"""
Knowledge Universe — Streaming Adapter
Produces streaming endpoint manifests for video and audio sources.
Useful for media players and transcript fetchers.
"""

from typing import Any, Dict
from src.api.models import Source
from src.format_adapters.base_adapter import BaseFormatAdapter


class StreamingAdapter(BaseFormatAdapter):
    """
    Returns a streaming manifest — structured metadata describing how
    to stream or access media (video, audio, podcast).

    Downstream: media players, transcript pipelines, caption extractors.
    """

    def transform(self, source: Source) -> Dict[str, Any]:
        media_links = [
            link for link in source.links
            if link.format.value in ("video", "audio", "podcast", "live", "animation")
        ]

        return {
            "manifest_version": "1.0",
            "source_id": source.id,
            "title": source.title,
            "platform": source.source_platform,
            "media_type": self._primary_media_type(source),

            "streams": [
                {
                    "url": link.url,
                    "format": link.format.value,
                    "access_method": link.access_method,
                    "quality": "auto",
                }
                for link in (media_links or source.links[:1])
            ],

            "metadata": {
                "duration_seconds": source.duration_seconds,
                "language": source.language,
                "thumbnail": source.thumbnail_url,
                "authors": source.authors,
                "open_access": source.open_access,
            },

            "transcript_options": self._transcript_options(source),
        }

    def _primary_media_type(self, source: Source) -> str:
        for fmt in source.formats:
            if fmt.value in ("video", "audio", "podcast"):
                return fmt.value
        return "media"

    def _transcript_options(self, source: Source) -> Dict[str, Any]:
        """Describe how to get a transcript if available."""
        if source.source_platform == "youtube":
            # Extract video ID from URL
            vid_id = ""
            if "v=" in source.url:
                vid_id = source.url.split("v=")[-1].split("&")[0]
            elif "youtu.be/" in source.url:
                vid_id = source.url.split("youtu.be/")[-1]

            return {
                "available": True,
                "method": "yt-dlp",
                "command": f"yt-dlp --write-auto-sub --skip-download {source.url}",
                "caption_url": f"https://www.youtube.com/api/timedtext?lang=en&v={vid_id}" if vid_id else None,
            }

        if source.source_platform == "podcast":
            return {
                "available": bool(any(
                    link.format.value == "transcript"
                    for link in source.links
                )),
                "method": "rss_feed",
                "note": "Check RSS feed for embedded transcript or SRT file",
            }

        return {"available": False}