package cli

import (
	"context"
	"errors"
	"fmt"
	"net"
)

// Three machines, each able to take over: the store's two machines are made
// control planes too, standing by while this one leads, as 'llmgw server add'
// makes any machine one. With the store replicated across them and etcd's
// three votes on the three, losing any one machine loses neither the store
// nor the gateway. With a floating address, clients keep the one address.

// ensureStandbys makes each machine of the replicated store a control plane,
// one after the other.
func (in *serverInit) ensureStandbys(ctx context.Context) error {
	if len(in.patroniNodes) == 0 {
		return errors.New("the standbys go on the store's machines: give them with --patroni")
	}
	var hosts []string
	if ip, _, err := net.ParseCIDR(in.vip); err == nil {
		hosts = []string{ip.String()}
	}
	for i, n := range in.patroniNodes {
		fmt.Fprintf(in.out, "  ..    making %s a control plane too\n", n.Name)
		sa := serverAdd{
			etcDir: in.etcDir, pkiDir: in.pkiDir, hosts: hosts, vip: in.vip,
			remote: n.Remote, noFirewall: in.noFirewall, addr: n.IP, ip: n.IP,
			out: in.out, priority: 100 - 10*i, quiet: true,
		}
		if err := sa.run(ctx); err != nil {
			return fmt.Errorf("%s: %w", n.Name, err)
		}
		in.done("%s (%s) is a control plane too, standing by while this one leads", n.Name, n.IP)
	}
	return nil
}