feat(writer): add GenerationContext.to_vars + ChapterContent.from_llm (T6 deps)

src/genesis/writer/models.py

@@ -21,6 +21,22 @@ class ContentBlock:
     style: str | None = None
     source_uris: list[str] = field(default_factory=list)
 
+    @classmethod
+    def from_dict(cls, block_id: str, data: dict) -> "ContentBlock":
+        """从 LLM 输出的 block dict 安全构造内容块。"""
+        return cls(
+            block_id=str(block_id),
+            type=data.get("type", "paragraph"),
+            level=data.get("level"),
+            text=data.get("text"),
+            caption=data.get("caption"),
+            headers=data.get("headers"),
+            rows=data.get("rows"),
+            items=data.get("items"),
+            style=data.get("style"),
+            source_uris=data.get("source_uris", []),
+        )
+
 
 @dataclass
 class ChapterContent:
@@ -29,6 +45,17 @@ class ChapterContent:
     title: str
     blocks: list[ContentBlock]
 
+    @classmethod
+    def from_llm(cls, chapter_id: str, title: str, data: dict) -> "ChapterContent":
+        """从 LLM 结构化输出（含 title、blocks 列表）构造章节内容。
+
+        对每个 block dict 用 ContentBlock.from_dict 安全取值；block_id 缺省为序号字符串。
+        """
+        blocks: list[ContentBlock] = []
+        for i, b in enumerate(data.get("blocks", [])):
+            blocks.append(ContentBlock.from_dict(str(b.get("block_id", i)), b))
+        return cls(chapter_id=chapter_id, version=1, title=title, blocks=blocks)
+
 
 @dataclass
 class ChapterSpec:
@@ -49,3 +76,18 @@ class GenerationContext:
     design_rules: list[str]
     template_styles: set[str]
     prior_state: object | None = None  # WriterState，避免循环 import 用 object
+
+    def to_vars(self) -> dict:
+        """返回供 prompt 渲染的变量字典。"""
+        tm = self.template_marker
+        template_marker = f"{tm.chapter_id}:{tm.title}" if tm is not None else ""
+        return {
+            "chapter_id": self.chapter_id,
+            "title": self.title,
+            "template_marker": template_marker,
+            "write_rules": "\n".join(self.write_rules),
+            "design_rules": "\n".join(self.design_rules),
+            "template_styles": ", ".join(sorted(self.template_styles)),
+            "prior_state": str(self.prior_state) if self.prior_state is not None else "",
+            "source": str(self.structured_source) if self.structured_source is not None else "",
+        }