import os
import streamlit as st
from pytube import YouTube, exceptions as pytube_exceptions
from urllib.error import URLError
from tempfile import NamedTemporaryFile
import speech_recognition as sr
import subprocess
import pydub
from langdetect import detect
from deep_translator import GoogleTranslator

def split_audio(file_path, chunk_length_ms=60000):
    audio = pydub.AudioSegment.from_wav(file_path)
    chunks = pydub.silence.split_on_silence(audio, min_silence_len=500, silence_thresh=audio.dBFS-14, keep_silence=500)
    chunk_files = []
    for i, chunk in enumerate(chunks):
        chunk_name = f"{file_path}_chunk{i}.wav"
        chunk.export(chunk_name, format="wav")
        chunk_files.append(chunk_name)
    return chunk_files

def download_audio(url):
    try:
        yt = YouTube(url)
        audio_stream = yt.streams.filter(only_audio=True).first()
        if audio_stream is None:
            raise ValueError("No audio stream found")
        with NamedTemporaryFile(delete=False) as tempfile:
            audio_stream.download(filename=tempfile.name)
            return tempfile.name
    except pytube_exceptions.PytubeError as e:
        st.error(f"Error downloading video: {e}")
        return None
    except Exception as e:
        st.error(f"An unexpected error occurred: {e}")
        return None

def convert_to_wav(original_file):
    target_format = "wav"
    output_file = original_file.split('.')[0] + '.' + target_format
    command = ['ffmpeg', '-i', original_file, '-ar', '16000', '-ac', '1', output_file]
    try:
        subprocess.run(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True)
    except subprocess.CalledProcessError as e:
        st.error(f"Error converting file to WAV: {e}")
        return None
    return output_file

def transcribe_and_translate(file_path):
    recognizer = sr.Recognizer()
    transcription = ""
    language = "unknown"
    translation = ""

    if not os.path.exists(file_path):
        return "[Error: File not found]", language, translation

    if os.path.getsize(file_path) / (1024 * 1024) > 10:
        chunk_files = split_audio(file_path)
    else:
        chunk_files = [file_path]

    for chunk_file in chunk_files:
        if os.path.exists(chunk_file):
            with sr.AudioFile(chunk_file) as source:
                audio_data = recognizer.record(source)
                try:
                    transcription += recognizer.recognize_google(audio_data) + " "
                except sr.UnknownValueError:
                    transcription += "[Unintelligible] "
                except sr.RequestError as e:
                    transcription += f"[Error: {e}] "
            os.remove(chunk_file)
        else:
            transcription += f"[Error: File {chunk_file} not found] "

    try:
        language = detect(transcription)
    except:
        language = "Detection failed"

    if language != "en":
        translator = GoogleTranslator(source=language, target='en')
        try:
            translation = translator.translate(transcription)
        except Exception as e:
            translation = f"Translation failed: {e}"

    return transcription, language, translation

def transcribe_youtube_video(url):
    try:
        audio_path = download_audio(url)
        if audio_path:
            wav_audio_path = convert_to_wav(audio_path)
            if wav_audio_path:
                transcription, detected_language, translation = transcribe_and_translate(wav_audio_path)
                os.remove(audio_path)
                os.remove(wav_audio_path)
                return transcription, detected_language, translation
            else:
                return "Failed to convert audio to WAV.", "unknown", ""
        else:
            return "Failed to download audio from YouTube.", "unknown", ""
    except URLError:
        return "Error in network connection. Please check your connection and try again.", "unknown", ""
    except Exception as e:
        return f"An unexpected error occurred: {e}", "unknown", ""

def main():
    st.title("YouTube Video Transcriber")
    url = st.text_input("Enter the URL of the YouTube video:")

    if st.button("Transcribe"):
        if url:
            with st.spinner('Transcribing...'):
                transcription, language, translation = transcribe_youtube_video(url)
                st.text_area("Transcription:", transcription, height=300)
                st.write(f"Detected Language: {language.title()}")
                st.text_area("Translation (English):", translation, height=300)
        else:
            st.error("Please enter a valid YouTube URL.")

if __name__ == "__main__":
    main()