app.py

import os
import uuid
import subprocess
import whisper

from fastapi import FastAPI, UploadFile, File
from fastapi.responses import FileResponse, HTMLResponse
from fastapi.staticfiles import StaticFiles

UPLOAD_DIR = "uploads"
OUTPUT_DIR = "outputs"

os.makedirs(UPLOAD_DIR, exist_ok=True)
os.makedirs(OUTPUT_DIR, exist_ok=True)

app = FastAPI()

app.mount("/static", StaticFiles(directory="static"), name="static")


@app.get("/", response_class=HTMLResponse)
def home():
    with open("static/index.html", "r", encoding="utf-8") as f:
        return f.read()


# 🔹 Load Whisper model ONCE
model = whisper.load_model("base")


# 🔹 Custom SRT writer (VERSION SAFE)
def format_timestamp(seconds: float) -> str:
    millis = int(seconds * 1000)
    hours = millis // 3_600_000
    minutes = (millis % 3_600_000) // 60_000
    seconds = (millis % 60_000) // 1000
    ms = millis % 1000
    return f"{hours:02}:{minutes:02}:{seconds:02},{ms:03}"


def write_srt_file(segments, file):
    for i, seg in enumerate(segments, start=1):
        file.write(f"{i}\n")
        file.write(
            f"{format_timestamp(seg['start'])} --> "
            f"{format_timestamp(seg['end'])}\n"
        )
        file.write(seg["text"].strip() + "\n\n")


@app.post("/upload")
async def upload_video(file: UploadFile = File(...)):
    uid = str(uuid.uuid4())

    video_path = f"{UPLOAD_DIR}/{uid}_{file.filename}"
    audio_path = f"{UPLOAD_DIR}/{uid}.wav"
    srt_path = f"{OUTPUT_DIR}/{uid}.srt"

    # Save video
    with open(video_path, "wb") as f:
        f.write(await file.read())

    # Video → audio
    subprocess.run([
        "ffmpeg", "-y", "-i", video_path,
        "-ar", "16000", "-ac", "1",
        audio_path
    ], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)

    # Whisper transcription (English only)
    result = model.transcribe(audio_path, language="en")

    # Write SRT
    with open(srt_path, "w", encoding="utf-8") as f:
        write_srt_file(result["segments"], f)

    # Cleanup
    os.remove(video_path)
    os.remove(audio_path)

    return {"id": uid}


@app.get("/download/{uid}")
def download(uid: str):
    for f in os.listdir(OUTPUT_DIR):
        if f.startswith(uid) and f.endswith(".srt"):
            return FileResponse(
                f"{OUTPUT_DIR}/{f}",
                filename="subtitles.srt"
            )

    return {"error": "Subtitle not found"}