TravelContentCreator/poster_v2/renderers/text.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
文字渲染器
"""

from pathlib import Path
from typing import Tuple, Optional, Union
from PIL import Image, ImageDraw, ImageFont

from ..config import get_font_path, FONT_FILES


class TextRenderer:
    """文字渲染器"""
    
    _font_cache = {}
    
    @classmethod
    def load_font(cls, font_name: str, size: int) -> ImageFont.FreeTypeFont:
        """加载字体 (带缓存)"""
        cache_key = (font_name, size)
        if cache_key not in cls._font_cache:
            font_path = get_font_path(font_name)
            try:
                cls._font_cache[cache_key] = ImageFont.truetype(str(font_path), size)
            except Exception:
                cls._font_cache[cache_key] = ImageFont.load_default()
        return cls._font_cache[cache_key]
    
    @staticmethod
    def draw_text(
        draw: ImageDraw.ImageDraw,
        pos: Tuple[int, int],
        text: str,
        font: ImageFont.FreeTypeFont,
        fill: Union[str, Tuple],
        anchor: str = "lt"
    ) -> Tuple[int, int]:
        """
        绘制文字
        
        Returns:
            (width, height) 文字尺寸
        """
        draw.text(pos, text, font=font, fill=fill, anchor=anchor)
        bbox = draw.textbbox((0, 0), text, font=font)
        return bbox[2] - bbox[0], bbox[3] - bbox[1]
    
    @staticmethod
    def draw_text_with_shadow(
        draw: ImageDraw.ImageDraw,
        pos: Tuple[int, int],
        text: str,
        font: ImageFont.FreeTypeFont,
        fill: Union[str, Tuple],
        shadow_color: Tuple[int, int, int, int] = (0, 0, 0, 60),
        offset: Tuple[int, int] = (2, 2)
    ) -> Tuple[int, int]:
        """绘制带阴影的文字"""
        x, y = pos
        # 阴影
        draw.text((x + offset[0], y + offset[1]), text, font=font, fill=shadow_color)
        # 主文字
        draw.text((x, y), text, font=font, fill=fill)
        bbox = draw.textbbox((0, 0), text, font=font)
        return bbox[2] - bbox[0], bbox[3] - bbox[1]
    
    @staticmethod
    def draw_emoji(
        draw: ImageDraw.ImageDraw,
        pos: Tuple[int, int],
        emoji: str,
        size: int = 109
    ) -> Tuple[int, int]:
        """绘制 emoji"""
        font = ImageFont.truetype(str(get_font_path("emoji")), size)
        draw.text(pos, emoji, font=font, embedded_color=True)
        return size, size
    
    @staticmethod
    def measure_text(
        text: str,
        font: ImageFont.FreeTypeFont
    ) -> Tuple[int, int]:
        """测量文字尺寸"""
        temp = Image.new("RGBA", (1, 1))
        draw = ImageDraw.Draw(temp)
        bbox = draw.textbbox((0, 0), text, font=font)
        return bbox[2] - bbox[0], bbox[3] - bbox[1]
    
    @classmethod
    def get_title_font(cls, size: int = 80) -> ImageFont.FreeTypeFont:
        """获取标题字体"""
        return cls.load_font("title_bold", size)
    
    @classmethod
    def get_body_font(cls, size: int = 28) -> ImageFont.FreeTypeFont:
        """获取正文字体"""
        return cls.load_font("body_regular", size)
    
    @classmethod
    def get_adaptive_title_font(cls, text: str, max_width: int, 
                                 base_size: int = 96, min_size: int = 48) -> ImageFont.FreeTypeFont:
        """
        获取自适应大小的标题字体
        
        根据文本长度和最大宽度，自动调整字体大小
        """
        size = base_size
        while size >= min_size:
            font = cls.load_font("title_bold", size)
            w, _ = cls.measure_text(text, font)
            if w <= max_width:
                return font
            size -= 4
        return cls.load_font("title_bold", min_size)
    
    @classmethod
    def wrap_text(cls, text: str, font: ImageFont.FreeTypeFont, max_width: int) -> list:
        """
        文本自动换行
        
        Args:
            text: 原始文本
            font: 字体
            max_width: 最大宽度
            
        Returns:
            换行后的文本行列表
        """
        if not text:
            return []
        
        lines = []
        current_line = ""
        
        for char in text:
            test_line = current_line + char
            w, _ = cls.measure_text(test_line, font)
            
            if w <= max_width:
                current_line = test_line
            else:
                if current_line:
                    lines.append(current_line)
                current_line = char
        
        if current_line:
            lines.append(current_line)
        
        return lines
    
    @classmethod
    def draw_wrapped_text(
        cls,
        draw: ImageDraw.ImageDraw,
        pos: Tuple[int, int],
        text: str,
        font: ImageFont.FreeTypeFont,
        fill: Union[str, Tuple],
        max_width: int,
        line_spacing: int = 8
    ) -> Tuple[int, int]:
        """
        绘制自动换行的文本
        
        Returns:
            (总宽度, 总高度)
        """
        lines = cls.wrap_text(text, font, max_width)
        
        x, y = pos
        total_height = 0
        max_line_width = 0
        
        for line in lines:
            w, h = cls.measure_text(line, font)
            draw.text((x, y), line, font=font, fill=fill)
            y += h + line_spacing
            total_height += h + line_spacing
            max_line_width = max(max_line_width, w)
        
        return max_line_width, total_height - line_spacing if lines else 0