feat(main): initial commit

core/services/scheduler.py

@@ -0,0 +1,108 @@
+from datetime import datetime, timedelta, date, time, timezone
+from core.models import Channel, ScheduleTemplate, ScheduleBlock, Airing, MediaItem
+import random
+
+class ScheduleGenerator:
+    """
+    A service that reads the latest ScheduleTemplate and Blocks for a given channel
+    and generates concrete Airings logic based on available matching MediaItems.
+    """
+    
+    def __init__(self, channel: Channel):
+        self.channel = channel
+        
+    def generate_for_date(self, target_date: date) -> int:
+        """
+        Idempotent generation of airings for a specific date on this channel.
+        Returns the number of new Airings created.
+        """
+        # 1. Get the highest priority active template valid on this date
+        template = ScheduleTemplate.objects.filter(
+            channel=self.channel,
+            is_active=True
+        ).filter(
+            # Start date is null or <= target_date
+            valid_from_date__isnull=True
+        ).order_by('-priority').first()
+        
+        # In a real app we'd construct complex Q objects for the valid dates,
+        # but for PYTV mock we will just grab the highest priority active template.
+        if not template:
+            template = ScheduleTemplate.objects.filter(channel=self.channel, is_active=True).order_by('-priority').first()
+            if not template:
+                return 0
+                
+        # 2. Extract day of week mask
+        # Python weekday: 0=Monday, 6=Sunday
+        # Our mask: bit 0 = Monday, bit 6 = Sunday
+        target_weekday_bit = 1 << target_date.weekday()
+        
+        blocks = template.scheduleblock_set.all()
+        airings_created = 0
+        
+        for block in blocks:
+            # Check if block runs on this day
+            if not (block.day_of_week_mask & target_weekday_bit):
+                continue
+                
+            # Naive time combining mapping local time to UTC timeline without specific tz logic for simplicity now
+            start_dt = datetime.combine(target_date, block.start_local_time, tzinfo=timezone.utc)
+            end_dt = datetime.combine(target_date, block.end_local_time, tzinfo=timezone.utc)
+            
+            # If the block wraps past midnight (e.g. 23:00 to 02:00)
+            if end_dt <= start_dt:
+                end_dt += timedelta(days=1)
+                
+            # Clear existing airings in this window to allow idempotency
+            Airing.objects.filter(
+                channel=self.channel,
+                starts_at__gte=start_dt,
+                starts_at__lt=end_dt
+            ).delete()
+            
+            # 3. Pull matching Media Items
+            # Simplistic matching: pull items from library matching the block's genre
+            items_query = MediaItem.objects.filter(media_source__library=self.channel.library)
+            if block.default_genre:
+                items_query = items_query.filter(genres=block.default_genre)
+                
+            available_items = list(items_query.exclude(item_kind="bumper"))
+            if not available_items:
+                continue
+
+            # Shuffle randomly for basic scheduling variety
+            random.shuffle(available_items)
+            
+            # 4. Fill the block
+            current_cursor = start_dt
+            item_index = 0
+            
+            while current_cursor < end_dt and item_index < len(available_items):
+                item = available_items[item_index]
+                duration = timedelta(seconds=item.runtime_seconds or 3600)
+                
+                # Check if this item fits
+                if current_cursor + duration > end_dt:
+                    # Item doesn't strictly fit, but we'll squeeze it in and break if needed
+                    # Real systems pad this out or trim the slot.
+                    pass
+                
+                import uuid
+                Airing.objects.create(
+                    channel=self.channel,
+                    schedule_template=template,
+                    schedule_block=block,
+                    media_item=item,
+                    starts_at=current_cursor,
+                    ends_at=current_cursor + duration,
+                    slot_kind="program",
+                    status="scheduled",
+                    source_reason="template",
+                    generation_batch_uuid=uuid.uuid4()
+                )
+                
+                current_cursor += duration
+                item_index += 1
+                airings_created += 1
+
+        return airings_created