"""Replicate 图像生成服务封装。"""

import uuid
from pathlib import Path

import httpx
import replicate

GENERATED_DIR = Path(__file__).parent.parent.parent / "generated"


async def _download_image(url: str) -> str:
    """下载远程图片到本地 generated/ 目录，返回本地 URL 路径。"""
    filename = f"{uuid.uuid4().hex}.png"
    filepath = GENERATED_DIR / filename
    async with httpx.AsyncClient() as client:
        resp = await client.get(url, follow_redirects=True)
        resp.raise_for_status()
        filepath.write_bytes(resp.content)
    return f"/generated/{filename}"


async def generate_images(
    prompt: str,
    num_images: int = 1,
    ref_image_url: str | None = None,
) -> list[str]:
    """
    调用 Replicate 生成图片。

    返回本地可访问的图片 URL 列表。
    """
    local_urls = []

    for _ in range(num_images):
        try:
            if ref_image_url and ref_image_url.startswith("/"):
                # 本地路径转为 file URI 不适用于 Replicate，
                # 需要用户上传的图先通过后端 URL 访问
                # MVP 阶段：参考图作为 prompt 的文字补充，不直接传给模型
                # 仅使用 flux-schnell 文生图
                output = await replicate.async_run(
                    "black-forest-labs/flux-schnell",
                    input={
                        "prompt": prompt,
                        "num_outputs": 1,
                        "aspect_ratio": "1:1",
                        "output_format": "png",
                    },
                )
            else:
                output = await replicate.async_run(
                    "black-forest-labs/flux-schnell",
                    input={
                        "prompt": prompt,
                        "num_outputs": 1,
                        "aspect_ratio": "1:1",
                        "output_format": "png",
                    },
                )

            # output 是 FileOutput 列表或单个 URL
            if isinstance(output, list):
                for item in output:
                    url = str(item)
                    local_url = await _download_image(url)
                    local_urls.append(local_url)
            else:
                url = str(output)
                local_url = await _download_image(url)
                local_urls.append(local_url)

        except Exception as e:
            local_urls.append(f"[生成失败: {e}]")

    return local_urls