"""
流式输出格式化器

在流式输出结束后，追加格式化结构（表格、引用等）
解决流式输出与模板渲染的冲突
"""

from typing import List, Dict, Any, Optional
from dataclasses import dataclass

from backend.app.core.formatter import get_formatter


@dataclass
class StreamAppend:
    """流式追加内容"""
    type: str  # "table" | "quote" | "list" | "divider" | "text"
    content: Any


class StreamFinalizer:
    """
    流式输出格式化器

    在流式输出结束后追加结构化内容：
    - 表格
    - 引用块
    - 分割线
    - 文本

    使用方式：
    1. 流式输出主体内容
    2. 调用 build_append() 获取追加内容
    3. 发送追加事件到前端
    """

    def __init__(self):
        self.formatter = get_formatter()
        self.md = self.formatter.md
        self._appends: List[StreamAppend] = []

    def reset(self):
        """重置追加队列"""
        self._appends = []
        return self

    def add_table(self, data: List[Dict], headers: Optional[List[str]] = None):
        """添加表格"""
        self._appends.append(StreamAppend(
            type="table",
            content={"data": data, "headers": headers}
        ))
        return self

    def add_quote(self, text: str, author: Optional[str] = None):
        """添加引用块"""
        self._appends.append(StreamAppend(
            type="quote",
            content={"text": text, "author": author}
        ))
        return self

    def add_list(self, items: List[str], numbered: bool = False):
        """添加列表"""
        self._appends.append(StreamAppend(
            type="list",
            content={"items": items, "numbered": numbered}
        ))
        return self

    def add_divider(self):
        """添加分割线"""
        self._appends.append(StreamAppend(type="divider", content=None))
        return self

    def add_text(self, text: str):
        """添加文本"""
        self._appends.append(StreamAppend(type="text", content=text))
        return self

    def add_knowledge_summary(self, topic: str, summary: str,
                              key_points: Optional[List[Dict]] = None,
                              table_data: Optional[List[Dict]] = None,
                              sources: Optional[List[Dict]] = None):
        """添加知识总结（使用模板）"""
        table = ""
        if table_data:
            table = self.md.table(table_data)

        self._appends.append(StreamAppend(
            type="template",
            content={
                "name": "knowledge_summary",
                "context": {
                    "topic": topic,
                    "timestamp": self._now(),
                    "summary": summary,
                    "key_points": key_points or [],
                    "table_data": table_data,
                    "table": table,
                    "sources": sources or [],
                }
            }
        ))
        return self

    def add_web_results(self, query: str, results: List[Dict]):
        """添加搜索结果"""
        self._appends.append(StreamAppend(
            type="template",
            content={
                "name": "web_search_result",
                "context": {
                    "query": query,
                    "result_count": len(results),
                    "results": results,
                }
            }
        ))
        return self

    def build_append(self) -> str:
        """
        构建追加内容

        Returns:
            格式化后的追加文本
        """
        if not self._appends:
            return ""

        lines = []
        lines.append("")  # 空行分隔
        lines.append(self.md.divider())
        lines.append("")

        for append in self._appends:
            if append.type == "table":
                lines.append(self.md.table(append.content["data"], append.content.get("headers")))
            elif append.type == "quote":
                lines.append(self.md.quote(append.content["text"], append.content.get("author")))
            elif append.type == "list":
                if append.content["numbered"]:
                    lines.append(self.md.numbered_list(append.content["items"]))
                else:
                    lines.append(self.md.bullet_list(append.content["items"]))
            elif append.type == "divider":
                lines.append(self.md.divider())
            elif append.type == "text":
                lines.append(append.content)
            elif append.type == "template":
                template_name = append.content["name"]
                context = append.content["context"]
                lines.append(self.formatter.render(template_name, **context))

            lines.append("")

        return "\n".join(lines)

    def build_events(self) -> List[Dict[str, Any]]:
        """
        构建追加事件列表（用于流式发送）

        Returns:
            事件列表，每项包含 type 和 content
        """
        if not self._appends:
            return []

        events = []
        for append in self._appends:
            if append.type == "table":
                events.append({
                    "type": "append_table",
                    "content": self.md.table(append.content["data"], append.content.get("headers"))
                })
            elif append.type == "quote":
                events.append({
                    "type": "append_quote",
                    "content": self.md.quote(append.content["text"], append.content.get("author"))
                })
            elif append.type == "list":
                events.append({
                    "type": "append_list",
                    "content": self.md.numbered_list(append.content["items"]) if append.content["numbered"]
                    else self.md.bullet_list(append.content["items"])
                })
            elif append.type == "divider":
                events.append({
                    "type": "append_divider",
                    "content": self.md.divider()
                })
            elif append.type == "text":
                events.append({
                    "type": "append_text",
                    "content": append.content
                })
            elif append.type == "template":
                template_name = append.content["name"]
                context = append.content["context"]
                events.append({
                    "type": "append_template",
                    "template": template_name,
                    "content": self.formatter.render(template_name, **context)
                })

        return events

    @staticmethod
    def _now() -> str:
        """获取当前时间"""
        from datetime import datetime
        return datetime.now().strftime('%Y-%m-%d %H:%M:%S')


# ========== 便捷函数 ==========

def create_finalizer() -> StreamFinalizer:
    """创建流式格式化器"""
    return StreamFinalizer()