"""
API router for MediaSource management (with YouTube support).

Endpoints:
  GET    /api/sources/                    – list all sources
  POST   /api/sources/                    – create a new source
  POST   /api/sources/cache-upcoming     – download videos for upcoming airings
  GET    /api/sources/download-status    – snapshot of all YouTube item cache state
  GET    /api/sources/{id}               – retrieve one source
  DELETE /api/sources/{id}               – delete a source
  POST   /api/sources/{id}/sync          – trigger yt-dlp metadata sync
  POST   /api/sources/{id}/download      – download a specific media item by ID

IMPORTANT: literal paths (/cache-upcoming, /download-status) MUST be declared
before parameterised paths (/{source_id}) so Django Ninja's URL dispatcher
matches them first.
"""

from typing import Optional, List
from datetime import datetime

from django.shortcuts import get_object_or_404
from ninja import Router
from pydantic import BaseModel

from core.models import Library, MediaSource, MediaItem
from core.services.youtube import sync_source, YOUTUBE_SOURCE_TYPES
from core.services.cache import run_cache, get_download_status as _get_download_status

router = Router(tags=["sources"])


# ---------------------------------------------------------------------------
# Schemas
# ---------------------------------------------------------------------------

class MediaSourceIn(BaseModel):
    library_id: int
    name: str
    source_type: str   # one of MediaSource.SourceType string values
    uri: str
    is_active: bool = True
    scan_interval_minutes: Optional[int] = None

class MediaSourceOut(BaseModel):
    id: int
    library_id: int
    name: str
    source_type: str
    uri: str
    is_active: bool
    scan_interval_minutes: Optional[int]
    last_scanned_at: Optional[datetime]
    created_at: datetime

    class Config:
        from_attributes = True

class SyncResult(BaseModel):
    created: int
    updated: int
    skipped: int
    max_videos: Optional[int] = None

class CacheRunResult(BaseModel):
    pruned: int
    downloaded: int
    already_cached: int
    failed: int
    items: List[dict]

class DownloadStatusResult(BaseModel):
    total: int
    cached: int
    items: List[dict]


# ---------------------------------------------------------------------------
# Collection endpoints  (no path parameters — must come FIRST)
# ---------------------------------------------------------------------------

@router.get("/", response=list[MediaSourceOut])
def list_sources(request):
    """List all media sources across all libraries."""
    return list(MediaSource.objects.select_related("library").all())


@router.post("/", response={201: MediaSourceOut})
def create_source(request, payload: MediaSourceIn):
    """Register a new media source (including YouTube channel/playlist URLs)."""
    library = get_object_or_404(Library, id=payload.library_id)
    source = MediaSource.objects.create(
        library=library,
        name=payload.name,
        source_type=payload.source_type,
        uri=payload.uri,
        is_active=payload.is_active,
        scan_interval_minutes=payload.scan_interval_minutes,
    )
    return 201, source


@router.post("/cache-upcoming", response=CacheRunResult)
def trigger_cache_upcoming(request, hours: int = 24, prune_only: bool = False):
    """
    Download YouTube videos for airings scheduled within the next `hours` hours.
    Equivalent to running: python manage.py cache_upcoming --hours N

    Query params:
      hours      – scan window in hours (default: 24)
      prune_only – if true, only delete stale cache files; skip downloads
    """
    result = run_cache(hours=hours, prune_only=prune_only)
    return result


@router.get("/download-status", response=DownloadStatusResult)
def download_status(request):
    """
    Return a snapshot of all YouTube-backed MediaItems with their local
    cache status (downloaded vs not downloaded).
    """
    return _get_download_status()


# ---------------------------------------------------------------------------
# Single-item endpoints  (path parameters — AFTER all literal paths)
# ---------------------------------------------------------------------------

@router.get("/{source_id}", response=MediaSourceOut)
def get_source(request, source_id: int):
    """Retrieve a single media source by ID."""
    return get_object_or_404(MediaSource, id=source_id)


@router.delete("/{source_id}", response={204: None})
def delete_source(request, source_id: int):
    """Delete a media source and all its associated media items."""
    source = get_object_or_404(MediaSource, id=source_id)
    source.delete()
    return 204, None


@router.post("/{source_id}/sync", response=SyncResult)
def trigger_sync(request, source_id: int, max_videos: Optional[int] = None):
    """
    Trigger a yt-dlp metadata sync for a YouTube source.
    Phase 1 only — video METADATA is fetched and upserted as MediaItem rows.
    No video files are downloaded here.

    Query params:
      max_videos – override the default cap (channel default: 50, playlist: 200)
    """
    source = get_object_or_404(MediaSource, id=source_id)
    if source.source_type not in YOUTUBE_SOURCE_TYPES:
        from ninja.errors import HttpError
        raise HttpError(400, "Source is not a YouTube source type.")
    result = sync_source(source, max_videos=max_videos)
    return {**result, "max_videos": max_videos}


@router.post("/{item_id}/download", response=dict)
def download_item(request, item_id: int):
    """
    Immediately download a single YouTube MediaItem to local cache.
    The item must already exist (synced) as a MediaItem in the database.
    """
    from core.services.youtube import download_for_airing
    item = get_object_or_404(MediaItem, id=item_id)
    if not item.youtube_video_id:
        from ninja.errors import HttpError
        raise HttpError(400, "MediaItem is not a YouTube video.")
    try:
        path = download_for_airing(item)
        return {"status": "downloaded", "path": str(path)}
    except Exception as exc:
        from ninja.errors import HttpError
        raise HttpError(500, f"Download failed: {exc}")