"""Skill 触发检测器 - Phase 9.5

检测消息中的 Skill 触发条件。
"""

import re
from typing import Any

from app.agents.skills.metadata import SkillMetadata


class SkillTriggerDetector:
    """Skill 触发检测器

    检测用户消息中是否触发了某个 Skill。
    """

    def __init__(self):
        self._skills: dict[str, SkillMetadata] = {}

    def register_skill(self, skill: SkillMetadata) -> None:
        """注册 Skill

        Args:
            skill: Skill 元数据
        """
        self._skills[skill.name] = skill

    def unregister_skill(self, name: str) -> bool:
        """注销 Skill

        Args:
            name: Skill 名称

        Returns:
            是否成功
        """
        if name in self._skills:
            del self._skills[name]
            return True
        return False

    def detect_triggered_skills(self, message: str) -> list[str]:
        """检测触发的 Skills

        Args:
            message: 用户消息

        Returns:
            触发的 Skill 名称列表
        """
        triggered = []
        message_lower = message.lower()

        for skill in self._skills.values():
            if not skill.enabled:
                continue

            if self._matches_triggers(message, message_lower, skill):
                triggered.append(skill.name)

        return triggered

    def _matches_triggers(self, message: str, message_lower: str, skill: SkillMetadata) -> bool:
        """检查消息是否匹配 Skill 触发条件

        Args:
            message: 原始消息
            message_lower: 小写消息
            skill: Skill 元数据

        Returns:
            是否匹配
        """
        for trigger in skill.triggers:
            trigger_lower = trigger.lower()

            # 前缀匹配，如 "/code" 或 "@git"
            if trigger_lower.startswith("/") or trigger_lower.startswith("@"):
                if message_lower.startswith(trigger_lower):
                    return True

            # 命令格式，如 "//analyze"
            if trigger_lower.startswith("//"):
                pattern = trigger_lower[2:]
                if re.search(rf"\b{re.escape(pattern)}\b", message_lower):
                    return True

            # 关键词匹配
            if trigger_lower in message_lower:
                return True

        return False

    def get_skill_prompt(self, skill_name: str) -> str | None:
        """获取 Skill 的提示词

        Args:
            skill_name: Skill 名称

        Returns:
            Skill 内容或 None
        """
        skill = self._skills.get(skill_name)
        if skill:
            return skill.content
        return None

    def get_triggered_skill_context(self, message: str) -> str:
        """获取触发的 Skills 上下文

        Args:
            message: 用户消息

        Returns:
            拼接的 Skill 上下文
        """
        triggered = self.detect_triggered_skills(message)
        if not triggered:
            return ""

        contexts = []
        for skill_name in triggered:
            skill = self._skills.get(skill_name)
            if skill:
                contexts.append(f"# {skill.name}\n\n{skill.content}")

        return "\n\n---\n\n".join(contexts)


# 全局检测器
_detector: SkillTriggerDetector | None = None


def get_skill_trigger_detector() -> SkillTriggerDetector:
    """获取全局 Skill 触发检测器"""
    global _detector
    if _detector is None:
        _detector = SkillTriggerDetector()
    return _detector