use super::State;
use crate::{pdu::PduBuilder, utils, ConduitResult, Database, Error, Ruma};
use ruma::{
    api::client::{
        error::ErrorKind,
        r0::message::{get_message_events, send_message_event},
    },
    events::EventContent,
    EventId,
};
use std::convert::{TryFrom, TryInto};

#[cfg(feature = "conduit_bin")]
use rocket::{get, put};

#[cfg_attr(
    feature = "conduit_bin",
    put("/_matrix/client/r0/rooms/<_>/send/<_>/<_>", data = "<body>")
)]
pub async fn send_message_event_route(
    db: State<'_, Database>,
    body: Ruma<send_message_event::Request<'_>>,
) -> ConduitResult<send_message_event::Response> {
    let sender_id = body.sender_id.as_ref().expect("user is authenticated");
    let device_id = body.device_id.as_ref().expect("user is authenticated");

    // Check if this is a new transaction id
    if let Some(response) = db
        .transaction_ids
        .existing_txnid(sender_id, device_id, &body.txn_id)?
    {
        // The client might have sent a txnid of the /sendToDevice endpoint
        // This txnid has no response associated with it
        if response.is_empty() {
            return Err(Error::BadRequest(
                ErrorKind::InvalidParam,
                "Tried to use txn id already used for an incompatible endpoint.",
            ));
        }

        let event_id = EventId::try_from(
            utils::string_from_bytes(&response)
                .map_err(|_| Error::bad_database("Invalid txnid bytes in database."))?,
        )
        .map_err(|_| Error::bad_database("Invalid event id in txnid data."))?;
        return Ok(send_message_event::Response { event_id }.into());
    }

    let mut unsigned = serde_json::Map::new();
    unsigned.insert("transaction_id".to_owned(), body.txn_id.clone().into());

    let event_id = db
        .rooms
        .build_and_append_pdu(
            PduBuilder {
                event_type: body.content.event_type().into(),
                content: serde_json::from_str(
                    body.json_body
                        .as_ref()
                        .ok_or(Error::BadRequest(ErrorKind::BadJson, "Invalid JSON body."))?
                        .get(),
                )
                .map_err(|_| Error::BadRequest(ErrorKind::BadJson, "Invalid JSON body."))?,
                unsigned: Some(unsigned),
                state_key: None,
                redacts: None,
            },
            &sender_id,
            &body.room_id,
            &db.globals,
            &db.sending,
            &db.account_data,
        )
        .await?;

    db.transaction_ids
        .add_txnid(sender_id, device_id, &body.txn_id, event_id.as_bytes())?;

    Ok(send_message_event::Response::new(event_id).into())
}

#[cfg_attr(
    feature = "conduit_bin",
    get("/_matrix/client/r0/rooms/<_>/messages", data = "<body>")
)]
pub fn get_message_events_route(
    db: State<'_, Database>,
    body: Ruma<get_message_events::Request<'_>>,
) -> ConduitResult<get_message_events::Response> {
    let sender_id = body.sender_id.as_ref().expect("user is authenticated");

    if !db.rooms.is_joined(sender_id, &body.room_id)? {
        return Err(Error::BadRequest(
            ErrorKind::Forbidden,
            "You don't have permission to view this room.",
        ));
    }

    let from = body
        .from
        .clone()
        .parse()
        .map_err(|_| Error::BadRequest(ErrorKind::InvalidParam, "Invalid `from` value."))?;

    let to = body.to.as_ref().map(|t| t.parse());

    // Use limit or else 10
    let limit = body
        .limit
        .try_into()
        .map_or(Ok::<_, Error>(10_usize), |l: u32| Ok(l as usize))?;

    match body.dir {
        get_message_events::Direction::Forward => {
            let events_after = db
                .rooms
                .pdus_after(&sender_id, &body.room_id, from)
                .take(limit)
                .filter_map(|r| r.ok()) // Filter out buggy events
                .filter_map(|(pdu_id, pdu)| {
                    db.rooms
                        .pdu_count(&pdu_id)
                        .map(|pdu_count| (pdu_count, pdu))
                        .ok()
                })
                .take_while(|&(k, _)| Some(Ok(k)) != to) // Stop at `to`
                .collect::<Vec<_>>();

            let end_token = events_after.last().map(|(count, _)| count.to_string());

            let events_after = events_after
                .into_iter()
                .map(|(_, pdu)| pdu.to_room_event())
                .collect::<Vec<_>>();

            let mut resp = get_message_events::Response::new();
            resp.start = Some(body.from.to_owned());
            resp.end = end_token;
            resp.chunk = events_after;
            resp.state = Vec::new();

            Ok(resp.into())
        }
        get_message_events::Direction::Backward => {
            let events_before = db
                .rooms
                .pdus_until(&sender_id, &body.room_id, from)
                .take(limit)
                .filter_map(|r| r.ok()) // Filter out buggy events
                .filter_map(|(pdu_id, pdu)| {
                    db.rooms
                        .pdu_count(&pdu_id)
                        .map(|pdu_count| (pdu_count, pdu))
                        .ok()
                })
                .take_while(|&(k, _)| Some(Ok(k)) != to) // Stop at `to`
                .collect::<Vec<_>>();

            let start_token = events_before.last().map(|(count, _)| count.to_string());

            let events_before = events_before
                .into_iter()
                .map(|(_, pdu)| pdu.to_room_event())
                .collect::<Vec<_>>();

            let mut resp = get_message_events::Response::new();
            resp.start = Some(body.from.to_owned());
            resp.end = start_token;
            resp.chunk = events_before;
            resp.state = Vec::new();

            Ok(resp.into())
        }
    }
}