package utils

import (
	"sync"

	"github.com/flipped-aurora/gin-vue-admin/server/global"
	swd "github.com/kirklin/go-swd"
	"go.uber.org/zap"
)

type SensitiveWordUtil struct {
	detector *swd.SWD
	once     sync.Once
	initErr  error
}

// 全局单例实例
var (
	sensitiveWordInstance *SensitiveWordUtil
	sensitiveWordOnce     sync.Once
)

// GetSensitiveWordUtil 获取敏感词工具单例实例
func GetSensitiveWordUtil() *SensitiveWordUtil {
	sensitiveWordOnce.Do(func() {
		sensitiveWordInstance = &SensitiveWordUtil{}
	})
	return sensitiveWordInstance
}

// InitDetector 初始化敏感词检测器（单例模式）
func (s *SensitiveWordUtil) InitDetector() error {
	s.once.Do(func() {
		detector, err := swd.New()
		if err != nil {
			s.initErr = err
			global.GVA_LOG.Error("Failed to initialize sensitive word detector", zap.Error(err))
			return
		}
		s.detector = detector
		global.GVA_LOG.Info("Sensitive word detector initialized successfully")
	})
	return s.initErr
}

// DetectSensitive 检测文本中的敏感词
func (s *SensitiveWordUtil) DetectSensitive(text string) ([]swd.SensitiveWord, error) {
	if s.detector == nil {
		if err := s.InitDetector(); err != nil {
			return nil, err
		}
	}

	words := s.detector.MatchAll(text)
	return words, nil
}

// HasSensitive 检查文本是否包含敏感词
func (s *SensitiveWordUtil) HasSensitive(text string) (bool, error) {
	if s.detector == nil {
		if err := s.InitDetector(); err != nil {
			return false, err
		}
	}

	return s.detector.Detect(text), nil
}

// FilterText 过滤文本中的敏感词，返回过滤后的文本和是否包含敏感词
func (s *SensitiveWordUtil) FilterText(text string) (filtered string, hasSensitive bool, err error) {
	if s.detector == nil {
		if err := s.InitDetector(); err != nil {
			return text, false, err
		}
	}

	// 检查是否包含敏感词
	hasSensitive = s.detector.Detect(text)

	if !hasSensitive {
		return text, false, nil
	}

	// 使用星号替换敏感词
	filtered = s.detector.ReplaceWithAsterisk(text)
	return filtered, true, nil
}

// FilterTextWithCustomReplace 使用自定义替换策略过滤敏感词
func (s *SensitiveWordUtil) FilterTextWithCustomReplace(text string, replaceFunc func(swd.SensitiveWord) string) (filtered string, hasSensitive bool, err error) {
	if s.detector == nil {
		if err := s.InitDetector(); err != nil {
			return text, false, err
		}
	}

	// 检查是否包含敏感词
	hasSensitive = s.detector.Detect(text)

	if !hasSensitive {
		return text, false, nil
	}

	// 使用自定义替换策略
	filtered = s.detector.ReplaceWithStrategy(text, replaceFunc)
	return filtered, true, nil
}

// GetFirstSensitiveWord 获取文本中第一个敏感词
func (s *SensitiveWordUtil) GetFirstSensitiveWord(text string) (*swd.SensitiveWord, error) {
	if s.detector == nil {
		if err := s.InitDetector(); err != nil {
			return nil, err
		}
	}

	word := s.detector.Match(text)
	return word, nil
}

// AddCustomWords 添加自定义敏感词
func (s *SensitiveWordUtil) AddCustomWords(words map[string]swd.Category) error {
	if s.detector == nil {
		if err := s.InitDetector(); err != nil {
			return err
		}
	}

	return s.detector.AddWords(words)
}

// RemoveWord 移除指定敏感词
func (s *SensitiveWordUtil) RemoveWord(word string) error {
	if s.detector == nil {
		if err := s.InitDetector(); err != nil {
			return err
		}
	}

	return s.detector.RemoveWord(word)
}

// Clear 清空词库
func (s *SensitiveWordUtil) Clear() error {
	if s.detector == nil {
		if err := s.InitDetector(); err != nil {
			return err
		}
	}

	return s.detector.Clear()
}