import streamlit as st
import librosa
import soundfile as sf
import numpy as np
from scipy import signal
import tempfile
import os

def convert_to_female_voice(audio_path, settings):
    # Load the audio file
    y, sr = librosa.load(audio_path, sr=None)
    
    # Step 1: Pitch shifting (female voice is typically higher)
    y_pitched = librosa.effects.pitch_shift(
        y=y,
        sr=sr,
        n_steps=settings['pitch_steps']
    )
    
    # Step 2: Simple formant shifting using resampling
    alpha = 1.2  # Formant scaling factor
    y_formant = librosa.effects.time_stretch(y_pitched, rate=alpha)
    
    # Step 3: Add slight breathiness
    noise = np.random.normal(0, 0.005, len(y_formant))
    noise_filtered = signal.filtfilt([1], [1, -0.99], noise)
    y_breathy = y_formant + settings['breathiness'] * noise_filtered
    
    # Final normalization
    y_normalized = librosa.util.normalize(y_breathy)
    
    return y_normalized, sr

# Streamlit interface
st.title("Simple Female Voice Converter")

# File upload
audio_file = st.file_uploader("Upload your audio file (WAV or MP3)", type=['wav', 'mp3'])

if audio_file is not None:
    # Save uploaded file temporarily
    with tempfile.NamedTemporaryFile(delete=False, suffix=os.path.splitext(audio_file.name)[1]) as tmp_file:
        tmp_file.write(audio_file.getvalue())
        temp_path = tmp_file.name
    
    # Voice type selection
    voice_type = st.selectbox(
        "Select voice type",
        ["Young Female", "Mature Female", "Custom"]
    )
    
    # Settings based on voice type
    if voice_type == "Young Female":
        settings = {
            'pitch_steps': 4.0,
            'breathiness': 0.1
        }
    elif voice_type == "Mature Female":
        settings = {
            'pitch_steps': 3.0,
            'breathiness': 0.08
        }
    else:  # Custom
        settings = {
            'pitch_steps': st.slider("Pitch (Higher = More Female)", 0.0, 6.0, 4.0, 0.5),
            'breathiness': st.slider("Breathiness", 0.0, 0.2, 0.1, 0.01)
        }
    
    # Convert button
    if st.button("Convert to Female Voice"):
        try:
            # Process the audio
            st.write("Converting... Please wait...")
            converted_audio, sr = convert_to_female_voice(temp_path, settings)
            
            # Save the processed audio
            output_path = "temp_output.wav"
            sf.write(output_path, converted_audio, sr)
            
            # Play the audio
            st.audio(output_path)
            
            # Provide download button
            with open(output_path, 'rb') as audio_file:
                st.download_button(
                    label="Download converted audio",
                    data=audio_file,
                    file_name="female_voice.wav",
                    mime="audio/wav"
                )
            
            # Clean up
            os.remove(temp_path)
            os.remove(output_path)
            
        except Exception as e:
            st.error(f"An error occurred: {str(e)}")

st.markdown("""
### How to use:
1. Upload an audio file (WAV or MP3)
2. Choose a preset or custom settings
3. Click 'Convert to Female Voice'
4. Listen to the result
5. Download if you like it

### Tips for best results:
- Use clear audio with minimal background noise
- Speak in a neutral tone
- Try different settings to find the best match
- Young female voice works best with pitch 4-5
- Mature female voice works best with pitch 3-4
""")