use serenity::all::{
    ComponentInteraction, Context, CreateInteractionResponse, CreateInteractionResponseMessage,
    EditInteractionResponse,
};

use super::controls::{self, ControlAction};
use super::voice;
use crate::app::buzzer::{
    BUZZER_CUSTOM_ID, BuzzerSessionKey, LOCK_CUSTOM_ID, RESET_CUSTOM_ID, UNLOCK_CUSTOM_ID,
    buzzer_sound, session_components,
};

pub async fn run(ctx: &Context, interaction: &ComponentInteraction) {
    match interaction.data.custom_id.as_str() {
        BUZZER_CUSTOM_ID => press(ctx, interaction).await,
        RESET_CUSTOM_ID => run_control(ctx, interaction, ControlAction::Reset).await,
        LOCK_CUSTOM_ID => run_control(ctx, interaction, ControlAction::Lock).await,
        UNLOCK_CUSTOM_ID => run_control(ctx, interaction, ControlAction::Unlock).await,
        _ => {}
    }
}

async fn press(ctx: &Context, interaction: &ComponentInteraction) {
    let session = {
        let data = ctx.data.read().await;
        data.get::<BuzzerSessionKey>().cloned()
    };

    let Some(session) = session else {
        respond_ephemeral(ctx, interaction, "The buzzer session is unavailable.").await;
        return;
    };

    let mut session = session.lock().await;
    let Some(active_session) = session.as_mut() else {
        respond_ephemeral(ctx, interaction, "There is no active buzzer session.").await;
        return;
    };

    let belongs_to_session = interaction.guild_id == Some(active_session.guild_id)
        && interaction.message.id == active_session.button_message_id;
    if !belongs_to_session {
        respond_ephemeral(ctx, interaction, "That buzzer is no longer active.").await;
        return;
    }

    let user_voice_channel = ctx.cache.guild(active_session.guild_id).and_then(|guild| {
        guild
            .voice_states
            .get(&interaction.user.id)
            .and_then(|state| state.channel_id)
    });
    if user_voice_channel != Some(active_session.voice_channel_id) {
        respond_ephemeral(
            ctx,
            interaction,
            "Join the buzzer session's voice channel before buzzing.",
        )
        .await;
        return;
    }

    if !active_session.is_open {
        let content = match active_session.buzzed_user {
            Some(user_id) => format!("The buzzer is locked; <@{user_id}> buzzed first."),
            None => "The buzzer is locked.".to_string(),
        };
        respond_ephemeral(ctx, interaction, &content).await;
        return;
    }

    active_session.is_open = false;
    active_session.buzzed_user = Some(interaction.user.id);

    let message = CreateInteractionResponseMessage::new()
        .content(format!("<@{}> buzzed first!", interaction.user.id))
        .components(session_components(false));

    if let Err(error) = interaction
        .create_response(&ctx.http, CreateInteractionResponse::UpdateMessage(message))
        .await
    {
        // Keep the state open if Discord could not disable the actual button.
        active_session.is_open = true;
        active_session.buzzed_user = None;
        tracing::error!(?error, "failed to lock buzzer message");
        return;
    }

    let guild_id = active_session.guild_id;
    match songbird::get(ctx).await {
        Some(manager) => match manager.get(guild_id) {
            Some(call) => {
                call.lock().await.play_only_input(buzzer_sound());
            }
            None => {
                tracing::error!(%guild_id, "bot is not connected to voice for active buzzer");
            }
        },
        None => tracing::error!("voice manager unavailable while playing buzzer"),
    }

    let exempt_user_ids = [active_session.host_id, interaction.user.id];
    let voice_result = voice::mute_channel_except(ctx, active_session, &exempt_user_ids).await;
    if voice_result.failures > 0 {
        tracing::warn!(
            failures = voice_result.failures,
            %guild_id,
            "buzzer locked with participant mute failures"
        );

        let warning = EditInteractionResponse::new().content(format!(
            "<@{}> buzzed first! I couldn't mute {} participant(s); check my Mute Members permission and role position.",
            interaction.user.id, voice_result.failures,
        ));
        if let Err(error) = interaction.edit_response(&ctx.http, warning).await {
            tracing::error!(?error, "failed to report participant mute failures");
        }
    }
}

async fn run_control(ctx: &Context, interaction: &ComponentInteraction, action: ControlAction) {
    let deferred =
        CreateInteractionResponse::Defer(CreateInteractionResponseMessage::new().ephemeral(true));
    if let Err(error) = interaction.create_response(&ctx.http, deferred).await {
        tracing::error!(
            ?error,
            ?action,
            "failed to defer buzzer control interaction"
        );
        return;
    }

    let content = match interaction.guild_id {
        Some(guild_id) => {
            controls::apply(
                ctx,
                guild_id,
                interaction.user.id,
                Some(interaction.message.id),
                action,
            )
            .await
        }
        None => "Buzzer controls can only be used in a server.".to_string(),
    };

    if let Err(error) = interaction
        .edit_response(&ctx.http, EditInteractionResponse::new().content(content))
        .await
    {
        tracing::error!(
            ?error,
            ?action,
            "failed to respond to buzzer control interaction"
        );
    }
}

async fn respond_ephemeral(ctx: &Context, interaction: &ComponentInteraction, content: &str) {
    let message = CreateInteractionResponseMessage::new()
        .content(content)
        .ephemeral(true);

    if let Err(error) = interaction
        .create_response(&ctx.http, CreateInteractionResponse::Message(message))
        .await
    {
        tracing::error!(?error, "failed to respond to buzzer interaction");
    }
}