"""
Mock 图片生成服务
使用 Pillow 生成带文字的占位设计图
"""
import os
from typing import Optional, Tuple, Union
from PIL import Image, ImageDraw, ImageFont


# 颜色映射表（中文颜色名 -> 十六进制）
COLOR_MAP = {
    # 和田玉国标色种
    "白玉": "#FEFEF2",
    "青白玉": "#E8EDE4",
    "青玉": "#7A8B6E",
    "碧玉": "#2D5F2D",
    "翠青": "#6BAF8D",
    "黄玉": "#D4A843",
    "糖玉": "#C4856C",
    "墨玉": "#2C2C2C",
    "藕粉": "#E8B4B8",
    "烟紫": "#8B7D9B",
    # 原有颜色
    "糖白": "#F5F0E8",
    # 通用颜色
    "白色": "#FFFFFF",
    "黑色": "#333333",
    "红色": "#C41E3A",
    "绿色": "#228B22",
    "蓝色": "#4169E1",
    "黄色": "#FFD700",
    "紫色": "#9370DB",
    "粉色": "#FFB6C1",
    "橙色": "#FF8C00",
}

# 默认背景色（浅灰）
DEFAULT_BG_COLOR = "#E8E4DF"


def hex_to_rgb(hex_color: str) -> Tuple[int, int, int]:
    """将十六进制颜色转换为 RGB 元组"""
    hex_color = hex_color.lstrip('#')
    return tuple(int(hex_color[i:i+2], 16) for i in (0, 2, 4))


def get_contrast_text_color(bg_color: str) -> str:
    """根据背景色计算合适的文字颜色（黑或白）"""
    r, g, b = hex_to_rgb(bg_color)
    # 使用亮度公式
    brightness = (r * 299 + g * 587 + b * 114) / 1000
    return "#333333" if brightness > 128 else "#FFFFFF"


def get_font(size: int = 24) -> Union[ImageFont.FreeTypeFont, ImageFont.ImageFont]:
    """
    获取字体，优先使用系统中文字体
    """
    # 常见中文字体路径
    font_paths = [
        # macOS
        "/System/Library/Fonts/PingFang.ttc",
        "/System/Library/Fonts/STHeiti Light.ttc",
        "/System/Library/Fonts/Supplemental/Arial Unicode.ttf",
        "/Library/Fonts/Arial Unicode.ttf",
        # Linux
        "/usr/share/fonts/truetype/droid/DroidSansFallbackFull.ttf",
        "/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc",
        "/usr/share/fonts/truetype/wqy/wqy-zenhei.ttc",
        # Windows
        "C:\\Windows\\Fonts\\msyh.ttc",
        "C:\\Windows\\Fonts\\simsun.ttc",
    ]
    
    for font_path in font_paths:
        if os.path.exists(font_path):
            try:
                return ImageFont.truetype(font_path, size)
            except Exception:
                continue
    
    # 回退到默认字体
    return ImageFont.load_default()


def generate_mock_design(
    category_name: str,
    sub_type_name: Optional[str],
    color_name: Optional[str],
    prompt: str,
    save_path: str,
    carving_technique: Optional[str] = None,
    design_style: Optional[str] = None,
    motif: Optional[str] = None,
    size_spec: Optional[str] = None,
    surface_finish: Optional[str] = None,
    usage_scene: Optional[str] = None,
) -> str:
    """
    生成 Mock 设计图
    
    Args:
        category_name: 品类名称
        sub_type_name: 子类型名称（可选）
        color_name: 颜色名称（可选）
        prompt: 用户设计需求
        save_path: 保存路径
        
    Returns:
        相对 URL 路径，如 /uploads/designs/1001.png
    """
    # 确定背景色
    if color_name and color_name in COLOR_MAP:
        bg_color = COLOR_MAP[color_name]
    elif color_name:
        # 尝试直接使用颜色名（可能是十六进制）
        bg_color = color_name if color_name.startswith("#") else DEFAULT_BG_COLOR
    else:
        bg_color = DEFAULT_BG_COLOR
    
    # 创建图片
    width, height = 800, 800
    bg_rgb = hex_to_rgb(bg_color)
    image = Image.new("RGB", (width, height), bg_rgb)
    draw = ImageDraw.Draw(image)
    
    # 获取文字颜色（与背景对比）
    text_color = get_contrast_text_color(bg_color)
    text_rgb = hex_to_rgb(text_color)
    
    # 获取字体
    title_font = get_font(48)
    info_font = get_font(32)
    prompt_font = get_font(28)
    
    # 绘制标题
    title = "玉宗设计"
    draw.text((width // 2, 100), title, font=title_font, fill=text_rgb, anchor="mm")
    
    # 绘制分隔线
    line_y = 160
    draw.line([(100, line_y), (700, line_y)], fill=text_rgb, width=2)
    
    # 绘制品类信息
    y_position = 220
    info_lines = [f"品类: {category_name}"]
    
    if sub_type_name:
        info_lines.append(f"类型: {sub_type_name}")
    
    if color_name:
        info_lines.append(f"颜色: {color_name}")
    
    if carving_technique:
        info_lines.append(f"工艺: {carving_technique}")
    
    if design_style:
        info_lines.append(f"风格: {design_style}")
    
    if motif:
        info_lines.append(f"题材: {motif}")
    
    if size_spec:
        info_lines.append(f"尺寸: {size_spec}")
    
    if surface_finish:
        info_lines.append(f"表面: {surface_finish}")
    
    if usage_scene:
        info_lines.append(f"用途: {usage_scene}")
    
    for line in info_lines:
        draw.text((width // 2, y_position), line, font=info_font, fill=text_rgb, anchor="mm")
        y_position += 50
    
    # 绘制分隔线
    y_position += 20
    draw.line([(100, y_position), (700, y_position)], fill=text_rgb, width=1)
    y_position += 40
    
    # 绘制用户需求标题
    draw.text((width // 2, y_position), "设计需求:", font=info_font, fill=text_rgb, anchor="mm")
    y_position += 50
    
    # 绘制用户需求文本（自动换行）
    max_chars_per_line = 20
    prompt_lines = []
    current_line = ""
    for char in prompt:
        current_line += char
        if len(current_line) >= max_chars_per_line:
            prompt_lines.append(current_line)
            current_line = ""
    if current_line:
        prompt_lines.append(current_line)
    
    # 限制最多显示 5 行
    for line in prompt_lines[:5]:
        draw.text((width // 2, y_position), line, font=prompt_font, fill=text_rgb, anchor="mm")
        y_position += 40
    
    if len(prompt_lines) > 5:
        draw.text((width // 2, y_position), "...", font=prompt_font, fill=text_rgb, anchor="mm")
    
    # 绘制底部装饰
    draw.rectangle([(50, 720), (750, 750)], outline=text_rgb, width=2)
    draw.text((width // 2, 735), "AI Generated Mock Design", font=get_font(20), fill=text_rgb, anchor="mm")
    
    # 确保目录存在
    os.makedirs(os.path.dirname(save_path), exist_ok=True)
    
    # 保存图片
    image.save(save_path, "PNG")
    
    # 返回相对 URL 路径
    # save_path 格式类似 uploads/designs/1001.png
    # 需要转换为 /uploads/designs/1001.png
    relative_path = save_path.replace("\\", "/")
    if not relative_path.startswith("/"):
        relative_path = "/" + relative_path
    
    return relative_path