"""Word 文档解析引擎"""
from docx import Document
from docx.paragraph import Paragraph
from docx.table import Table as DocxTable
from typing import List, Dict, Any


def parse_document(file_path: str) -> List[Dict[str, Any]]:
    """
    解析 Word 文档，返回 block 列表（不含表格数据，仅标记位置）。
    每个 block 包含：type, text, level, style
    """
    doc = Document(file_path)
    blocks = []

    for para in doc.paragraphs:
        block = classify_paragraph(para)
        if block:
            blocks.append(block)

    return blocks


def classify_paragraph(para: Paragraph) -> Dict[str, Any] | None:
    """识别段落类型"""
    text = para.text.strip()
    style_name = para.style.name if para.style else ""

    if not text and "Heading" not in style_name:
        return None  # 跳过空段落

    if "Heading" in style_name:
        level = int(style_name.replace("Heading", "").strip()) if style_name.replace("Heading", "").strip().isdigit() else 1
        return {"type": "heading", "text": text, "level": level, "style": style_name}
    else:
        return {"type": "paragraph", "text": text, "level": 0, "style": style_name}


def parse_tables(doc: Document) -> List[Dict[str, Any]]:
    """解析 Word 表格"""
    tables = []
    for i, table in enumerate(doc.tables):
        headers = [cell.text.strip() for cell in table.rows[0].cells] if table.rows else []
        tables.append({
            "type": "table",
            "text": " | ".join(headers),
            "level": 0,
            "rows": len(table.rows),
            "cols": len(table.columns),
            "headers": headers,
            "table_index": i,
        })
    return tables


def generate_block_id(index: int) -> str:
    """生成 block_id，格式：block_001"""
    return f"block_{index:03d}"


def build_tree(blocks: List[Dict]) -> Dict:
    """构建层级树结构"""
    tree = []
    stack = []  # 存父级节点

    for block in blocks:
        node = {"block_id": block["block_id"], "text": block["text"][:50], "children": []}
        level = block.get("level", 0)

        # 回退栈
        while stack and stack[-1]["level"] >= level:
            stack.pop()

        if stack:
            parent = stack[-1]["node"]
            parent["children"].append(node)
            block["parent_block_id"] = parent["block_id"]
        else:
            tree.append(node)
            block["parent_block_id"] = None

        # 非叶子节点入栈
        if level < 2 or block["type"] == "heading":
            stack.append({"level": level, "node": node})

    return {"blocks": tree}