#!/usr/bin/env python3
# -*- coding: utf-8 -*-

"""
图像处理工具类
用于处理base64编码、图像转换等功能
"""

import base64
import io
import logging
from typing import Dict, Any, List, Optional, Tuple
from pathlib import Path
from PIL import Image
import json

logger = logging.getLogger(__name__)


class ImageProcessor:
    """图像处理工具类"""
    
    @staticmethod
    def image_to_base64(image_path: str, format: str = "PNG") -> str:
        """
        将图像文件转换为base64编码
        
        Args:
            image_path: 图像文件路径
            format: 输出格式 (PNG, JPEG等)
            
        Returns:
            base64编码的字符串
        """
        try:
            with open(image_path, "rb") as image_file:
                # 读取图像文件
                image_data = image_file.read()
                
                # 转换为base64
                base64_data = base64.b64encode(image_data).decode('utf-8')
                
                # 添加MIME类型前缀
                mime_type = f"image/{format.lower()}"
                if format.upper() == "JPEG":
                    mime_type = "image/jpeg"
                elif format.upper() == "PNG":
                    mime_type = "image/png"
                
                return f"data:{mime_type};base64,{base64_data}"
                
        except Exception as e:
            logger.error(f"图像转base64失败: {e}")
            return ""
    
    @staticmethod
    def pil_image_to_base64(image: Image.Image, format: str = "PNG") -> str:
        """
        将PIL图像对象转换为base64编码
        
        Args:
            image: PIL图像对象
            format: 输出格式 (PNG, JPEG等)
            
        Returns:
            base64编码的字符串
        """
        try:
            # 创建内存缓冲区
            buffer = io.BytesIO()
            
            # 保存图像到缓冲区
            if format.upper() == "JPEG":
                image.save(buffer, format="JPEG", quality=85)
            else:
                image.save(buffer, format="PNG")
            
            # 获取字节数据
            image_data = buffer.getvalue()
            
            # 转换为base64
            base64_data = base64.b64encode(image_data).decode('utf-8')
            
            # 添加MIME类型前缀
            mime_type = f"image/{format.lower()}"
            if format.upper() == "JPEG":
                mime_type = "image/jpeg"
            elif format.upper() == "PNG":
                mime_type = "image/png"
            
            return f"data:{mime_type};base64,{base64_data}"
            
        except Exception as e:
            logger.error(f"PIL图像转base64失败: {e}")
            return ""
    
    @staticmethod
    def base64_to_image(base64_string: str) -> Optional[Image.Image]:
        """
        将base64编码转换为PIL图像对象
        
        Args:
            base64_string: base64编码的字符串
            
        Returns:
            PIL图像对象，如果转换失败则返回None
        """
        try:
            # 移除MIME类型前缀
            if "data:image" in base64_string:
                base64_data = base64_string.split(",")[1]
            else:
                base64_data = base64_string
            
            # 解码base64
            image_data = base64.b64decode(base64_data)
            
            # 创建PIL图像对象
            image = Image.open(io.BytesIO(image_data))
            
            return image
            
        except Exception as e:
            logger.error(f"base64转图像失败: {e}")
            return None
    
    @staticmethod
    def get_image_metadata(image_path: str) -> Dict[str, Any]:
        """
        获取图像文件的元数据
        
        Args:
            image_path: 图像文件路径
            
        Returns:
            元数据字典
        """
        try:
            with Image.open(image_path) as image:
                metadata = {
                    "width": image.width,
                    "height": image.height,
                    "format": image.format,
                    "mode": image.mode,
                    "size_bytes": Path(image_path).stat().st_size if Path(image_path).exists() else 0
                }
                
                # 获取EXIF数据（如果有）
                if hasattr(image, '_getexif') and image._getexif():
                    metadata["exif"] = dict(image._getexif())
                
                return metadata
                
        except Exception as e:
            logger.error(f"获取图像元数据失败: {e}")
            return {}
    
    @staticmethod
    def resize_image(image: Image.Image, max_width: int = 1920, max_height: int = 1080) -> Image.Image:
        """
        调整图像尺寸
        
        Args:
            image: PIL图像对象
            max_width: 最大宽度
            max_height: 最大高度
            
        Returns:
            调整后的图像对象
        """
        try:
            # 计算缩放比例
            width, height = image.size
            scale = min(max_width / width, max_height / height, 1.0)
            
            if scale < 1.0:
                new_width = int(width * scale)
                new_height = int(height * scale)
                image = image.resize((new_width, new_height), Image.Resampling.LANCZOS)
            
            return image
            
        except Exception as e:
            logger.error(f"调整图像尺寸失败: {e}")
            return image
    
    @staticmethod
    def create_collage_from_paths(image_paths: List[str], target_size: Tuple[int, int] = (900, 1200)) -> Optional[Image.Image]:
        """
        从图像路径列表创建拼图
        
        Args:
            image_paths: 图像路径列表
            target_size: 目标尺寸 (宽度, 高度)
            
        Returns:
            拼图图像对象，如果创建失败则返回None
        """
        try:
            if not image_paths:
                logger.warning("没有提供图像路径")
                return None
            
            # 加载图像
            images = []
            for path in image_paths[:4]:  # 最多使用4张图片
                try:
                    with Image.open(path) as img:
                        # 转换为RGB模式
                        if img.mode != 'RGB':
                            img = img.convert('RGB')
                        images.append(img)
                except Exception as e:
                    logger.warning(f"加载图像失败 {path}: {e}")
                    continue
            
            if not images:
                logger.error("没有成功加载任何图像")
                return None
            
            # 创建拼图画布
            collage = Image.new('RGB', target_size, (255, 255, 255))
            
            # 计算每个图像的位置和尺寸
            if len(images) == 1:
                # 单张图片，居中显示
                img = images[0]
                img = ImageProcessor.resize_image(img, target_size[0], target_size[1])
                x = (target_size[0] - img.width) // 2
                y = (target_size[1] - img.height) // 2
                collage.paste(img, (x, y))
            elif len(images) == 2:
                # 两张图片，上下排列
                for i, img in enumerate(images):
                    img = ImageProcessor.resize_image(img, target_size[0], target_size[1] // 2)
                    x = (target_size[0] - img.width) // 2
                    y = i * (target_size[1] // 2)
                    collage.paste(img, (x, y))
            elif len(images) >= 3:
                # 多张图片，2x2网格
                cell_width = target_size[0] // 2
                cell_height = target_size[1] // 2
                
                for i, img in enumerate(images[:4]):
                    img = ImageProcessor.resize_image(img, cell_width, cell_height)
                    row = i // 2
                    col = i % 2
                    x = col * cell_width
                    y = row * cell_height
                    collage.paste(img, (x, y))
            
            return collage
            
        except Exception as e:
            logger.error(f"创建拼图失败: {e}")
            return None
    
    @staticmethod
    def process_images_for_poster(image_paths: List[str], 
                                target_size: Tuple[int, int] = (900, 1200),
                                create_collage: bool = False) -> Dict[str, Any]:
        """
        处理图像用于海报生成
        
        Args:
            image_paths: 图像路径列表
            target_size: 目标尺寸
            create_collage: 是否创建拼图
            
        Returns:
            处理结果字典
        """
        result = {
            "main_image": None,
            "collage_image": None,
            "all_images": [],
            "metadata": {}
        }
        
        try:
            # 处理所有图像
            for i, path in enumerate(image_paths):
                try:
                    # 转换为base64
                    base64_data = ImageProcessor.image_to_base64(path)
                    
                    # 获取元数据
                    metadata = ImageProcessor.get_image_metadata(path)
                    
                    image_info = {
                        "index": i,
                        "path": path,
                        "base64": base64_data,
                        "metadata": metadata
                    }
                    
                    result["all_images"].append(image_info)
                    
                    # 第一张图片作为主图
                    if i == 0:
                        result["main_image"] = image_info
                        
                except Exception as e:
                    logger.error(f"处理图像失败 {path}: {e}")
                    continue
            
            # 如果需要创建拼图
            if create_collage and len(image_paths) > 1:
                collage = ImageProcessor.create_collage_from_paths(image_paths, target_size)
                if collage:
                    collage_base64 = ImageProcessor.pil_image_to_base64(collage, "JPEG")
                    result["collage_image"] = {
                        "base64": collage_base64,
                        "metadata": {
                            "width": collage.width,
                            "height": collage.height,
                            "format": "JPEG",
                            "type": "collage"
                        }
                    }
            
            # 添加总体元数据
            result["metadata"] = {
                "total_images": len(result["all_images"]),
                "has_collage": result["collage_image"] is not None,
                "target_size": target_size
            }
            
            return result
            
        except Exception as e:
            logger.error(f"处理图像失败: {e}")
            return result