use iced::widget::{button, column, row, text};
use iced::widget::text_input;
use iced::executor;
use iced::keyboard;
use iced::subscription;
use iced::{Alignment, Element, Application, Settings, Subscription, Theme, Command};
use iced_futures::backend::native::async_std::time::every;
use handlebars::Handlebars;
use serde_json::{json, Value};
use std::time::{SystemTime, UNIX_EPOCH};
use std::thread;
use reqwest;

use crate::stream::OutputStream;
use crate::config::{GUI,GUIFeedback};

pub fn main(cfg: GUI, output_stream: Box<dyn OutputStream>) -> iced::Result {
   let def: iced::Settings<()> = Settings::default();
   let settings = Settings{
      flags: Flags {
         output_stream: output_stream,
         cfg: cfg,
      },
      antialiasing: def.antialiasing,
      default_font: def.default_font,
      default_text_size: def.default_text_size,
      exit_on_close_request: def.exit_on_close_request,
      id: def.id,
      text_multithreading: def.text_multithreading,
      try_opengles_first: def.try_opengles_first,
      window: iced::window::Settings{
         size: (300, 720),
         position: iced::window::Position::Specific(0, 0),
         ..iced::window::Settings::default()
      },
   };
   Main::run(settings)
}

struct Main {
   feedback_recv_c: std::sync::mpsc::Receiver<Feedback>,
   feedback_send_c: std::sync::mpsc::Sender<Feedback>,
   ntfy_from_client: String,
   ntfy_from_server: String,
   configuring: Option<Message>,
   inputs: Inputs,
   keys_newly_down: Vec<iced::keyboard::KeyCode>,
   keys_already_down: Vec<iced::keyboard::KeyCode>,
   keys_up: Vec<iced::keyboard::KeyCode>,
   flags: Flags,
   input_text_entry_instruction: String,
   input_text_entry_value: String,
}

struct Flags {
   output_stream: Box<dyn OutputStream>,
   cfg: GUI,
}

struct Inputs {
   stick: Stick,
   a: iced::keyboard::KeyCode,
   b: iced::keyboard::KeyCode,
   x: iced::keyboard::KeyCode,
   y: iced::keyboard::KeyCode,
   l: iced::keyboard::KeyCode,
   r: iced::keyboard::KeyCode,
}

struct Stick {
   up: iced::keyboard::KeyCode,
   down: iced::keyboard::KeyCode,
   left: iced::keyboard::KeyCode,
   right: iced::keyboard::KeyCode,
}

#[derive(Debug, Clone)]
enum Message {
   EventOccurred(iced_native::Event),
   Tick,
   InputTextEntryUpdate(String),
   InputTextEntrySubmitSay,
   InputTextEntrySubmitSend,
   Up,
   Down,
   Left,
   Right,
   A,
   B,
   X,
   Y,
   L,
   R,
}

#[derive(Debug, Clone)]
enum Feedback {
   Heard(String),
   Say(String),
   Send(String),
}

fn controller_button_to_string(btn: Message, cur: iced::keyboard::KeyCode) -> String {
   return format!("{:?} => {:?}", cur, btn);
}

impl Main {
   fn key_code_to_string(&self, key_code: &iced::keyboard::KeyCode) -> Option<&String> {
      match key_code {
         _ if key_code == &self.inputs.stick.up => Some(&self.flags.cfg.buttons.up),
         _ if key_code == &self.inputs.stick.down => Some(&self.flags.cfg.buttons.down),
         _ if key_code == &self.inputs.stick.left => Some(&self.flags.cfg.buttons.left),
         _ if key_code == &self.inputs.stick.right => Some(&self.flags.cfg.buttons.right),
         _ if key_code == &self.inputs.a => Some(&self.flags.cfg.buttons.a),
         _ if key_code == &self.inputs.b => Some(&self.flags.cfg.buttons.b),
         _ if key_code == &self.inputs.x => Some(&self.flags.cfg.buttons.x),
         _ if key_code == &self.inputs.y => Some(&self.flags.cfg.buttons.y),
         _ if key_code == &self.inputs.l => Some(&self.flags.cfg.buttons.l),
         _ if key_code == &self.inputs.r => Some(&self.flags.cfg.buttons.r),
         _ => None,
      }
   }

   fn send_from_client(&mut self, text: Feedback) {
      match text.clone() {
         Feedback::Say(s) | Feedback::Send(s) if s.len() > 0 && s.len() < 1000 => {},
         _ => return,
      };
      match self.feedback_send_c.send(text) {
         Ok(_) => {},
         Err(err) => eprintln!("main.send_say() failed to enqueue: {}", err),
      };
   }

   fn exchange(&mut self) {
      self.exchange_send();
      self.exchange_recv();
   }

   fn exchange_recv(&mut self) {
      loop {
         match self.feedback_recv_c.try_recv() {
            Ok(msg) => {
               match msg {
                  Feedback::Heard(msg) => self.ntfy_from_server = msg,
                  _ => break,
               };
            },
            _ => break,
         };
      }
   }

   fn exchange_send(&mut self) {
      let mut s = vec![];
      for key_code in self.keys_newly_down.iter() {
         match self.key_code_to_string(key_code) {
            Some(x) => {
               for c in x.chars() {
                  s.push(c);
               }
               self.keys_already_down.push(*key_code);
            },
            None => {},
         };
      }
      let mut t = vec![];
      self.keys_newly_down.clear();
      for key_code in self.keys_up.iter() {
         match self.key_code_to_string(key_code) {
            Some(x) => {
               for c in x.chars() {
                  for c in self.flags.cfg.release_prefix.chars() {
                     t.push(c);
                  }
                  t.push(c);
               }
            },
            None => {},
         };
      }
      if t.len() + s.len() > 0 {
         self.flags.output_stream.put(self.sprintf_pressed_released(s, t));
      }
      self.keys_up.clear();
   }

   fn sprintf(&self, format: &String, content: &Value) -> Vec<char> {
      return Handlebars::new().render_template(format, content).unwrap().chars().collect();
   }

   fn sprintf_pressed_released(&self, pressed: Vec<char>, released: Vec<char>) -> Vec<char> {
      match self.flags.cfg.format_keys.clone() {
         Some(x) => {
            return self.sprintf(&x, &json!({
               "pressed": pressed.iter().collect::<String>(),
               "released": released.iter().collect::<String>(),
               "ms": SystemTime::now().duration_since(UNIX_EPOCH).unwrap().as_millis(),
               "user": self.flags.cfg.user,
            }));
         },
         None => {
            let mut combo = vec![];
            combo.extend(pressed);
            combo.extend(released);
            return combo;
         },
      }
   }
}

impl Application for Main {
   type Message = Message;
   type Flags = Flags;
   type Theme = Theme;
   type Executor = executor::Default;

   fn new(flags: Self::Flags) -> (Self, Command<Message>) {
      let (sender1, receiver1) = std::sync::mpsc::channel();
      let (sender2, receiver2) = std::sync::mpsc::channel();
      let feedback_cfg = flags.cfg.feedback.clone();
      thread::spawn(move || {
         Feedbacker{
            send_c: sender1,
            recv_c: receiver2,
            cfg: feedback_cfg,
         }.listen()
      });
      return (Self {
         feedback_send_c: sender2,
         feedback_recv_c: receiver1,
         ntfy_from_client: String::from(" "),
         ntfy_from_server: String::from(" "),
         configuring: None,
         inputs: Inputs{
            stick: Stick {
               up: iced::keyboard::KeyCode::W,
               down: iced::keyboard::KeyCode::S,
               left: iced::keyboard::KeyCode::A,
               right: iced::keyboard::KeyCode::D,
            },
            a: iced::keyboard::KeyCode::Key1,
            b: iced::keyboard::KeyCode::Key2,
            x: iced::keyboard::KeyCode::Key3,
            y: iced::keyboard::KeyCode::Key4,
            l: iced::keyboard::KeyCode::Q,
            r: iced::keyboard::KeyCode::E,
         },
         flags: flags,
         keys_newly_down: vec![],
         keys_already_down: vec![],
         keys_up: vec![],
         input_text_entry_instruction: String::from(""),
         input_text_entry_value: String::from(""),
      }, Command::none())
   }

   fn title(&self) -> String {
      return String::from("Rusty Pipe")
   }

   fn update(&mut self, msg: Message) -> Command<Message> {
      match msg.clone() {
         Message::Tick => {
            self.exchange();
         },
         Message::InputTextEntryUpdate(payload) => {
            self.input_text_entry_value = payload;
         },
         Message::InputTextEntrySubmitSend => {
            self.send_from_client(Feedback::Send(self.input_text_entry_value.clone()));
            self.input_text_entry_value = String::from("");
         },
         Message::InputTextEntrySubmitSay => {
            self.send_from_client(Feedback::Say(self.input_text_entry_value.clone()));
            self.input_text_entry_value = String::from("");
         },
         Message::EventOccurred(event) if self.configuring.is_some() => {
            match event {
               iced::event::Event::Keyboard(keyboard::Event::KeyPressed{
                  key_code,
                  modifiers: _,
                  ..
               }) => {
                  match self.configuring.as_ref().unwrap() {
                     Message::Up => { self.inputs.stick.up = key_code },
                     Message::Down => { self.inputs.stick.down = key_code },
                     Message::Left => { self.inputs.stick.left = key_code },
                     Message::Right => { self.inputs.stick.right = key_code },
                     Message::A => { self.inputs.a = key_code },
                     Message::B => { self.inputs.b = key_code },
                     Message::X => { self.inputs.x = key_code },
                     Message::Y => { self.inputs.y = key_code },
                     Message::L => { self.inputs.l = key_code },
                     Message::R => { self.inputs.r = key_code },
                     _ => {},
                  };
                  self.ntfy_from_client = format!("{:?} => {:?}", key_code.clone(), self.configuring.as_ref().unwrap());
                  self.configuring = None;
               },
               _ => {},
            };
         },
         Message::EventOccurred(event) => {
            match event {
               iced::event::Event::Keyboard(keyboard::Event::KeyPressed{
                  key_code,
                  modifiers: _,
                  ..
               }) => {
                  match self.keys_already_down.iter().position(|x| *x == key_code) {
                     Some(_) => {},
                     None => {
                        self.keys_newly_down.push(key_code);
                        self.keys_newly_down.dedup();
                     },
                  };
                  self.exchange();
               },
               iced::event::Event::Keyboard(keyboard::Event::KeyReleased{
                  key_code,
                  ..
               }) => {
                  match self.keys_already_down.iter().position(|x| *x == key_code) {
                     Some(idx) => {
                        self.keys_already_down.remove(idx);
                        self.keys_up.push(key_code);
                     },
                     None => {},
                  };
                  match self.keys_newly_down.iter().position(|x| *x == key_code) {
                     Some(idx) => {
                        self.keys_newly_down.remove(idx);
                        self.keys_up.push(key_code);
                     },
                     None => {},
                  };
                  self.exchange();
               },
               _ => {},
            };
         },
         _ => {
            self.configuring = Some(msg.clone());
            self.ntfy_from_client = format!("push a key to bind to {:?}", msg.clone());
         },
      }
      return Command::none();
   }

   fn subscription(&self) -> Subscription<Message> {
      return subscription::Subscription::batch(vec![
         subscription::events_with(|event, status| match status {
            iced::event::Status::Ignored => match event {
               iced::Event::Keyboard(_) => Some(Message::EventOccurred(event)),
               _ => None,
            },
            _ => None,
         }),
         every(std::time::Duration::from_millis(5000)).map(|_| Message::Tick),
      ]);
   }

   fn view(&self) -> Element<Message> {
      let new_cfg_button = |msg: Message, s| button(text(controller_button_to_string(msg.clone(), s))).on_press(msg.clone());
      return column![
         text(String::from("= MAYHEM PARTY =")).size(32),
         column![
            column![
               text(String::from("Button Mapping")).size(24),
               text(String::from("--------------")).size(24),
               new_cfg_button(Message::Up, self.inputs.stick.up),
               new_cfg_button(Message::Down, self.inputs.stick.down),
               new_cfg_button(Message::Left, self.inputs.stick.left),
               new_cfg_button(Message::Right, self.inputs.stick.right),
               new_cfg_button(Message::A, self.inputs.a),
               new_cfg_button(Message::B, self.inputs.b),
               new_cfg_button(Message::X, self.inputs.x),
               new_cfg_button(Message::Y, self.inputs.y),
               new_cfg_button(Message::L, self.inputs.l),
               new_cfg_button(Message::R, self.inputs.r),
               text(String::from("--------------")).size(24),
               text(self.ntfy_from_client.clone()).size(18),
            ].padding(20).align_items(Alignment::Center),
            column![
               text_input(
                  &self.input_text_entry_instruction,
                  &self.input_text_entry_value,
                  Message::InputTextEntryUpdate
               ),
               row![
                  button(text("Say")).on_press(Message::InputTextEntrySubmitSay).padding(20),
                  button(text("Send")).on_press(Message::InputTextEntrySubmitSend).padding(20),
               ].padding(20).align_items(Alignment::Center),
               text(self.ntfy_from_server.clone()).size(18),
            ].padding(20).align_items(Alignment::Center),
         ].padding(0).align_items(Alignment::Center),
      ].padding(0).align_items(Alignment::Center).into();
    }
}

struct Feedbacker {
   send_c: std::sync::mpsc::Sender<Feedback>,
   recv_c: std::sync::mpsc::Receiver<Feedback>,
   cfg: GUIFeedback,
}

impl Feedbacker {
   fn listen(&mut self) {
      loop {
         std::thread::sleep(std::time::Duration::from_secs(2));
         match self.read_from_server() {
            Some(msg) if msg.len() > 0 => {
               self.write_from_server(msg.clone());
            },
            _ => {},
         };
         match self.read_from_client() {
            Some(msg) => self.write_from_client(msg.clone()),
            _ => {},
         };
      }
   }

   fn read_from_server(&mut self) -> Option<String> {
      return match &self.cfg.url_read {
         Some(url) => {
            match reqwest::blocking::get(url) {
               Ok(resp) => match resp.text() {
                  Ok(text) => Some(text),
                  _ => None,
               },
               Err(err) => {
                  eprintln!("feedback.read: cannot fetch: {}", err);
                  None
               },
            }
         },
         _ => None,
      };
   }

   fn write_from_server(&mut self, msg: String) {
      match self.send_c.send(Feedback::Heard(msg.clone())) {
         Ok(_) => {},
         Err(err) => eprintln!("feedback.listen() failed to display {}: {}", msg, err),
      };
   }

   fn read_from_client(&mut self) -> Option<Feedback> {
      let mut last: Option<Feedback> = None;
      loop {
         match self.recv_c.try_recv() {
            Ok(msg) => {
               last = Some(msg);
            },
            _ => break,
         };
      }
      return last;
   }

   fn write_from_client(&mut self, msg: Feedback) {
      match msg {
         Feedback::Say(say) | Feedback::Send(say) if say.len() > 0 => match &self.cfg.url_say {
            Some(url) => {
               match reqwest::blocking::get(format!("{}{}", url, say)) {
                  Err(err) => {
                     eprintln!("feedback.write_from_client: cannot say: {}", err);
                  },
                  _ => {},
               };
            },
            _ => {},
         },
         _ => {},
      };
   }
}