"""
YOLO 目录页检测与 OCR 提取模块

用于在文档处理流程早期检测目录页并提取目录内容，
输出结构与 outline 保持一致，便于后续进行目录完整性检查。
"""

import io
import os
import re
from dataclasses import dataclass
from typing import Dict, Any, List, Optional, Tuple
from pathlib import Path

import fitz
import numpy as np

from utils_test.minimal_pipeline._simple_logger import review_logger as logger

from ultralytics import YOLO
from PIL import Image


@dataclass
class CatalogItem:
    """目录项结构"""
    index: int           # 章节序号（1-based）
    title: str           # 章节标题
    page: str            # 页码（字符串）
    original: str        # 原始文本
    level: int = 1       # 层级（1=章，2=节）
    parent_title: str = ""  # 父章节标题（用于二级）


@dataclass
class CatalogSection:
    """目录节结构（对应二级目录）"""
    title: str
    page: str
    level: int
    original: str


@dataclass
class CatalogChapter:
    """目录章结构（对应一级目录）"""
    index: int
    title: str
    page: str
    original: str
    subsections: List[CatalogSection]


class TOCCatalogExtractor:
    """
    目录页检测与内容提取器

    使用 YOLO 模型检测目录页，使用 GLM-OCR 提取目录文本，
    解析为结构化数据，输出格式与 outline 保持一致。
    """

    # YOLO 配置
    DEFAULT_MODEL_PATH = "best.pt"  # 本地副本
    CONF_THRESHOLD = 0.25
    MAX_CHECK_PAGES = 50
    DPI = 150

    # OCR 配置（高 DPI 渲染后缩放到 800px，确保目录文字清晰）
    OCR_DPI = 600
    MAX_SHORT_EDGE = 800
    JPEG_QUALITY = 85
    MAX_IMAGE_SIZE_MB = 5

    def __init__(
        self,
        model_path: str = None,
        ocr_api_url: str = "http://183.220.37.46:25429/v1/chat/completions",
        ocr_api_key: str = "",
        ocr_timeout: int = 600,
    ):
        self.model_path = model_path or self.DEFAULT_MODEL_PATH
        self.ocr_api_url = ocr_api_url
        self.ocr_api_key = ocr_api_key
        self.ocr_timeout = ocr_timeout

        self._model = None

    def _load_model(self) -> bool:
        """加载 YOLO 模型，缺少依赖或模型文件直接报错"""
        if not os.path.exists(self.model_path):
            raise FileNotFoundError(f"[TOC检测] YOLO模型文件不存在: {self.model_path}")

        if self._model is None:
            logger.info(f"[TOC检测] 正在加载YOLO模型: {self.model_path}")
            self._model = YOLO(self.model_path)
        return True

    def detect_and_extract(
        self,
        file_content: bytes,
        progress_callback=None
    ) -> Optional[Dict[str, Any]]:
        """
        检测目录页并提取目录内容

        Args:
            file_content: PDF文件字节流
            progress_callback: 进度回调函数

        Returns:
            目录结构字典，格式与 outline 保持一致：
            {
                "chapters": [...],
                "total_chapters": N
            }
        """
        if not self._load_model():
            return None

        doc = fitz.open(stream=file_content)
        try:
            # 1. 检测目录页范围
            toc_pages = self._detect_toc_pages(doc, progress_callback)
            if not toc_pages:
                logger.info("[TOC检测] 未检测到目录页")
                return None

            logger.info(f"[TOC检测] 检测到目录页: 第{toc_pages[0]+1}页 - 第{toc_pages[-1]+1}页")

            # 2. OCR 提取目录页内容
            if progress_callback:
                progress_callback("目录识别", 10, f"检测到{len(toc_pages)}页目录，开始OCR识别...")

            toc_text = self._ocr_toc_pages(doc, toc_pages, progress_callback)

            if not toc_text:
                return None

            # 3. 解析目录文本为结构化数据
            if progress_callback:
                progress_callback("目录识别", 80, "解析目录结构...")

            catalog = self._parse_toc_text(toc_text)

            # 添加目录页页码范围（1-based）
            if toc_pages:
                catalog["toc_page_range"] = {
                    "start": toc_pages[0] + 1,  # 转换为1-based页码
                    "end": toc_pages[-1] + 1
                }

            if progress_callback:
                progress_callback("目录识别", 100, f"目录提取完成，共{catalog['total_chapters']}章")

            return catalog

        finally:
            doc.close()

    def _detect_toc_pages(
        self,
        doc: fitz.Document,
        progress_callback=None
    ) -> List[int]:
        """
        使用 YOLO 检测目录页范围

        Returns:
            目录页索引列表（0-based）
        """
        toc_pages = []
        total_pages = len(doc)
        pages_to_check = min(total_pages, self.MAX_CHECK_PAGES)

        for page_idx in range(pages_to_check):
            page = doc.load_page(page_idx)

            # 渲染页面
            zoom = self.DPI / 72
            mat = fitz.Matrix(zoom, zoom)
            pix = page.get_pixmap(matrix=mat)

            # 转换为 numpy 数组
            img = Image.frombytes("RGB", [pix.width, pix.height], pix.samples)
            img_array = np.array(img)

            # YOLO 检测
            results = self._model(img_array, conf=self.CONF_THRESHOLD, verbose=False)

            # 检查是否检测到 catalogs 类别
            has_catalogs = False
            for result in results:
                if result.boxes is not None:
                    for box in result.boxes:
                        cls_id = int(box.cls.item())
                        class_name = self._model.names.get(cls_id, f"class_{cls_id}")
                        if class_name == 'catalogs':
                            has_catalogs = True
                            break
                if has_catalogs:
                    break

            if has_catalogs:
                toc_pages.append(page_idx)
                logger.debug(f"  第{page_idx + 1:3d}页: 检测到目录")
            else:
                logger.debug(f"  第{page_idx + 1:3d}页: 未检测到目录")
                # 如果已经检测到目录，且现在没有检测到，认为目录结束
                if toc_pages:
                    break

            if progress_callback and (page_idx + 1) % 5 == 0:
                progress = int((page_idx + 1) / pages_to_check * 10)
                progress_callback("目录识别", progress, f"扫描页面 {page_idx + 1}/{pages_to_check}")

        return toc_pages

    def _ocr_toc_pages(
        self,
        doc: fitz.Document,
        toc_pages: List[int],
        progress_callback=None
    ) -> str:
        """
        对目录页进行 OCR 识别

        Returns:
            合并后的目录文本
        """
        import base64
        import io
        import requests
        import time

        all_texts = []
        total = len(toc_pages)

        for idx, page_idx in enumerate(toc_pages):
            page = doc.load_page(page_idx)

            try:
                # 渲染页面（使用较低DPI避免图片过大）
                pix = page.get_pixmap(dpi=self.OCR_DPI)
                img_bytes = pix.tobytes("jpeg")

                # 压缩图片
                compressed = self._compress_image(img_bytes)
                img_size_mb = len(compressed) / (1024 * 1024)
                logger.debug(f"  第{page_idx + 1}页图片大小: {img_size_mb:.2f}MB")

                # 检查图片大小
                if img_size_mb > self.MAX_IMAGE_SIZE_MB:
                    logger.warning(f"  第{page_idx + 1}页图片过大({img_size_mb:.2f}MB)，尝试进一步压缩")
                    # 再次压缩
                    compressed = self._compress_image(compressed, force_smaller=True)
                    img_size_mb = len(compressed) / (1024 * 1024)
                    logger.debug(f"  压缩后大小: {img_size_mb:.2f}MB")

                img_base64 = base64.b64encode(compressed).decode('utf-8')

                # 请求 OCR
                payload = {
                    "model": "GLM-OCR",
                    "messages": [
                        {
                            "role": "user",
                            "content": [
                                {
                                    "type": "text",
                                    "text": "识别目录内容，按原文格式输出。保留章节层级和页码。"
                                },
                                {
                                    "type": "image_url",
                                    "image_url": {"url": f"data:image/jpeg;base64,{img_base64}"}
                                }
                            ]
                        }
                    ],
                    "max_tokens": 1024,       # 2048 -> 1024，目录页486 tokens够用
                    "temperature": 0.1,
                    "seed": 42                # 固定采样随机性
                }

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

                # 指数退避重试
                max_retries = 3
                for attempt in range(max_retries):
                    try:
                        response = requests.post(
                            self.ocr_api_url,
                            headers=headers,
                            json=payload,
                            timeout=self.ocr_timeout
                        )

                        # 记录响应状态
                        if response.status_code != 200:
                            logger.error(f"  第{page_idx + 1}页OCR请求失败: HTTP {response.status_code}, 响应: {response.text[:200]}")
                            response.raise_for_status()

                        result = response.json()

                        content = ""
                        if "choices" in result and result["choices"]:
                            content = result["choices"][0].get("message", {}).get("content", "")

                        if content:
                            all_texts.append(content)
                            logger.info(f"  第{page_idx + 1}页目录OCR成功")
                        break

                    except requests.exceptions.HTTPError as e:
                        if response.status_code == 400:
                            logger.error(f"  第{page_idx + 1}页OCR请求格式错误(400)，可能是图片过大")
                            break  # 400错误不需要重试
                        if attempt < max_retries - 1:
                            wait_time = 2 ** (attempt + 1)
                            logger.warning(f"  第{page_idx + 1}页目录OCR失败，{wait_time}秒后重试...")
                            time.sleep(wait_time)
                        else:
                            logger.error(f"  第{page_idx + 1}页目录OCR最终失败: {e}")
                    except Exception as e:
                        if attempt < max_retries - 1:
                            wait_time = 2 ** (attempt + 1)
                            logger.warning(f"  第{page_idx + 1}页目录OCR失败，{wait_time}秒后重试...")
                            time.sleep(wait_time)
                        else:
                            logger.error(f"  第{page_idx + 1}页目录OCR最终失败: {e}")

                if progress_callback:
                    progress = 10 + int((idx + 1) / total * 60)
                    progress_callback("目录识别", progress, f"OCR识别中 {idx + 1}/{total}")

            except Exception as e:
                logger.error(f"  第{page_idx + 1}页OCR处理出错: {e}")

        return "\n".join(all_texts)

    def _compress_image(self, img_bytes: bytes, force_smaller: bool = False) -> bytes:
        """
        压缩图片

        Args:
            img_bytes: 图片字节
            force_smaller: 是否强制更小的尺寸（用于处理过大的图片）
        """
        try:
            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')

            # 计算目标尺寸
            max_edge = self.MAX_SHORT_EDGE
            if force_smaller:
                max_edge = 640  # 强制小尺寸

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

            # 二值化增强：将浅灰文字变黑，提高 OCR 识别率
            img = img.convert('L')
            img = img.point(lambda x: 0 if x < 220 else 255)
            img = img.convert('RGB')

            buffer = io.BytesIO()
            img.save(buffer, format='PNG', optimize=True)
            return buffer.getvalue()

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

    def _parse_toc_text(self, text: str) -> Dict[str, Any]:
        """
        解析目录文本为结构化数据，输出标准格式

        标准格式：
        第X章 XXX
        一、XXX
        二、XXX

        Returns:
            {
                "chapters": [...],
                "total_chapters": N,
                "raw_ocr_text": "原始OCR文本",
                "formatted_text": "标准格式文本"
            }
        """
        lines = text.strip().split('\n')
        chapters = []
        current_chapter = None

        # 正则表达式模式
        chapter_pattern = re.compile(
            r'第\s*([一二三四五六七八九十百0-9]+)\s*章\s*[\s\.]*(.+?)\s*[\.\s]*(\d+)\s*$',
            re.IGNORECASE
        )
        section_pattern = re.compile(
            r'([一二三四五六七八九十]+)\s*[、\.\s]+\s*(.+?)\s*[\.\s]*(\d+)\s*$'
        )
        generic_pattern = re.compile(
            r'([0-9]+)[\.\s]+(.+?)\s*[\.\s]+(\d+)\s*$'
        )

        # 中文数字映射
        chinese_nums = {
            '一': 1, '二': 2, '三': 3, '四': 4, '五': 5,
            '六': 6, '七': 7, '八': 8, '九': 9, '十': 10,
            '十一': 11, '十二': 12, '十三': 13, '十四': 14, '十五': 15
        }

        for line in lines:
            line = line.strip()
            if not line or len(line) < 3:
                continue

            # 移除 Markdown 表格符号
            line = re.sub(r'^[\|\s]+|[\|\s]+$', '', line)
            line = line.replace('|', ' ')

            # 尝试匹配章
            chapter_match = chapter_pattern.search(line)
            if chapter_match:
                chapter_num = chapter_match.group(1)
                title = chapter_match.group(2).strip()
                page = chapter_match.group(3).strip()

                # 保存上一个章
                if current_chapter:
                    chapters.append(current_chapter)

                # 标准化为阿拉伯数字
                if chapter_num.isdigit():
                    idx = int(chapter_num)
                else:
                    idx = chinese_nums.get(chapter_num, len(chapters) + 1)

                # 从原始行提取完整标题（保留原文格式）
                # 移除行尾页码，保留章节号+标题的原文形式
                original_title = re.sub(r'[\.\s]*(\d+)\s*$', '', line).strip()

                current_chapter = {
                    "index": idx,
                    "title": original_title,
                    "page": page,
                    "original": line,
                    "subsections": []
                }
                continue

            # 尝试匹配节（二级）- 标准化为一、二、三格式
            section_match = section_pattern.search(line)
            if section_match and current_chapter:
                section_num = section_match.group(1)
                title = section_match.group(2).strip()
                page = section_match.group(3).strip()

                # 标准化节编号
                if section_num.isdigit():
                    section_idx = int(section_num)
                    section_cn = self._number_to_chinese(section_idx)
                else:
                    section_cn = section_num

                current_chapter["subsections"].append({
                    "title": title,
                    "page": page,
                    "level": 2,
                    "original": line
                })
                continue

            # 尝试通用匹配（数字开头）
            generic_match = generic_pattern.search(line)
            if generic_match and current_chapter:
                title = generic_match.group(2).strip()
                page = generic_match.group(3).strip()

                # 判断是章还是节（根据内容特征）
                if any(kw in title for kw in ['编制依据', '工程概况', '施工计划', '施工工艺',
                                               '安全保证', '质量保证', '环境保证', '人员配备',
                                               '验收要求']):
                    chapters.append(current_chapter)
                    idx = len(chapters) + 1
                    # 保留原标题，只移除页码
                    original_title = re.sub(r'[\.\s]*(\d+)\s*$', '', line).strip()
                    current_chapter = {
                        "index": idx,
                        "title": original_title,
                        "page": page,
                        "original": line,
                        "subsections": []
                    }
                else:
                    # 作为节，保留原标题
                    current_chapter["subsections"].append({
                        "title": title,
                        "page": page,
                        "level": 2,
                        "original": line
                    })

        # 添加最后一个章
        if current_chapter:
            chapters.append(current_chapter)

        # 如果没有匹配到章，尝试按空行或缩进分割
        if not chapters and lines:
            chapters = self._fallback_parse(lines)

        # 构建标准格式文本
        formatted_lines = []
        for ch in chapters:
            formatted_lines.append(ch["title"])
            for sub in ch.get("subsections", []):
                formatted_lines.append(f"  {sub['title']}")

        formatted_text = "\n".join(formatted_lines)

        # 日志输出完整的目录解析结果
        logger.info(f"[TOC解析] 共 {len(chapters)} 章，标准格式文本:\n{formatted_text}")

        return {
            "chapters": chapters,
            "total_chapters": len(chapters),
            "raw_ocr_text": text,
            "formatted_text": formatted_text
        }

    def _fallback_parse(self, lines: List[str]) -> List[Dict[str, Any]]:
        """
        降级解析策略：当正则无法匹配时使用启发式方法
        输出标准格式：第X章 XXX / 一、XXX
        """
        chapters = []
        idx = 0
        section_idx = 0

        for line in lines:
            line = line.strip()
            if not line:
                continue

            # 检查是否包含页码（行尾数字）
            page_match = re.search(r'(\d+)\s*$', line)
            if not page_match:
                continue

            page = page_match.group(1)
            title = re.sub(r'[\.\s]+\d+\s*$', '', line).strip()

            # 根据内容特征判断层级
            is_chapter = any(kw in title for kw in ['编制依据', '工程概况', '施工计划',
                                                       '施工工艺', '安全保证', '质量保证',
                                                       '环境保证', '人员配备', '验收',
                                                       '其他资料'])

            if is_chapter or len(chapters) == 0:
                idx += 1
                section_idx = 0  # 重置节计数
                chapters.append({
                    "index": idx,
                    "title": title,
                    "page": page,
                    "original": line,
                    "subsections": []
                })
            else:
                # 作为上一章的节，保留原标题
                if chapters:
                    section_idx += 1
                    chapters[-1]["subsections"].append({
                        "title": title,
                        "page": page,
                        "level": 2,
                        "original": line
                    })

        return chapters

    def _number_to_chinese(self, num: int) -> str:
        """阿拉伯数字转中文数字"""
        chinese_nums = {
            1: '一', 2: '二', 3: '三', 4: '四', 5: '五',
            6: '六', 7: '七', 8: '八', 9: '九', 10: '十',
            11: '十一', 12: '十二', 13: '十三', 14: '十四', 15: '十五'
        }
        return chinese_nums.get(num, str(num))


def extract_catalog_from_pdf(
    file_content: bytes,
    model_path: str = None,
    ocr_api_url: str = "http://183.220.37.46:25429/v1/chat/completions",
    ocr_api_key: str = "",
    progress_callback=None
) -> Optional[Dict[str, Any]]:
    """
    便捷函数：从 PDF 提取目录结构

    Returns:
        {"chapters": [...], "total_chapters": N} 或 None
    """
    extractor = TOCCatalogExtractor(
        model_path=model_path,
        ocr_api_url=ocr_api_url,
        ocr_api_key=ocr_api_key
    )
    return extractor.detect_and_extract(file_content, progress_callback)