extern crate sdl2;

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

    let available = joystick_subsystem.num_joysticks()
        .map_err(|e| format!("can't enumerate joysticks: {}", e))?;

    println!("{} joysticks available", available);

    // Iterate over all available joysticks and stop once we manage to open one.
    let mut joystick = (0..available).find_map(|id| match joystick_subsystem.open(id) {
        Ok(c) => {
            println!("Success: opened \"{}\"", c.name());
            Some(c)
        },
        Err(e) => {
            println!("failed: {:?}", e);
            None
        },
    }).expect("Couldn't open any joystick");

    // Print the joystick's power level
    println!("\"{}\" power level: {:?}", joystick.name(), joystick.power_level()
        .map_err(|e| e.to_string())?);

    let (mut lo_freq, mut hi_freq) = (0, 0);

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

        match event {
            Event::JoyAxisMotion{ axis_idx, value: val, .. } => {
                // Axis motion is an absolute value in the range
                // [-32768, 32767]. Let's simulate a very rough dead
                // zone to ignore spurious events.
                let dead_zone = 10_000;
                if val > dead_zone || val < -dead_zone {
                    println!("Axis {} moved to {}", axis_idx, val);
                }
            }
            Event::JoyButtonDown{ button_idx, .. } => {
                println!("Button {} down", button_idx);
                if button_idx == 0 {
                    lo_freq = 65535;
                } else if button_idx == 1 {
                    hi_freq = 65535;
                }
                if button_idx < 2 {
                    match joystick.set_rumble(lo_freq, hi_freq, 15000) {
                        Ok(()) => println!("Set rumble to ({}, {})", lo_freq, hi_freq),
                        Err(e) => println!("Error setting rumble to ({}, {}): {:?}", lo_freq, hi_freq, e),
                    }
                }
            }
            Event::JoyButtonUp{ button_idx, .. } => {
                println!("Button {} up", button_idx);
                if button_idx == 0 {
                    lo_freq = 0;
                } else if button_idx == 1 {
                    hi_freq = 0;
                }
                if button_idx < 2 {
                    match joystick.set_rumble(lo_freq, hi_freq, 15000) {
                        Ok(()) => println!("Set rumble to ({}, {})", lo_freq, hi_freq),
                        Err(e) => println!("Error setting rumble to ({}, {}): {:?}", lo_freq, hi_freq, e),
                    }
                }
            }
            Event::JoyHatMotion{ hat_idx, state, .. } =>
                println!("Hat {} moved to {:?}", hat_idx, state),
            Event::Quit{..} => break,
            _ => (),
        }
    }

    Ok(())
}