use crate::{
    OneToManyUniqueBTreeMap, UserManager,
    option_ext::OptionExt as _,
    recording_data::{Clip, Recording, RecordingData, RecordingManager},
    user_capnp::user::Consent,
    user_data::RECORD_IF_CONSENT_UNSPECIFIED,
};
use async_trait::async_trait;
use futures::FutureExt;
use songbird::{
    CoreEvent, Event, EventContext, EventHandler, Songbird,
    driver::{Channels, SampleRate},
};
use std::{
    sync::{Arc, Mutex},
    time::Instant,
};
use time::UtcDateTime;
use twilight_model::id::{
    Id,
    marker::{ChannelMarker, GuildMarker, UserMarker},
};

#[derive(Debug, Clone)]
struct Handler {
    start_instant: Instant,
    start_utc: UtcDateTime,

    recording_manager: RecordingManager,

    guild_id: Id<GuildMarker>,
    channel_id: Id<ChannelMarker>,

    known_ssrcs: Arc<Mutex<OneToManyUniqueBTreeMap<Id<UserMarker>, u32>>>,

    audio_channels: u16,
    audio_sample_rate: u32,

    user_manager: UserManager,
}

#[async_trait]
impl EventHandler for Handler {
    async fn act(&self, ctx: &EventContext<'_>) -> Option<Event> {
        match ctx {
            EventContext::Track(_items) => {
                // Not expected to fire
            }
            EventContext::SpeakingStateUpdate(speaking) => {
                tracing::error!(?speaking);

                if let Some(user_id) = speaking.user_id {
                    let user_id = Id::new(user_id.0);

                    self.known_ssrcs
                        .lock()
                        .unwrap()
                        .insert(user_id, speaking.ssrc);
                }
            }
            EventContext::VoiceTick(voice_tick) => {
                tracing::debug!(?voice_tick);

                for (ssrc, voice_data) in &voice_tick.speaking {
                    let user_id = {
                        let known_ssrcs = self.known_ssrcs.lock().unwrap();
                        tracing::debug!(?known_ssrcs, ?ssrc);
                        known_ssrcs.get_left_for(ssrc).cloned()
                    };

                    tracing::info!(?user_id);

                    if let Some(pcm) = &voice_data.decoded_voice {
                        let may_record = user_id
                            .map_async(|user_id| {
                                self.user_manager
                                    .with(user_id, |user_data| {
                                        user_data.get_voice_recording_consent().unwrap()
                                    })
                                    .map(|result| result.expect("TODO"))
                            })
                            .await
                            .map_or(RECORD_IF_CONSENT_UNSPECIFIED, |consent| match consent {
                                Consent::Unspecified => RECORD_IF_CONSENT_UNSPECIFIED,
                                Consent::Granted => true,
                                Consent::Withheld => false,
                            });

                        if !may_record {
                            tracing::warn!(?user_id, "may not be recorded");
                            continue;
                        }

                        let elapsed = self.start_instant.elapsed();
                        let elapsed = elapsed.try_into().expect("TODO");

                        let now_utc = self.start_utc.checked_add(elapsed).expect("TODO");

                        let year = now_utc.year();
                        let month = now_utc.month();
                        let day = now_utc.day();

                        let hour = now_utc.hour();
                        let minute = now_utc.minute();
                        let second = now_utc.second();

                        let microsecond = now_utc.microsecond();

                        let guild = self.guild_id;
                        let voice_channel = self.channel_id;

                        let user = user_id;

                        let clip = Clip {
                            second,
                            microsecond,
                            guild,
                            voice_channel,
                            user,
                        };

                        let recording = Recording {
                            year,
                            month,
                            day,
                            hour,
                            minute,
                            clip,
                        };

                        let channels = self.audio_channels;
                        let sample_rate = self.audio_sample_rate;

                        tracing::info!("going to write the audio shortly");

                        let recording_manager = self.recording_manager.clone();
                        let samples = pcm.clone();

                        let recording_data = RecordingData {
                            channels,
                            sample_rate,
                            samples,
                        };

                        tokio::spawn(async move {
                            recording_manager
                                .write(&recording, recording_data)
                                .await
                                .expect("TODO");
                            tracing::info!(?recording, "successfully wrote the audio!");
                        });
                    }
                }
            }
            EventContext::RtpPacket(_rtp_data) => {}
            EventContext::RtcpPacket(_rtcp_data) => {}
            EventContext::ClientDisconnect(_client_disconnect) => {
                // This is already taken care of elsewhere
            }
            EventContext::DriverConnect(_connect_data) => {}
            EventContext::DriverReconnect(_connect_data) => {}
            EventContext::DriverDisconnect(_disconnect_data) => {}
            other => {
                tracing::warn!(?other, "cannot be handled yet");
            }
        }

        None
    }
}

#[bon::builder]
#[tracing::instrument]
pub async fn join_and_record(
    audio_channels: Channels,
    audio_sample_rate: SampleRate,
    guild_id: Id<GuildMarker>,
    recording_manager: RecordingManager,
    songbird: &Songbird,
    user_manager: UserManager,
    voice_channel_id: Id<ChannelMarker>,
) -> Result<(), songbird::error::JoinError> {
    let start_instant = Instant::now();
    let start_utc = UtcDateTime::now();

    let audio_channels = opus2::Channels::from(audio_channels) as u16;

    let audio_sample_rate = u32::from(audio_sample_rate);

    let handler = Handler {
        start_instant,
        start_utc,
        recording_manager,
        guild_id,
        channel_id: voice_channel_id,
        known_ssrcs: Default::default(),

        audio_channels,
        audio_sample_rate,

        user_manager,
    };

    let call = songbird.get_or_insert(guild_id);
    {
        let mut call = call.lock().await;
        call.remove_all_global_events(); // TODO: WIP: investigating

        call.add_global_event(CoreEvent::SpeakingStateUpdate.into(), handler.clone());
        call.add_global_event(CoreEvent::VoiceTick.into(), handler);

        if let Err(muting_error) = call.mute(true).await {
            tracing::warn!(?muting_error, "couldn't mute, but that's okay");
        };
    }

    songbird.join(guild_id, voice_channel_id).await?;

    Ok(())
}