"""
扑克牌渲染工具 - 使用 Pillow 在服务器端生成牌面 PNG。

渲染图层结构（从下到上）：
  1. 背景层（颜色或图片）
  2. 边框层
  3. 主体层（数字牌的花色阵列 / JQK 的人物对称 / 大小王的图案 + JOKER 文字）
  4. 角标层（左上 + 右下 旋转 180°）
"""
from PIL import Image, ImageDraw, ImageFont
import io
import os

# 标准扑克牌花色符号（用作默认渲染）
SUIT_TEXT = {
    'spade':   '♠',
    'heart':   '♥',
    'club':    '♣',
    'diamond': '♦',
}
RED_SUITS = {'heart', 'diamond'}
BLACK_SUITS = {'spade', 'club'}

# 数字牌点数 1-10 的花色位置（相对坐标 0~1）
LAYOUT_POSITIONS = {
    1:  [(0.50, 0.50)],
    2:  [(0.50, 0.25), (0.50, 0.75)],
    3:  [(0.50, 0.20), (0.50, 0.50), (0.50, 0.80)],
    4:  [(0.30, 0.25), (0.70, 0.25), (0.30, 0.75), (0.70, 0.75)],
    5:  [(0.30, 0.20), (0.70, 0.20), (0.50, 0.50), (0.30, 0.80), (0.70, 0.80)],
    6:  [(0.30, 0.20), (0.70, 0.20), (0.30, 0.50), (0.70, 0.50), (0.30, 0.80), (0.70, 0.80)],
    7:  [(0.30, 0.15), (0.70, 0.15), (0.50, 0.35), (0.30, 0.55), (0.70, 0.55), (0.30, 0.85), (0.70, 0.85)],
    8:  [(0.30, 0.15), (0.70, 0.15), (0.50, 0.32), (0.30, 0.50), (0.70, 0.50), (0.50, 0.68), (0.30, 0.85), (0.70, 0.85)],
    9:  [(0.30, 0.15), (0.70, 0.15), (0.50, 0.30), (0.22, 0.50), (0.50, 0.50), (0.78, 0.50), (0.50, 0.70), (0.30, 0.85), (0.70, 0.85)],
    10: [(0.30, 0.15), (0.70, 0.15), (0.30, 0.35), (0.70, 0.35), (0.50, 0.45), (0.50, 0.55), (0.30, 0.65), (0.70, 0.65), (0.30, 0.85), (0.70, 0.85)],
}


def hex_to_rgba(hex_color, alpha=255):
    """将 #RRGGBB 转为 (r, g, b, a)"""
    if not hex_color:
        return (255, 255, 255, alpha)
    h = hex_color.lstrip('#')
    if len(h) == 3:
        h = ''.join(c * 2 for c in h)
    try:
        return (int(h[0:2], 16), int(h[2:4], 16), int(h[4:6], 16), alpha)
    except Exception:
        return (255, 255, 255, alpha)


def is_red(suit):
    return suit in RED_SUITS


def is_black(suit):
    return suit in BLACK_SUITS


def get_effective_design(project, card_key):
    """合并项目级设计与单牌覆盖，返回最终 design dict"""
    base = dict(project.design or {})
    overrides = (project.card_overrides or {}).get(card_key, {})
    if overrides:
        base.update(overrides)
    return base


def get_effective_back_design(project):
    """获取背面设计配置，合并 back_design 与 card_overrides['back']"""
    base = dict(project.back_design or {})
    overrides = (project.card_overrides or {}).get('back', {})
    if overrides:
        base.update(overrides)
    return base


def load_image_safe(file_path):
    """加载图片，找不到时返回 None"""
    if not file_path:
        return None
    if not os.path.exists(file_path):
        return None
    try:
        return Image.open(file_path).convert('RGBA')
    except Exception:
        return None


def draw_background(canvas, design, project, card_key):
    """绘制背景层"""
    w, h = canvas.size
    bg_color = design.get('background_color', '#FFFFFF') or '#FFFFFF'
    canvas.paste(hex_to_rgba(bg_color, 255), (0, 0, w, h))

    bg_image = design.get('background_image')
    if bg_image:
        bg_path = os.path.join(project._meta.get_field('design').model._meta.app_config and
                                os.path.dirname(__file__) or '',
                               bg_image)
        # 优先尝试绝对路径 / media 根
        candidates = [bg_image,
                      os.path.join(os.path.dirname(os.path.dirname(os.path.dirname(__file__))), 'media', bg_image)]
        for path in candidates:
            img = load_image_safe(path)
            if img:
                img = img.resize((w, h), Image.LANCZOS)
                canvas.alpha_composite(img)
                break


def draw_border(canvas, design):
    """绘制边框"""
    w, h = canvas.size
    color = design.get('border_color', '#333333') or '#333333'
    width = int(design.get('border_width', 0) or 0)
    if width <= 0:
        return
    draw = ImageDraw.Draw(canvas)
    half = max(1, width // 2)
    draw.rectangle(((half, half), (w - half, h - half)),
                   outline=hex_to_rgba(color, 255), width=width)


def make_text_font(family, size, bold=False):
    """根据字体族名尝试加载字体；找不到时退回默认"""
    if not family:
        return ImageFont.load_default()
    # 仅在 Windows 上尝试用注册字体
    if os.name == 'nt':
        candidates = [
            family,
            family.replace(' ', '') + (' Bold' if bold else ''),
            family + (' Bold' if bold else ''),
        ]
        for name in candidates:
            try:
                # 走 Windows 字体名
                return ImageFont.truetype(name + '.ttf', size)
            except Exception:
                pass
        # 一些常见回退
        try:
            return ImageFont.truetype('arial.ttf', size)
        except Exception:
            pass
    return ImageFont.load_default()


def draw_corner_index(canvas, design, suit, rank, project, card_key):
    """绘制左上角 + 右下角（旋转 180°）的牌面角标
    角标由 上方的 rank + 小花色 组成
    """
    w, h = canvas.size
    color = hex_to_rgba(design.get('suit_symbols', {}).get(suit, {}).get('color')
                        or ('#E53935' if is_red(suit) else '#000000'), 255)

    # 角标和中心花色大小（占牌面宽度比例）
    corner_ratio = float(design.get('corner_size_ratio', 0.13) or 0.13)
    pip_ratio = float(design.get('pip_size_ratio', 0.16) or 0.16)

    corner_size = max(20, int(w * corner_ratio))
    font = make_text_font(design.get('font_family', 'Times New Roman'), corner_size)
    suit_font = make_text_font('Arial', int(corner_size * 0.9))

    # 左上角
    pad = max(8, int(w * 0.04))
    rank_str = str(rank)
    draw = ImageDraw.Draw(canvas)
    rank_bbox = draw.textbbox((0, 0), rank_str, font=font)
    rank_h = rank_bbox[3] - rank_bbox[1]
    rank_w = rank_bbox[2] - rank_bbox[0]
    suit_bbox = draw.textbbox((0, 0), SUIT_TEXT[suit], font=suit_font)
    suit_h = suit_bbox[3] - suit_bbox[1]
    suit_w = suit_bbox[2] - suit_bbox[0]

    # rank 在上、suit 在下
    top_y = pad
    canvas_rgba = canvas
    draw.text((pad, top_y), rank_str, font=font, fill=color)
    draw.text((pad, top_y + rank_h + 2), SUIT_TEXT[suit], font=suit_font, fill=color)

    # 右下角：旋转 180° 整体贴到 (w-pad, h-pad)
    block_w = max(rank_w, suit_w)
    block_h = rank_h + 2 + suit_h
    # 透明小图旋转
    corner_img = Image.new('RGBA', (block_w + 4, block_h + 4), (0, 0, 0, 0))
    cdraw = ImageDraw.Draw(corner_img)
    cdraw.text((0, 0), rank_str, font=font, fill=color)
    cdraw.text((0, rank_h + 2), SUIT_TEXT[suit], font=suit_font, fill=color)
    corner_img = corner_img.rotate(180)
    canvas_rgba.alpha_composite(corner_img, (w - block_w - 4 - pad, h - block_h - 4 - pad))


def draw_number_card(canvas, design, suit, rank, project, card_key):
    """绘制数字牌：中心花色阵列"""
    w, h = canvas.size
    pip_ratio = float(design.get('pip_size_ratio', 0.16) or 0.16)
    pip_size = max(40, int(w * pip_ratio))
    suit_color = hex_to_rgba(design.get('suit_symbols', {}).get(suit, {}).get('color')
                             or ('#E53935' if is_red(suit) else '#000000'), 255)
    font = make_text_font('Arial', pip_size)

    # 决定位置：优先用项目里的 number_layout 覆盖默认
    rank_int = int(rank) if str(rank).isdigit() else 1
    default_positions = LAYOUT_POSITIONS.get(rank_int, LAYOUT_POSITIONS[1])
    layout_key = str(rank_int)
    user_overrides = (project.number_layout or {}).get(layout_key, [])

    positions = []
    for i, (fx, fy) in enumerate(default_positions):
        if i < len(user_overrides) and isinstance(user_overrides[i], dict):
            dx = float(user_overrides[i].get('dx', 0))
            dy = float(user_overrides[i].get('dy', 0))
            scale = float(user_overrides[i].get('scale', 1))
        else:
            dx = dy = 0
            scale = 1.0
        positions.append((fx + dx, fy + dy, scale))

    draw = ImageDraw.Draw(canvas)
    symbol = SUIT_TEXT[suit]
    for fx, fy, scale in positions:
        sz = max(20, int(pip_size * scale))
        fnt = make_text_font('Arial', sz)
        bbox = draw.textbbox((0, 0), symbol, font=fnt)
        tw = bbox[2] - bbox[0]
        th = bbox[3] - bbox[1]
        cx = int(fx * w)
        cy = int(fy * h)
        draw.text((cx - tw // 2, cy - th // 2), symbol, font=fnt, fill=suit_color)


def draw_face_card(canvas, design, suit, rank, project, card_key, asset):
    """绘制 JQK 人物图：上半 + 上下翻转的下半，形成中心对称
    资源找不到时退化为一个大花色符号 + 字母
    """
    w, h = canvas.size
    # 主体区域：留出上下 25% 边距给角标
    body_pad_x = int(w * 0.15)
    body_pad_y_top = int(h * 0.13)
    body_pad_y_bot = int(h * 0.13)
    body_w = w - 2 * body_pad_x
    body_h = h - body_pad_y_top - body_pad_y_bot

    if asset:
        try:
            img = asset.copy()
            # 等比缩放 fill body_w x body_h
            img_ratio = img.width / img.height
            target_ratio = body_w / body_h
            if img_ratio > target_ratio:
                new_w = body_w
                new_h = int(body_w / img_ratio)
            else:
                new_h = body_h
                new_w = int(body_h * img_ratio)
            img = img.resize((new_w, new_h), Image.LANCZOS)

            # 取上半部分 + 下半部分
            top = img.crop((0, 0, img.width, img.height // 2))
            bot_src = img.crop((0, img.height // 2, img.width, img.height))
            # symmetry_mode: 'flip' = 垂直翻转；'rotate' = 180° 旋转
            sym_mode = design.get('symmetry_mode', 'flip')
            if sym_mode == 'rotate':
                # 180° 旋转 = 先水平翻转再垂直翻转（PIL 没有一步到位的 180 旋转 transpose）
                bot_src = bot_src.transpose(Image.FLIP_LEFT_RIGHT)
                bot_src = bot_src.transpose(Image.FLIP_TOP_BOTTOM)
            else:  # 'flip'（默认）
                bot_src = bot_src.transpose(Image.FLIP_TOP_BOTTOM)

            # 拼接成 body_h 高的新图
            full = Image.new('RGBA', (img.width, body_h), (0, 0, 0, 0))
            top = top.resize((img.width, body_h // 2), Image.LANCZOS)
            bot_src = bot_src.resize((img.width, body_h - body_h // 2), Image.LANCZOS)
            full.paste(top, (0, 0), top)
            full.paste(bot_src, (0, body_h // 2), bot_src)

            full = full.resize((body_w, body_h), Image.LANCZOS)
            canvas.alpha_composite(full, (body_pad_x, body_pad_y_top))
            return
        except Exception:
            pass

    # 退化：绘制大字 + 花色
    suit_color = hex_to_rgba(design.get('suit_symbols', {}).get(suit, {}).get('color')
                             or ('#E53935' if is_red(suit) else '#000000'), 255)
    big = max(80, int(h * 0.35))
    fnt_rank = make_text_font('Times New Roman', big, bold=True)
    fnt_suit = make_text_font('Arial', big)
    draw = ImageDraw.Draw(canvas)
    rb = draw.textbbox((0, 0), rank, font=fnt_rank)
    rw = rb[2] - rb[0]
    rh = rb[3] - rb[1]
    draw.text(((w - rw) // 2, body_pad_y_top + (body_h - rh) // 2 - big // 2),
              rank, font=fnt_rank, fill=suit_color)
    sb = draw.textbbox((0, 0), SUIT_TEXT[suit], font=fnt_suit)
    sw = sb[2] - sb[0]
    sh = sb[3] - sb[1]
    draw.text(((w - sw) // 2, body_pad_y_top + (body_h - sh) // 2 + big // 4),
              SUIT_TEXT[suit], font=fnt_suit, fill=suit_color)


def draw_joker(canvas, design, which, project, card_key, asset):
    """绘制大小王：独立背景 + 主体图 + 文字"""
    w, h = canvas.size

    # 大小王默认有自己的背景色（绿/红），不被整副牌的 background_color 覆盖
    # 除非用户显式在 card_overrides 里设了 background_color
    default_bg = '#1B5E20' if which == 'big' else '#B71C1C'
    card_overrides = (project.card_overrides or {}).get(card_key, {})
    if 'background_color' in card_overrides:
        bg_color = card_overrides['background_color']
    else:
        bg_color = default_bg
    canvas.paste(hex_to_rgba(bg_color, 255), (0, 0, w, h))

    # 主体图
    body_pad_x = int(w * 0.15)
    body_pad_y_top = int(h * 0.18)
    body_pad_y_bot = int(h * 0.22)
    body_w = w - 2 * body_pad_x
    body_h = h - body_pad_y_top - body_pad_y_bot
    if asset:
        try:
            half_h = body_h // 2
            image_dx = float(design.get('image_dx', 0))
            image_dy = float(design.get('image_dy', 0))
            image_scale = float(design.get('image_scale', 1))
            offset_x = int(body_w * image_dx)
            offset_y = int(body_h * image_dy)

            img_copy = asset.copy()
            img_copy = img_copy.resize((body_w, half_h), Image.LANCZOS)
            if image_scale != 1:
                sw = max(1, int(img_copy.width * image_scale))
                sh = max(1, int(img_copy.height * image_scale))
                img_copy = img_copy.resize((sw, sh), Image.LANCZOS)
            x = body_pad_x + offset_x + (body_w - img_copy.width) // 2
            y_top = body_pad_y_top + offset_y + (half_h - img_copy.height) // 2
            canvas.alpha_composite(img_copy, (x, y_top))
            # symmetry_mode: 'flip' = 垂直翻转；'rotate' = 180° 旋转
            sym_mode = design.get('symmetry_mode', 'flip')
            if sym_mode == 'rotate':
                img_bot = img_copy.transpose(Image.ROTATE_180)
            else:
                img_bot = img_copy.transpose(Image.FLIP_TOP_BOTTOM)
            y_bot = body_pad_y_top + half_h + offset_y + (half_h - img_bot.height) // 2
            canvas.alpha_composite(img_bot, (x, y_bot))
        except Exception:
            pass
    else:
        # 退化
        fnt = make_text_font('Times New Roman', max(80, int(h * 0.25)), bold=True)
        draw = ImageDraw.Draw(canvas)
        text = 'JOKER'
        color = (255, 255, 255, 255) if which == 'big' else (255, 255, 255, 255)
        bb = draw.textbbox((0, 0), text, font=fnt)
        tw, th = bb[2] - bb[0], bb[3] - bb[1]
        draw.text(((w - tw) // 2, (h - th) // 2), text, font=fnt, fill=color)

    # 文字标识
    label = 'BIG' if which == 'big' else 'SMALL'
    text = 'JOKER'
    fnt_label = make_text_font('Times New Roman', max(20, int(w * 0.06)), bold=True)
    fnt_text = make_text_font('Times New Roman', max(16, int(w * 0.045)))
    color = (255, 255, 255, 255)
    draw = ImageDraw.Draw(canvas)
    bb = draw.textbbox((0, 0), text, font=fnt_text)
    tw = bb[2] - bb[0]
    th = bb[3] - bb[1]
    pad = max(8, int(w * 0.04))
    # 左上
    draw.text((pad, pad), text, font=fnt_text, fill=color)
    draw.text((pad, pad + th + 2), label, font=fnt_label, fill=color)
    # 右下
    block = Image.new('RGBA', (tw + 4, 2 * th + 6), (0, 0, 0, 0))
    bdraw = ImageDraw.Draw(block)
    bdraw.text((0, 0), text, font=fnt_text, fill=color)
    bdraw.text((0, th + 2), label, font=fnt_label, fill=color)
    block = block.rotate(180)
    canvas.alpha_composite(block, (w - tw - 4 - pad, h - 2 * th - 6 - pad))


def draw_back(canvas, back_design, asset):
    """绘制背面：素材图 + 位置微调 + 色调叠加，无素材时退化为文字"""
    w, h = canvas.size
    # 填充背景色
    bg_color = back_design.get('background_color', '#1A237E') or '#1A237E'
    canvas.paste(hex_to_rgba(bg_color, 255), (0, 0, w, h))

    body_pad_x = int(w * 0.15)
    body_pad_y_top = int(h * 0.18)
    body_pad_y_bot = int(h * 0.22)
    body_w = w - 2 * body_pad_x
    body_h = h - body_pad_y_top - body_pad_y_bot

    if asset:
        try:
            image_dx = float(back_design.get('image_dx', 0))
            image_dy = float(back_design.get('image_dy', 0))
            image_scale = float(back_design.get('image_scale', 1))
            offset_x = int(body_w * image_dx)
            offset_y = int(body_h * image_dy)

            img = asset.copy()
            img.thumbnail((body_w, body_h), Image.LANCZOS)
            if image_scale != 1:
                sw = max(1, int(img.width * image_scale))
                sh = max(1, int(img.height * image_scale))
                img = img.resize((sw, sh), Image.LANCZOS)
            x = body_pad_x + offset_x + (body_w - img.width) // 2
            y = body_pad_y_top + offset_y + (body_h - img.height) // 2
            canvas.alpha_composite(img, (x, y))

            # 色调叠加
            pattern_color = back_design.get('pattern_color')
            if pattern_color:
                tint = Image.new('RGBA', (w, h), hex_to_rgba(pattern_color, 80))
                canvas.alpha_composite(tint)
        except Exception:
            pass
    else:
        # 退化：绘制边框 + 文字
        border_color = back_design.get('border_color', '#C0A050') or '#C0A050'
        draw = ImageDraw.Draw(canvas)
        border_width = int(back_design.get('border_width', 3) or 3)
        if border_width > 0:
            half = max(1, border_width // 2)
            draw.rectangle(((half, half), (w - half, h - half)),
                           outline=hex_to_rgba(border_color, 255), width=border_width)
        fnt = make_text_font('Times New Roman', max(40, int(h * 0.08)), bold=True)
        text = 'CARD BACK'
        color = hex_to_rgba(border_color, 255)
        bb = draw.textbbox((0, 0), text, font=fnt)
        tw, th = bb[2] - bb[0], bb[3] - bb[1]
        draw.text(((w - tw) // 2, (h - th) // 2), text, font=fnt, fill=color)


def generate_card_png(project, card_key, resolution='standard'):
    """根据项目配置生成单张牌 PNG"""
    scale_map = {'standard': 1, 'hd': 2, 'ultra-hd': 4}
    scale = scale_map.get(resolution, 1)

    w = int(project.card_width * scale)
    h = int(project.card_height * scale)
    canvas = Image.new('RGBA', (w, h), (255, 255, 255, 255))

    design = get_effective_design(project, card_key)

    # 1. 背景
    draw_background(canvas, design, project, card_key)

    # 2. 边框
    draw_border(canvas, design)

    # 3. 主体内容
    if card_key.startswith('joker-'):
        # which 是去掉前缀的 'big'/'small'，但 asset_key 含 'joker-' 前缀
        which = card_key.split('-', 1)[1]  # big / small
        asset = None
        for a in project.assets.filter(asset_type='joker', asset_key=card_key):
            p = os.path.join('media', a.file_path) if a.file_path else None
            asset = load_image_safe(p) if p else None
            break
        draw_joker(canvas, design, which, project, card_key, asset)
    elif card_key in ('back', 'card-back'):
        back_design = get_effective_back_design(project)
        back_asset = None
        for a in project.assets.filter(asset_type='back'):
            p = os.path.join('media', a.file_path) if a.file_path else None
            back_asset = load_image_safe(p) if p else None
            break
        draw_back(canvas, back_design, back_asset)
        return canvas
    else:
        # 'suit-rank'
        parts = card_key.split('-')
        suit = parts[0]
        rank = parts[1]
        is_face = rank in ('J', 'Q', 'K')
        if is_face:
            asset = None
            for a in project.assets.filter(asset_type='face_card', asset_key=card_key):
                p = os.path.join('media', a.file_path) if a.file_path else None
                asset = load_image_safe(p) if p else None
                break
            draw_face_card(canvas, design, suit, rank, project, card_key, asset)
        else:
            # A 写成 '1'，但角标用 'A'
            rk = 'A' if rank == '1' else rank
            draw_number_card(canvas, design, suit, rank, project, card_key)
            # 角标
            draw_corner_index(canvas, design, suit, rk, project, card_key)
            return canvas

        # JQK 角标：花色小，rank 字母 J/Q/K
        draw_corner_index(canvas, design, suit, rank, project, card_key)

    return canvas