use matrix_sdk::{
    async_trait,
    room::{Joined, Room},
    ruma::{
        events::{
            room::{
                message::{
                    FormattedBody, MessageEventContent, MessageFormat, MessageType, Relation,
                },
                redaction::RedactionEventContent,
            },
            AnyMessageEventContent, AnySyncRoomEvent, SyncMessageEvent,
        },
        EventId, UserId,
    },
    ClientConfig, EventHandler, SyncSettings,
};
pub use matrix_sdk::{ruma::RoomId, Client};

use log::info;
use tokio::sync::mpsc;
use url::Url;

use crate::{
    message_ast::{
        convert_matrix, convert_plain, format_discord, format_matrix, MessageComponent,
        MessageContent,
    },
    messages::{MessageAuthor, MessageEvent, MessageReference, SentMessage},
};

impl From<(&RoomId, &EventId)> for MessageReference {
    fn from((room_id, event_id): (&RoomId, &EventId)) -> Self {
        let room_string = room_id.as_str().to_string();
        let event_string = event_id.as_str().to_string();

        Self::Matrix(room_string, event_string)
    }
}

fn _find_content(event: &AnySyncRoomEvent) -> Option<AnyMessageEventContent> {
    match event {
        AnySyncRoomEvent::Message(message) => Some(message.content()),
        AnySyncRoomEvent::RedactedMessage(message) => {
            if let Some(ref redaction_event) = message.unsigned().redacted_because {
                Some(AnyMessageEventContent::RoomRedaction(
                    redaction_event.content.clone(),
                ))
            } else {
                Some(AnyMessageEventContent::RoomRedaction(
                    RedactionEventContent::new(),
                ))
            }
        }
        AnySyncRoomEvent::RedactedState(state) => {
            if let Some(ref redaction_event) = state.unsigned().redacted_because {
                Some(AnyMessageEventContent::RoomRedaction(
                    redaction_event.content.clone(),
                ))
            } else {
                Some(AnyMessageEventContent::RoomRedaction(
                    RedactionEventContent::new(),
                ))
            }
        }

        _ => None,
    }
}

struct MatrixHandler {
    message_tx: mpsc::UnboundedSender<MessageEvent>,
    current_user_id: UserId,
}

impl MatrixHandler {
    async fn get_message_author(&self, room: &Joined, user_id: &UserId) -> Option<MessageAuthor> {
        if let Ok(Some(sender)) = room.get_member(user_id).await {
            Some(MessageAuthor {
                display_name: sender
                    .display_name()
                    .unwrap_or_else(|| sender.name())
                    .to_string(),
            })
        } else {
            None
        }
    }

    fn get_content(&self, body: &str, formatted_body: &Option<FormattedBody>) -> MessageContent {
        if let Some(html) = formatted_body
            .as_ref()
            .filter(|f| f.format == MessageFormat::Html)
            .map(|f| &f.body)
        {
            convert_matrix(html)
        } else {
            convert_plain(body)
        }
    }
}

#[async_trait]
impl EventHandler for MatrixHandler {
    async fn on_room_message(&self, room: Room, event: &SyncMessageEvent<MessageEventContent>) {
        if event.sender == self.current_user_id {
            return;
        }

        if let Room::Joined(room) = room {
            let message_ref = MessageReference::from((room.room_id(), &event.event_id));

            let message_type =
                if let Some(Relation::Replacement(replacement)) = &event.content.relates_to {
                    &replacement.new_content.msgtype
                } else {
                    &event.content.msgtype
                };

            match message_type {
                MessageType::Text(text) => {
                    let content = self.get_content(&text.body, &text.formatted);

                    if let Some(author) = self.get_message_author(&room, &event.sender).await {
                        let _ = self.message_tx.send(MessageEvent::Send(SentMessage {
                            source: message_ref,
                            content,
                            author,
                        }));
                    }
                }

                MessageType::Emote(emote) => {
                    let mut content = self.get_content(&emote.body, &emote.formatted);
                    content.insert(0, MessageComponent::Plain("* ".to_string()));

                    if let Some(author) = self.get_message_author(&room, &event.sender).await {
                        let _ = self.message_tx.send(MessageEvent::Send(SentMessage {
                            source: message_ref,
                            content,
                            author,
                        }));
                    }
                }

                // TODO: Handle reactions, uploads (audio, video, image, file), and any other types of event
                _ => {}
            };

            let _ = room.read_receipt(&event.event_id).await;
        }
    }
}

pub async fn forward_to_matrix(
    client: &Client,
    room_id: RoomId,
    message: &SentMessage,
) -> Option<MessageReference> {
    if let Some(room) = client.get_joined_room(&room_id) {
        let event = room
            .send(
                AnyMessageEventContent::RoomMessage(MessageEventContent::text_html(
                    format_discord(&message.content),
                    format_matrix(&message.content),
                )),
                None,
            )
            .await
            .ok()?;

        return Some(MessageReference::from((&room_id, &event.event_id)));
    }

    None
}

pub async fn create_matrix_client(
    homeserver_url: String,
    username: String,
    password: String,
    message_tx: mpsc::UnboundedSender<MessageEvent>,
) -> Client {
    let client_config = ClientConfig::new().store_path("./data/matrix_state");

    let homeserver_url =
        Url::parse(&homeserver_url).expect("Failed to parse the matrix homeserver URL");
    let client = Client::new_with_config(homeserver_url, client_config).unwrap();

    info!("Matrix logging in…");
    client
        .login(&username, &password, None, Some("phoebe"))
        .await
        .expect("Failed to log in");

    info!("Matrix starting…");
    client.sync_once(SyncSettings::default()).await.unwrap();

    let current_user_id = client.user_id().await.unwrap();

    let event_handler = MatrixHandler {
        message_tx,
        current_user_id,
    };
    client.set_event_handler(Box::new(event_handler)).await;

    client
}