# Use the official lightweight Python image.
# "Slim" keeps the file size down (better for cloud costs).
FROM python:3.9-slim

# Set the working directory inside the container
WORKDIR /app

# Prevent Python from writing pyc files to disc (useless in containers)
ENV PYTHONDONTWRITEBYTECODE=1
# Prevent Python from buffering stdout/stderr (so you see logs immediately)
ENV PYTHONUNBUFFERED=1

# Install system dependencies (sometimes needed for Plotly/Pandas)
RUN apt-get update && apt-get install -y \
    build-essential \
    curl \
    software-properties-common \
    git \
    && rm -rf /var/lib/apt/lists/*

# Copy the requirements file first (for better caching)
COPY requirements.txt .

# Install Python dependencies
RUN pip3 install --no-cache-dir -r requirements.txt

# Copy the rest of the application code
COPY . .

# Expose the port Streamlit runs on
EXPOSE 8501

# The Healthcheck (Critical for "High Availability" systems)
HEALTHCHECK CMD curl --fail http://localhost:8501/_stcore/health || exit 1

# Command to run the app
# address=0.0.0.0 is MANDATORY for Docker
ENTRYPOINT ["streamlit", "run", "app.py", "--server.port=8501", "--server.address=0.0.0.0"]