package index

import (
	"encoding/json"

	"git.novox.be/novox/mesh-sdk/go/catalogue"
)

// readManifest reads a manifest as the catalogue's parser does, for the inputs of its fingerprint (issue 1751). A config
// value falling back to a predefined key (novox/hq ADR 0348 §7) is judged against the list the mesh published when the
// process holds one; the indexer holds none, since the list is read where a manifest is judged (the merge gate, from the
// tree's root) and by the controller, so each key a value names is taken as the value declares it: of its type, trusted
// when it is. What the list adds is the judging of the value, which the gate and the controller do; no input of a
// fingerprint comes from it. Everything else the parser refuses is refused here too.
func readManifest(raw []byte) (catalogue.Manifest, error) {
	list := catalogue.PublishedPredefined()
	if list == nil {
		list = fallbacksOf(raw)
	}
	return catalogue.ParseManifestWith(raw, list)
}

// fallbacksOf is the list of the predefined keys the 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) catalogue.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 := catalogue.PredefinedList{}
	if json.Unmarshal(raw, &m) != nil {
		return list
	}
	for _, d := range m.Config {
		if d.Predefined != "" {
			list[d.Predefined] = catalogue.PredefinedKey{Type: d.Type, Description: d.Description, Trusted: d.Trusted}
		}
	}
	return list
}