            } => {
                println!("Device {}: Button {} pressed", which, button_idx);
            }
            Event::JoyButtonUp {
                which, button_idx, ..
            } => {
                println!("Device {}: Button {} released", which, button_idx);
            }
            Event::JoyHatMotion {
                which,
                hat_idx,
                state,
                ..
            } => {
                println!("Device {}: Hat {} moved to {:?}", which, hat_idx, state);
            }
            Event::JoyDeviceRemoved { which, .. } => {
                joysticks.iter().for_each(|joy| {
                    if joy.id == which {
                        println!("Device ({}){} removed", joy.id, joy.name);
                    }
                });
                joysticks.retain(|joy: &JoyDevice| joy.id != which);
            }
            Event::JoyDeviceAdded { which, .. } => {
                let joy_device = read_joy_device(which, &joystick_subsystem);
                if GUIDS.contains(&joy_device.guid.to_string().as_str()) {
                    println!("Device ({}){} added", joy_device.id, joy_device.name);
                    joysticks.push(joy_device);
                }
            }
            Event::Quit { .. } => break,

            // 其他事件
            oe => {
                println!("Other event: {:?}", oe);
            }
        }
    }

    Ok(())
}