// TODO: rename this module to auth

use std::net;

use rand::{Rng, RngCore};
use bcrypt;

use libpso::packet::login::*;
use libpso::{PacketParseError, PSOPacket};
use libpso::crypto::{CipherError, PSOCipher, NullCipher};
use libpso::crypto::bb::PSOBBCipher;

use elseware::{pktvec, utf8_to_array};
use elseware::common::pktvec::PktVec;
use elseware::common::cipherkeys::{ELSEWHERE_PRIVATE_KEY, ELSEWHERE_PARRAY};
//use elseware::common::network::{PacketNetworkError};
use elseware::common::client::Client;
use elseware::common::serverstate::{SendServerPacket,  RecvServerPacket, ServerState, OnConnect, ClientId};
use elseware::common::util::array_to_utf8;

use crate::dataaccess::DataAccess;
use crate::entities::UserAccount;

pub const LOGIN_PORT: u16 = 12000;

#[derive(Debug)]
pub enum LoginError {
}


#[derive(Debug, PartialEq)]
pub enum RecvLoginPacket {
    Login(Login),
}

impl RecvServerPacket for RecvLoginPacket {
    fn from_bytes(data: &[u8]) -> Result<RecvLoginPacket, PacketParseError> {
        match data[2] {
            0x93 => Ok(RecvLoginPacket::Login(Login::from_bytes(data)?)),
            _ => Err(PacketParseError::WrongPacketForServerType)
        }
    }
}


#[derive(Debug, PartialEq)]
pub enum SendLoginPacket {
    LoginResponse(LoginResponse),
    LoginWelcome(LoginWelcome),
    RedirectClient(RedirectClient),
}

impl SendServerPacket for SendLoginPacket {
    fn as_bytes(&self) -> Vec<u8> {
        match self {
            SendLoginPacket::LoginResponse(pkt) => pkt.as_bytes(),
            SendLoginPacket::LoginWelcome(pkt) => pkt.as_bytes(),
            SendLoginPacket::RedirectClient(pkt) => pkt.as_bytes(),
        }
    }
}


#[derive(Clone)]
pub struct SharedLoginState<DA: DataAccess> {
    pub data_access: DA,
}

impl<DA: DataAccess> SharedLoginState<DA> {
    pub fn new(data_access: DA) -> SharedLoginState<DA> {
        SharedLoginState {
            data_access: data_access,
        }
    }
}

pub struct LoginServerState<DA: DataAccess> {
    data_access: DA,
}


pub fn get_login_status(data_access: &dyn DataAccess, pkt: &Login) -> Result<UserAccount, AccountStatus> {
    let username = array_to_utf8(pkt.username).map_err(|_err| AccountStatus::Error)?;
    let password = array_to_utf8(pkt.password).map_err(|_err| AccountStatus::Error)?;
    let user = data_access.get_user_by_name(username).ok_or(AccountStatus::InvalidUser)?;
    let verified = bcrypt::verify(password, user.password.as_str()).map_err(|_err| AccountStatus::Error)?;
    match verified {
        true => Ok(user),
        false => Err(AccountStatus::InvalidPassword)
    }
}


impl<DA: DataAccess> LoginServerState<DA> {
    pub fn new(data_access: DA) -> LoginServerState<DA> {
        LoginServerState {
            data_access: data_access,
        }
    }

    fn validate_login(&mut self, pkt: &Login) -> Vec<SendLoginPacket> {
        match get_login_status(&self.data_access, pkt) {
            Ok(_user) => {
                let response = SendLoginPacket::LoginResponse(LoginResponse::by_status(AccountStatus::Ok, pkt.security_data));
                let ip = net::Ipv4Addr::new(127,0,0,1);
                let ip = u32::from_ne_bytes(ip.octets());
                vec![response,
                     SendLoginPacket::RedirectClient(RedirectClient::new(ip, crate::character::CHARACTER_PORT))]
            },
            Err(err) => {
                vec![SendLoginPacket::LoginResponse(LoginResponse::by_status(err, pkt.security_data))]
            }
        }
    }
}

impl<DA: DataAccess> ServerState for LoginServerState<DA> {
    type SendPacket = SendLoginPacket;
    type RecvPacket = RecvLoginPacket;
    type PacketError = LoginError;

    fn on_connect(&mut self) -> Vec<OnConnect<Self::SendPacket>> {
        let mut rng = rand::thread_rng();

        let mut server_key = [0u8; 48];
        let mut client_key = [0u8; 48];
        rng.fill(&mut server_key[..]);
        rng.fill(&mut client_key[..]);

        vec![OnConnect::Packet(SendLoginPacket::LoginWelcome(LoginWelcome::new(server_key, client_key))),
             OnConnect::Cipher((Box::new(PSOBBCipher::new(ELSEWHERE_PARRAY, ELSEWHERE_PRIVATE_KEY, client_key)),
                                Box::new(PSOBBCipher::new(ELSEWHERE_PARRAY, ELSEWHERE_PRIVATE_KEY, server_key))))
        ]
    }

    fn handle(&mut self, id: ClientId, pkt: &Self::RecvPacket) -> Box<dyn Iterator<Item = (ClientId, Self::SendPacket)>> {
        match pkt {
            RecvLoginPacket::Login(login) => {
                Box::new(self.validate_login(login)
                         .into_iter()
                         .map(move |pkt| {
                             (id, pkt)
                         }))
            }
        }
    }
}

#[cfg(test)]
mod test {
    use std::time::SystemTime;
    use super::*;

    #[test]
    fn test_correct_login() {
        struct TestData {
        }

        impl DataAccess for TestData {
            fn get_user_by_name(&self, name: String) -> Option<UserAccount> {
                assert!(name == "testuser");
                Some(UserAccount {
                    id: 1,
                    username: "testuser".to_owned(),
                    password: bcrypt::hash("mypassword", 5).unwrap(),
                    guildcard: None,
                    team_id: None,
                    banned: false,
                    muted_until: SystemTime::now(),
                    created_at: SystemTime::now(),
                })
            }
        }

        let mut server = LoginServerState::new(TestData {});

        let send = server.handle(1, &RecvLoginPacket::Login(Login {
            flag: 0,
            tag: 65536,
            guildcard: 0,
            version: 65,
            unknown1: [0, 0, 0, 255, 0, 14],
            team: 0,
            username: utf8_to_array!("testuser", 16),
            unknown2: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
            password: utf8_to_array!("mypassword", 16),
            unknown3: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                       0, 0, 0, 0, 0, 0, 0, 0],
            hwinfo: [129, 1, 1, 1, 1, 1, 1, 1],
            security_data: [74, 97, 107, 101, 115, 101, 114, 118, 50, 48, 50, 48, 0, 0, 0, 0,
                            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],

        })).collect::<Vec<_>>();
        assert!(send == vec![
            (1, SendLoginPacket::LoginResponse(LoginResponse {
                flag: 0,
                status: AccountStatus::Ok,
                tag: 65536,
                guildcard: 0,
                team_id: 0,
                security_data: [74, 97, 107, 101, 115, 101, 114, 118, 50, 48, 50, 48, 0, 0, 0, 0,
                                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
                caps: 258
            })),
            (1, SendLoginPacket::RedirectClient(RedirectClient {
                flag: 0,
                ip: 16777343,
                port: 12001,
                padding: 0,
            }))])
    }
}