package store

import (
	"context"
	"errors"
	"fmt"

	"gcy_hpc_server/internal/model"

	"gorm.io/gorm"
)

type FolderStore struct {
	db *gorm.DB
}

func NewFolderStore(db *gorm.DB) *FolderStore {
	return &FolderStore{db: db}
}

func (s *FolderStore) Create(ctx context.Context, folder *model.Folder) error {
	return s.db.WithContext(ctx).Create(folder).Error
}

func (s *FolderStore) GetByID(ctx context.Context, id int64) (*model.Folder, error) {
	var folder model.Folder
	err := s.db.WithContext(ctx).First(&folder, id).Error
	if errors.Is(err, gorm.ErrRecordNotFound) {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}
	return &folder, nil
}

func (s *FolderStore) GetByPath(ctx context.Context, path string) (*model.Folder, error) {
	var folder model.Folder
	err := s.db.WithContext(ctx).Where("path = ?", path).First(&folder).Error
	if errors.Is(err, gorm.ErrRecordNotFound) {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}
	return &folder, nil
}

func (s *FolderStore) ListByParentID(ctx context.Context, parentID *int64) ([]model.Folder, error) {
	var folders []model.Folder
	query := s.db.WithContext(ctx)
	if parentID == nil {
		query = query.Where("parent_id IS NULL")
	} else {
		query = query.Where("parent_id = ?", *parentID)
	}
	if err := query.Order("name ASC").Find(&folders).Error; err != nil {
		return nil, err
	}
	return folders, nil
}

// GetSubTree returns all folders whose path starts with the given prefix.
func (s *FolderStore) GetSubTree(ctx context.Context, path string) ([]model.Folder, error) {
	var folders []model.Folder
	if err := s.db.WithContext(ctx).Where("path LIKE ?", path+"%").Find(&folders).Error; err != nil {
		return nil, err
	}
	return folders, nil
}

// HasChildren checks if a folder has sub-folders or files.
func (s *FolderStore) HasChildren(ctx context.Context, id int64) (bool, error) {
	folder, err := s.GetByID(ctx, id)
	if err != nil {
		return false, err
	}
	if folder == nil {
		return false, nil
	}

	// Check for sub-folders
	var subFolderCount int64
	if err := s.db.WithContext(ctx).Model(&model.Folder{}).Where("parent_id = ?", id).Count(&subFolderCount).Error; err != nil {
		return false, fmt.Errorf("count sub-folders: %w", err)
	}
	if subFolderCount > 0 {
		return true, nil
	}

	// Check for files
	var fileCount int64
	if err := s.db.WithContext(ctx).Model(&model.File{}).Where("folder_id = ?", id).Count(&fileCount).Error; err != nil {
		return false, fmt.Errorf("count files: %w", err)
	}
	return fileCount > 0, nil
}

func (s *FolderStore) Delete(ctx context.Context, id int64) error {
	result := s.db.WithContext(ctx).Delete(&model.Folder{}, id)
	if result.Error != nil {
		return result.Error
	}
	return nil
}