package moderation

import (
	"regexp"
	"strings"

	"github.com/mozillazg/go-pinyin"
	"github.com/tinode/chat/server/store/types"
)

func matchLocalWords(text, scene string, words *types.SensitiveWordSet) *ProviderResult {
	normalized := strings.ToLower(strings.TrimSpace(text))
	if normalized == "" || words == nil {
		return nil
	}
	for _, rule := range words.Items {
		if rule == nil || strings.TrimSpace(rule.Word) == "" || !sceneEnabled(rule.Scenes, scene) {
			continue
		}
		matched := false
		switch strings.ToLower(strings.TrimSpace(rule.MatchType)) {
		case "exact":
			matched = normalized == strings.ToLower(strings.TrimSpace(rule.Word))
		case "regex":
			pattern, err := regexp.Compile(rule.Word)
			matched = err == nil && pattern.MatchString(text)
		case "pinyin":
			args := pinyin.NewArgs()
			args.Style = pinyin.Normal
			textPinyin := strings.Join(pinyin.LazyConvert(text, &args), "")
			wordPinyin := strings.Join(pinyin.LazyConvert(rule.Word, &args), "")
			if wordPinyin == "" {
				wordPinyin = strings.ToLower(strings.TrimSpace(rule.Word))
			}
			matched = wordPinyin != "" && strings.Contains(strings.ToLower(textPinyin), strings.ToLower(wordPinyin))
		default:
			matched = strings.Contains(normalized, strings.ToLower(strings.TrimSpace(rule.Word)))
		}
		if matched {
			return &ProviderResult{RiskLevel: normalizedRisk(rule.RiskLevel), RiskLabels: []string{"local_sensitive_word"}, Summary: normalizedAction(rule.Action)}
		}
	}
	return nil
}

func sceneEnabled(scenes []string, scene string) bool {
	if len(scenes) == 0 {
		return true
	}
	for _, value := range scenes {
		if value == "*" || value == scene {
			return true
		}
	}
	return false
}

func normalizedRisk(value string) string {
	switch strings.ToLower(strings.TrimSpace(value)) {
	case "high", "medium", "low":
		return strings.ToLower(strings.TrimSpace(value))
	default:
		return "none"
	}
}

func normalizedAction(value string) string {
	switch strings.ToLower(strings.TrimSpace(value)) {
	case ActionBlock, ActionAuditOnly:
		return strings.ToLower(strings.TrimSpace(value))
	default:
		return ActionAllow
	}
}