use crate::config::Engine;

use hidapi::HidApi;
use rusb::UsbContext;
use gilrs::{Gilrs, Button, Event};

pub trait InputEngine {
   fn get(&mut self) -> Vec<char>;
}

pub fn build_input_engine(cfg: &Engine) -> Result<Box<dyn InputEngine>, String> {
   match cfg.name.as_str() {
      "stdin" => return Ok(Box::new(InputEngineStdin{})),
      "kafka" => return build_input_engine_kafka(&cfg),
      "udp" => return build_input_engine_udp(&cfg),
      "device" => return build_input_engine_device(&cfg),
      _ => return Err("unknown input engine name".to_string() + &cfg.name),
   }
}

struct InputEngineDevice {
}

pub fn build_input_engine_device(cfg: &Engine) -> Result<Box<dyn InputEngine>, String> {
   return build_input_engine_device_gilrs(cfg)
}

pub fn build_input_engine_device_gilrs(cfg: &Engine) -> Result<Box<dyn InputEngine>, String> {
   let _device_cfg = cfg.device.as_ref().unwrap();

   let mut gilrs = Gilrs::new().unwrap();

   println!("printing gamepads");
   for (_id, gamepad) in gilrs.gamepads() {
      println!("{} is {:?}", gamepad.name(), gamepad.power_info());
   }

   println!("printing gamepads events");
   loop {
      // println!("reading gamepads events");
      // Examine new events
      while let Some(Event { id, event, time }) = gilrs.next_event() {
         println!("{:?} New event from {}: {:?}", time, id, event);
         let active_gamepad = Some(id);

         println!("inspecting event");
         // You can also use cached gamepad state
         if let Some(gamepad) = active_gamepad.map(|id| gilrs.gamepad(id)) {
            if gamepad.is_pressed(Button::South) {
                println!("Button South is pressed (XBox - A, PS - X)");
            }
         }
         break;
      }
      std::thread::sleep(std::time::Duration::from_millis(15));
      break;
   }

   return Err("do what".to_string());
}

pub fn build_input_engine_device_hidapi(cfg: &Engine) -> Result<Box<dyn InputEngine>, String> {
   let _device_cfg = cfg.device.as_ref().unwrap();

   match HidApi::new() {
      Ok(api) => {
         for device in api.devices() {
            println!("{:#?}", device);
         }
      },
      Err(e) => {
         eprintln!("Error: {}", e);
      },
   };
   return Err("do what".to_string());
}

pub fn build_input_engine_device_rusb(cfg: &Engine) -> Result<Box<dyn InputEngine>, String> {
   let _device_cfg = cfg.device.as_ref().unwrap();

   assert!(rusb::has_capability());

   let ctx = rusb::Context::new().unwrap();
   assert!(ctx.devices().unwrap().len() > 0);

   for device in ctx.devices().unwrap().iter() {
       let device_desc = device.device_descriptor().unwrap();
       println!("Bus {:03} Device {:03} ID {:04x}:{:04x}",
           device.bus_number(),
           device.address(),
           device_desc.vendor_id(),
           device_desc.product_id());
   }
   return Err("do what".to_string());
}

impl InputEngine for InputEngineDevice {
   fn get(&mut self) -> Vec<char> {
      Err("end".to_string()).unwrap()
   }
}

struct InputEngineUDP {
   last_socket: Option<std::net::UdpSocket>,
   port: i32,
}

pub fn build_input_engine_udp(cfg: &Engine) -> Result<Box<dyn InputEngine>, String> {
   let udp_cfg = cfg.udp.as_ref().unwrap();
   return Ok(Box::new(InputEngineUDP{
      last_socket: None,
      port: udp_cfg.port,
   }));
}

impl InputEngine for InputEngineUDP {
   fn get(&mut self) -> Vec<char> {
      let addr = "0.0.0.0:".to_string() + &self.port.to_string();
      println!("$ echo -n 'hello world' | nc -4u -w0 localhost {}", &self.port.to_string());
      if self.last_socket.is_none() {
         self.last_socket = Some(std::net::UdpSocket::bind(addr).unwrap());
      }

      let result = self._get();

      if result.is_err() {
         self.last_socket = None;
         return Vec::<char>::new();
      }
      return result.unwrap();
   }
}

impl InputEngineUDP {
   fn _get(&mut self) -> Result<Vec<char>, std::io::Error> {
      let mut buf = [0; 128];
      let socket = self.last_socket.ok_or(std::io::Error::new(std::io::ErrorKind::Other, "no socket"))?;
      let (amt, _) = socket.recv_from(&mut buf)?;
      let buf = &mut buf[..amt];
      return Ok(std::str::from_utf8(buf).unwrap().chars().collect());
   }
}

struct InputEngineKafka {
}

pub fn build_input_engine_kafka(cfg: &Engine) -> Result<Box<dyn InputEngine>, String> {
   let _kafka_cfg = cfg.kafka.as_ref().unwrap();
   return Err("do what".to_string());
}

impl InputEngine for InputEngineKafka {
   fn get(&mut self) -> Vec<char> {
      Err("end".to_string()).unwrap()
   }
}

struct InputEngineStdin {}

impl InputEngine for InputEngineStdin {
   fn get(&mut self) -> Vec<char> {
      let stdin = std::io::stdin();
      let mut result = String::new();
      stdin.read_line(&mut result).unwrap();
      return result.trim().chars().collect();
   }
}

#[cfg(test)]
mod test_input {
   use super::*;

   struct InputEngineTest {}
   impl InputEngine for InputEngineTest {
      fn get(&mut self) -> Vec<char> {
         return "hello world".chars().collect();
      }
   }

   #[test]
   fn test_input_engine_impl() {
      let mut input_engine_test = InputEngineTest{};
      _test_input_engine_impl(&mut input_engine_test);
   }

   fn _test_input_engine_impl(engine: &mut dyn InputEngine) {
      assert_eq!("hello world".to_string(), engine.get().iter().cloned().collect::<String>());
   }
}

pub trait OutputEngine {
   fn put(&self, v: Vec<char>);
}

pub fn build_output_engine(cfg: &Engine) -> Result<Box<dyn OutputEngine>, String> {
   match cfg.name.as_str() {
      "stdout" => return Ok(Box::new(OutputEngineStdout{})),
      "udp" => return build_output_engine_udp(&cfg),
      _ => return Err("unknown output engine name".to_string() + &cfg.name),
   }
}

struct OutputEngineStdout {}

impl OutputEngine for OutputEngineStdout {
   fn put(&self, v: Vec<char>) {
      println!("{}", v.iter().cloned().collect::<String>());
   }
}

#[cfg(test)]
mod test_output {
   use super::*;

   struct OutputEngineTest {}
   impl OutputEngine for OutputEngineTest {
      fn put(&self, _v: Vec<char>) {
      }
   }

   #[test]
   fn test_output_engine_impl() {
      let output_engine_test = OutputEngineTest{};
      _test_output_engine_impl(&output_engine_test);
   }

   fn _test_output_engine_impl(engine: &dyn OutputEngine) {
      engine.put("teehee".to_string().chars().collect());
   }
}

struct OutputEngineUDP {
   host: String,
   port: i32,
}

pub fn build_output_engine_udp(cfg: &Engine) -> Result<Box<dyn OutputEngine>, String> {
   let udp_cfg = cfg.udp.as_ref().unwrap();
   return Ok(Box::new(OutputEngineUDP{
      host: udp_cfg.host.clone().unwrap(),
      port: udp_cfg.port,
   }));
}

impl OutputEngine for OutputEngineUDP {
   fn put(&self, v: Vec<char>) {
      let socket = std::net::UdpSocket::bind("127.0.0.1:".to_string() + &(self.port+10).to_string()).unwrap();
      socket.connect(self.host.to_string() + ":" + &self.port.to_string()).unwrap();
      socket.send(&v.iter().cloned().collect::<String>().as_bytes()).unwrap();
   }
}