import os
import tempfile
import logging
import subprocess
from fastapi import FastAPI, UploadFile, File, HTTPException
from fastapi.middleware.cors import CORSMiddleware
import uvicorn

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = FastAPI(title="Speaker Diarization Service")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

pipeline = None


# ─────────────────────────────────────────────────────────────
# Convert webm → wav (REQUIRED for pyannote)
# ─────────────────────────────────────────────────────────────
def convert_to_wav(input_path):
    output_path = input_path.replace(".webm", ".wav")

    try:
        subprocess.run([
            "ffmpeg",
            "-y",
            "-i", input_path,
            "-ac", "1",        # mono
            "-ar", "16000",    # 16kHz (required)
            output_path
        ], check=True, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)

        return output_path

    except subprocess.CalledProcessError as e:
        logger.error(f"FFmpeg conversion failed: {e}")
        raise Exception("Audio conversion failed (ffmpeg error)")


# ─────────────────────────────────────────────────────────────
# Load diarization pipeline
# ─────────────────────────────────────────────────────────────
@app.on_event("startup")
async def load_pipeline():
    global pipeline

    hf_token = os.environ.get("HF_TOKEN")
    logger.info(f"HF_TOKEN exists: {bool(hf_token)}")

    if not hf_token:
        logger.error("HF_TOKEN not set — diarization will not work")
        return

    try:
        from pyannote.audio import Pipeline
        import torch

        logger.info("Loading pyannote speaker diarization pipeline...")

        pipeline = Pipeline.from_pretrained(
            "pyannote/speaker-diarization-3.1",
            use_auth_token=hf_token
        )

        pipeline = pipeline.to(torch.device("cpu"))

        logger.info("Pipeline loaded successfully on cpu")

    except Exception as e:
        logger.error(f"Failed to load pipeline: {e}")
        import traceback
        logger.error(traceback.format_exc())
        pipeline = None


# ─────────────────────────────────────────────────────────────
# Health check
# ─────────────────────────────────────────────────────────────
@app.get("/health")
def health():
    return {
        "status": "ok",
        "pipeline_loaded": pipeline is not None
    }


# ─────────────────────────────────────────────────────────────
# Diarization endpoint
# ─────────────────────────────────────────────────────────────
@app.post("/diarize")
async def diarize(
    file: UploadFile = File(...),
    num_speakers: int = None
):
    if pipeline is None:
        raise HTTPException(
            status_code=503,
            detail="Diarization pipeline not loaded. Check HF_TOKEN and logs."
        )

    suffix = os.path.splitext(file.filename or "audio.webm")[1] or ".webm"
    tmp_path = None
    wav_path = None

    try:
        # Save uploaded file
        with tempfile.NamedTemporaryFile(suffix=suffix, delete=False) as tmp:
            content = await file.read()
            tmp.write(content)
            tmp_path = tmp.name

        logger.info(
            f"Diarizing {file.filename} ({len(content)/1024:.1f}KB), "
            f"num_speakers={num_speakers}"
        )

        # ── Convert to WAV (CRITICAL FIX) ───────────────────────
        wav_path = convert_to_wav(tmp_path)

        diarize_kwargs = {}

        if num_speakers and num_speakers > 1:
            diarize_kwargs["num_speakers"] = num_speakers

        diarization = pipeline(wav_path, **diarize_kwargs)

        segments = []
        speakers_seen = set()

        for turn, _, speaker in diarization.itertracks(yield_label=True):
            segments.append({
                "start": round(turn.start, 3),
                "end": round(turn.end, 3),
                "speaker": speaker
            })
            speakers_seen.add(speaker)

        logger.info(f"Done: {len(segments)} segments, {len(speakers_seen)} speakers")

        return {
            "segments": segments,
            "num_speakers_detected": len(speakers_seen)
        }

    except Exception as e:
        logger.error(f"Diarization error: {e}")
        raise HTTPException(status_code=500, detail=str(e))

    finally:
        # Cleanup temp files
        if tmp_path and os.path.exists(tmp_path):
            os.unlink(tmp_path)

        if wav_path and os.path.exists(wav_path):
            os.unlink(wav_path)



if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=7860)