# Use an official Python runtime as the base image
# This image contains Python 3.9 and is a lightweight slim version to minimize image size
FROM python:3.9-slim

# Set the working directory inside the container
# All subsequent commands will run in this /app directory
WORKDIR /app

# Copy the local files into the container
# Copies everything from the current directory on the host machine to /app in the container
COPY . /app

# Set environment variable for Hugging Face cache directory
# This helps set a custom cache location for Hugging Face models and datasets
ENV HF_HOME=/app/.cache

# Create the necessary cache directories for Hugging Face
# This ensures that Hugging Face has the required directories set up for caching

RUN mkdir -p /app/.cache/huggingface/hub && \
    chmod -R 777 /app/.cache && \
    chmod -R 777 /app/.cache/huggingface

# Upgrade pip to the latest version
# This ensures you are using the most up-to-date version of pip for installing dependencies
RUN pip install --upgrade pip

# Install the dependencies listed in requirements.txt
# The --no-cache-dir flag ensures pip does not use or store cached versions of packages, saving space
RUN pip install --no-cache-dir -r requirements.txt

# Copy the requirements.txt file with ownership changes
# --chown=user ensures that the requirements.txt file inside the container is owned by a specific user (e.g., user) for security and permissions
COPY --chown=user ./requirements.txt requirements.txt

# Reinstall dependencies from the requirements.txt
# Installing again to ensure the dependencies are properly set with the correct ownership and permissions
RUN pip install --no-cache-dir --upgrade -r requirements.txt

# Expose the port the app will run on
# FastAPI typically runs on port 8000, but we’re using 7860 in this case
EXPOSE 7860

# Command to run the application using uvicorn
# Uvicorn is an ASGI server that runs the FastAPI app
# --host 0.0.0.0 makes the app accessible to any IP address, so it's reachable from outside the container
# --port 7860 sets the port number on which the FastAPI app will be available
CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "7860"]