package intent

import (
	"strings"

	"golang.org/x/text/unicode/norm"
)

// foldMatchText 做识别用折叠。nfkc 只做兼容等价（全角 ASCII、组合字符），
// 不做繁简转换。caseSensitive 为真时保留大小写。
func foldMatchText(s string, nfkc, caseSensitive bool) string {
	if nfkc {
		s = norm.NFKC.String(s)
	}
	if !caseSensitive {
		s = strings.ToLower(s)
	}
	return s
}

// foldInput 返回用于匹配的文本：第一段保留大小写（可选 NFKC），第二段是其小写。
func (s *Snapshot) foldInput(input string) (matchInput, folded string) {
	if s == nil {
		return input, strings.ToLower(input)
	}
	matchInput = foldMatchText(input, s.nfkc, true)
	return matchInput, strings.ToLower(matchInput)
}

func cloneStrings(in []string) []string {
	if in == nil {
		return nil
	}
	return append([]string(nil), in...)
}

func cloneIntentSpec(in IntentSpec) IntentSpec {
	out := in
	out.Matcher.IncludesAny = cloneStrings(in.Matcher.IncludesAny)
	out.Matcher.IncludesAll = cloneStrings(in.Matcher.IncludesAll)
	out.Matcher.ExcludesAny = cloneStrings(in.Matcher.ExcludesAny)
	out.Matcher.Patterns = cloneStrings(in.Matcher.Patterns)
	if in.Slots != nil {
		out.Slots = append([]SlotSpec(nil), in.Slots...)
		for i := range out.Slots {
			out.Slots[i].Enum = cloneStrings(in.Slots[i].Enum)
			out.Slots[i].Normalize = cloneStrings(in.Slots[i].Normalize)
		}
	}
	if in.Metadata != nil {
		out.Metadata = make(map[string]string, len(in.Metadata))
		for k, v := range in.Metadata {
			out.Metadata[k] = v
		}
	}
	return out
}

// catalogMetadataAllow 是目录与 Markdown 允许带出的 metadata 键。
// handler 仍留在 CatalogSpec 供执行器按名分派，但不写入 Markdown。
var catalogMetadataAllow = map[string]bool{
	"blueprint": true,
	"guidance":  true,
}

func catalogMetadata(in map[string]string) map[string]string {
	if len(in) == 0 {
		return nil
	}
	out := map[string]string{}
	for k, v := range in {
		if catalogMetadataAllow[k] {
			out[k] = v
		}
	}
	if len(out) == 0 {
		return nil
	}
	return out
}