"""Show CRUD endpoints."""

from __future__ import annotations

import logging
import uuid
from datetime import datetime
from typing import Optional

import feedparser
import httpx
from fastapi import APIRouter, Depends, HTTPException, Query
from pydantic import BaseModel
from sqlalchemy import select, func, delete
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import selectinload

from app.api.deps import get_user_id, get_db_session
from app.models import Show, Episode, Progress

log = logging.getLogger(__name__)

router = APIRouter(prefix="/api/shows", tags=["shows"])


# ── Schemas ──

class ShowCreate(BaseModel):
    feed_url: Optional[str] = None
    local_path: Optional[str] = None
    title: Optional[str] = None


class ShowOut(BaseModel):
    id: str
    title: str
    author: Optional[str] = None
    description: Optional[str] = None
    artwork_url: Optional[str] = None
    feed_url: Optional[str] = None
    local_path: Optional[str] = None
    show_type: str
    episode_count: int = 0
    unplayed_count: int = 0
    created_at: Optional[str] = None
    updated_at: Optional[str] = None


# ── Helpers ──

def _parse_duration(value: str) -> Optional[int]:
    """Parse HH:MM:SS or MM:SS or seconds string to integer seconds."""
    if not value:
        return None
    parts = value.strip().split(":")
    try:
        if len(parts) == 3:
            return int(parts[0]) * 3600 + int(parts[1]) * 60 + int(parts[2])
        elif len(parts) == 2:
            return int(parts[0]) * 60 + int(parts[1])
        else:
            return int(float(parts[0]))
    except (ValueError, IndexError):
        return None


async def _fetch_and_parse_feed(feed_url: str, etag: str = None, last_modified: str = None):
    """Fetch RSS feed and parse with feedparser."""
    headers = {}
    if etag:
        headers["If-None-Match"] = etag
    if last_modified:
        headers["If-Modified-Since"] = last_modified

    async with httpx.AsyncClient(timeout=30, follow_redirects=True) as client:
        resp = await client.get(feed_url, headers=headers)

    if resp.status_code == 304:
        return None, None, None  # Not modified

    resp.raise_for_status()

    feed = feedparser.parse(resp.text)
    new_etag = resp.headers.get("ETag")
    new_last_modified = resp.headers.get("Last-Modified")

    return feed, new_etag, new_last_modified


def _extract_show_info(feed) -> dict:
    """Extract show metadata from parsed feed."""
    f = feed.feed
    artwork = None
    if hasattr(f, "image") and f.image:
        artwork = getattr(f.image, "href", None)
    if not artwork and hasattr(f, "itunes_image"):
        artwork = f.get("itunes_image", {}).get("href") if isinstance(f.get("itunes_image"), dict) else None
    # Try another common location
    if not artwork:
        for link in getattr(f, "links", []):
            if link.get("rel") == "icon" or link.get("type", "").startswith("image/"):
                artwork = link.get("href")
                break

    return {
        "title": getattr(f, "title", "Unknown Show"),
        "author": getattr(f, "author", None) or getattr(f, "itunes_author", None),
        "description": getattr(f, "summary", None) or getattr(f, "subtitle", None),
        "artwork_url": artwork,
    }


def _extract_episodes(feed, show_id: uuid.UUID, user_id: str) -> list[dict]:
    """Extract episodes from parsed feed."""
    episodes = []
    for entry in feed.entries:
        audio_url = None
        file_size = None
        for enc in getattr(entry, "enclosures", []):
            if enc.get("type", "").startswith("audio/") or enc.get("href", "").split("?")[0].endswith(
                (".mp3", ".m4a", ".ogg", ".opus")
            ):
                audio_url = enc.get("href")
                file_size = int(enc.get("length", 0)) or None
                break
        # Fallback: check links
        if not audio_url:
            for link in getattr(entry, "links", []):
                if link.get("type", "").startswith("audio/"):
                    audio_url = link.get("href")
                    file_size = int(link.get("length", 0)) or None
                    break

        if not audio_url:
            continue  # Skip entries without audio

        # Duration
        duration = None
        itunes_duration = getattr(entry, "itunes_duration", None)
        if itunes_duration:
            duration = _parse_duration(str(itunes_duration))

        # Published date
        published = None
        if hasattr(entry, "published_parsed") and entry.published_parsed:
            try:
                from time import mktime
                published = datetime.fromtimestamp(mktime(entry.published_parsed))
            except (TypeError, ValueError, OverflowError):
                pass

        # GUID
        guid = getattr(entry, "id", None) or audio_url

        # Episode artwork
        ep_artwork = None
        itunes_image = getattr(entry, "itunes_image", None)
        if itunes_image and isinstance(itunes_image, dict):
            ep_artwork = itunes_image.get("href")

        episodes.append({
            "id": uuid.uuid4(),
            "show_id": show_id,
            "user_id": user_id,
            "title": getattr(entry, "title", None),
            "description": getattr(entry, "summary", None),
            "audio_url": audio_url,
            "duration_seconds": duration,
            "file_size_bytes": file_size,
            "published_at": published,
            "guid": guid,
            "artwork_url": ep_artwork,
        })

    return episodes


async def _scan_local_folder(local_path: str, show_id: uuid.UUID, user_id: str) -> list[dict]:
    """Scan a local folder for audio files and create episode dicts."""
    import os
    from mutagen import File as MutagenFile
    from app.config import AUDIO_EXTENSIONS

    episodes = []
    if not os.path.isdir(local_path):
        return episodes

    files = sorted(os.listdir(local_path))
    for i, fname in enumerate(files):
        ext = os.path.splitext(fname)[1].lower()
        if ext not in AUDIO_EXTENSIONS:
            continue

        fpath = os.path.join(local_path, fname)
        if not os.path.isfile(fpath):
            continue

        # Read metadata with mutagen
        title = os.path.splitext(fname)[0]
        duration = None
        file_size = os.path.getsize(fpath)

        try:
            audio = MutagenFile(fpath)
            if audio and audio.info:
                duration = int(audio.info.length)
            # Try to get title from tags
            if audio and audio.tags:
                for tag_key in ("title", "TIT2", "\xa9nam"):
                    tag_val = audio.tags.get(tag_key)
                    if tag_val:
                        title = str(tag_val[0]) if isinstance(tag_val, list) else str(tag_val)
                        break
        except Exception:
            pass

        stat = os.stat(fpath)
        published = datetime.fromtimestamp(stat.st_mtime)

        episodes.append({
            "id": uuid.uuid4(),
            "show_id": show_id,
            "user_id": user_id,
            "title": title,
            "description": None,
            "audio_url": fpath,
            "duration_seconds": duration,
            "file_size_bytes": file_size,
            "published_at": published,
            "guid": f"local:{fpath}",
            "artwork_url": None,
        })

    return episodes


# ── Endpoints ──

@router.get("")
async def list_shows(
    user_id: str = Depends(get_user_id),
    db: AsyncSession = Depends(get_db_session),
):
    """List user's shows with episode counts and unplayed counts."""
    # Subquery: total episodes per show
    ep_count_sq = (
        select(
            Episode.show_id,
            func.count(Episode.id).label("episode_count"),
        )
        .where(Episode.user_id == user_id)
        .group_by(Episode.show_id)
        .subquery()
    )

    # Subquery: episodes with completed progress
    played_sq = (
        select(
            Episode.show_id,
            func.count(Progress.id).label("played_count"),
        )
        .join(Progress, Progress.episode_id == Episode.id)
        .where(Episode.user_id == user_id, Progress.is_completed == True)  # noqa: E712
        .group_by(Episode.show_id)
        .subquery()
    )

    stmt = (
        select(
            Show,
            func.coalesce(ep_count_sq.c.episode_count, 0).label("episode_count"),
            func.coalesce(played_sq.c.played_count, 0).label("played_count"),
        )
        .outerjoin(ep_count_sq, ep_count_sq.c.show_id == Show.id)
        .outerjoin(played_sq, played_sq.c.show_id == Show.id)
        .where(Show.user_id == user_id)
        .order_by(Show.title)
    )

    result = await db.execute(stmt)
    rows = result.all()

    return [
        {
            "id": str(show.id),
            "title": show.title,
            "author": show.author,
            "description": show.description,
            "artwork_url": show.artwork_url,
            "feed_url": show.feed_url,
            "local_path": show.local_path,
            "show_type": show.show_type,
            "episode_count": ep_count,
            "unplayed_count": ep_count - played_count,
            "created_at": show.created_at.isoformat() if show.created_at else None,
            "updated_at": show.updated_at.isoformat() if show.updated_at else None,
        }
        for show, ep_count, played_count in rows
    ]


@router.post("", status_code=201)
async def create_show(
    body: ShowCreate,
    user_id: str = Depends(get_user_id),
    db: AsyncSession = Depends(get_db_session),
):
    """Create a show from RSS feed or local folder."""
    if not body.feed_url and not body.local_path:
        raise HTTPException(400, "Either feed_url or local_path is required")

    show_id = uuid.uuid4()

    if body.feed_url:
        # RSS podcast
        try:
            feed, etag, last_modified = await _fetch_and_parse_feed(body.feed_url)
        except Exception as e:
            log.error("Failed to fetch feed %s: %s", body.feed_url, e)
            raise HTTPException(400, f"Failed to fetch feed: {e}")

        if feed is None:
            raise HTTPException(400, "Feed returned no content")

        info = _extract_show_info(feed)
        show = Show(
            id=show_id,
            user_id=user_id,
            title=body.title or info["title"],
            author=info["author"],
            description=info["description"],
            artwork_url=info["artwork_url"],
            feed_url=body.feed_url,
            show_type="podcast",
            etag=etag,
            last_modified=last_modified,
            last_fetched_at=datetime.utcnow(),
        )
        db.add(show)
        await db.flush()

        ep_dicts = _extract_episodes(feed, show_id, user_id)
        for ep_dict in ep_dicts:
            db.add(Episode(**ep_dict))

        await db.commit()
        await db.refresh(show)

        return {
            "id": str(show.id),
            "title": show.title,
            "show_type": show.show_type,
            "episode_count": len(ep_dicts),
        }

    else:
        # Local folder
        if not body.title:
            raise HTTPException(400, "title is required for local shows")

        show = Show(
            id=show_id,
            user_id=user_id,
            title=body.title,
            local_path=body.local_path,
            show_type="local",
            last_fetched_at=datetime.utcnow(),
        )
        db.add(show)
        await db.flush()

        ep_dicts = await _scan_local_folder(body.local_path, show_id, user_id)
        for ep_dict in ep_dicts:
            db.add(Episode(**ep_dict))

        await db.commit()
        await db.refresh(show)

        return {
            "id": str(show.id),
            "title": show.title,
            "show_type": show.show_type,
            "episode_count": len(ep_dicts),
        }


@router.get("/{show_id}")
async def get_show(
    show_id: str,
    user_id: str = Depends(get_user_id),
    db: AsyncSession = Depends(get_db_session),
):
    """Get show details with episodes."""
    show = await db.get(Show, uuid.UUID(show_id))
    if not show or show.user_id != user_id:
        raise HTTPException(404, "Show not found")

    # Fetch episodes with progress
    stmt = (
        select(Episode, Progress)
        .outerjoin(Progress, (Progress.episode_id == Episode.id) & (Progress.user_id == user_id))
        .where(Episode.show_id == show.id)
        .order_by(Episode.published_at.desc().nullslast())
    )
    result = await db.execute(stmt)
    rows = result.all()

    episodes = []
    for ep, prog in rows:
        episodes.append({
            "id": str(ep.id),
            "title": ep.title,
            "description": ep.description,
            "audio_url": ep.audio_url,
            "duration_seconds": ep.duration_seconds,
            "file_size_bytes": ep.file_size_bytes,
            "published_at": ep.published_at.isoformat() if ep.published_at else None,
            "artwork_url": ep.artwork_url,
            "progress": {
                "position_seconds": prog.position_seconds,
                "is_completed": prog.is_completed,
                "playback_speed": prog.playback_speed,
                "last_played_at": prog.last_played_at.isoformat() if prog.last_played_at else None,
            } if prog else None,
        })

    return {
        "id": str(show.id),
        "title": show.title,
        "author": show.author,
        "description": show.description,
        "artwork_url": show.artwork_url,
        "feed_url": show.feed_url,
        "local_path": show.local_path,
        "show_type": show.show_type,
        "last_fetched_at": show.last_fetched_at.isoformat() if show.last_fetched_at else None,
        "created_at": show.created_at.isoformat() if show.created_at else None,
        "episodes": episodes,
    }


@router.delete("/{show_id}", status_code=204)
async def delete_show(
    show_id: str,
    user_id: str = Depends(get_user_id),
    db: AsyncSession = Depends(get_db_session),
):
    """Delete a show and all its episodes."""
    show = await db.get(Show, uuid.UUID(show_id))
    if not show or show.user_id != user_id:
        raise HTTPException(404, "Show not found")

    await db.delete(show)
    await db.commit()


@router.post("/{show_id}/refresh")
async def refresh_show(
    show_id: str,
    user_id: str = Depends(get_user_id),
    db: AsyncSession = Depends(get_db_session),
):
    """Re-fetch RSS feed or re-scan local folder for new episodes."""
    show = await db.get(Show, uuid.UUID(show_id))
    if not show or show.user_id != user_id:
        raise HTTPException(404, "Show not found")

    new_count = 0

    if show.show_type == "podcast" and show.feed_url:
        try:
            feed, etag, last_modified = await _fetch_and_parse_feed(
                show.feed_url, show.etag, show.last_modified
            )
        except Exception as e:
            raise HTTPException(400, f"Failed to fetch feed: {e}")

        if feed is None:
            return {"new_episodes": 0, "message": "Feed not modified"}

        info = _extract_show_info(feed)
        show.title = info["title"] or show.title
        show.author = info["author"] or show.author
        show.description = info["description"] or show.description
        show.artwork_url = info["artwork_url"] or show.artwork_url
        show.etag = etag
        show.last_modified = last_modified
        show.last_fetched_at = datetime.utcnow()

        ep_dicts = _extract_episodes(feed, show.id, user_id)

        # Get existing guids
        existing = await db.execute(
            select(Episode.guid).where(Episode.show_id == show.id)
        )
        existing_guids = {row[0] for row in existing.all()}

        for ep_dict in ep_dicts:
            if ep_dict["guid"] not in existing_guids:
                db.add(Episode(**ep_dict))
                new_count += 1

    elif show.show_type == "local" and show.local_path:
        ep_dicts = await _scan_local_folder(show.local_path, show.id, user_id)

        existing = await db.execute(
            select(Episode.guid).where(Episode.show_id == show.id)
        )
        existing_guids = {row[0] for row in existing.all()}

        for ep_dict in ep_dicts:
            if ep_dict["guid"] not in existing_guids:
                db.add(Episode(**ep_dict))
                new_count += 1

        show.last_fetched_at = datetime.utcnow()

    await db.commit()
    return {"new_episodes": new_count}