"""
OCR 处理模块 - 表格检测与识别

提供 PDF 表格区域检测和 OCR 识别功能，支持：
- RapidLayout 表格区域检测
- GLM-OCR 并发识别
- 表格文本替换回填
"""

import base64
import io
import time
from concurrent.futures import ThreadPoolExecutor, as_completed
from dataclasses import dataclass
from typing import Dict, Any, List, Optional, Tuple, Set

import fitz
import numpy as np
import requests

from utils_test.minimal_pipeline._simple_logger import review_logger as logger

# 尝试导入 RapidLayout
try:
    from rapid_layout import RapidLayout
    RAPID_LAYOUT_AVAILABLE = True
except ImportError:
    RAPID_LAYOUT_AVAILABLE = False
    RapidLayout = None


@dataclass
class TableRegion:
    """表格区域信息"""
    page_num: int
    page: fitz.Page
    bbox: Tuple[float, float, float, float]
    score: float
    label: str = "table"  # YOLO 原始标签: table / figure


@dataclass
class OcrResult:
    """OCR 结果"""
    page_num: int
    bbox: Tuple[float, float, float, float]
    score: float
    text: str
    success: bool


class OcrProcessor:
    """OCR 处理器：表格检测与识别"""

    # 默认配置
    MAX_SHORT_EDGE = 1024
    JPEG_QUALITY = 90
    OCR_DPI = 200
    OCR_CONFIDENCE_THRESHOLD = 0.5
    OCR_CONCURRENT_WORKERS = 20

    def __init__(
        self,
        ocr_api_url: str = "http://183.220.37.46:25429/v1/chat/completions",
        ocr_timeout: int = 600,
        ocr_api_key: str = "",
        max_short_edge: int = 1024,
        jpeg_quality: int = 90,
        ocr_dpi: int = 200,
        confidence_threshold: float = 0.5,
        concurrent_workers: int = 20,
    ):
        """
        初始化 OCR 处理器

        Args:
            ocr_api_url: OCR API 地址
            ocr_timeout: OCR 请求超时时间（秒）
            ocr_api_key: OCR API 密钥
            max_short_edge: 图片压缩后短边最大尺寸
            jpeg_quality: JPEG 压缩质量
            ocr_dpi: OCR 渲染 DPI
            confidence_threshold: 表格检测置信度阈值
            concurrent_workers: OCR 并发工作线程数
        """
        self.ocr_api_url = ocr_api_url
        self.ocr_timeout = ocr_timeout
        self.ocr_api_key = ocr_api_key
        self.max_short_edge = max_short_edge
        self.jpeg_quality = jpeg_quality
        self.ocr_dpi = ocr_dpi
        self.confidence_threshold = confidence_threshold
        self.concurrent_workers = concurrent_workers

        self._layout_engine: Optional[Any] = None

        if not RAPID_LAYOUT_AVAILABLE:
            logger.warning("RapidLayout 未安装，表格检测功能不可用")

    def is_available(self) -> bool:
        """检查 OCR 功能是否可用"""
        return RAPID_LAYOUT_AVAILABLE

    def _get_layout_engine(self) -> Optional[Any]:
        """延迟初始化 RapidLayout"""
        if self._layout_engine is None and RAPID_LAYOUT_AVAILABLE:
            self._layout_engine = RapidLayout()
        return self._layout_engine

    def detect_table_regions(
        self,
        page: fitz.Page,
        page_num: int,
        clip_box: fitz.Rect
    ) -> List[Tuple[Tuple[float, float, float, float], float]]:
        """
        检测页面中的表格区域

        Args:
            page: PDF 页面对象
            page_num: 页码（用于日志）
            clip_box: 裁剪区域

        Returns:
            列表，元素为 ((x1, y1, x2, y2), score)
        """
        table_regions: List[Tuple[Tuple[float, float, float, float], float, str]] = []

        if not RAPID_LAYOUT_AVAILABLE:
            return table_regions

        layout_engine = self._get_layout_engine()
        if layout_engine is None:
            return table_regions

        # 渲染页面（裁剪区域）
        pix = page.get_pixmap(dpi=self.ocr_dpi, clip=clip_box)
        img = np.frombuffer(pix.samples, dtype=np.uint8).reshape(pix.height, pix.width, 3)

        try:
            layout_output = layout_engine(img)

            # 解析版面结果
            if hasattr(layout_output, 'boxes') and hasattr(layout_output, 'class_names'):
                # 获取缩放比例
                scale_x = clip_box.width / img.shape[1]
                scale_y = clip_box.height / img.shape[0]

                table_count = 0
                figure_count = 0
                for box, label, score in zip(layout_output.boxes, layout_output.class_names, layout_output.scores):
                    if label in ("table", "figure") and score > self.confidence_threshold:
                        # 转换为 PDF 坐标
                        pdf_x1 = clip_box.x0 + box[0] * scale_x
                        pdf_y1 = clip_box.y0 + box[1] * scale_y
                        pdf_x2 = clip_box.x0 + box[2] * scale_x
                        pdf_y2 = clip_box.y0 + box[3] * scale_y

                        table_regions.append(((pdf_x1, pdf_y1, pdf_x2, pdf_y2), score, label))
                        if label == "table":
                            table_count += 1
                        else:
                            figure_count += 1

                if table_count or figure_count:
                    logger.info(f"  [YOLO] 第{page_num}页: table={table_count}, figure={figure_count}")

        except Exception as e:
            logger.warning(f"  第 {page_num} 页: 版面分析失败 ({e})")

        return table_regions

    def process_ocr_concurrent(
        self,
        regions: List[TableRegion],
        progress_callback=None
    ) -> List[OcrResult]:
        """
        同步并发处理 OCR

        Args:
            regions: 表格区域列表
            progress_callback: 进度回调函数，接收 (completed, total) 参数

        Returns:
            OCR 结果列表
        """
        results: List[OcrResult] = []
        total = len(regions)
        completed = 0

        # 统计
        table_total = sum(1 for r in regions if r.label == "table")
        figure_total = sum(1 for r in regions if r.label == "figure")
        logger.info(f"[OCR] 开始并发识别: table={table_total}, figure={figure_total}, workers={self.concurrent_workers}")

        with ThreadPoolExecutor(max_workers=self.concurrent_workers) as executor:
            # 提交所有任务
            future_to_region = {
                executor.submit(self._ocr_table_region, r.page, r.bbox): r
                for r in regions
            }

            # 处理完成的结果
            non_table_count = 0
            table_ok_count = 0
            for future in as_completed(future_to_region):
                region = future_to_region[future]
                completed += 1
                try:
                    text = future.result()
                    if text.strip():
                        table_ok_count += 1
                    else:
                        non_table_count += 1
                    results.append(OcrResult(
                        page_num=region.page_num,
                        bbox=region.bbox,
                        score=region.score,
                        text=text,
                        success=True,
                    ))
                except Exception as e:
                    non_table_count += 1
                    logger.error(f"  第 {region.page_num} 页 {region.label} OCR 失败: {e}")
                    results.append(OcrResult(
                        page_num=region.page_num,
                        bbox=region.bbox,
                        score=region.score,
                        text="",
                        success=False,
                    ))

                # 每完成5个或最后一个时推送进度
                if progress_callback and (completed % 5 == 0 or completed == total):
                    progress_callback(completed, total)

        logger.info(f"[OCR] 完成: table={table_total}, figure={figure_total}, "
                     f"有效表格={table_ok_count}, Non-table/失败={non_table_count}")
        return results

    def _ocr_table_region(
        self,
        page: fitz.Page,
        bbox: Tuple[float, float, float, float],
        max_retries: int = 3
    ) -> str:
        """
        对指定区域进行 OCR 识别（使用 GLM-OCR），支持指数退避重试

        Args:
            page: PDF 页面对象
            bbox: 区域坐标 (x1, y1, x2, y2)
            max_retries: 最大重试次数

        Returns:
            识别的文本内容
        """
        # 渲染指定区域
        rect = fitz.Rect(bbox)
        pix = page.get_pixmap(dpi=self.ocr_dpi, clip=rect)
        img_bytes = pix.tobytes("jpeg")

        # 压缩图片
        compressed = self._compress_image(img_bytes)
        img_base64 = base64.b64encode(compressed).decode('utf-8')

        # 请求 OCR
        payload = {
            "model": "GLM-OCR",
            "messages": [
                {
                    "role": "user",
                    "content": [
                        {
                            "type": "text",
                            "text": "判断图片中是否包含表格。"
                                    "- 若包含表格：用 Markdown 表格格式提取内容，保持行列对齐。"
                                    "- 若不包含任何表格：只输出 Non-table。"
                                    "只输出结果，不要解释。"
                        },
                        {
                            "type": "image_url",
                            "image_url": {"url": f"data:image/jpeg;base64,{img_base64}"}
                        }
                    ]
                }
            ],
            "max_tokens": 2048,
            "temperature": 0.1
        }

        headers = {"Content-Type": "application/json"}
        if self.ocr_api_key:
            headers["Authorization"] = f"Bearer {self.ocr_api_key}"

        # 指数退避重试
        last_error = None
        for attempt in range(max_retries):
            try:
                response = requests.post(
                    self.ocr_api_url,
                    headers=headers,
                    json=payload,
                    timeout=self.ocr_timeout
                )
                response.raise_for_status()

                result = response.json()
                return self._extract_ocr_content(result)

            except Exception as e:
                last_error = e
                if attempt < max_retries - 1:
                    # 指数退避: 2, 4, 8 秒
                    wait_time = 2 ** (attempt + 1)
                    logger.warning(f"  第 {page.number + 1} 页表格 OCR 第 {attempt + 1} 次失败: {e}, {wait_time}秒后重试...")
                    time.sleep(wait_time)
                else:
                    logger.error(f"  第 {page.number + 1} 页表格 OCR 最终失败（已重试{max_retries}次）: {e}")

        # 所有重试都失败，抛出最后一个错误
        raise last_error

    def _compress_image(self, img_bytes: bytes) -> bytes:
        """
        压缩图片

        Args:
            img_bytes: 原始图片字节

        Returns:
            压缩后的图片字节
        """
        try:
            from PIL import Image
            img = Image.open(io.BytesIO(img_bytes))

            if img.mode in ('RGBA', 'LA', 'P'):
                background = Image.new('RGB', img.size, (255, 255, 255))
                if img.mode == 'P':
                    img = img.convert('RGBA')
                if img.mode in ('RGBA', 'LA'):
                    background.paste(img, mask=img.split()[-1])
                img = background
            elif img.mode != 'RGB':
                img = img.convert('RGB')

            min_edge = min(img.size)
            if min_edge > self.max_short_edge:
                ratio = self.max_short_edge / min_edge
                new_size = (int(img.width * ratio), int(img.height * ratio))
                img = img.resize(new_size, Image.Resampling.LANCZOS)

            buffer = io.BytesIO()
            img.save(buffer, format='JPEG', quality=self.jpeg_quality, optimize=True)
            return buffer.getvalue()

        except Exception as e:
            logger.warning(f"图片压缩失败，使用原图: {e}")
            return img_bytes

    def _extract_ocr_content(self, result: Dict) -> str:
        """
        从 OCR 响应提取内容，并将 HTML 表格转换为 Markdown

        Args:
            result: OCR API 响应

        Returns:
            提取的文本内容
        """
        content = ""
        if "choices" in result and isinstance(result["choices"], list):
            if len(result["choices"]) > 0:
                message = result["choices"][0].get("message", {})
                content = message.get("content", "")

        # GLM 判定为非表格区域，返回空字符串，下游自然跳过
        if content and content.strip().startswith("Non-table"):
            return ""

        # 如果内容包含 HTML 标签，转换为 Markdown
        if content and "<" in content and ">" in content:
            try:
                from utils_test.minimal_pipeline._html_to_md import convert_html_to_markdown
                content = convert_html_to_markdown(content)
            except Exception as e:
                logger.debug(f"HTML 转 Markdown 失败，保留原始内容: {e}")

        return content

    def replace_table_regions(
        self,
        page: fitz.Page,
        original_text: str,
        ocr_results: List[Dict],
        clip_box: fitz.Rect
    ) -> str:
        """
        用 OCR 结果替换原始文本中的表格区域

        Args:
            page: PDF 页面对象
            original_text: 原始文本
            ocr_results: OCR 结果列表，每个元素包含 region_index, bbox, score, ocr_text
            clip_box: 裁剪区域

        Returns:
            替换后的文本
        """
        if not ocr_results:
            return original_text

        # 获取页面上的文本块及其坐标
        text_blocks = []
        for block in page.get_text("blocks"):
            x0, y0, x1, y1, text, _, _ = block
            # 只考虑裁剪区域内的文本
            if y0 >= clip_box.y0 and y1 <= clip_box.y1:
                text_blocks.append({
                    "bbox": (x0, y0, x1, y1),
                    "text": text.strip(),
                })

        # 按 Y 坐标排序
        text_blocks.sort(key=lambda b: (b["bbox"][1], b["bbox"][0]))

        # 找出属于表格区域的文本块
        replaced_indices: Set[int] = set()
        for ocr_result in ocr_results:
            bbox = ocr_result["bbox"]
            rx0, ry0, rx1, ry1 = bbox

            for idx, block in enumerate(text_blocks):
                if idx in replaced_indices:
                    continue
                bx0, by0, bx1, by1 = block["bbox"]

                # 检查重叠
                overlap_x = max(0, min(bx1, rx1) - max(bx0, rx0))
                overlap_y = max(0, min(by1, ry1) - max(by0, ry0))
                overlap_area = overlap_x * overlap_y
                block_area = (bx1 - bx0) * (by1 - by0)

                if block_area > 0 and overlap_area / block_area > 0.5:
                    replaced_indices.add(idx)

        # 构建新文本
        result_parts: List[str] = []
        last_idx = 0

        for ocr_result in sorted(ocr_results, key=lambda r: r["bbox"][1]):
            bbox = ocr_result["bbox"]
            rx0, ry0, rx1, ry1 = bbox

            # 找到该表格区域之前的文本
            region_start_idx = None
            for idx, block in enumerate(text_blocks):
                if idx in replaced_indices:
                    bx0, by0, bx1, by1 = block["bbox"]
                    if (bx0 >= rx0 - 5 and bx1 <= rx1 + 5 and
                        by0 >= ry0 - 5 and by1 <= ry1 + 5):
                        if region_start_idx is None:
                            region_start_idx = idx
                        last_idx = idx + 1

            if region_start_idx is not None:
                # 添加表格前的非表格文本
                for idx in range(last_idx - (last_idx - region_start_idx), region_start_idx):
                    if idx not in replaced_indices and idx < len(text_blocks):
                        result_parts.append(text_blocks[idx]["text"])
                        result_parts.append("\n")

                # 添加 OCR 结果
                result_parts.append(ocr_result["ocr_text"])
                result_parts.append("\n")

        # 添加剩余文本
        for idx in range(last_idx, len(text_blocks)):
            if idx not in replaced_indices:
                result_parts.append(text_blocks[idx]["text"])
                result_parts.append("\n")

        return "".join(result_parts).strip() or original_text