//! Shared types used across moqbox modules.

use std::fmt;

use chrono::{DateTime, Utc};
use serde::Serialize;
use tokio::sync::{broadcast, mpsc, watch};

/// Typed identifier for a queued / active / history track.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
#[serde(transparent)]
pub(crate) struct TrackId(pub(crate) uuid::Uuid);

impl TrackId {
    pub(crate) fn new() -> Self {
        Self(uuid::Uuid::now_v7())
    }

    /// Sentinel value: no specific track.  Used in PersistMetadata effects
    /// generated by URL-keyed operations where the effect targets media_cache,
    /// not a particular track row.
    pub(crate) fn nil() -> Self {
        Self(uuid::Uuid::nil())
    }

    pub(crate) fn as_str_buf(&self) -> String {
        self.0.to_string()
    }
}

impl fmt::Display for TrackId {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.fmt(f)
    }
}

/// Typed identifier for a perpetual playlist entry.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
#[serde(transparent)]
pub(crate) struct PlaylistEntryId(pub(crate) uuid::Uuid);

impl PlaylistEntryId {
    pub(crate) fn new() -> Self {
        Self(uuid::Uuid::now_v7())
    }

    pub(crate) fn parse(s: &str) -> Option<Self> {
        uuid::Uuid::parse_str(s).ok().map(Self)
    }

    pub(crate) fn as_str_buf(&self) -> String {
        self.0.to_string()
    }
}

impl fmt::Display for PlaylistEntryId {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.fmt(f)
    }
}

/// Typed identifier for a chat message.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
#[serde(transparent)]
pub(crate) struct ChatMessageId(pub(crate) uuid::Uuid);

impl ChatMessageId {
    pub(crate) fn new() -> Self {
        Self(uuid::Uuid::now_v7())
    }

    pub(crate) fn as_str_buf(&self) -> String {
        self.0.to_string()
    }
}

impl fmt::Display for ChatMessageId {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.fmt(f)
    }
}

/// Opaque room identifier backed by a UUIDv7.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
#[serde(transparent)]
pub(crate) struct RoomId(pub(crate) uuid::Uuid);

impl RoomId {
    pub(crate) fn new() -> Self {
        Self(uuid::Uuid::now_v7())
    }

    pub(crate) fn as_str_buf(&self) -> String {
        self.0.to_string()
    }

    /// Parse a UUID string into a `RoomId`. Returns `None` if invalid.
    pub(crate) fn parse(s: &str) -> Option<Self> {
        uuid::Uuid::parse_str(s).ok().map(Self)
    }
}

impl fmt::Display for RoomId {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.fmt(f)
    }
}

/// Snapshot of the currently playing track for state publishing.
#[derive(Debug, Clone, Serialize)]
pub(crate) struct TrackState {
    pub(crate) id: TrackId,
    /// Stable hash of the media URL, used for file serving.
    pub(crate) hash: String,
    pub(crate) title: String,
    pub(crate) url: String,
    pub(crate) duration: String,
    pub(crate) thumbnail: Option<String>,
    pub(crate) started_at: i64,
}

/// Summary of a queued track for state publishing.
#[derive(Debug, Clone, Serialize)]
pub(crate) struct QueueSummary {
    pub(crate) id: TrackId,
    /// Stable hash of the media URL, used for file serving.
    pub(crate) hash: String,
    pub(crate) title: String,
    pub(crate) url: String,
    pub(crate) duration: String,
    pub(crate) thumbnail: Option<String>,
    /// True while metadata is being extracted / download in progress.
    #[serde(skip_serializing_if = "is_false")]
    pub(crate) pending: bool,
}

fn is_false(b: &bool) -> bool {
    !*b
}

#[derive(Debug, Clone, Serialize)]
pub(crate) struct HistoryEntry {
    pub(crate) id: TrackId,
    pub(crate) hash: String,
    pub(crate) title: String,
    pub(crate) url: String,
    pub(crate) duration: String,
    pub(crate) thumbnail: Option<String>,
    pub(crate) played_at: String,
}

/// A chat message returned from send/recent operations.
#[derive(Debug, Clone, Serialize)]
pub(crate) struct ChatMessage {
    pub(crate) id: ChatMessageId,
    pub(crate) user_name: String,
    pub(crate) content: String,
    pub(crate) msg_type: String,
    pub(crate) created_at: String,
}

/// WebSocket publishers for a room.
///
/// Replaces the old MoQ `TrackPublishers`. Provides a `watch` channel for
/// state snapshots and a `broadcast` channel for chat messages.
#[derive(Clone)]
pub(crate) struct RoomPublishers {
    pub(crate) state_tx: watch::Sender<serde_json::Value>,
    pub(crate) chat_tx: broadcast::Sender<ChatMessage>,
}

impl RoomPublishers {
    pub(crate) fn new() -> Self {
        let (state_tx, _) = watch::channel(serde_json::Value::Null);
        let (chat_tx, _) = broadcast::channel(256);
        Self { state_tx, chat_tx }
    }
}

/// Re-exported from [`crate::room`] for convenience.
pub(crate) use crate::room::RoomCommand;

/// Ephemeral info about the active track, stored in-memory only.
#[derive(Debug, Clone, PartialEq, Eq)]
pub(crate) struct ActiveTrackInfo {
    pub(crate) id: TrackId,
    pub(crate) title: String,
    pub(crate) url: String,
    pub(crate) duration: String,
    pub(crate) thumbnail: Option<String>,
    /// Epoch ms when the track started, for client-side elapsed computation.
    pub(crate) started_at_wall: i64,
}

/// Public handle to a room: allows sending commands and reading publishers.
#[derive(Clone)]
pub(crate) struct RoomHandle {
    pub(crate) cmd_tx: mpsc::Sender<RoomCommand>,
    pub(crate) publishers: RoomPublishers,
    pub(crate) last_active: watch::Receiver<DateTime<Utc>>,
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_room_id_display() {
        let id = RoomId::new();
        assert!(
            id.to_string().contains('-'),
            "RoomId should be UUID with hyphens"
        );
    }
}