"""
Music Orchestrator — FastAPI backend
"""

from typing import Any

from fastapi import FastAPI, HTTPException, Query
from fastapi.responses import FileResponse
from pydantic import BaseModel

import search as music_search
import youtube
import library as lib

# In production, nginx sits in front and serves the frontend statically,
# proxying /api/* to this process on 127.0.0.1:8000. CORS is not needed
# because all requests appear same-origin to the browser.
# In dev, Vite's proxy does the same job. No CORS middleware required.
app = FastAPI(title="Music Orchestrator", docs_url=None, redoc_url=None)


# ── Request / Response models ─────────────────────────────────────────────────

class DownloadRequest(BaseModel):
    videoId: str
    trackName: str
    artistName: str
    albumName: str
    trackNumber: int | None = None
    year: str = ""
    genre: str = ""
    artworkUrl: str = ""


# ── Music search ──────────────────────────────────────────────────────────────

@app.get("/api/search/music")
async def search_music(q: str = Query(..., min_length=1)) -> list[dict[str, Any]]:
    """Search iTunes for song metadata."""
    try:
        return await music_search.search_music(q)
    except Exception as exc:
        raise HTTPException(status_code=502, detail=f"iTunes search failed: {exc}")


# ── YouTube search ────────────────────────────────────────────────────────────

@app.get("/api/search/youtube")
async def search_youtube(q: str = Query(..., min_length=1)) -> list[dict[str, Any]]:
    """Search YouTube and return top 5 results (no download)."""
    try:
        return await youtube.search_youtube(q)
    except Exception as exc:
        raise HTTPException(status_code=502, detail=f"YouTube search failed: {exc}")


# ── Download ──────────────────────────────────────────────────────────────────

@app.post("/api/download")
async def start_download(req: DownloadRequest) -> dict[str, str]:
    """
    Start an async download + tag job. Returns a job_id to poll.
    Metadata comes from iTunes (req body), not from the YouTube video.
    """
    job_id = await youtube.start_download(
        video_id=req.videoId,
        artist=req.artistName,
        album=req.albumName,
        track_name=req.trackName,
        track_number=req.trackNumber,
        year=req.year,
        genre=req.genre,
        artwork_url=req.artworkUrl,
    )
    return {"jobId": job_id}


@app.get("/api/download/{job_id}/status")
def download_status(job_id: str) -> dict[str, Any]:
    """Poll download job status. Returns { status, progress, filename, error }."""
    job = youtube.get_job_status(job_id)
    if job is None:
        raise HTTPException(status_code=404, detail="Job not found.")
    return {
        "status": job["status"],
        "progress": job["progress"],
        "filename": job.get("filename"),
        "error": job.get("error"),
    }


# ── Library ───────────────────────────────────────────────────────────────────

@app.get("/api/library")
def get_library() -> list[dict[str, Any]]:
    """Return the full nested artist → album → tracks structure."""
    return lib.get_library()


@app.delete("/api/library")
def delete_library_item(path: str = Query(...)) -> dict[str, str]:
    """
    Delete a file or folder inside the music library.
    `path` is relative to MUSIC_DIR, e.g. 'Artist/Album/01 - Song.mp3'
    """
    try:
        lib.delete_path(path)
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    except FileNotFoundError as exc:
        raise HTTPException(status_code=404, detail=str(exc))
    return {"deleted": path}


@app.get("/api/library/download")
def download_track(path: str = Query(...)) -> FileResponse:
    """
    Stream a file from the music library to the browser as a download.
    `path` is relative to MUSIC_DIR.
    """
    try:
        abs_path = lib.resolve_track_path(path)
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    except FileNotFoundError as exc:
        raise HTTPException(status_code=404, detail=str(exc))

    return FileResponse(
        path=str(abs_path),
        media_type="audio/mpeg",
        filename=abs_path.name,
        headers={"Content-Disposition": f'attachment; filename="{abs_path.name}"'},
    )