cloudfoundry/cf-k8s-controllers

package presenter

import (
    "net/url"
    "path"
    "time"
)

type Lifecycle struct {
    Type string        `json:"type"`
    Data LifecycleData `json:"data"`
}

type LifecycleData struct {
    Buildpacks []string `json:"buildpacks,omitempty"`
    Stack      string   `json:"stack,omitempty"`
}

type Relationships map[string]Relationship

type Relationship struct {
    Data *RelationshipData `json:"data"`
}

type RelationshipData struct {
    GUID string `json:"guid"`
}

type Metadata struct {
    Labels      map[string]string `json:"labels"`
    Annotations map[string]string `json:"annotations"`
}

type Link struct {
    HRef   string `json:"href,omitempty"`
    Method string `json:"method,omitempty"`
}

type ListResponse[T any] struct {
    PaginationData PaginationData `json:"pagination"`
    Resources      []T            `json:"resources"`
    Included       *IncludedData  `json:"included,omitempty"`
}

type PaginationData struct {
    TotalResults int     `json:"total_results"`
    TotalPages   int     `json:"total_pages"`
    First        PageRef `json:"first"`
    Last         PageRef `json:"last"`
    Next         *int    `json:"next"`
    Previous     *int    `json:"previous"`
}

type IncludedData struct {
    Apps []interface{} `json:"apps"`
}

type PageRef struct {
    HREF string `json:"href"`
}

type itemPresenter[T, S any] func(T, url.URL) S

func ForList[T, S any](itemPresenter itemPresenter[T, S], resources []T, baseURL, requestURL url.URL) ListResponse[S] {
    presenters := []S{}
    for _, resource := range resources {
        presenters = append(presenters, itemPresenter(resource, baseURL))
    }
    return ListResponse[S]{
        PaginationData: PaginationData{
            TotalResults: len(resources),
            TotalPages:   1,
            First: PageRef{
                HREF: buildURL(baseURL).appendPath(requestURL.Path).setQuery(requestURL.RawQuery).build(),
            },
            Last: PageRef{
                HREF: buildURL(baseURL).appendPath(requestURL.Path).setQuery(requestURL.RawQuery).build(),
            },
        },
        Resources: presenters,
    }
}

type buildURL url.URL

func (u buildURL) appendPath(subpath ...string) buildURL {
    rest := path.Join(subpath...)
    if u.Path == "" {
        u.Path = rest
    } else {
        u.Path = path.Join(u.Path, rest)
    }

    return u
}

func (u buildURL) setQuery(rawQuery string) buildURL {
    u.RawQuery = rawQuery

    return u
}

func (u buildURL) build() string {
    native := url.URL(u)
    nativeP := &native

    return nativeP.String()
}

func emptyMapIfNil[V any](m map[string]V) map[string]V {
    if m == nil {
        return map[string]V{}
    }
    return m
}

func emptySliceIfNil(m []string) []string {
    if m == nil {
        return []string{}
    }
    return m
}

func formatTimestamp(t *time.Time) string {
    if t == nil {
        return ""
    }
    return t.UTC().Format(time.RFC3339)
}