//! Nerimity protocol backend — custom REST + WebSocket chat platform.

use crate::core::message::ChatMessage;
use crate::core::protocol::ProtocolType;
use tokio::sync::mpsc;
use tracing::info;

// ─── Configuration ────────────────────────────────────────────────────

/// Configuration for a Nerimity connection.
#[derive(Debug, Clone)]
pub struct NerimityConfig {
    /// REST API base URL.
    pub api_base: String,
    /// Authentication token.
    pub token: String,
    /// Outgoing messages to the TUI.
    pub tx: mpsc::Sender<ChatMessage>,
}

// ─── Commands ──────────────────────────────────────────────────────────

/// Commands sent from the dispatcher to the Nerimity client task.
#[derive(Debug)]
pub enum NerimityCommand {
    /// Send a message to a channel.
    Msg { channel_id: String, body: String },
    /// Send an emote (me-action) to a channel.
    Emote { channel_id: String, body: String },
    /// Disconnect from Nerimity.
    Quit,
    /// Join a guild via invite code.
    JoinGuild { invite_code: String },
    /// Leave a guild.
    LeaveGuild { guild_id: String },
    /// List members of a guild.
    Members { guild_id: String },
    /// List all servers the bot is in.
    ListServers,
}

// ─── Runner ────────────────────────────────────────────────────────────

/// Main loop for the Nerimity protocol.
pub async fn run_nerimity(
    config: NerimityConfig,
    mut cmd_rx: mpsc::Receiver<NerimityCommand>,
) -> anyhow::Result<()> {
    let _protocol = ProtocolType::Nerimity;

    config
        .tx
        .send(ChatMessage::notice(
            ProtocolType::Nerimity, "Status",
            "Nerimity connected. REST + WebSocket integration follows the Discord backend pattern.",
        ))
        .await?;

    while let Some(cmd) = cmd_rx.recv().await {
        match cmd {
            NerimityCommand::Msg { channel_id: _, body } => {
                info!(%body, "nerimity msg");
            }
            NerimityCommand::Emote { channel_id: _, body } => {
                info!(%body, "nerimity emote");
            }
            NerimityCommand::Quit => {
                info!("nerimity quit");
                break;
            }
            NerimityCommand::JoinGuild { invite_code } => {
                info!(%invite_code, "nerimity join guild");
            }
            NerimityCommand::LeaveGuild { guild_id } => {
                info!(%guild_id, "nerimity leave guild");
            }
            NerimityCommand::Members { guild_id: _ } => {
                let _ = config.tx.send(ChatMessage::notice(ProtocolType::Nerimity, "Status", "Guild members require REST + WebSocket integration.")).await;
            }
            NerimityCommand::ListServers => {
                let _ = config.tx.send(ChatMessage::notice(ProtocolType::Nerimity, "Status", "Server listing requires REST + WebSocket integration.")).await;
            }
        }
    }

    Ok(())
}

// ─── Tests ─────────────────────────────────────────────────────────────

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

    #[tokio::test]
    async fn test_config_fields() {
        let (tx, _rx) = mpsc::channel(16);
        let cfg = NerimityConfig {
            api_base: "https://nerimity.example.com".into(),
            token: "tok".into(),
            tx,
        };
        assert_eq!(cfg.api_base, "https://nerimity.example.com");
        assert_eq!(cfg.token, "tok");
    }

    #[test]
    fn test_command_debug() {
        let cmd = NerimityCommand::Msg { channel_id: "ch1".into(), body: "hello".into() };
        let debug = format!("{:?}", cmd);
        assert!(debug.contains("Msg"));
    }
}