package services

import (
	"context"
	"errors"
	"fmt"

	"github.com/google/uuid"
	"go.uber.org/zap"

	"veza-backend-api/internal/models"
	"veza-backend-api/internal/repositories"
)

// GearService handles gear inventory business logic
type GearService struct {
	repo   repositories.GearRepository
	logger *zap.Logger
}

// NewGearService creates a new GearService
func NewGearService(repo repositories.GearRepository, logger *zap.Logger) *GearService {
	return &GearService{repo: repo, logger: logger}
}

// List returns all gear items for a user
func (s *GearService) List(ctx context.Context, userID uuid.UUID) ([]*models.GearItem, error) {
	return s.repo.ListByUserID(ctx, userID)
}

// ListPublicGearByUsername returns public gear items for a given username
func (s *GearService) ListPublicGearByUsername(ctx context.Context, username string) ([]*models.GearItem, error) {
	return s.repo.ListPublicByUsername(ctx, username)
}

// Search returns gear items matching a query for a user
func (s *GearService) Search(ctx context.Context, userID uuid.UUID, query string) ([]*models.GearItem, error) {
	return s.repo.SearchByUserID(ctx, userID, query)
}

// Get returns a single gear item by ID (with ownership check)
func (s *GearService) Get(ctx context.Context, id, userID uuid.UUID) (*models.GearItem, error) {
	item, err := s.repo.GetByID(ctx, id)
	if err != nil {
		return nil, err
	}
	if item.UserID != userID {
		return nil, errors.New("gear item not found")
	}
	return item, nil
}

// Create creates a new gear item for a user
func (s *GearService) Create(ctx context.Context, userID uuid.UUID, item *models.GearItem) (*models.GearItem, error) {
	if item.Name == "" {
		return nil, errors.New("name is required")
	}
	item.UserID = userID
	if err := s.repo.Create(ctx, item); err != nil {
		return nil, fmt.Errorf("failed to create gear item: %w", err)
	}
	return item, nil
}

// Update updates an existing gear item (with ownership check)
func (s *GearService) Update(ctx context.Context, id, userID uuid.UUID, item *models.GearItem) (*models.GearItem, error) {
	existing, err := s.repo.GetByID(ctx, id)
	if err != nil {
		return nil, err
	}
	if existing.UserID != userID {
		return nil, errors.New("gear item not found")
	}
	item.ID = id
	item.UserID = userID
	if err := s.repo.Update(ctx, item); err != nil {
		return nil, fmt.Errorf("failed to update gear item: %w", err)
	}
	return item, nil
}

// Delete deletes a gear item (with ownership check)
func (s *GearService) Delete(ctx context.Context, id, userID uuid.UUID) error {
	existing, err := s.repo.GetByID(ctx, id)
	if err != nil {
		return err
	}
	if existing.UserID != userID {
		return errors.New("gear item not found")
	}
	return s.repo.Delete(ctx, id)
}