package knowledge

import (
	"encoding/json"
	"strings"

	branddomain "haixun-backend/internal/model/brand/domain/usecase"
)

// PatrolTagInput grounds海巡 tag in研究地圖與品牌／產品輸入。
type PatrolTagInput struct {
	BrandName       string
	ProductName     string
	ProductFeatures string
	AudienceSummary string
	MatchTags       []string
	Questions       []string
	Pillars         []string
	PatrolKeywords  []string
}

type productContextFields struct {
	Brand    string `json:"brand"`
	Product  string `json:"product"`
	Features string `json:"features"`
}

func parseProductContextFields(raw string) productContextFields {
	raw = strings.TrimSpace(raw)
	if raw == "" {
		return productContextFields{}
	}
	var parsed productContextFields
	if err := json.Unmarshal([]byte(raw), &parsed); err != nil {
		return productContextFields{Features: raw}
	}
	parsed.Brand = strings.TrimSpace(parsed.Brand)
	parsed.Product = strings.TrimSpace(parsed.Product)
	parsed.Features = strings.TrimSpace(parsed.Features)
	return parsed
}

func PatrolTagInputFromBrand(brand *branddomain.BrandSummary, productBrief string) PatrolTagInput {
	if brand == nil {
		return PatrolTagInput{}
	}
	fields := parseProductContextFields(brand.ProductContext)
	productName := productLabelFromBrand(brand)
	if productName == "" {
		productName = fields.Product
	}
	brandName := strings.TrimSpace(brand.DisplayName)
	if brandName == "" {
		brandName = fields.Brand
	}
	features := fields.Features
	if features == "" {
		features = strings.TrimSpace(productBrief)
	}
	if features == "" {
		features = strings.TrimSpace(brand.ProductBrief)
	}
	return PatrolTagInput{
		BrandName:       brandName,
		ProductName:     productName,
		ProductFeatures: features,
		AudienceSummary: strings.TrimSpace(brand.ResearchMap.AudienceSummary),
		MatchTags:       matchTagsFromBrand(brand),
		Questions:       append([]string{}, brand.ResearchMap.Questions...),
		Pillars:         append([]string{}, brand.ResearchMap.Pillars...),
		PatrolKeywords:  append([]string{}, brand.ResearchMap.PatrolKeywords...),
	}
}

func productLabelFromBrand(brand *branddomain.BrandSummary) string {
	if brand == nil {
		return ""
	}
	productID := strings.TrimSpace(brand.ProductID)
	if productID == "" {
		return ""
	}
	for _, item := range brand.Products {
		if item.ID == productID {
			label := strings.TrimSpace(item.Label)
			if label != "" {
				return label
			}
			return parseProductContextFields(item.ProductContext).Product
		}
	}
	return ""
}

func matchTagsFromBrand(brand *branddomain.BrandSummary) []string {
	if brand == nil {
		return nil
	}
	productID := strings.TrimSpace(brand.ProductID)
	seen := map[string]struct{}{}
	out := []string{}
	add := func(tag string) {
		tag = strings.TrimSpace(tag)
		if tag == "" {
			return
		}
		if _, ok := seen[tag]; ok {
			return
		}
		seen[tag] = struct{}{}
		out = append(out, tag)
	}
	for _, item := range brand.Products {
		if productID != "" && item.ID != productID {
			continue
		}
		for _, tag := range item.MatchTags {
			add(tag)
		}
		if productID != "" {
			break
		}
	}
	return out
}

func (in PatrolTagInput) HasResearchMap() bool {
	return len(in.Questions) > 0 || len(in.Pillars) > 0 || strings.TrimSpace(in.AudienceSummary) != ""
}

func (in PatrolTagInput) HasProductContext() bool {
	return strings.TrimSpace(in.ProductName) != "" ||
		strings.TrimSpace(in.ProductFeatures) != "" ||
		len(in.MatchTags) > 0
}

func productCategoryHint(productName, features string) string {
	combined := productName + " " + features
	for _, hint := range []string{
		"沐浴乳", "沐浴露", "洗髮精", "洗髮乳", "洗面乳", "洗面奶", "乳液", "精華",
		"防曬", "卸妝", "潔面", "身體乳", "洗手乳", "清潔",
	} {
		if strings.Contains(combined, hint) {
			return hint
		}
	}
	return ""
}