mod client_init;
mod scene;
mod ui;

use super::char_selection::CharSelectionState;
#[cfg(feature = "singleplayer")]
use crate::singleplayer::Singleplayer;
use crate::{
    i18n::LocalizationHandle, render::Renderer, settings::Settings, window::Event, Direction,
    GlobalState, PlayState, PlayStateResult,
};
use client::{
    addr::ConnectionArgs,
    error::{InitProtocolError, NetworkConnectError, NetworkError},
    Client, ServerInfo,
};
use client_init::{ClientInit, Error as InitError, Msg as InitMsg};
use common::comp;
use common_base::span;
use scene::Scene;
use std::sync::Arc;
use tokio::runtime;
use tracing::error;
use ui::{Event as MainMenuEvent, MainMenuUi};

// TODO: show status messages for waiting on server creation, client init, and
// pipeline creation (we can show progress of pipeline creation)
enum InitState {
    None,
    // Waiting on the client initialization
    Client(ClientInit),
    // Client initialized but still waiting on Renderer pipeline creation
    Pipeline(Box<Client>),
}

impl InitState {
    fn client(&self) -> Option<&ClientInit> {
        if let Self::Client(client_init) = &self {
            Some(client_init)
        } else {
            None
        }
    }
}

pub struct MainMenuState {
    main_menu_ui: MainMenuUi,
    init: InitState,
    scene: Scene,
}

impl MainMenuState {
    /// Create a new `MainMenuState`.
    pub fn new(global_state: &mut GlobalState) -> Self {
        Self {
            main_menu_ui: MainMenuUi::new(global_state),
            init: InitState::None,
            scene: Scene::new(global_state.window.renderer_mut()),
        }
    }
}

impl PlayState for MainMenuState {
    fn enter(&mut self, global_state: &mut GlobalState, _: Direction) {
        // Kick off title music
        if global_state.settings.audio.output.is_enabled() && global_state.audio.music_enabled() {
            global_state.audio.play_title_music();
        }

        // Reset singleplayer server if it was running already
        #[cfg(feature = "singleplayer")]
        {
            global_state.singleplayer = None;
        }

        // Updated localization in case the selected language was changed
        self.main_menu_ui
            .update_language(global_state.i18n, &global_state.settings);
        // Set scale mode in case it was change
        self.main_menu_ui
            .set_scale_mode(global_state.settings.interface.ui_scale);
    }

    #[allow(clippy::single_match)] // TODO: remove when event match has multiple arms
    fn tick(&mut self, global_state: &mut GlobalState, events: Vec<Event>) -> PlayStateResult {
        span!(_guard, "tick", "<MainMenuState as PlayState>::tick");

        // Poll server creation
        #[cfg(feature = "singleplayer")]
        {
            if let Some(singleplayer) = &global_state.singleplayer {
                match singleplayer.receiver.try_recv() {
                    Ok(Ok(runtime)) => {
                        // Attempt login after the server is finished initializing
                        attempt_login(
                            &mut global_state.info_message,
                            "singleplayer".to_owned(),
                            "".to_owned(),
                            ConnectionArgs::Mpsc(14004),
                            &mut self.init,
                            Some(runtime),
                        );
                    },
                    Ok(Err(e)) => {
                        error!(?e, "Could not start server");
                        global_state.singleplayer = None;
                        self.init = InitState::None;
                        self.main_menu_ui.cancel_connection();
                        self.main_menu_ui.show_info(format!("Error: {:?}", e));
                    },
                    Err(_) => (),
                }
            }
        }

        // Handle window events.
        for event in events {
            // Pass all events to the ui first.
            if self.main_menu_ui.handle_event(event.clone()) {
                continue;
            }

            match event {
                Event::Close => return PlayStateResult::Shutdown,
                // Ignore all other events.
                _ => {},
            }
        }
        // Poll client creation.
        match self.init.client().and_then(|init| init.poll()) {
            Some(InitMsg::Done(Ok(mut client))) => {
                // Register voxygen components / resources
                crate::ecs::init(client.state_mut().ecs_mut());
                self.init = InitState::Pipeline(Box::new(client));
            },
            Some(InitMsg::Done(Err(e))) => {
                self.init = InitState::None;
                tracing::trace!(?e, "raw Client Init error");
                let e = get_client_msg_error(e, &global_state.i18n);
                // Log error for possible additional use later or incase that the error
                // displayed is cut of.
                error!(?e, "Client Init failed");
                global_state.info_message = Some(e);
            },
            Some(InitMsg::IsAuthTrusted(auth_server)) => {
                if global_state
                    .settings
                    .networking
                    .trusted_auth_servers
                    .contains(&auth_server)
                {
                    // Can't fail since we just polled it, it must be Some
                    self.init.client().unwrap().auth_trust(auth_server, true);
                } else {
                    // Show warning that auth server is not trusted and prompt for approval
                    self.main_menu_ui.auth_trust_prompt(auth_server);
                }
            },
            None => {},
        }

        // Tick the client to keep the connection alive if we are waiting on pipelines
        let localized_strings = &global_state.i18n.read();
        if let InitState::Pipeline(client) = &mut self.init {
            match client.tick(
                comp::ControllerInputs::default(),
                global_state.clock.dt(),
                |_| {},
            ) {
                Ok(events) => {
                    for event in events {
                        match event {
                            client::Event::SetViewDistance(vd) => {
                                global_state.settings.graphics.view_distance = vd;
                                global_state.settings.save_to_file_warn();
                            },
                            client::Event::Disconnect => {
                                global_state.info_message = Some(
                                    localized_strings
                                        .get("main.login.server_shut_down")
                                        .to_owned(),
                                );
                                self.init = InitState::None;
                            },
                            _ => {},
                        }
                    }
                },
                Err(err) => {
                    global_state.info_message =
                        Some(localized_strings.get("common.connection_lost").to_owned());
                    error!(?err, "[main menu] Failed to tick the client");
                    self.init = InitState::None;
                },
            }
        }

        // Poll renderer pipeline creation
        if let InitState::Pipeline(..) = &self.init {
            // If not complete go to char select screen
            if global_state
                .window
                .renderer()
                .pipeline_creation_status()
                .is_none()
            {
                // Always succeeds since we check above
                if let InitState::Pipeline(client) =
                    core::mem::replace(&mut self.init, InitState::None)
                {
                    self.main_menu_ui.connected();
                    return PlayStateResult::Push(Box::new(CharSelectionState::new(
                        global_state,
                        std::rc::Rc::new(std::cell::RefCell::new(*client)),
                    )));
                }
            }
        }

        // Maintain the UI.
        for event in self
            .main_menu_ui
            .maintain(global_state, global_state.clock.dt())
        {
            match event {
                MainMenuEvent::LoginAttempt {
                    username,
                    password,
                    server_address,
                } => {
                    let mut net_settings = &mut global_state.settings.networking;
                    let use_quic = net_settings.use_quic;
                    net_settings.username = username.clone();
                    net_settings.default_server = server_address.clone();
                    if !net_settings.servers.contains(&server_address) {
                        net_settings.servers.push(server_address.clone());
                    }
                    global_state.settings.save_to_file_warn();

                    let connection_args = if use_quic {
                        ConnectionArgs::Quic {
                            hostname: server_address,
                            prefer_ipv6: false,
                        }
                    } else {
                        ConnectionArgs::Tcp {
                            hostname: server_address,
                            prefer_ipv6: false,
                        }
                    };
                    attempt_login(
                        &mut global_state.info_message,
                        username,
                        password,
                        connection_args,
                        &mut self.init,
                        None,
                    );
                },
                MainMenuEvent::CancelLoginAttempt => {
                    // init contains InitState::Client(ClientInit), which spawns a thread which
                    // contains a TcpStream::connect() call This call is
                    // blocking TODO fix when the network rework happens
                    #[cfg(feature = "singleplayer")]
                    {
                        global_state.singleplayer = None;
                    }
                    self.init = InitState::None;
                    self.main_menu_ui.cancel_connection();
                },
                MainMenuEvent::ChangeLanguage(new_language) => {
                    global_state.settings.language.selected_language =
                        new_language.language_identifier;
                    global_state.i18n = LocalizationHandle::load_expect(
                        &global_state.settings.language.selected_language,
                    );
                    global_state.i18n.read().log_missing_entries();
                    global_state
                        .i18n
                        .set_english_fallback(global_state.settings.language.use_english_fallback);
                    self.main_menu_ui
                        .update_language(global_state.i18n, &global_state.settings);
                },
                #[cfg(feature = "singleplayer")]
                MainMenuEvent::StartSingleplayer => {
                    let singleplayer = Singleplayer::new();

                    global_state.singleplayer = Some(singleplayer);
                },
                MainMenuEvent::Quit => return PlayStateResult::Shutdown,
                // Note: Keeping in case we re-add the disclaimer
                /*MainMenuEvent::DisclaimerAccepted => {
                    global_state.settings.show_disclaimer = false
                },*/
                MainMenuEvent::AuthServerTrust(auth_server, trust) => {
                    if trust {
                        global_state
                            .settings
                            .networking
                            .trusted_auth_servers
                            .insert(auth_server.clone());
                        global_state.settings.save_to_file_warn();
                    }
                    self.init
                        .client()
                        .map(|init| init.auth_trust(auth_server, trust));
                },
            }
        }

        if let Some(info) = global_state.info_message.take() {
            self.main_menu_ui.show_info(info);
        }

        PlayStateResult::Continue
    }

    fn name(&self) -> &'static str { "Title" }

    fn render(&mut self, renderer: &mut Renderer, _: &Settings) {
        let mut drawer = match renderer
            .start_recording_frame(self.scene.global_bind_group())
            .expect("Unrecoverable render error when starting a new frame!")
        {
            Some(d) => d,
            // Couldn't get swap chain texture this frame
            None => return,
        };

        // Draw the UI to the screen.
        if let Some(mut ui_drawer) = drawer.third_pass().draw_ui() {
            self.main_menu_ui.render(&mut ui_drawer);
        };
    }
}

fn get_client_msg_error(e: client_init::Error, localized_strings: &LocalizationHandle) -> String {
    let localization = localized_strings.read();

    // When a network error is received and there is a mismatch between the client
    // and server version it is almost definitely due to this mismatch rather than
    // a true networking error.
    let net_e = |error: String, mismatched_server_info: Option<ServerInfo>| -> String {
        if let Some(server_info) = mismatched_server_info {
            format!(
                "{} {}: {} {}: {}",
                localization.get("main.login.network_wrong_version"),
                localization.get("main.login.client_version"),
                common::util::GIT_HASH.to_string(),
                localization.get("main.login.server_version"),
                server_info.git_hash
            )
        } else {
            format!(
                "{}: {}",
                localization.get("main.login.network_error"),
                error
            )
        }
    };

    use client::Error;
    match e {
        InitError::ClientError {
            error,
            mismatched_server_info,
        } => match error {
            Error::SpecsErr(e) => {
                format!("{}: {}", localization.get("main.login.internal_error"), e)
            },
            Error::AuthErr(e) => format!(
                "{}: {}",
                localization.get("main.login.authentication_error"),
                e
            ),
            Error::Kicked(e) => e,
            Error::TooManyPlayers => localization.get("main.login.server_full").into(),
            Error::AuthServerNotTrusted => {
                localization.get("main.login.untrusted_auth_server").into()
            },
            Error::ServerTimeout => localization.get("main.login.timeout").into(),
            Error::ServerShutdown => localization.get("main.login.server_shut_down").into(),
            Error::NotOnWhitelist => localization.get("main.login.not_on_whitelist").into(),
            Error::Banned(reason) => {
                format!("{}: {}", localization.get("main.login.banned"), reason)
            },
            Error::InvalidCharacter => localization.get("main.login.invalid_character").into(),
            Error::NetworkErr(NetworkError::ConnectFailed(NetworkConnectError::Handshake(
                InitProtocolError::WrongVersion(_),
            ))) => net_e(
                localization
                    .get("main.login.network_wrong_version")
                    .to_owned(),
                mismatched_server_info,
            ),
            Error::NetworkErr(e) => net_e(e.to_string(), mismatched_server_info),
            Error::ParticipantErr(e) => net_e(e.to_string(), mismatched_server_info),
            Error::StreamErr(e) => net_e(e.to_string(), mismatched_server_info),
            Error::HostnameLookupFailed(e) => {
                format!("{}: {}", localization.get("main.login.server_not_found"), e)
            },
            Error::Other(e) => {
                format!("{}: {}", localization.get("common.error"), e)
            },
            Error::AuthClientError(e) => match e {
                // TODO: remove parentheses
                client::AuthClientError::RequestError(e) => format!(
                    "{}: {}",
                    localization.get("main.login.failed_sending_request"),
                    e
                ),
                client::AuthClientError::JsonError(e) => format!(
                    "{}: {}",
                    localization.get("main.login.failed_sending_request"),
                    e
                ),
                client::AuthClientError::InsecureSchema => {
                    localization.get("main.login.insecure_auth_scheme").into()
                },
                client::AuthClientError::ServerError(_, e) => {
                    String::from_utf8_lossy(&e).to_string()
                },
            },
            Error::AuthServerUrlInvalid(e) => {
                format!(
                    "{}: https://{}",
                    localization.get("main.login.failed_auth_server_url_invalid"),
                    e
                )
            },
        },
        InitError::ClientCrashed => localization.get("main.login.client_crashed").into(),
    }
}

fn attempt_login(
    info_message: &mut Option<String>,
    username: String,
    password: String,
    connection_args: ConnectionArgs,
    init: &mut InitState,
    runtime: Option<Arc<runtime::Runtime>>,
) {
    if let Err(err) = comp::Player::alias_validate(&username) {
        *info_message = Some(err.to_string());
        return;
    }

    // Don't try to connect if there is already a connection in progress.
    if let InitState::None = init {
        *init = InitState::Client(ClientInit::new(
            connection_args,
            username,
            password,
            runtime,
        ));
    }
}