at-container-registry/pkg/appview/holdclient/helm_config.go

package holdclient

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
	"strings"
	"time"

	"atcr.io/pkg/atproto"
)

// HelmChartMeta is the parsed Chart.yaml-equivalent metadata extracted from a
// helm chart's OCI config blob (media type
// application/vnd.cncf.helm.config.v1+json). The helm config blob is Chart.yaml
// rendered as JSON, so the field names mirror Chart.yaml.
type HelmChartMeta struct {
	Name         string
	Version      string
	AppVersion   string
	Type         string // "application" | "library" (empty in older charts; treat as "application")
	Description  string
	KubeVersion  string
	Home         string
	Icon         string
	Sources      []string
	Keywords     []string
	Maintainers  []HelmMaintainer
	Dependencies []HelmDependency
	Annotations  map[string]string
	Deprecated   bool
}

type HelmMaintainer struct {
	Name  string
	Email string
	URL   string
}

type HelmDependency struct {
	Name       string
	Version    string
	Repository string
	Alias      string
	Condition  string
}

// helmConfigJSON matches the on-the-wire shape of a helm OCI config blob.
// Field names track Chart.yaml's JSON form (lowerCamelCase for some fields,
// kebab-case for none — helm's CLI marshals Chart.yaml struct directly).
type helmConfigJSON struct {
	Name         string               `json:"name"`
	Version      string               `json:"version"`
	AppVersion   string               `json:"appVersion"`
	Type         string               `json:"type"`
	Description  string               `json:"description"`
	KubeVersion  string               `json:"kubeVersion"`
	Home         string               `json:"home"`
	Icon         string               `json:"icon"`
	Sources      []string             `json:"sources"`
	Keywords     []string             `json:"keywords"`
	Maintainers  []helmMaintainerJSON `json:"maintainers"`
	Dependencies []helmDependencyJSON `json:"dependencies"`
	Annotations  map[string]string    `json:"annotations"`
	Deprecated   bool                 `json:"deprecated"`
}

type helmMaintainerJSON struct {
	Name  string `json:"name"`
	Email string `json:"email"`
	URL   string `json:"url"`
}

type helmDependencyJSON struct {
	Name       string `json:"name"`
	Version    string `json:"version"`
	Repository string `json:"repository"`
	Alias      string `json:"alias"`
	Condition  string `json:"condition"`
}

// FetchHelmChartMeta fetches a helm chart's config blob from the hold and
// parses it as Chart.yaml metadata. Uses the same getImageConfig XRPC as
// FetchImageConfig but applies a helm-specific schema to the JSON.
func FetchHelmChartMeta(ctx context.Context, holdURL, manifestDigest string) (*HelmChartMeta, error) {
	reqURL := fmt.Sprintf("%s%s?digest=%s",
		strings.TrimSuffix(holdURL, "/"),
		atproto.HoldGetImageConfig,
		url.QueryEscape(manifestDigest),
	)

	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
	defer cancel()

	req, err := http.NewRequestWithContext(ctx, "GET", reqURL, nil)
	if err != nil {
		return nil, fmt.Errorf("build request: %w", err)
	}

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("fetch helm chart config: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("hold returned status %d for %s", resp.StatusCode, reqURL)
	}

	var record struct {
		ConfigJSON string `json:"configJson"`
	}
	if err := json.NewDecoder(resp.Body).Decode(&record); err != nil {
		return nil, fmt.Errorf("parse image config response: %w", err)
	}

	var raw helmConfigJSON
	if err := json.Unmarshal([]byte(record.ConfigJSON), &raw); err != nil {
		return nil, fmt.Errorf("parse helm chart config JSON: %w", err)
	}

	meta := &HelmChartMeta{
		Name:        raw.Name,
		Version:     raw.Version,
		AppVersion:  raw.AppVersion,
		Type:        raw.Type,
		Description: raw.Description,
		KubeVersion: raw.KubeVersion,
		Home:        raw.Home,
		Icon:        raw.Icon,
		Sources:     raw.Sources,
		Keywords:    raw.Keywords,
		Annotations: raw.Annotations,
		Deprecated:  raw.Deprecated,
	}
	if meta.Type == "" {
		meta.Type = "application"
	}
	for _, m := range raw.Maintainers {
		meta.Maintainers = append(meta.Maintainers, HelmMaintainer(m))
	}
	for _, d := range raw.Dependencies {
		meta.Dependencies = append(meta.Dependencies, HelmDependency(d))
	}
	return meta, nil
}