// Package busstate is how a bundle uses its own bus state through the runtime (novox/hq ADR 0595 §9, design 25 §
// 12.5): the object store's put, get, list, delete and fill, each naming an entry by the local name its module asks for
// it by in `requires`. The runtime serves the calls from the module's own bindings, its own entries only. The shapes
// are package buscalls's; this package makes the calls.
package busstate

import (
	"encoding/json"
	"fmt"

	stdio "git.novox.be/novox/mesh-sdk/go"
	"git.novox.be/novox/mesh-sdk/go/buscalls"
)

// Objects is one object store the module asks for in `requires` (the template objects, ADR 0595 §2), by its local name.
type Objects struct{ local string }

// ObjectsOf is the object store of that local name.
func ObjectsOf(local string) Objects { return Objects{local: local} }

func call[T any](method string, params any) (T, error) {
	var out T
	raw, err := stdio.BusState(method, params)
	if err != nil {
		return out, err
	}
	if err := json.Unmarshal(raw, &out); err != nil {
		return out, fmt.Errorf("the runtime's answer to %s: %w", method, err)
	}
	return out, nil
}

// Put stores one object whole under its name, replacing one of that name, and answers it as the store holds it.
func (o Objects) Put(name string, data []byte, description string) (buscalls.ObjectInfo, error) {
	return call[buscalls.ObjectInfo](buscalls.ObjectsPut, buscalls.ObjectsPutRequest{Objects: o.local, Name: name,
		Data: data, Description: description})
}

// Get is one object, its info and its bytes.
func (o Objects) Get(name string) (buscalls.ObjectData, error) {
	return call[buscalls.ObjectData](buscalls.ObjectsGet, buscalls.ObjectsNameRequest{Objects: o.local, Name: name})
}

// List is every object the store holds.
func (o Objects) List() ([]buscalls.ObjectInfo, error) {
	l, err := call[buscalls.ObjectsListed](buscalls.ObjectsList, buscalls.ObjectsRequest{Objects: o.local})
	return l.Objects, err
}

// Delete removes one object.
func (o Objects) Delete(name string) error {
	_, err := call[buscalls.Done](buscalls.ObjectsDelete, buscalls.ObjectsNameRequest{Objects: o.local, Name: name})
	return err
}

// Fill is how much the store holds against its cap.
func (o Objects) Fill() (buscalls.Fill, error) {
	return call[buscalls.Fill](buscalls.ObjectsInfo, buscalls.ObjectsRequest{Objects: o.local})
}