package billing

import (
	"context"
	"errors"
	"fmt"
	"strings"

	"github.com/google/uuid"
)

// FeatureKeyFromError extracts the feature key from an ErrFeatureDisabled wrap
// ("feature_disabled: marketing.campaigns.generate_ai").
func FeatureKeyFromError(err error) string {
	if err == nil || !errors.Is(err, ErrFeatureDisabled) {
		return ""
	}
	msg := err.Error()
	const prefix = "feature_disabled:"
	idx := strings.Index(strings.ToLower(msg), prefix)
	if idx < 0 {
		return ""
	}
	return strings.TrimSpace(msg[idx+len(prefix):])
}

// FeatureKeysForProcessingType maps a processing job type to registry keys that
// must be effective before StartJob may proceed.
func FeatureKeysForProcessingType(processingType string) []string {
	switch strings.ToLower(strings.TrimSpace(processingType)) {
	case "title":
		return []string{"capability.ai_processing", "catalog.products.process_ai_titles"}
	case "description":
		return []string{"capability.ai_processing", "catalog.products.process_ai_descriptions"}
	case "enhance", "enhance_only", "enhance-only", "seo", "seo_ai":
		return []string{"capability.ai_processing"}
	case "eprel", "eprel_only":
		return []string{"capability.eprel"}
	case "email_campaign", "email_campaign_ai", "campaign_ai":
		return []string{"capability.campaign_ai", "marketing.campaigns.generate_ai"}
	case "normalize", "specs", "fill", "categories", "attributes", "full", "":
		return []string{"capability.normalize_specs_fill"}
	default:
		return []string{"capability.normalize_specs_fill"}
	}
}

// AssertFeatures fails closed on the first disabled key.
// Loads Capabilities once for the whole key set (avoids N×CapabilitiesForCompany).
func (s *Service) AssertFeatures(ctx context.Context, companyID uuid.UUID, keys ...string) error {
	if len(keys) == 0 {
		return nil
	}
	caps, err := s.CapabilitiesForCompany(ctx, companyID)
	if err != nil {
		return err
	}
	for _, key := range keys {
		key = strings.TrimSpace(key)
		if key == "" {
			continue
		}
		if caps.Features == nil || !caps.Features[key] {
			return fmt.Errorf("%w: %s", ErrFeatureDisabled, key)
		}
	}
	return nil
}

// AssertProcessingFeatures enforces plan ∩ global feature keys for a job type.
func (s *Service) AssertProcessingFeatures(ctx context.Context, companyID uuid.UUID, processingType string) error {
	if s == nil {
		return nil
	}
	return s.AssertFeatures(ctx, companyID, FeatureKeysForProcessingType(processingType)...)
}