package repository

import (
	"context"
	"permission/reborn/domain/entity"
	"permission/reborn/domain/errors"
	"permission/reborn/domain/repository"

	"gorm.io/gorm"
)

type permissionRepository struct {
	db    *gorm.DB
	cache repository.CacheRepository
}

// NewPermissionRepository 建立權限 Repository
func NewPermissionRepository(db *gorm.DB, cache repository.CacheRepository) repository.PermissionRepository {
	return &permissionRepository{
		db:    db,
		cache: cache,
	}
}

func (r *permissionRepository) Get(ctx context.Context, id int64) (*entity.Permission, error) {
	var perm entity.Permission
	err := r.db.WithContext(ctx).
		Where("id = ? AND status != ?", id, entity.StatusDeleted).
		First(&perm).Error

	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, errors.ErrPermissionNotFound
		}
		return nil, errors.Wrap(errors.ErrCodeDBQuery, "failed to get permission", err)
	}

	return &perm, nil
}

func (r *permissionRepository) GetByName(ctx context.Context, name string) (*entity.Permission, error) {
	var perm entity.Permission
	err := r.db.WithContext(ctx).
		Where("name = ? AND status != ?", name, entity.StatusDeleted).
		First(&perm).Error

	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, errors.ErrPermissionNotFound
		}
		return nil, errors.Wrap(errors.ErrCodeDBQuery, "failed to get permission by name", err)
	}

	return &perm, nil
}

func (r *permissionRepository) GetByNames(ctx context.Context, names []string) ([]*entity.Permission, error) {
	if len(names) == 0 {
		return []*entity.Permission{}, nil
	}

	var perms []*entity.Permission
	err := r.db.WithContext(ctx).
		Where("name IN ? AND status != ?", names, entity.StatusDeleted).
		Find(&perms).Error

	if err != nil {
		return nil, errors.Wrap(errors.ErrCodeDBQuery, "failed to get permissions by names", err)
	}

	return perms, nil
}

func (r *permissionRepository) GetByHTTP(ctx context.Context, path, method string) (*entity.Permission, error) {
	var perm entity.Permission
	err := r.db.WithContext(ctx).
		Where("http_path = ? AND http_method = ? AND status != ?", path, method, entity.StatusDeleted).
		First(&perm).Error

	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, errors.ErrPermissionNotFound
		}
		return nil, errors.Wrap(errors.ErrCodeDBQuery, "failed to get permission by http", err)
	}

	return &perm, nil
}

func (r *permissionRepository) List(ctx context.Context, filter repository.PermissionFilter) ([]*entity.Permission, error) {
	query := r.buildQuery(ctx, filter)

	var perms []*entity.Permission
	if err := query.Find(&perms).Error; err != nil {
		return nil, errors.Wrap(errors.ErrCodeDBQuery, "failed to list permissions", err)
	}

	return perms, nil
}

func (r *permissionRepository) ListActive(ctx context.Context) ([]*entity.Permission, error) {
	// 嘗試從快取取得
	if r.cache != nil {
		var perms []*entity.Permission
		err := r.cache.GetObject(ctx, repository.CacheKeyPermissionList, &perms)
		if err == nil && len(perms) > 0 {
			return perms, nil
		}
	}

	// 從資料庫查詢
	var perms []*entity.Permission
	err := r.db.WithContext(ctx).
		Where("status = ?", entity.StatusActive).
		Order("parent_id, id").
		Find(&perms).Error

	if err != nil {
		return nil, errors.Wrap(errors.ErrCodeDBQuery, "failed to list active permissions", err)
	}

	// 存入快取
	if r.cache != nil {
		_ = r.cache.SetObject(ctx, repository.CacheKeyPermissionList, perms, 0) // 使用預設 TTL
	}

	return perms, nil
}

func (r *permissionRepository) GetChildren(ctx context.Context, parentID int64) ([]*entity.Permission, error) {
	var perms []*entity.Permission
	err := r.db.WithContext(ctx).
		Where("parent_id = ? AND status != ?", parentID, entity.StatusDeleted).
		Find(&perms).Error

	if err != nil {
		return nil, errors.Wrap(errors.ErrCodeDBQuery, "failed to get children permissions", err)
	}

	return perms, nil
}

func (r *permissionRepository) buildQuery(ctx context.Context, filter repository.PermissionFilter) *gorm.DB {
	query := r.db.WithContext(ctx).
		Model(&entity.Permission{}).
		Where("status != ?", entity.StatusDeleted)

	if filter.Type != nil {
		query = query.Where("type = ?", *filter.Type)
	}

	if filter.Status != nil {
		query = query.Where("status = ?", *filter.Status)
	}

	if filter.ParentID != nil {
		query = query.Where("parent_id = ?", *filter.ParentID)
	}

	return query.Order("parent_id, id")
}