import os
import re
import shutil
import subprocess
NULL_SINK = "NUL" if os.name == "nt" else "/dev/null"
from fastapi import FastAPI, UploadFile, File
from fastapi.responses import JSONResponse

app = FastAPI(title="iRecite MVP API")
@app.get("/")
def root():
    return {"status": "ok", "message": "iRecite MVP API is running. Go to /docs"}
@app.get("/")
def root():
    return {"status": "ok", "message": "iRecite MVP API is running. Go to /docs"}

WORKDIR = os.path.dirname(os.path.abspath(__file__))
PYTHON = os.path.join(WORKDIR, ".venv", "Scripts", "python.exe")
UPLOADS = os.path.join(WORKDIR, "uploads")
OUTPUT_DIR = os.path.join(WORKDIR, "output")
API_JSON = os.path.join(OUTPUT_DIR, "api_response.json")

import sys

def run(cmd):
    # Always run child scripts with the same Python interpreter as the server
    if cmd and cmd[0].lower() == "python":
        cmd = [sys.executable] + cmd[1:]
    subprocess.check_call(cmd, cwd=WORKDIR)

def detect_trim_times(wav_path: str):
    """
    Use ffmpeg silencedetect to get start/end of main speech.
    Returns (start_sec, end_sec). If detection fails, returns (0, full_duration).
    """
    # Run silencedetect and capture output
    p = subprocess.run(
        ["ffmpeg", "-i", wav_path, "-af", "silencedetect=noise=-35dB:d=0.35", "-f", "null", NULL_SINK],
        cwd=WORKDIR,
        stdout=subprocess.PIPE,
        stderr=subprocess.STDOUT,
        text=True,
        encoding="utf-8",
        errors="ignore"
    )
    txt = p.stdout

    # Find first "silence_end" near the beginning (speech start)
    # and last "silence_start" near the end (speech end)
    silence_end = None
    silence_start_last = None

    for line in txt.splitlines():
        if "silence_end:" in line:
            m = re.search(r"silence_end:\s*([0-9.]+)", line)
            if m and silence_end is None:
                silence_end = float(m.group(1))
        if "silence_start:" in line:
            m = re.search(r"silence_start:\s*([0-9.]+)", line)
            if m:
                silence_start_last = float(m.group(1))

    # Get full duration using ffprobe
    pr = subprocess.run(
        ["ffprobe", "-v", "error", "-show_entries", "format=duration", "-of", "default=nw=1:nk=1", wav_path],
        cwd=WORKDIR,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        text=True
    )
    try:
        full_dur = float(pr.stdout.strip())
    except Exception:
        full_dur = None

    start = max(0.0, (silence_end if silence_end is not None else 0.0))
    end = (silence_start_last if silence_start_last is not None else (full_dur if full_dur is not None else 0.0))

    # Sanity checks
    if full_dur is not None:
        end = min(end, full_dur)
    if end <= start + 1.0:
        # fallback: don't trim
        return 0.0, full_dur if full_dur is not None else 0.0

    # small padding
    start = max(0.0, start - 0.10)
    end = end + 0.10
    if full_dur is not None:
        end = min(end, full_dur)

    return start, end

@app.post("/analyze")
async def analyze(file: UploadFile = File(...)):
    os.makedirs(UPLOADS, exist_ok=True)
    os.makedirs(OUTPUT_DIR, exist_ok=True)

    # Save upload
    upload_path = os.path.join(UPLOADS, file.filename)
    with open(upload_path, "wb") as f:
        shutil.copyfileobj(file.file, f)

    # Convert to 16k mono wav
    sample_wav = os.path.join(WORKDIR, "sample.wav")
    run(["ffmpeg", "-y", "-i", upload_path, "-ac", "1", "-ar", "16000", sample_wav])

    # Auto trim -> sample_trim.wav
    sample_trim = os.path.join(WORKDIR, "sample_trim.wav")
    start, end = detect_trim_times(sample_wav)
    if end and end > start:
        run(["ffmpeg", "-y", "-i", sample_wav, "-ss", f"{start:.2f}", "-to", f"{end:.2f}", "-ac", "1", "-ar", "16000", sample_trim])
    else:
        shutil.copy(sample_wav, sample_trim)

    # Run pipeline (ordered)
    run(["python", "step7_fallback_phonemes_and_madd.py"])  # ensures fallback json exists
    run(["python", "step8_madd_signal.py"])
    run(["python", "step9_madd_feedback_json.py"])
    run(["python", "step13_arabic_ctc_transcribe.py"])      # now writes output/asr_raw.txt automatically
    run(["python", "step14_align_text_to_canonical.py"])
    run(["python", "step15_global_word_alignment.py"])
    run(["python", "step16b_token_interpolation_timestamps.py"])
    run(["python", "step17_make_api_response.py"])

    if not os.path.exists(API_JSON):
        return JSONResponse({"error": "api_response.json not generated"}, status_code=500)

    import json
    with open(API_JSON, "r", encoding="utf-8") as f:
        data = json.load(f)

    # include trim info for debugging
    data["debug"] = {"trim": {"start": round(start, 2), "end": round(end, 2)}}

    return data