feat(mcp): implement media channel management and scheduling features

k-tv-backend/mcp/src/tools/schedule.rs

@@ -0,0 +1,47 @@
+use chrono::Utc;
+use domain::{ScheduleEngineService, ScheduledSlot};
+use serde::Serialize;
+use std::sync::Arc;
+use uuid::Uuid;
+
+use crate::error::{domain_err, ok_json};
+
+/// Serializable DTO for CurrentBroadcast (domain type does not derive Serialize).
+#[derive(Serialize)]
+struct CurrentBroadcastDto {
+    slot: ScheduledSlot,
+    offset_secs: u32,
+}
+
+pub async fn generate_schedule(engine: &Arc<ScheduleEngineService>, channel_id: Uuid) -> String {
+    match engine.generate_schedule(channel_id, Utc::now()).await {
+        Ok(schedule) => ok_json(&schedule),
+        Err(e) => domain_err(e),
+    }
+}
+
+pub async fn get_active_schedule(engine: &Arc<ScheduleEngineService>, channel_id: Uuid) -> String {
+    match engine.get_active_schedule(channel_id, Utc::now()).await {
+        Ok(Some(schedule)) => ok_json(&schedule),
+        Ok(None) => "null".to_string(),
+        Err(e) => domain_err(e),
+    }
+}
+
+pub async fn get_current_broadcast(
+    engine: &Arc<ScheduleEngineService>,
+    channel_id: Uuid,
+) -> String {
+    let schedule = match engine.get_active_schedule(channel_id, Utc::now()).await {
+        Ok(Some(s)) => s,
+        Ok(None) => return "null".to_string(),
+        Err(e) => return domain_err(e),
+    };
+    match ScheduleEngineService::get_current_broadcast(&schedule, Utc::now()) {
+        Some(b) => ok_json(&CurrentBroadcastDto {
+            slot: b.slot,
+            offset_secs: b.offset_secs,
+        }),
+        None => "null".to_string(),
+    }
+}