import base64
import os

import requests


def generate_image(
    prompt_file: str,
    reference_images: list[str],
    output_file: str,
    aspect_ratio: str = "16:9",
) -> str:
    with open(prompt_file, "r") as f:
        prompt = f.read()
    parts = []
    i = 0
    for reference_image in reference_images:
        i += 1
        with open(reference_image, "rb") as f:
            image_b64 = base64.b64encode(f.read()).decode("utf-8")
        parts.append(
            {
                "inlineData": {
                    "mimeType": "image/jpeg",
                    "data": image_b64,
                }
            }
        )

    api_key = os.getenv("GEMINI_API_KEY")
    if not api_key:
        return "GEMINI_API_KEY is not set"
    response = requests.post(
        "https://generativelanguage.googleapis.com/v1beta/models/gemini-3-pro-image-preview:generateContent",
        headers={
            "x-goog-api-key": api_key,
            "Content-Type": "application/json",
        },
        json={
            "generationConfig": {"imageConfig": {"aspectRatio": aspect_ratio}},
            "contents": [{"parts": [*parts, {"text": prompt}]}],
        },
    )
    json = response.json()
    parts: list[dict] = json["candidates"][0]["content"]["parts"]
    image_parts = [part for part in parts if part.get("inlineData", False)]
    if len(image_parts) == 1:
        base64_image = image_parts[0]["inlineData"]["data"]
        # Save the image to a file
        with open(output_file, "wb") as f:
            f.write(base64.b64decode(base64_image))
        return f"Successfully generated image to {output_file}"
    else:
        raise Exception("Failed to generate image")


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser(description="Generate images using Gemini API")
    parser.add_argument(
        "--prompt-file",
        required=True,
        help="Absolute path to JSON prompt file",
    )
    parser.add_argument(
        "--reference-images",
        nargs="*",
        default=[],
        help="Absolute paths to reference images (space-separated)",
    )
    parser.add_argument(
        "--output-file",
        required=True,
        help="Output path for generated image",
    )
    parser.add_argument(
        "--aspect-ratio",
        required=False,
        default="16:9",
        help="Aspect ratio of the generated image",
    )

    args = parser.parse_args()

    try:
        print(
            generate_image(
                args.prompt_file,
                args.reference_images,
                args.output_file,
                args.aspect_ratio,
            )
        )
    except Exception:
        print("Error while generating image.")