import os
import sys
import argparse
from pathlib import Path
sys.path.append(str(Path(__file__).resolve().parent.parent))

import banana_pro_image

# Default template image path located under inverse_uv/template.png
DEFAULT_TEMPLATE_PATH = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'template', 'template5.png')


def _build_template_refs(count):
    """Build the [图2][图3]...[图N+1] reference string for the prompt."""
    return "".join(f"[图{i}]" for i in range(2, count + 2))


# Default prompt for real-to-render Minecraft character generation.
# {template_refs} is replaced at runtime based on the number of templates.
DEFAULT_PROMPT = """把[图1]中角色生成为参考图片的风格：{template_refs}

1. 包含内层/外层贴图的双图层模型，不能有额外元素。texture不能高于Minecraft所支持的分辨率，参考{template_refs}。

2. 生成角色的尺寸、朝向、姿势必须与{template_refs}完全一致，轮廓与内层或外层皮肤完全贴合，不能用超出内外层皮肤的任何元素表达角色的特征，无光影特效。

3. 使用容易区分前景的纯色背景。

4. 准确的还原包括外貌特征、全身所有服装、各种饰品等（不包括手持物品和披风）"""


def real2render(
    image_path,
    template_paths=None,
    output_path=None,
    prompt=None,
    aspect_ratio="1:1",
    image_size="1K",
):
    """
    High-level API to generate a Minecraft 3D character render from a real character photo using Nano Banana Pro.

    :param image_path: Path to the real character input image (Graph 1).
    :param template_paths: List of paths to template reference images (Graph 2, Graph 3, ...).
                           Defaults to [DEFAULT_TEMPLATE_PATH] if None or empty.
    :param output_path: Output PNG path.
    :param prompt: Custom prompt text. Use {template_refs} to insert the reference image tags.
                   Defaults to the standard Minecraft real-to-render prompt.
    :param aspect_ratio: Image aspect ratio (default: "1:1").
    :param image_size: Image resolution (default: "1K").
    :return: Path to generated image file.
    """
    if not os.path.exists(image_path):
        raise FileNotFoundError(f"Real character image '{image_path}' does not exist.")

    if not template_paths:
        template_paths = [DEFAULT_TEMPLATE_PATH]

    for i, tp in enumerate(template_paths):
        if not os.path.exists(tp):
            raise FileNotFoundError(f"Template image {i + 2} '{tp}' does not exist.")

    template_refs = _build_template_refs(len(template_paths))
    prompt_text = (prompt or DEFAULT_PROMPT).format(template_refs=template_refs)

    print(f"[*] Real Image (Graph 1): {image_path}")
    for i, tp in enumerate(template_paths):
        print(f"[*] Template Image (Graph {i + 2}): {tp}")
    print(f"[*] Image Size: {image_size}, Aspect Ratio: {aspect_ratio}")
    print(f"[*] Prompt:\n{prompt_text}\n")

    local_image_paths = [image_path] + list(template_paths)

    output_file = banana_pro_image.generate_img2img(
        local_image_paths=local_image_paths,
        prompt=prompt_text,
        output_path=output_path,
        aspect_ratio=aspect_ratio,
        image_size=image_size
    )
    return output_file


def main():
    parser = argparse.ArgumentParser(description="Convert real character photo to Minecraft render using Nano Banana Pro.")
    parser.add_argument("image", help="Path to local real character photo (Graph 1).")
    parser.add_argument(
        "-t", "--template",
        action="append",
        default=None,
        help="Path to a reference template image. May be specified multiple times "
             "(e.g. -t t1.png -t t2.png -t t3.png). "
             "Defaults to the built-in template if omitted."
    )
    parser.add_argument("-o", "--output", help="Output path for the generated image.")
    parser.add_argument("-p", "--prompt", default=None,
                        help="Path to a prompt text file. Use {template_refs} as placeholder for reference image tags in the file.")
    parser.add_argument("-a", "--aspect-ratio", default="1:1",
                        choices=["1:1", "2:3", "3:2", "3:4", "4:3", "4:5", "5:4", "9:16", "16:9", "21:9"],
                        help="Aspect ratio.")
    parser.add_argument("-s", "--image-size", default="2K", choices=["1K", "2K", "4K"], help="Resolution size (default: 2K).")
    args = parser.parse_args()

    try:
        prompt_content = None
        if args.prompt:
            with open(args.prompt, "r", encoding="utf-8") as f:
                prompt_content = f.read()

        output_file = real2render(
            image_path=args.image,
            template_paths=args.template,
            output_path=args.output,
            prompt=prompt_content,
            aspect_ratio=args.aspect_ratio,
            image_size=args.image_size
        )
        print(f"[+] Task completed successfully. Output saved to: {output_file}")
    except Exception as e:
        print(f"[!] Execution failed: {e}")
        sys.exit(1)


if __name__ == '__main__':
    main()