"""Bootstrap 拼装 — L2 引擎注入层

4 段结构（~800 tokens）：
  1. 任务上下文：title / description / must_haves / status
  2. 前序产出：depends_on 产出摘要 + handoff comment
  3. 角色操作规范全文：通过 ROLE_SKILL_MAP 从 Skill 文件读取
  4. 硬约束：状态流转约束

A 类 Skill 由引擎确定性注入全文，不靠 Description 触发。
"""

import logging
import os
from pathlib import Path
from typing import Any, Dict, List, Optional

logger = logging.getLogger("moziplus-v2.bootstrap")

CHARS_PER_TOKEN = 3.0


def estimate_tokens(text: str) -> int:
    """估算文本 token 数"""
    return max(1, int(len(text) / CHARS_PER_TOKEN))


class BootstrapBuilder:
    """L2 引擎注入层构建器（v2.1 四段式）"""

    ROLE_SKILL_MAP = {
        "executor":          "blackboard-executor",
        "reviewer":          "blackboard-reviewer",
        "reviewer-simayi":   "blackboard-reviewer-simayi",
        "reviewer-pangtong": "blackboard-reviewer-pangtong",
        "planner":           "blackboard-planner",
        "claim":             "blackboard-claim",
    }

    # 默认从环境变量或配置读取，fallback 到默认路径
    SKILL_BASE_PATH = os.environ.get(
        "MOZI_SKILL_PATH",
        os.path.expanduser("~/.sanguo_projects/sanguo_mozi/skills")
    )

    def __init__(self, max_tokens: int = 4096):
        self.max_tokens = max_tokens

    def build(self, task: dict, role: str) -> str:
        """构建 4 段 bootstrap 文本

        Args:
            task: 任务数据字典，需包含 title/description/must_haves/status 等字段
            role: 角色，对应 ROLE_SKILL_MAP 的 key

        Returns:
            拼装好的 bootstrap 文本
        """
        sections: List[str] = []

        # 段 1: 任务上下文
        sections.append(self._format_task_context(task))

        # 段 2: 前序产出（有依赖时注入）
        if task.get("depends_on_outputs"):
            sections.append(self._format_prior_outputs(task["depends_on_outputs"]))

        # 段 3: 角色操作规范全文（通过 ROLE_SKILL_MAP 从 Skill 文件读取）
        skill_name = self.ROLE_SKILL_MAP.get(role)
        if skill_name:
            skill_content = self._read_skill(skill_name)
            if skill_content:
                sections.append(skill_content)
        elif role not in ("discussion",):
            logger.warning("No skill mapping for role: %s", role)

        # 段 4: 硬约束
        sections.append(self._format_constraints(role))

        bootstrap = "\n\n---\n\n".join(sections)

        # Token 预算检查（warn 但不截断）
        tokens = max(1, int(len(bootstrap) / CHARS_PER_TOKEN))
        if tokens > 800:
            logger.warning("Bootstrap exceeds 800 token budget: %d tokens (role=%s)",
                           tokens, role)

        return bootstrap

    def build_for_task(self, task: Any, role: str, **kwargs) -> str:
        """从 Task 对象构建 bootstrap（便捷方法，兼容旧调用）

        忽略 kwargs 中的 project_config/experiences 等旧参数。
        must_haves 包含验收标准（不需要 project_context）。
        """
        task_dict = {
            "task_id": task.id,
            "title": task.title,
            "description": task.description,
            "must_haves": task.must_haves,
            "status": getattr(task, 'status', ''),
        }
        # depends_on_outputs 如果有的话
        if hasattr(task, 'depends_on_outputs'):
            task_dict["depends_on_outputs"] = task.depends_on_outputs

        return self.build(task=task_dict, role=role)

    def _read_skill(self, skill_name: str) -> str:
        """从 Skill 文件读取全文（带 fallback）"""
        path = os.path.join(self.SKILL_BASE_PATH, skill_name, "SKILL.md")
        try:
            with open(path, encoding="utf-8") as f:
                return f.read()
        except FileNotFoundError:
            logger.error("Skill file not found: %s", path)
            return ""

    def _format_task_context(self, task: dict) -> str:
        """格式化任务上下文（段 1）"""
        parts = ["## 任务上下文"]
        if task.get("task_id"):
            parts.append(f"任务ID: {task['task_id']}")
        if task.get("title"):
            parts.append(f"标题: {task['title']}")
        if task.get("description"):
            parts.append(f"描述: {task['description']}")
        if task.get("must_haves"):
            parts.append(f"必须完成: {task['must_haves']}")
        if task.get("status"):
            parts.append(f"当前状态: {task['status']}")
        return "\n".join(parts)

    def _format_prior_outputs(self, outputs: list) -> str:
        """格式化前序产出摘要（段 2）"""
        parts = ["## 前序产出"]
        for out in outputs:
            parts.append(f"- [{out.get('task_id', '?')}] {out.get('summary', '无摘要')}")
        return "\n".join(parts)

    def _format_constraints(self, role: str) -> str:
        """格式化硬约束（段 4）"""
        constraints = ["## 硬约束"]
        if role == "executor":
            constraints.extend([
                "- 完成后必须标 review",
                "- 产出物不能为空（系统会验证）",
                "- handoff comment ≥ 50 字符",
            ])
        elif role.startswith("reviewer"):
            constraints.extend([
                "- 审查结果必须明确 pass/fail",
                "- 评审意见须附证据（文件:行号）",
            ])
        elif role == "planner":
            constraints.extend([
                "- 需求不清时提问，不要猜",
                "- 子任务必须有明确的终态定义",
            ])
        return "\n".join(constraints)