package catalogue

import "encoding/json"

// ParseManifestForInputs reads a manifest for the inputs of its build and its fingerprint: the indexer's and the
// builder's read (novox/hq issue 1751). It is never a judge of config values. A value falling back to a predefined key
// (ADR 0348 §7) is judged against the list the mesh published when this process holds one (PublishedPredefined);
// where it holds none, as in the indexer and the builder, each key a value names is taken as the value declares it (its
// type, trusted when it is), since the list is read where a manifest is judged: the merge gate from the tree's root,
// the controller from what it published. No input of a fingerprint or a build comes from the list. Everything else
// ParseManifest refuses is refused here too.
func ParseManifestForInputs(raw []byte) (Manifest, error) {
	list := PublishedPredefined()
	if list == nil {
		list = fallbacksOf(raw)
	}
	return parseManifest(raw, list)
}

// fallbacksOf is the list of the predefined keys a manifest's config values fall back to, each as the value declares
// it. A manifest that is not JSON gives an empty list, and the parser says what is wrong with it.
func fallbacksOf(raw []byte) PredefinedList {
	var m struct {
		Config map[string]struct {
			Type        string `json:"type"`
			Description string `json:"description"`
			Predefined  string `json:"predefined"`
			Trusted     bool   `json:"trusted"`
		} `json:"config"`
	}
	list := PredefinedList{}
	if json.Unmarshal(raw, &m) != nil {
		return list
	}
	for _, d := range m.Config {
		if d.Predefined != "" {
			list[d.Predefined] = PredefinedKey{Type: d.Type, Description: d.Description, Trusted: d.Trusted}
		}
	}
	return list
}