//! `ChatServer` is an actor. It maintains list of connection client session.
//! And manages available rooms. Peers send messages to other peers in same
//! room through `ChatServer`.

use actix::prelude::*;
use rand::{rngs::ThreadRng, Rng};
use std::collections::{HashMap, HashSet};
use serde::{Deserialize, Serialize};
use serde_json::{Result, Value};
use bcrypt::{verify};
use std::str::FromStr;

use {Crud, Joinable, establish_connection};
use actions::community::*;
use actions::user::*;

#[derive(EnumString,ToString,Debug)]
pub enum UserOperation {
  Login, Register, Logout, CreateCommunity, Join, Edit, Reply, Vote, Delete, NextPage, Sticky
}


#[derive(EnumString,ToString,Debug)]
pub enum MessageToUser {
  Comments, Users, Ping, Pong, Error
}

#[derive(Serialize, Deserialize)]
pub struct ErrorMessage {
  op: String,
  error: String
}

/// Chat server sends this messages to session
#[derive(Message)]
pub struct WSMessage(pub String);

/// Message for chat server communications

/// New chat session is created
#[derive(Message)]
#[rtype(usize)]
pub struct Connect {
  pub addr: Recipient<WSMessage>,
}

/// Session is disconnected
#[derive(Message)]
pub struct Disconnect {
  pub id: usize,
}

/// Send message to specific room
#[derive(Message)]
pub struct ClientMessage {
  /// Id of the client session
  pub id: usize,
  /// Peer message
  pub msg: String,
  /// Room name
  pub room: String,
}

#[derive(Serialize, Deserialize)]
pub struct StandardMessage {
  /// Id of the client session
  pub id: usize,
  /// Peer message
  pub msg: String,
}

impl actix::Message for StandardMessage {
  type Result = String;
}

#[derive(Serialize, Deserialize)]
pub struct StandardResponse<T> {
  op: String,
  response: T
}

/// List of available rooms
pub struct ListRooms;

impl actix::Message for ListRooms {
  type Result = Vec<String>;
}

/// Join room, if room does not exists create new one.
#[derive(Message)]
pub struct Join {
  /// Client id
  pub id: usize,
  /// Room name
  pub name: String,
}

#[derive(Serialize, Deserialize)]
pub struct Login {
  pub username_or_email: String,
  pub password: String
}

#[derive(Serialize, Deserialize)]
pub struct Register {
  username: String,
  email: Option<String>,
  password: String,
  password_verify: String
}

#[derive(Serialize, Deserialize)]
pub struct LoginResponse {
  op: String,
  jwt: String
}

#[derive(Serialize, Deserialize)]
pub struct CreateCommunity {
  name: String,
}

#[derive(Serialize, Deserialize)]
pub struct CreateCommunityResponse {
  op: String,
  data: Community
}

/// `ChatServer` manages chat rooms and responsible for coordinating chat
/// session. implementation is super primitive
pub struct ChatServer {
  sessions: HashMap<usize, Recipient<WSMessage>>, // A map from generated random ID to session addr
  rooms: HashMap<String, HashSet<usize>>, // A map from room name to set of connectionIDs
  rng: ThreadRng,
}

impl Default for ChatServer {
  fn default() -> ChatServer {
    // default room
    let mut rooms = HashMap::new();
    rooms.insert("Main".to_owned(), HashSet::new());

    ChatServer {
      sessions: HashMap::new(),
      rooms: rooms,
      rng: rand::thread_rng(),
    }
  }
}

impl ChatServer {
  /// Send message to all users in the room
  fn send_room_message(&self, room: &str, message: &str, skip_id: usize) {
    if let Some(sessions) = self.rooms.get(room) {
      for id in sessions {
        if *id != skip_id {
          if let Some(addr) = self.sessions.get(id) {
            let _ = addr.do_send(WSMessage(message.to_owned()));
          }
        }
      }
    }
  }

  /// Send message only to self
  fn send(&self, message: &str, id: &usize) {
    // println!("{:?}", self.sessions);
    if let Some(addr) = self.sessions.get(id) {
      println!("msg: {}", message); 
      // println!("{:?}", addr.connected());
      let _ = addr.do_send(WSMessage(message.to_owned()));
    }
  }
}

/// Make actor from `ChatServer`
impl Actor for ChatServer {
  /// We are going to use simple Context, we just need ability to communicate
  /// with other actors.
  type Context = Context<Self>;
}

/// Handler for Connect message.
///
/// Register new session and assign unique id to this session
impl Handler<Connect> for ChatServer {
  type Result = usize;

  fn handle(&mut self, msg: Connect, _: &mut Context<Self>) -> Self::Result {
    println!("Someone joined");

    // notify all users in same room
    self.send_room_message(&"Main".to_owned(), "Someone joined", 0);

    // register session with random id
    let id = self.rng.gen::<usize>();
    self.sessions.insert(id, msg.addr);

    // auto join session to Main room
    self.rooms.get_mut(&"Main".to_owned()).unwrap().insert(id);

    // send id back
    id
  }
}

/// Handler for Disconnect message.
impl Handler<Disconnect> for ChatServer {
  type Result = ();

  fn handle(&mut self, msg: Disconnect, _: &mut Context<Self>) {
    println!("Someone disconnected");

    let mut rooms: Vec<String> = Vec::new();

    // remove address
    if self.sessions.remove(&msg.id).is_some() {
      // remove session from all rooms
      for (name, sessions) in &mut self.rooms {
        if sessions.remove(&msg.id) {
          rooms.push(name.to_owned());
        }
      }
    }
    // send message to other users
    for room in rooms {
      self.send_room_message(&room, "Someone disconnected", 0);
    }
  }
}

/// Handler for Message message.
impl Handler<ClientMessage> for ChatServer {
  type Result = ();

  fn handle(&mut self, msg: ClientMessage, _: &mut Context<Self>) {
    self.send_room_message(&msg.room, msg.msg.as_str(), msg.id);
  }
}

/// Handler for Message message.
impl Handler<StandardMessage> for ChatServer {
  type Result = MessageResult<StandardMessage>;

  fn handle(&mut self, msg: StandardMessage, _: &mut Context<Self>) -> Self::Result {

    let json: Value = serde_json::from_str(&msg.msg)
      .expect("Couldn't parse message");

    let data: &Value = &json["data"];
    let op = &json["op"].as_str().unwrap();
    let auth = &json["auth"].as_str();
    let user_operation: UserOperation = UserOperation::from_str(&op).unwrap();

    let res: String = match user_operation {
      UserOperation::Login => {
        let login: Login = serde_json::from_str(&data.to_string()).unwrap();
        login.perform()
      },
      UserOperation::Register => {
        let register: Register = serde_json::from_str(&data.to_string()).unwrap();
        register.perform()
      },
      UserOperation::CreateCommunity => {
        let create_community: CreateCommunity = serde_json::from_str(&data.to_string()).unwrap();
        match auth {
          Some(auth) => {
            create_community.perform(auth)
          },
          None => serde_json::to_string(
            &ErrorMessage {
              op: UserOperation::CreateCommunity.to_string(),
              error: "Not logged in.".to_string()
            }
            )
            .unwrap()
        }
      },
      _ => {
        let e = ErrorMessage { 
          op: "Unknown".to_string(),
          error: "Unknown User Operation".to_string()
        };
        serde_json::to_string(&e).unwrap()
      }
      // _ => "no".to_string()
    };



    // let data: &Value = &json["data"];
    // let res = StandardResponse {op: "nope".to_string(), response: "hi".to_string()};
    // let out = serde_json::to_string(&res).unwrap();
    MessageResult(res)
  }
}

// /// Handler for `ListRooms` message.
// impl Handler<ListRooms> for ChatServer {
//   type Result = MessageResult<ListRooms>;

//   fn handle(&mut self, _: ListRooms, _: &mut Context<Self>) -> Self::Result {
//     let mut rooms = Vec::new();

//     for key in self.rooms.keys() {
//       rooms.push(key.to_owned())
//     }

//     MessageResult(rooms)
//   }
// }

// /// Join room, send disconnect message to old room
// /// send join message to new room
// impl Handler<Join> for ChatServer {
//   type Result = ();

//   fn handle(&mut self, msg: Join, _: &mut Context<Self>) {
//     let Join { id, name } = msg;
//     let mut rooms = Vec::new();

//     // remove session from all rooms
//     for (n, sessions) in &mut self.rooms {
//       if sessions.remove(&id) {
//         rooms.push(n.to_owned());
//       }
//     }
//     // send message to other users
//     for room in rooms {
//       self.send_room_message(&room, "Someone disconnected", 0);
//     }

//     if self.rooms.get_mut(&name).is_none() {
//       self.rooms.insert(name.clone(), HashSet::new());
//     }
//     self.send_room_message(&name, "Someone connected", id);
//     self.rooms.get_mut(&name).unwrap().insert(id);
//   }

// }

pub trait Perform {
  fn perform(&self) -> String;
}

pub trait PerformAuth {
  fn perform(&self, auth: &str) -> String;
}

impl Perform for Login {
  fn perform(&self) -> String {

    let conn = establish_connection();

    // Fetch that username / email
    let user: User_ = match User_::find_by_email_or_username(&conn, &self.username_or_email) {
      Ok(user) => user,
      Err(e) => return serde_json::to_string(
        &ErrorMessage {
          op: UserOperation::Login.to_string(), 
          error: "Couldn't find that username or email".to_string()
        }
        )
        .unwrap()
    };

    // Verify the password
    let valid: bool = verify(&self.password, &user.password_encrypted).unwrap_or(false);
    if !valid {
      return serde_json::to_string(
        &ErrorMessage {
          op: UserOperation::Login.to_string(), 
          error: "Password incorrect".to_string()
        }
        )
        .unwrap()
    }

    // Return the jwt
    serde_json::to_string(
      &LoginResponse {
        op: UserOperation::Login.to_string(),
        jwt: user.jwt()
      }
      )
      .unwrap()
  }
}

impl Perform for Register {
  fn perform(&self) -> String {

    let conn = establish_connection();

    // Make sure passwords match
    if &self.password != &self.password_verify {
      return serde_json::to_string(
        &ErrorMessage {
          op: UserOperation::Register.to_string(), 
          error: "Passwords do not match.".to_string()
        }
        )
        .unwrap();
    }

    // Register the new user
    let user_form = UserForm {
      name: self.username.to_owned(),
      email: self.email.to_owned(),
      password_encrypted: self.password.to_owned(),
      preferred_username: None,
      updated: None
    };

    // Create the user
    let inserted_user = match User_::create(&conn, &user_form) {
      Ok(user) => user,
      Err(e) => {
        return serde_json::to_string(
          &ErrorMessage {
            op: UserOperation::Register.to_string(), 
            error: "User already exists.".to_string() // overwrite the diesel error
          }
          )
          .unwrap()
      }
    };

    // Return the jwt
    serde_json::to_string(
      &LoginResponse {
        op: UserOperation::Register.to_string(), 
        jwt: inserted_user.jwt()
      }
      )
      .unwrap()

  }
}

impl PerformAuth for CreateCommunity {
  fn perform(&self, auth: &str) -> String {

    let conn = establish_connection();

    let claims = match Claims::decode(&auth) {
      Ok(claims) => claims.claims,
      Err(e) => {
        return serde_json::to_string(
          &ErrorMessage {
            op: UserOperation::CreateCommunity.to_string(), 
            error: "Community user already exists.".to_string() // overwrite the diesel error
          }
          )
          .unwrap();
      }
    };

    let user_id = claims.id;
    let iss = claims.iss;

    // Register the new user
    let community_form = CommunityForm {
      name: self.name.to_owned(),
      updated: None
    };

    let inserted_community = match Community::create(&conn, &community_form) {
      Ok(community) => community,
      Err(e) => {
        return serde_json::to_string(
          &ErrorMessage {
            op: UserOperation::CreateCommunity.to_string(), 
            error: "Community already exists.".to_string() // overwrite the diesel error
          }
          )
          .unwrap()
      }
    };

    let community_user_form = CommunityUserForm {
      community_id: inserted_community.id,
      fedi_user_id: format!("{}/{}", iss, user_id)
    };

    let inserted_community_user = match CommunityUser::join(&conn, &community_user_form) {
      Ok(user) => user,
      Err(e) => {
        return serde_json::to_string(
          &ErrorMessage {
            op: UserOperation::CreateCommunity.to_string(), 
            error: "Community user already exists.".to_string() // overwrite the diesel error
          }
          )
          .unwrap()
      }
    };


    // Return the jwt
    serde_json::to_string(
      &CreateCommunityResponse {
        op: UserOperation::CreateCommunity.to_string(), 
        data: inserted_community
      }
      )
      .unwrap()

  }
}
// impl Handler<Login> for ChatServer {

//   type Result = MessageResult<Login>;
//   fn handle(&mut self, msg: Login, _: &mut Context<Self>) -> Self::Result {

//     let conn = establish_connection();

//     // Fetch that username / email
//     let user: User_ = match User_::find_by_email_or_username(&conn, &msg.username_or_email) {
//       Ok(user) => user,
//       Err(e) => return MessageResult(
//         Err(
//           ErrorMessage {
//             op: UserOperation::Login.to_string(), 
//             error: "Couldn't find that username or email".to_string()
//           }
//           )
//         )
//     };

//     // Verify the password
//     let valid: bool = verify(&msg.password, &user.password_encrypted).unwrap_or(false);
//     if !valid {
//       return MessageResult(
//         Err(
//           ErrorMessage {
//             op: UserOperation::Login.to_string(), 
//             error: "Password incorrect".to_string()
//           }
//           )
//         )
//     }

//     // Return the jwt
//     MessageResult(
//       Ok(
//         LoginResponse {
//           op: UserOperation::Login.to_string(), 
//           jwt: user.jwt()
//         }
//         )
//       )
//   }
// }

// impl Handler<Register> for ChatServer {

//   type Result = MessageResult<Register>;
//   fn handle(&mut self, msg: Register, _: &mut Context<Self>) -> Self::Result {

//     let conn = establish_connection();

//     // Make sure passwords match
//     if msg.password != msg.password_verify {
//       return MessageResult(
//         Err(
//           ErrorMessage {
//             op: UserOperation::Register.to_string(), 
//             error: "Passwords do not match.".to_string()
//           }
//           )
//         );
//     }

//     // Register the new user
//     let user_form = UserForm {
//       name: msg.username,
//       email: msg.email,
//       password_encrypted: msg.password,
//       preferred_username: None,
//       updated: None
//     };

//     // Create the user
//     let inserted_user = match User_::create(&conn, &user_form) {
//       Ok(user) => user,
//       Err(e) => return MessageResult(
//         Err(
//           ErrorMessage {
//             op: UserOperation::Register.to_string(), 
//             error: "User already exists.".to_string() // overwrite the diesel error
//           }
//           )
//         )
//     };

//     // Return the jwt
//     MessageResult(
//       Ok(
//         LoginResponse {
//           op: UserOperation::Register.to_string(), 
//           jwt: inserted_user.jwt()
//         }
//         )
//       )

//   }
// }


// impl Handler<CreateCommunity> for ChatServer {

//   type Result = MessageResult<CreateCommunity>;

//   fn handle(&mut self, msg: CreateCommunity, _: &mut Context<Self>) -> Self::Result {
//     let conn = establish_connection();

//     let user_id = Claims::decode(&msg.auth).id;

//     let community_form = CommunityForm {
//       name: msg.name,
//       updated: None
//     };

//     let community = match Community::create(&conn, &community_form) {
//       Ok(community) => community,
//       Err(e) => return MessageResult(
//         Err(
//           ErrorMessage {
//             op: UserOperation::CreateCommunity.to_string(), 
//             error: "Community already exists.".to_string() // overwrite the diesel error
//           }
//           )
//         )
//     };
    
//     MessageResult(
//       Ok(
//         CreateCommunityResponse {
//           op: UserOperation::CreateCommunity.to_string(), 
//           community: community
//         }
//         )
//       )
//   }
// }