#!/usr/bin/env python3
"""
figma-asset-fetch.py — Figma asset 取 + auto-detect 实际格式 + 保存正确扩展名。

避免反模式 (2026-05-13 retrospection Lesson 7):
- AI 假设 Figma MCP asset URLs 是 PNG (错的, 实际是 SVG)
- AI 没 verify 实际格式就 approximate 重画 / 错走 raster 路径

Usage:
  python3 scripts/figma-asset-fetch.py <figma-url-or-uuid> [output-dir]

例:
  # 仅 UUID
  python3 scripts/figma-asset-fetch.py 858c8478-b20d-4f06-b7cf-890118845106
  # → ./858c8478-b20d-4f06-b7cf-890118845106.svg (auto-detected)

  # 完整 URL + output dir
  python3 scripts/figma-asset-fetch.py https://www.figma.com/api/mcp/asset/abc... ./assets/

输出:
  - 实际格式 (SVG / PNG / JPEG / GIF / WebP / TIFF)
  - 文件大小
  - 正确扩展名命名的本地文件 (e.g. logo.svg / image.png)

R8 v2 acceptance criteria 强制: 任何 Figma asset 处理前必须用此 script
取 (不允许 manual curl + 假设格式).
"""
import sys
import subprocess
import shutil
import tempfile
import os
import re

# Mapping from `file` command output keywords → file extension
EXT_MAP = {
    "SVG": "svg",
    "PNG": "png",
    "JPEG": "jpg",
    "GIF": "gif",
    "WebP": "webp",
    "TIFF": "tif",
}


def detect_extension(file_info: str) -> str:
    """Map `file` command output to a file extension; fallback 'bin'."""
    for keyword, ext in EXT_MAP.items():
        if keyword in file_info:
            return ext
    return "bin"


def fetch(url_or_uuid: str, out_dir: str = ".") -> str:
    # Normalize input → full URL
    if url_or_uuid.startswith("http"):
        url = url_or_uuid
    else:
        url = f"https://www.figma.com/api/mcp/asset/{url_or_uuid}"

    # Download to temp via curl (cross-platform, avoids Python SSL cert issues)
    with tempfile.NamedTemporaryFile(delete=False) as tmp:
        tmp_path = tmp.name
    curl_result = subprocess.run(
        ["curl", "-sSL", "-o", tmp_path, url],
        capture_output=True,
        text=True,
    )
    if curl_result.returncode != 0:
        raise RuntimeError(f"curl failed: {curl_result.stderr.strip()}")

    # Detect real format via `file` command (cross-platform, ground truth)
    result = subprocess.run(
        ["file", "-b", tmp_path], capture_output=True, text=True, check=True
    )
    file_info = result.stdout.strip()
    ext = detect_extension(file_info)

    if ext == "bin":
        print(
            f"⚠️  Unknown format: {file_info}\n"
            f"    File saved as .bin (manual inspect needed)",
            file=sys.stderr,
        )

    # Compose output filename using UUID from URL as base
    uuid_match = re.search(r"/asset/([a-f0-9-]{8,})", url)
    name = uuid_match.group(1) if uuid_match else "figma-asset"

    os.makedirs(out_dir, exist_ok=True)
    out_path = os.path.join(out_dir, f"{name}.{ext}")
    shutil.move(tmp_path, out_path)

    size = os.path.getsize(out_path)
    print(f"✅ Saved: {out_path}")
    print(f"   Format: {file_info}")
    print(f"   Size:   {size:,} bytes")
    return out_path


def main() -> int:
    if len(sys.argv) < 2:
        print(__doc__, file=sys.stderr)
        return 2

    url_or_uuid = sys.argv[1]
    out_dir = sys.argv[2] if len(sys.argv) > 2 else "."

    try:
        fetch(url_or_uuid, out_dir)
        return 0
    except Exception as e:
        print(f"❌ Error: {e}", file=sys.stderr)
        return 1


if __name__ == "__main__":
    sys.exit(main())