"""Audio upload, file listing, waveform, and beat analysis endpoints."""
import asyncio
import shutil
from pathlib import Path
from fastapi import APIRouter, HTTPException, Request, UploadFile, File
from lightsync.audio.waveform import extract_peaks
from lightsync.audio.beats import analyze_async

router = APIRouter()

SUPPORTED_EXTENSIONS = {".mp3", ".wav", ".flac", ".ogg"}
SHOWS_DIR = Path("/app/shows")


@router.get("/files")
async def list_audio_files():
    """List audio files available in the shows directory."""
    SHOWS_DIR.mkdir(parents=True, exist_ok=True)
    files = sorted(
        p.name for p in SHOWS_DIR.iterdir()
        if p.is_file() and p.suffix.lower() in SUPPORTED_EXTENSIONS
    )
    return {"files": files, "directory": str(SHOWS_DIR)}


@router.post("/upload")
async def upload_audio(request: Request, file: UploadFile = File(...)):
    """Upload an audio file to the shows directory and run beat analysis.

    After upload, librosa beat detection runs in a thread and the result is
    cached in app.state.beats keyed by the absolute file path.
    """
    suffix = Path(file.filename).suffix.lower()
    if suffix not in SUPPORTED_EXTENSIONS:
        raise HTTPException(
            status_code=400,
            detail=f"Unsupported format: {suffix}. Supported: {', '.join(sorted(SUPPORTED_EXTENSIONS))}"
        )

    SHOWS_DIR.mkdir(parents=True, exist_ok=True)
    dest = SHOWS_DIR / file.filename

    with dest.open("wb") as f:
        shutil.copyfileobj(file.file, f)

    # Run beat analysis in background — cache result keyed by filepath
    dest_str = str(dest)
    try:
        beat_data = await analyze_async(dest_str)
        if not hasattr(request.app.state, "beats") or request.app.state.beats is None:
            request.app.state.beats = {}
        request.app.state.beats[dest_str] = beat_data
    except Exception as exc:
        # Beat analysis failure is non-fatal — upload still succeeds
        beat_data = None
        import logging
        logging.getLogger(__name__).warning("Beat analysis failed for %s: %s", dest_str, exc)

    return {
        "status": "uploaded",
        "path": dest_str,
        "filename": file.filename,
        "beats": beat_data,
    }


@router.get("/beats")
async def get_beats(request: Request, path: str):
    """Return cached beat data for a loaded file.

    Query params:
        path: absolute path to the audio file (must have been uploaded/analyzed)

    Returns:
        {"tempo": float, "beats": [float, ...], "file": str}
    """
    beats_cache: dict = getattr(request.app.state, "beats", None) or {}

    if path not in beats_cache:
        # Not cached — run analysis now (may be slow)
        p = Path(path)
        if not p.exists():
            raise HTTPException(status_code=404, detail=f"File not found: {path}")
        if p.suffix.lower() not in SUPPORTED_EXTENSIONS:
            raise HTTPException(status_code=400, detail=f"Unsupported format: {p.suffix}")
        try:
            beat_data = await analyze_async(path)
            if not hasattr(request.app.state, "beats") or request.app.state.beats is None:
                request.app.state.beats = {}
            request.app.state.beats[path] = beat_data
        except Exception as exc:
            raise HTTPException(status_code=500, detail=f"Beat analysis failed: {exc}") from exc
    else:
        beat_data = beats_cache[path]

    return {**beat_data, "file": path}


@router.get("/waveform")
async def get_waveform(path: str, peaks: int = 1000):
    """Get waveform peak data for a file (AUD-05).

    Query params:
        path: absolute path to audio file
        peaks: number of peak samples (default 1000, max 5000)
    """
    p = Path(path)
    if not p.exists():
        raise HTTPException(status_code=404, detail=f"File not found: {path}")

    num_peaks = min(max(peaks, 100), 5000)

    try:
        data = await asyncio.to_thread(extract_peaks, path, num_peaks)
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Waveform extraction failed: {e}")

    return {"peaks": data, "count": len(data), "file": path}