package loaders

import (
	"context"
	"git.aiterp.net/stufflog/server/database/repositories"
	"git.aiterp.net/stufflog/server/models"
	"time"
)

var projectPermissionCtxKey = "ctx.stufflog.ProjectPermissionLoader"

func ProjectPermissionLoaderFromContext(ctx context.Context) *ProjectPermissionLoader {
	return ctx.Value(projectPermissionCtxKey).(*ProjectPermissionLoader)
}

func NewProjectPermissionLoader(ctx context.Context, user *models.User, projectRepo repositories.ProjectRepository) *ProjectPermissionLoader {
	return &ProjectPermissionLoader{
		wait:     time.Millisecond / 2,
		maxBatch: 16,
		fetch: func(keys []string) ([]*models.ProjectPermission, []error) {
			errors := make([]error, len(keys))
			results := make([]*models.ProjectPermission, len(keys))

			if user == nil {
				for i, key := range keys {
					results[i] = &models.ProjectPermission{
						ProjectID: key,
						UserID:    "",
						Level:     models.ProjectPermissionLevelNoAccess,
					}
				}
				return results, errors
			}

			indices := make(map[string]int)
			for i, key := range keys {
				indices[key] = i
			}

			permissions, err := projectRepo.GetUserPermissions(ctx, *user, keys)
			if err != nil {
				for i := range errors {
					errors[i] = err
				}

				return results, errors
			}

			for _, permission := range permissions {
				results[indices[permission.ProjectID]] = permission
			}

			return results, errors
		},
	}
}