app.py

import streamlit as st
import importlib
from io import BytesIO

st.set_page_config(page_title="Multilingual Translator", page_icon="🌐", layout="centered")

# Import LANGUAGES from translation.py
from translation import LANGUAGES

def main():
    translation = importlib.import_module("translation")
    lang_detect = importlib.import_module("lang_detect")
    audio_processor = importlib.import_module("audio_processor")

    # Header
    st.markdown("<h1 style='text-align: center; color: #4285F4;'>Multilingual Translator</h1>", unsafe_allow_html=True)

    # Language and Input/Output Layout
    col1, col2 = st.columns(2)
    with col1:
        detected_options = lang_detect.detect_language(st.session_state.get("input_text", "")) if st.session_state.get("input_text", "").strip() and len(st.session_state.get("input_text", "").strip()) >= 10 else [("English", 1.0, "English")]
        source_lang = detected_options[0][0] if detected_options else "English"
        source_lang_code = next((k for k, v in LANGUAGES.items() if v[1] == source_lang), "en")
        source_lang_display = st.selectbox("Source", options=[LANGUAGES[source_lang_code][0]] + [v[0] for v in LANGUAGES.values()], index=0, key="source_lang")
        input_type = st.radio("Input", ["Text", "File"], horizontal=True, key="input_type")
        if input_type == "Text":
            input_text = st.text_area("", height=200, key="input_text", on_change=trigger_translation, args=(translation, lang_detect, audio_processor,))
        else:
            input_text = st.file_uploader("", type=["txt", "docx", "pdf"], key="file_input", on_change=trigger_translation, args=(translation, lang_detect, audio_processor,))
            if input_text:
                st.session_state.input_text = input_text.read().decode("utf-8").strip()
        st.button("Translate", key="translate_btn", on_click=trigger_translation, args=(translation, lang_detect, audio_processor,))
    with col2:
        target_lang_display = st.selectbox("Target", options=[v[0] for v in LANGUAGES.values()], index=list(LANGUAGES.values()).index(LANGUAGES["hi"]), key="target_lang")
        target_lang = next((k for k, v in LANGUAGES.items() if v[0] == target_lang_display), "hi")
        if "translated_text" in st.session_state:
            st.text_area("", value=st.session_state.translated_text, height=200, key="output_text", disabled=True)
        if st.button("", key="audio_btn", on_click=play_audio, args=(audio_processor,), help="Play audio"):
            pass  # Handled by play_audio

def trigger_translation(translation, lang_detect, audio_processor):
    text = st.session_state.input_text.strip()
    if text:
        source_lang = next((k for k, v in LANGUAGES.items() if v[0] == st.session_state.source_lang), "en")
        target_lang = next((k for k, v in LANGUAGES.items() if v[0] == st.session_state.target_lang), "hi")
        if source_lang != "en" and target_lang != "en":
            temp = translation.translate(text, source_lang, "en")
            if temp and len(temp.split()) >= 2:
                st.session_state.translated_text = translation.translate(temp, "en", target_lang)
            else:
                st.session_state.translated_text = text
        else:
            st.session_state.translated_text = translation.translate(text, source_lang, target_lang) or text

def play_audio(audio_processor):
    if "translated_text" in st.session_state and st.session_state.translated_text:
        target_lang = next((k for k, v in LANGUAGES.items() if v[0] == st.session_state.target_lang), "hi")
        audio = audio_processor.text_to_speech(st.session_state.translated_text, target_lang)
        if audio and audio.getbuffer().nbytes > 0:
            st.audio(audio, format="audio/mp3")
        else:
            audio_fallback = audio_processor.text_to_speech(st.session_state.translated_text, "en")
            if audio_fallback and audio_fallback.getbuffer().nbytes > 0:
                st.audio(audio_fallback, format="audio/mp3")

if __name__ == "__main__":
    main()