use std::str::FromStr;

use chrono::Utc;
use lampada::{Connected, SupervisorSender};
use stanza::client::{Stanza, iq::Iq};
use uuid::Uuid;

use crate::{
    UpdateMessage,
    chat::{Body, Message},
    error::{DatabaseError, Error, IqError, MessageRecvError, PresenceError, RosterError},
    presence::{Offline, Online, Presence, PresenceType, Show},
    roster::Contact,
};

use super::ClientLogic;

pub async fn handle_stanza(logic: ClientLogic, stanza: Stanza, connection: Connected) {
    let result = process_stanza(logic.clone(), stanza, connection).await;
    match result {
        Ok(u) => match u {
            Some(UpdateMessage::Unsupported(stanza)) => logic.handle_unsupported(stanza).await,
            _ => {
                if let Some(u) = u {
                    logic.handle_update(u).await
                }
            }
        },
        Err(e) => logic.handle_error(e).await,
    }
}

pub async fn recv_message(
    logic: ClientLogic,
    stanza_message: stanza::client::message::Message,
) -> Result<Option<UpdateMessage>, MessageRecvError> {
    if let Some(mut from) = stanza_message.from {
        // TODO: don't ignore delay from. xep says SHOULD send error if incorrect.
        let timestamp = stanza_message
            .delay
            .map(|delay| delay.stamp)
            .unwrap_or_else(|| Utc::now());
        // TODO: group chat messages
        let mut message = Message {
            id: stanza_message
                .id
                // TODO: proper id storage
                .map(|id| Uuid::from_str(&id).unwrap_or_else(|_| Uuid::new_v4()))
                .unwrap_or_else(|| Uuid::new_v4()),
            from: from.clone(),
            timestamp,
            body: Body {
                // TODO: should this be an option?
                body: stanza_message
                    .body
                    .map(|body| body.body)
                    .unwrap_or_default()
                    .unwrap_or_default(),
            },
        };
        // TODO: can this be more efficient?
        logic
            .db()
            .create_message_with_user_resource_and_chat(message.clone(), from.clone())
            .await
            .map_err(|e| DatabaseError(e.into()))?;
        message.from = message.from.as_bare();
        from = from.as_bare();
        Ok(Some(UpdateMessage::Message { to: from, message }))
    } else {
        Err(MessageRecvError::MissingFrom)
    }
}

pub async fn recv_presence(
    presence: stanza::client::presence::Presence,
) -> Result<Option<UpdateMessage>, PresenceError> {
    if let Some(from) = presence.from {
        match presence.r#type {
            Some(r#type) => match r#type {
                // error processing a presence from somebody
                stanza::client::presence::PresenceType::Error => {
                    // TODO: is there any other information that should go with the error? also MUST have an error, otherwise it's a different error. maybe it shoulnd't be an option.
                    // TODO: ughhhhhhhhhhhhh these stanza errors should probably just have an option, and custom display
                    Err(PresenceError::StanzaError(
                        presence
                            .errors
                            .first()
                            .cloned()
                            .expect("error MUST have error"),
                    ))
                }
                // should not happen (error to server)
                stanza::client::presence::PresenceType::Probe => {
                    // TODO: should probably write an error and restart stream
                    Err(PresenceError::Unsupported)
                }
                stanza::client::presence::PresenceType::Subscribe => {
                    // may get a subscription request from somebody who is not a contact!!! therefore should be its own kind of event
                    Ok(Some(UpdateMessage::SubscriptionRequest(from)))
                }
                stanza::client::presence::PresenceType::Unavailable => {
                    let offline = Offline {
                        status: presence.status.map(|status| status.status.0),
                    };
                    let timestamp = presence
                        .delay
                        .map(|delay| delay.stamp)
                        .unwrap_or_else(|| Utc::now());
                    Ok(Some(UpdateMessage::Presence {
                        from,
                        presence: Presence {
                            timestamp,
                            presence: PresenceType::Offline(offline),
                        },
                    }))
                }
                // for now, do nothing, as these are simply informational. will receive roster push from the server regarding the changes to do with them.
                stanza::client::presence::PresenceType::Subscribed => Ok(None),
                stanza::client::presence::PresenceType::Unsubscribe => Ok(None),
                stanza::client::presence::PresenceType::Unsubscribed => Ok(None),
            },
            None => {
                let online = Online {
                    show: presence.show.map(|show| match show {
                        stanza::client::presence::Show::Away => Show::Away,
                        stanza::client::presence::Show::Chat => Show::Chat,
                        stanza::client::presence::Show::Dnd => Show::DoNotDisturb,
                        stanza::client::presence::Show::Xa => Show::ExtendedAway,
                    }),
                    status: presence.status.map(|status| status.status.0),
                    priority: presence.priority.map(|priority| priority.0),
                };
                let timestamp = presence
                    .delay
                    .map(|delay| delay.stamp)
                    .unwrap_or_else(|| Utc::now());
                Ok(Some(UpdateMessage::Presence {
                    from,
                    presence: Presence {
                        timestamp,
                        presence: PresenceType::Online(online),
                    },
                }))
            }
        }
    } else {
        Err(PresenceError::MissingFrom)
    }
}

pub async fn recv_iq(logic: ClientLogic, iq: Iq) -> Result<Option<UpdateMessage>, IqError> {
    match iq.r#type {
        stanza::client::iq::IqType::Error | stanza::client::iq::IqType::Result => {
            let send;
            {
                send = logic.pending().lock().await.remove(&iq.id);
            }
            if let Some(send) = send {
                send.send(Ok(Stanza::Iq(iq)));
                Ok(None)
            } else {
                Err(IqError::NoMatchingId(iq.id))
            }
        }
        // TODO: send unsupported to server
        // TODO: proper errors i am so tired please
        stanza::client::iq::IqType::Get => Ok(None),
        stanza::client::iq::IqType::Set => {
            if let Some(query) = iq.query {
                match query {
                    stanza::client::iq::Query::Roster(mut query) => {
                        // TODO: there should only be one
                        if let Some(item) = query.items.pop() {
                            match item.subscription {
                                Some(stanza::roster::Subscription::Remove) => {
                                    logic.db().delete_contact(item.jid.clone()).await;
                                    Ok(Some(UpdateMessage::RosterDelete(item.jid)))
                                }
                                _ => {
                                    let contact: Contact = item.into();
                                    if let Err(e) = logic.db().upsert_contact(contact.clone()).await
                                    {
                                        let _ = logic
                                            .update_sender()
                                            .send(UpdateMessage::Error(Error::Roster(
                                                RosterError::Cache(e.into()),
                                            )))
                                            .await;
                                    }
                                    Ok(Some(UpdateMessage::RosterUpdate(contact)))
                                    // TODO: send result
                                    // write_handle.write(Stanza::Iq(stanza::client::iq::Iq {
                                    //     from: ,
                                    //     id: todo!(),
                                    //     to: todo!(),
                                    //     r#type: todo!(),
                                    //     lang: todo!(),
                                    //     query: todo!(),
                                    //     errors: todo!(),
                                    // }));
                                }
                            }
                        } else {
                            Ok(None)
                        }
                    }
                    // TODO: send unsupported to server
                    _ => Ok(None),
                }
            } else {
                // TODO: send error (unsupported) to server
                Ok(None)
            }
        }
    }
}

pub async fn process_stanza(
    logic: ClientLogic,
    stanza: Stanza,
    connection: Connected,
) -> Result<Option<UpdateMessage>, Error> {
    let update = match stanza {
        Stanza::Message(stanza_message) => Ok(recv_message(logic, stanza_message).await?),
        Stanza::Presence(presence) => Ok(recv_presence(presence).await?),
        Stanza::Iq(iq) => Ok(recv_iq(logic, iq).await?),
        // unreachable, always caught by lampada
        // TODO: make cleaner
        Stanza::Error(error) => {
            unreachable!()
        }
        Stanza::OtherContent(content) => {
            Err(Error::UnrecognizedContent)
            // TODO: send error to write_thread
        }
    };
    update
}