package company

import (
	"context"
	"strings"
)

const recommendedTendersPageCacheKeyPrefix = "ai:recommendations:page:"

func recommendedTendersPageCacheKey(companyID, language string) string {
	return recommendedTendersPageCacheKeyPrefix +
		strings.TrimSpace(companyID) + ":" +
		strings.ToLower(strings.TrimSpace(language))
}

func (s *companyService) invalidateRecommendedTendersPageCache(ctx context.Context, companyID string) {
	if s.redisClient == nil {
		return
	}

	for _, language := range s.pageCacheLanguages {
		lang := strings.ToLower(strings.TrimSpace(language))
		if lang == "" {
			continue
		}
		_ = s.redisClient.Del(ctx, recommendedTendersPageCacheKey(companyID, lang))
	}
}

func (s *companyService) scheduleRecommendedTendersPageCacheRefresh(companyID string) {
	if s.pageCacheRefresher == nil {
		return
	}
	s.pageCacheRefresher.ScheduleRefreshRecommendedTendersPageCache(companyID)
}

// SetRecommendedTendersPageCacheRefresher wires async page-cache rebuilds from the tender service.
func (s *companyService) SetRecommendedTendersPageCacheRefresher(refresher RecommendedTendersPageCacheRefresher) {
	s.pageCacheRefresher = refresher
}

// SetPageCacheLanguages configures which language variants are invalidated in Redis.
func (s *companyService) SetPageCacheLanguages(languages []string) {
	s.pageCacheLanguages = normalizePageCacheLanguages("", languages)
}

func normalizePageCacheLanguages(defaultLanguage string, languages []string) []string {
	seen := make(map[string]struct{})
	out := make([]string, 0, len(languages)+1)

	add := func(lang string) {
		lang = strings.ToLower(strings.TrimSpace(lang))
		if lang == "" {
			return
		}
		if _, ok := seen[lang]; ok {
			return
		}
		seen[lang] = struct{}{}
		out = append(out, lang)
	}

	add(defaultLanguage)
	for _, lang := range languages {
		add(lang)
	}
	if len(out) == 0 {
		out = append(out, "en")
	}
	return out
}