import streamlit as st
import os
import importlib

# Set page config as the absolute first Streamlit command
st.set_page_config(page_title="Multilingual Translator", page_icon="🌐", layout="centered")

# Main app function
def main():
    # Lazy import modules to avoid Streamlit initialization during import
    translation = importlib.import_module("translation")
    lang_detect = importlib.import_module("lang_detect")
    audio_processor = importlib.import_module("audio_processor")

    # Title and header with styling
    st.markdown("<h1 style='text-align: center; color: #2E86C1;'>Multilingual Translator</h1>", unsafe_allow_html=True)
    st.markdown("<p style='text-align: center; color: #666;'>Translate text or audio for multilingual support.</p>", unsafe_allow_html=True)

    # Tabs for input methods
    tab1, tab2, tab3 = st.tabs(["Text Input", "Audio Input", "Document Upload"])

    # Initialize session state for results
    if 'translated_text' not in st.session_state:
        st.session_state.translated_text = None
        st.session_state.audio_path = None
        st.session_state.source_lang = None
        st.session_state.detected_options = []

    with tab1:
        # Text input
        user_text = st.text_area("Enter Text", placeholder="Type or paste your text here...", height=150, key="text_input")
        if user_text:
            handle_input(user_text, "text", translation, lang_detect, audio_processor)

    with tab2:
        # Audio input
        audio_file = st.file_uploader("Upload Audio (MP3/WAV)", type=["mp3", "wav"], key="audio_input")
        if audio_file:
            user_text = audio_processor.transcribe_audio(audio_file)
            st.write(f"Transcribed Text: {user_text}")
            handle_input(user_text, "audio", translation, lang_detect, audio_processor)

    with tab3:
        # Document input
        doc_file = st.file_uploader("Upload Document (TXT)", type=["txt"], key="doc_input")
        if doc_file:
            user_text = doc_file.read().decode("utf-8")
            st.write(f"Document Text: {user_text}")
            handle_input(user_text, "doc", translation, lang_detect, audio_processor)

# Handle input processing
def handle_input(text, input_type, translation, lang_detect, audio_processor):
    # Auto-detect source language with options
    if len(text) < 10:  # Minimum length for reliable detection
        detected_options = [("English", 1.0, "English")]
    else:
        detected_options = lang_detect.detect_language(text)
    st.session_state.detected_options = detected_options

    # Set initial source language to the top detected option
    st.session_state.source_lang = detected_options[0][0] if detected_options else "English"

    # Display native language names for detected options
    native_lang_map = {
        "English": "English",
        "French": "Français",
        "Spanish": "Español",
        "German": "Deutsch",
        "Hindi": "हिन्दी",
        "Chinese": "中文",
        "Arabic": "العربية",
        "Russian": "Русский",
        "Japanese": "日本語",
    }
    display_options = ["Auto"] + [f"{native_lang_map.get(lang, lang)} ({conf:.2f})" for lang, conf, _ in detected_options] + list(translation.LANGUAGES.keys())
    override_lang = st.selectbox("Override Detected Language", display_options, index=0, key=f"override_lang_{input_type}")

    # Map override selection to supported language
    if override_lang != "Auto":
        selected_lang = next((lang for lang, _, _ in detected_options if native_lang_map.get(lang, lang) in override_lang), override_lang)
        st.session_state.source_lang = selected_lang
        if selected_lang not in translation.SUPPORTED_PAIRS.get(st.session_state.source_lang, []):
            st.session_state.source_lang = "English"
            st.warning(f"Translation from {native_lang_map.get(selected_lang, selected_lang)} is not supported. Using English instead.")

    st.info(f"Selected Source Language: {native_lang_map.get(st.session_state.source_lang, st.session_state.source_lang)}")

    # Target language selection with native names
    target_options = {lang: native_lang_map.get(lang, lang) for lang in translation.LANGUAGES}
    target_lang = st.selectbox("Target Language", [target_options[lang] for lang in translation.LANGUAGES],
                              index=1, key=f"target_lang_{input_type}", format_func=lambda x: x)
    target_lang = next(key for key, value in target_options.items() if value == target_lang)

    # Translate button
    if st.button("Translate", key=f"translate_button_{input_type}"):
        with st.spinner("Translating..."):
            try:
                # Translate the text
                st.session_state.translated_text = translation.translate(text, st.session_state.source_lang, target_lang)
                
                # Display results in a styled container
                st.markdown("<h3 style='color: #2E86C1;'>Translation Result</h3>", unsafe_allow_html=True)
                
                # Output options: Text and Audio
                output_option = st.radio("Output Format", ["Text", "Audio"], key=f"output_option_{input_type}")
                
                if output_option == "Text":
                    st.success("Translated Text:")
                    st.write(st.session_state.translated_text)
                
                elif output_option == "Audio":
                    st.success("Translated Audio:")
                    st.session_state.audio_path = audio_processor.text_to_speech(st.session_state.translated_text, target_lang)
                    if st.session_state.audio_path:
                        st.audio(st.session_state.audio_path)
                    else:
                        st.error("Failed to generate audio. Please try again or check the input.")
                
                # Show footer after translation
                st.markdown("""
                    <p style='font-size: small; color: grey; text-align: center; margin-top: 20px;'>
                        Developed By: Krishna Prakash
                        <a href='https://www.linkedin.com/in/krishnaprakash-profile/' target='_blank'>
                            <img src='https://img.icons8.com/ios-filled/30/0077b5/linkedin.png' alt='LinkedIn' style='vertical-align: middle; margin: 0 5px;'/>
                        </a>
                    </p>
                """, unsafe_allow_html=True)
            except Exception as e:
                st.error(f"Translation failed: {str(e)}")

# Run the app
if __name__ == "__main__":
    main()