feat: generate doc preview html

backend/app/services/html_generator.py

@@ -1,5 +1,25 @@
 """HTML 预览生成服务"""
-from typing import List, Dict, Any
+from html import escape
+from typing import Any, Dict, List
+
+
+PAGE_STYLE = (
+    "width:794px;min-height:1123px;margin:0 auto;background:#fff;"
+    "padding:72px 64px;box-sizing:border-box;color:#1a1d24;"
+    "font-family:-apple-system,BlinkMacSystemFont,'PingFang SC','Microsoft YaHei',sans-serif;"
+    "font-size:14px;line-height:1.8;"
+)
+
+HEADING_STYLE = (
+    "font-size:16px;font-weight:700;text-align:center;margin:24px 0 14px;"
+    "padding-bottom:6px;border-bottom:2px solid #1a1d24;"
+)
+
+PARAGRAPH_STYLE = "text-indent:2em;margin:8px 0;line-height:1.8;text-align:justify;"
+
+TABLE_STYLE = "width:100%;border-collapse:collapse;margin:14px 0;font-size:13px;"
+TH_STYLE = "padding:7px 10px;border:1px solid #d8dbe2;background:#f0f1f3;text-align:left;font-weight:600;"
+TD_STYLE = "padding:7px 10px;border:1px solid #d8dbe2;text-align:left;min-height:24px;"
 
 
 def generate_preview_html(blocks: List[Dict[str, Any]]) -> str:
@@ -7,21 +27,56 @@ def generate_preview_html(blocks: List[Dict[str, Any]]) -> str:
     将 block 列表转为带 data-block-id 的 HTML 预览字符串。
     每个元素都会带上 data-block-id 属性供前端点击交互。
     """
-    html_parts = ['<div class="doc-preview-content">']
+    html_parts = [f'<div class="doc-preview-content" style="{PAGE_STYLE}">']
 
     for block in blocks:
         block_id = block.get("block_id", "")
-        block_type = block.get("type", "")
-        text = block.get("text", "")
+        block_type = block.get("type") or block.get("block_type", "")
+        text = block.get("text") or block.get("text_preview") or ""
 
         if block_type == "heading":
-            html = f'<h2 data-block-id="{block_id}" style="font-size:16px;font-weight:600;margin:20px 0 10px;padding-bottom:6px;border-bottom:2px solid #1a1d24">{text}</h2>'
+            html = render_heading(block_id, text)
         elif block_type == "table":
-            html = f'<div data-block-id="{block_id}" style="margin:12px 0;padding:8px;background:#f7f8fa;border:1px dashed #ccc;border-radius:4px;color:#5b626e">📊 {text[:80]}</div>'
+            html = render_table(block)
         else:
-            html = f'<p data-block-id="{block_id}" style="text-indent:2em;margin:8px 0;line-height:1.8;text-align:justify">{text}</p>'
+            html = render_paragraph(block_id, text)
 
         html_parts.append(html)
 
     html_parts.append('</div>')
     return "\n".join(html_parts)
+
+
+def render_heading(block_id: str, text: str) -> str:
+    return f'<h2 data-block-id="{escape(block_id)}" style="{HEADING_STYLE}">{escape(text)}</h2>'
+
+
+def render_paragraph(block_id: str, text: str) -> str:
+    return f'<p data-block-id="{escape(block_id)}" style="{PARAGRAPH_STYLE}">{escape(text)}</p>'
+
+
+def render_table(block: Dict[str, Any]) -> str:
+    block_id = escape(block.get("block_id", ""))
+    headers = [escape(str(header)) for header in block.get("headers", []) if str(header).strip()]
+    rows = int(block.get("rows") or block.get("table_rows") or 1)
+    cols = int(block.get("cols") or block.get("table_cols") or max(len(headers), 1))
+    cols = max(cols, len(headers), 1)
+    body_rows = max(rows - 1, 1)
+
+    if not headers:
+        text = block.get("text") or block.get("text_preview") or "表格"
+        headers = [escape(str(text))] + ["" for _ in range(cols - 1)]
+
+    header_html = "".join(f'<th style="{TH_STYLE}">{header}</th>' for header in headers[:cols])
+    if len(headers) < cols:
+        header_html += "".join(f'<th style="{TH_STYLE}"></th>' for _ in range(cols - len(headers)))
+
+    row_html = "".join(f'<td style="{TD_STYLE}"></td>' for _ in range(cols))
+    body_html = "\n".join(f"<tr>{row_html}</tr>" for _ in range(body_rows))
+
+    return (
+        f'<table data-block-id="{block_id}" style="{TABLE_STYLE}">'
+        f"<thead><tr>{header_html}</tr></thead>"
+        f"<tbody>{body_html}</tbody>"
+        "</table>"
+    )