use std::{ops::{Deref, DerefMut}, str::FromStr, sync::Arc, thread::sleep, time::{self, Duration}};

use filamento::{chat::{Chat, Message}, db::Db, error::{CommandError, ConnectionError, DatabaseError}, files::FilesMem, user::User, UpdateMessage};
use indexmap::IndexMap;
use jid::JID;
use leptos::{prelude::*, task::spawn_local};
use futures::stream::StreamExt;
use leptos_meta::Stylesheet;
use leptos_query::{create_query, provide_query_client, provide_query_client_with_options, DefaultQueryOptions, QueryOptions, QueryResult, QueryScope};
use leptos_reactive::{SignalGetUntracked, SignalStream};
use stylance::import_style;
use thiserror::Error;
use tokio::{sync::mpsc::Receiver};
use tracing::debug;
use uuid::Uuid;

pub enum AppState {
    LoggedOut,
    LoggedIn,
}

#[derive(Clone)]
pub struct Client {
    client: filamento::Client<FilesMem>,
    jid: Arc<JID>,
    file_store: FilesMem,
}

impl Deref for Client {
    type Target = filamento::Client<FilesMem>;

    fn deref(&self) -> &Self::Target {
        &self.client
    }
}

impl DerefMut for Client {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.client
    }
}

#[component]
pub fn App() -> impl IntoView {
    let (app, set_app) = signal(AppState::LoggedOut);
    let client: RwSignal<Option<(Client, Receiver<UpdateMessage>)>, LocalStorage> = RwSignal::new_local(None);

    view! {
        {move || match &*app.read() {
            AppState::LoggedOut => view! { <LoginPage set_app set_client=client /> }.into_any(),
            AppState::LoggedIn => {
                if let Some((client, updates)) = client.write_untracked().take() {
                    view! { <Macaw client updates /> }.into_any()
                } else {
                    set_app.set(AppState::LoggedOut);
                    view! { <LoginPage set_app set_client=client /> }.into_any()
                }
            }
        }}
    }
}

#[derive(Clone, Debug, Error)]
pub enum LoginError {
    #[error("Missing Password")]
    MissingPassword,
    #[error("Missing JID")]
    MissingJID,
    #[error("Invalid JID: {0}")]
    InvalidJID(#[from] jid::ParseError),
    #[error("Connection Error: {0}")]
    ConnectionError(#[from] CommandError<ConnectionError>),
}

#[component]
fn LoginPage(set_app: WriteSignal<AppState>, set_client: RwSignal<Option<(Client, Receiver<UpdateMessage>)>, LocalStorage>) -> impl IntoView {
    let jid = RwSignal::new("".to_string());
    let password = RwSignal::new("".to_string());
    let remember_me = RwSignal::new(false);
    let connect_on_login = RwSignal::new(true);

    let (error, set_error) = signal_local(None::<LoginError>);
    let error_message = move || {
        error.with(|error| {
            if let Some(error) = error {
                view! { <div class="error">{error.to_string()}</div> }.into_any()
            } else {
                view! {}.into_any()
            }
        })
    };

    let (login_pending, set_login_pending) = signal(false);

    let login = Action::new_local(move |_| {
        async move {
            set_login_pending.set(true);

            if jid.read_untracked().is_empty() {
                set_error.set(Some(LoginError::MissingJID));
                set_login_pending.set(false);
                return
            }

            if password.read_untracked().is_empty() {
                set_error.set(Some(LoginError::MissingPassword));
                set_login_pending.set(false);
                return
            }

            let jid = match JID::from_str(&jid.read_untracked()) {
                Ok(j) => j,
                Err(e) => {
                    set_error.set(Some(e.into()));
                    set_login_pending.set(false);
                    return
                },
            };

            // initialise the client
            let db = Db::create_connect_and_migrate("mem.db").await.unwrap();
            let files_mem = FilesMem::new();
            let (client, updates) =
                filamento::Client::new(jid.clone(), password.read_untracked().clone(), db, files_mem.clone());
            // TODO: remember_me
            let client = Client {
                client,
                jid: Arc::new(jid),
                file_store: files_mem,
            };
            // TODO: connect on login
            if *connect_on_login.read_untracked() {
                match client.connect().await {
                    Ok(_) => {},
                    Err(e) => {
                        set_error.set(Some(e.into()));
                        set_login_pending.set(false);
                        return
                    },
                }
            }

            // debug!("before setting app state");
            set_client.set(Some((client, updates)));
            set_app.set(AppState::LoggedIn);
        }
    });

    view! {
        <div class="center fill">
            <div id="login-form" class="panel">
                <div id="hero">
                    <img src="/assets/icon.png" />
                    <h1>Macaw Instant Messenger</h1>
                </div>
                {error_message}
                <form on:submit=move |ev| {
                    ev.prevent_default();
                    login.dispatch(());
                }>
                    <label for="jid">JID</label>
                    <input
                        disabled=login_pending
                        placeholder="caw@macaw.chat"
                        type="text"
                        bind:value=jid
                        name="jid"
                        id="jid"
                        autofocus="true"
                    />
                    <label for="password">Password</label>
                    <input
                        disabled=login_pending
                        placeholder="••••••••"
                        type="password"
                        bind:value=password
                        name="password"
                        id="password"
                    />
                    <div>
                        <label for="remember_me">Remember me</label>
                        <input
                            disabled=login_pending
                            type="checkbox"
                            bind:checked=remember_me
                            name="remember_me"
                            id="remember_me"
                        />
                    </div>
                    <div>
                        <label for="connect_on_login">Connect on login</label>
                        <input
                            disabled=login_pending
                            type="checkbox"
                            bind:checked=connect_on_login
                            name="connect_on_login"
                            id="connect_on_login"
                        />
                    </div>
                    <input disabled=login_pending class="button" type="submit" value="Log In" />
                </form>
            </div>
        </div>
    }
}

#[component]
fn Macaw(
    // TODO: logout
    // app_state: WriteSignal<Option<essage>)>, LocalStorage>,
    client: Client,
    mut updates: Receiver<UpdateMessage>,
) -> impl IntoView {
    // TODO: is there some kind of context_local?
    let client = RwSignal::new_local(client);
    provide_context(client);

    let (new_messages, set_new_messages) = signal(None::<(JID, MacawMessage)>);
    provide_context(new_messages);

    provide_query_client_with_options(DefaultQueryOptions {
        resource_option: leptos_query::ResourceOption::Local,
        ..Default::default()
    });

    let updates_routine = OnceResource::new(async move {
        while let Some(update) = updates.recv().await {
            match update {
                UpdateMessage::Online(online, items) => {},
                UpdateMessage::Offline(offline) => {},
                UpdateMessage::RosterUpdate(contact, user) => {},
                UpdateMessage::RosterDelete(jid) => {},
                UpdateMessage::Presence { from, presence } => {},
                UpdateMessage::Message { to, from, message } => {
                    let new_message = MacawMessage::got_message_and_user(message, from);
                    set_new_messages.set(Some((to, new_message)));
                },
                UpdateMessage::MessageDelivery { id, chat, delivery } => {},
                UpdateMessage::SubscriptionRequest(jid) => {},
                UpdateMessage::NickChanged { jid, nick } => {},
                UpdateMessage::AvatarChanged { jid, id } => {},
            }
        }
    });

    view! {
        "logged in"
        <ChatsList />
    }
}

fn chat_query() -> QueryScope<JID, Result<Chat, String>> {
    create_query(get_chat, QueryOptions::default())
}

async fn get_chat(jid: JID) -> Result<Chat, String> {
    let client: Client = use_context::<RwSignal<Client, LocalStorage>>().unwrap().read_untracked().clone();
    client.get_chat(jid).await.map_err(|e| e.to_string())
}

fn user_query() -> QueryScope<JID, Result<User, String>> {
    create_query(get_user, QueryOptions::default())
}

async fn get_user(jid: JID) -> Result<User, String> {
    let client: Client = use_context::<RwSignal<Client, LocalStorage>>().unwrap().read_untracked().clone();
    client.get_user(jid).await.map_err(|e| e.to_string())
}

fn message_query() -> QueryScope<Uuid, Result<Message, String>> {
    create_query(get_message, QueryOptions::default())
}

async fn get_message(id: Uuid) -> Result<Message, String> {
    let client: Client = use_context::<RwSignal<Client, LocalStorage>>().unwrap().read_untracked().clone();
    client.get_message(id).await.map_err(|e| e.to_string())
}

// fn got_chat(chat: Chat) -> QueryScope<JID, MacawChat> {
//     let fetcher = move |_| {
//         let chat = (&chat).clone();
//         async {
//         MacawChat {
//             chat
//         }
//     }};
//     create_query(fetcher, QueryOptions::default())
// }

#[derive(Clone)]
struct MacawChat {
    chat: ReadSignal<Option<Option<Result<Chat, String>>>>,
    user: ReadSignal<Option<Option<Result<User, String>>>>,
}

impl MacawChat {
    fn got_chat_and_user(chat: Chat, user: User) -> Self {
        let correspondent = chat.correspondent.clone();
        let chat_query = chat_query();
        chat_query.set_query_data(correspondent.clone(), Ok(chat));
        let chat = chat_query.use_query(move || correspondent.clone());
        let jid = user.jid.clone();
        let user_query = user_query();
        user_query.set_query_data(jid.clone(), Ok(user));
        let user = user_query.use_query(move || jid.clone());
        Self {
            chat: ReadSignal::from_stream_unsync(chat.data.to_stream()),
            user: ReadSignal::from_stream_unsync(user.data.to_stream()),
        }
    }

    fn get(jid: JID) -> Self {
        let jid1 = jid.clone();
        let chat = chat_query().use_query(move || (&jid1).clone());
        let user = user_query().use_query(move || (&jid).clone());
        Self {
            chat: ReadSignal::from_stream_unsync(chat.data.to_stream()),
            user: ReadSignal::from_stream_unsync(user.data.to_stream()),
        }
    }
}

impl Deref for MacawChat {
    type Target = ReadSignal<Option<Option<Result<Chat, String>>>>;

    fn deref(&self) -> &Self::Target {
        &self.chat
    }
}

impl DerefMut for MacawChat {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.chat
    }
}

#[derive(Clone)]
struct MacawMessage {
    message: ReadSignal<Option<Option<Result<Message, String>>>>,
    user: ReadSignal<Option<Option<Result<User, String>>>>,
}

impl MacawMessage {
    fn got_message_and_user(message: Message, user: User) -> Self {
        debug!("executing the got message");
        let message_id = message.id;
        let message_query = message_query();
        message_query.set_query_data(message.id, Ok(message));
        let message = message_query.use_query(move || message_id);
        let jid = user.jid.clone();
        let user_query = user_query();
        user_query.set_query_data(jid.clone(), Ok(user));
        let user = user_query.use_query(move || jid.clone());
        Self {
            message: ReadSignal::from_stream_unsync(message.data.to_stream()),
            user: ReadSignal::from_stream_unsync(user.data.to_stream()),
        }
    }
}

impl Deref for MacawMessage {
    type Target = ReadSignal<Option<Option<Result<Message, String>>>>;

    fn deref(&self) -> &Self::Target {
        &self.message
    }
}

impl DerefMut for MacawMessage {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.message
    }
}

fn ChatsList() -> impl IntoView {
    let chats: LocalResource<std::result::Result<(ReadSignal<IndexMap<JID, (MacawChat, MacawMessage)>, LocalStorage>, WriteSignal<IndexMap<JID, (MacawChat, MacawMessage)>, LocalStorage>), String>>  = LocalResource::new(move || async move || -> Result<_, _> {
        let client: Client = use_context::<RwSignal<Client, LocalStorage>>().unwrap().read().clone();
        let chats = client.get_chats_ordered_with_latest_messages_and_users().await.map_err(|e| e.to_string())?;
        let chats = chats.into_iter().map(|((chat, chat_user), (message, message_user))| {
            (chat.correspondent.clone(), (MacawChat::got_chat_and_user(chat, chat_user), MacawMessage::got_message_and_user(message, message_user)))
            
        }).collect::<IndexMap<JID, _>>();
        let (chats, set_chats) = signal_local(chats);
        Ok((chats, set_chats))
    }());

    // TODO: filter new messages signal
    let new_messages_signal: ReadSignal<Option<(JID, MacawMessage)>> = use_context().unwrap();
    OnceResource::new(async move {
        let mut new_message = new_messages_signal.to_stream();
        match chats.await {
            Ok((c, set_c)) => {
                while let Some(new_message) = new_message.next().await {
                    debug!("got new message in let");
                    if let Some((to, new_message)) = new_message {
                        if let Some((chat, _latest_message)) = set_c.write().shift_remove(&to) {
                            debug!("chat existed");
                            set_c.write().insert_before(0, to, (chat, new_message));
                            debug!("done setting");
                        } else {
                            debug!("the chat didn't exist");
                            let chat = MacawChat::get(to.clone());
                            set_c.write().insert_before(0, to, (chat, new_message));
                            debug!("done setting");
                        }
                    }
                }
                debug!("set the new message");
            }
            Err(_) => {},
        }
    });

    view! {
        <div class="chats-list panel">
            <h2>Chats</h2>
            <div>
                {move || {
                    if let Some(chats) = &*chats.read() {
                        match &**chats {
                            Ok((chats, _)) => {
                                let chats = chats.clone();
                                view! {
                                    <For
                                        each=move || chats.get()
                                        key=|chat| chat.0.clone()
                                        let(chat)
                                    >
                                        <p>{chat.0.to_string()}</p>
                                    </For>
                                }
                                    .into_any()
                            }
                            Err(e) => {
                                view! { <div class="error">{format!("{}", e)}</div> }.into_any()
                            }
                        }
                    } else {
                        None::<String>.into_any()
                    }
                }}
            </div>
        </div>
    }
}