portainer/portainer

package dataservices

import (
    "errors"
    "fmt"

    perrors "github.com/portainer/portainer/api/dataservices/errors"

    "github.com/rs/zerolog/log"
)

// ErrStop signals the stop of computation when filtering results
var ErrStop = errors.New("stop")

func IsErrObjectNotFound(e error) bool {
    return errors.Is(e, perrors.ErrObjectNotFound)
}

// AppendFn appends elements to the given collection slice
func AppendFn[T any](collection *[]T) func(obj interface{}) (interface{}, error) {
    return func(obj interface{}) (interface{}, error) {
        element, ok := obj.(*T)
        if !ok {
            log.Debug().Str("obj", fmt.Sprintf("%#v", obj)).Msg("type assertion failed")
            return nil, fmt.Errorf("failed to convert to %T object: %#v", new(T), obj)
        }

        *collection = append(*collection, *element)

        return new(T), nil
    }
}

// FilterFn appends elements to the given collection when the predicate is true
func FilterFn[T any](collection *[]T, predicate func(T) bool) func(obj interface{}) (interface{}, error) {
    return func(obj interface{}) (interface{}, error) {
        element, ok := obj.(*T)
        if !ok {
            log.Debug().Str("obj", fmt.Sprintf("%#v", obj)).Msg("type assertion failed")
            return nil, fmt.Errorf("failed to convert to %T object: %#v", new(T), obj)
        }

        if predicate(*element) {
            *collection = append(*collection, *element)
        }

        return new(T), nil
    }
}

// FirstFn sets the element to the first one that satisfies the predicate and stops the computation, returns ErrStop on
// success
func FirstFn[T any](element *T, predicate func(T) bool) func(obj interface{}) (interface{}, error) {
    return func(obj interface{}) (interface{}, error) {
        e, ok := obj.(*T)
        if !ok {
            log.Debug().Str("obj", fmt.Sprintf("%#v", obj)).Msg("type assertion failed")
            return nil, fmt.Errorf("failed to convert to %T object: %#v", new(T), obj)
        }

        if predicate(*e) {
            *element = *e
            return new(T), ErrStop
        }

        return new(T), nil
    }
}