package services

import (
	"errors"
	"lost-and-found/internal/models"
	"lost-and-found/internal/repositories"
	"time"

	"gorm.io/gorm"
)

type LostItemService struct {
	lostItemRepo *repositories.LostItemRepository
	categoryRepo *repositories.CategoryRepository
	auditLogRepo *repositories.AuditLogRepository
}

func NewLostItemService(db *gorm.DB) *LostItemService {
	return &LostItemService{
		lostItemRepo: repositories.NewLostItemRepository(db),
		categoryRepo: repositories.NewCategoryRepository(db),
		auditLogRepo: repositories.NewAuditLogRepository(db),
	}
}

// CreateLostItemRequest represents create lost item data
type CreateLostItemRequest struct {
	Name        string    `json:"name" binding:"required"`
	CategoryID  uint      `json:"category_id" binding:"required"`
	Color       string    `json:"color"`
	Location    string    `json:"location"`
	Description string    `json:"description" binding:"required"`
	DateLost    time.Time `json:"date_lost" binding:"required"`
}

// UpdateLostItemRequest represents update lost item data
type UpdateLostItemRequest struct {
	Name        string    `json:"name"`
	CategoryID  uint      `json:"category_id"`
	Color       string    `json:"color"`
	Location    string    `json:"location"`
	Description string    `json:"description"`
	DateLost    time.Time `json:"date_lost"`
}

// GetAllLostItems gets all lost items
func (s *LostItemService) GetAllLostItems(page, limit int, status, category, search string, userID *uint) ([]models.LostItemResponse, int64, error) {
	lostItems, total, err := s.lostItemRepo.FindAll(page, limit, status, category, search, userID)
	if err != nil {
		return nil, 0, err
	}

	var responses []models.LostItemResponse
	for _, lostItem := range lostItems {
		responses = append(responses, lostItem.ToResponse())
	}

	return responses, total, nil
}

// GetLostItemByID gets lost item by ID
func (s *LostItemService) GetLostItemByID(id uint) (*models.LostItem, error) {
	return s.lostItemRepo.FindByID(id)
}

// CreateLostItem creates a new lost item report
func (s *LostItemService) CreateLostItem(userID uint, req CreateLostItemRequest, ipAddress, userAgent string) (*models.LostItem, error) {
	// Verify category exists
	if _, err := s.categoryRepo.FindByID(req.CategoryID); err != nil {
		return nil, errors.New("invalid category")
	}

	lostItem := &models.LostItem{
		UserID:      userID,
		Name:        req.Name,
		CategoryID:  req.CategoryID,
		Color:       req.Color,
		Location:    req.Location,
		Description: req.Description,
		DateLost:    req.DateLost,
		Status:      models.LostItemStatusActive,
	}

	if err := s.lostItemRepo.Create(lostItem); err != nil {
		return nil, errors.New("failed to create lost item report")
	}

	// Log audit
	s.auditLogRepo.Log(&userID, models.ActionCreate, models.EntityLostItem, &lostItem.ID,
		"Lost item report created: "+lostItem.Name, ipAddress, userAgent)

	// Load with relations
	return s.lostItemRepo.FindByID(lostItem.ID)
}

// UpdateLostItem updates a lost item report
func (s *LostItemService) UpdateLostItem(userID, lostItemID uint, req UpdateLostItemRequest, ipAddress, userAgent string) (*models.LostItem, error) {
	lostItem, err := s.lostItemRepo.FindByID(lostItemID)
	if err != nil {
		return nil, err
	}

	// Only owner can update
	if lostItem.UserID != userID {
		return nil, errors.New("unauthorized to update this lost item report")
	}

	// Only active reports can be updated
	if !lostItem.IsActive() {
		return nil, errors.New("cannot update non-active lost item report")
	}

	// Update fields
	if req.Name != "" {
		lostItem.Name = req.Name
	}
	if req.CategoryID != 0 {
		// Verify category exists
		if _, err := s.categoryRepo.FindByID(req.CategoryID); err != nil {
			return nil, errors.New("invalid category")
		}
		lostItem.CategoryID = req.CategoryID
	}
	if req.Color != "" {
		lostItem.Color = req.Color
	}
	if req.Location != "" {
		lostItem.Location = req.Location
	}
	if req.Description != "" {
		lostItem.Description = req.Description
	}
	if !req.DateLost.IsZero() {
		lostItem.DateLost = req.DateLost
	}

	if err := s.lostItemRepo.Update(lostItem); err != nil {
		return nil, errors.New("failed to update lost item report")
	}

	// Log audit
	s.auditLogRepo.Log(&userID, models.ActionUpdate, models.EntityLostItem, &lostItemID,
		"Lost item report updated: "+lostItem.Name, ipAddress, userAgent)

	return lostItem, nil
}

// UpdateLostItemStatus updates lost item status
func (s *LostItemService) UpdateLostItemStatus(userID, lostItemID uint, status string, ipAddress, userAgent string) error {
	lostItem, err := s.lostItemRepo.FindByID(lostItemID)
	if err != nil {
		return err
	}

	// Only owner can update
	if lostItem.UserID != userID {
		return errors.New("unauthorized to update this lost item report")
	}

	if err := s.lostItemRepo.UpdateStatus(lostItemID, status); err != nil {
		return errors.New("failed to update lost item status")
	}

	// Log audit
	s.auditLogRepo.Log(&userID, models.ActionUpdate, models.EntityLostItem, &lostItemID,
		"Lost item status updated to: "+status, ipAddress, userAgent)

	return nil
}

// DeleteLostItem deletes a lost item report
func (s *LostItemService) DeleteLostItem(userID, lostItemID uint, ipAddress, userAgent string) error {
	lostItem, err := s.lostItemRepo.FindByID(lostItemID)
	if err != nil {
		return err
	}

	// Only owner can delete
	if lostItem.UserID != userID {
		return errors.New("unauthorized to delete this lost item report")
	}

	if err := s.lostItemRepo.Delete(lostItemID); err != nil {
		return errors.New("failed to delete lost item report")
	}

	// Log audit
	s.auditLogRepo.Log(&userID, models.ActionDelete, models.EntityLostItem, &lostItemID,
		"Lost item report deleted: "+lostItem.Name, ipAddress, userAgent)

	return nil
}

// GetLostItemsByUser gets lost items by user
func (s *LostItemService) GetLostItemsByUser(userID uint, page, limit int) ([]models.LostItemResponse, int64, error) {
	lostItems, total, err := s.lostItemRepo.FindByUser(userID, page, limit)
	if err != nil {
		return nil, 0, err
	}

	var responses []models.LostItemResponse
	for _, lostItem := range lostItems {
		responses = append(responses, lostItem.ToResponse())
	}

	return responses, total, nil
}