package meshmoduleassignerclient

import (
	"encoding/json"
	"fmt"
	"strings"

	seat "git.novox.be/novox/mesh-contracts/placement/go/seats/meshmoduleassigner"
)

// SeatHoldersKey is a seat's key in the state `seat-holders`: `<seat>` for a seat held once for the mesh (node empty),
// `<seat>.<node>` for a node seat on one node.
func SeatHoldersKey(name, node string) (string, error) {
	if err := checkName("seat", name); err != nil {
		return "", err
	}
	if node == "" {
		return seat.SeatHoldersBySeatKey(name), nil
	}
	if err := checkName("node", node); err != nil {
		return "", err
	}
	return seat.SeatHoldersBySeatNodeKey(name, node), nil
}

// HoldersOf reads who holds the seat named (on node, for a node seat) from the state's keys as a reader watched them: the
// node's key first, then the seat's. None when nobody holds it.
func HoldersOf(keys map[string][]byte, name, node string) ([]seat.SeatHoldersHoldersItem, error) {
	for _, n := range []string{node, ""} {
		key, err := SeatHoldersKey(name, n)
		if err != nil {
			if n == "" {
				return nil, err
			}
			continue
		}
		raw, ok := keys[key]
		if !ok {
			continue
		}
		var sh seat.SeatHolders
		if err := json.Unmarshal(raw, &sh); err != nil {
			return nil, fmt.Errorf("meshmoduleassignerclient: the holders of %s are not readable: %w", key, err)
		}
		if sh.V != Version {
			return nil, fmt.Errorf("meshmoduleassignerclient: the holders of %s are of version %d, and this reads %d", key, sh.V, Version)
		}
		return sh.Holders, nil
	}
	return nil, nil
}

var _ = strings.Cut