package agent

import (
	"slices"
	"strings"
	"testing"

	"gitea.mynodes.xyz/ilker/llmgw/internal/tlsconf"
)

func normalized(t *testing.T, c Config) Config {
	t.Helper()
	if err := c.normalizeServerURL(); err != nil {
		t.Fatalf("normalising %+v: %v", c, err)
	}
	return c
}

func TestOneServerStillWorksExactlyAsBefore(t *testing.T) {
	// Every agent configuration written before there could be a second control
	// plane names one address, and none of them should have to change.
	c := normalized(t, Config{Server: "10.0.0.140:7443"})
	if !slices.Equal(c.Servers, []string{"http://10.0.0.140:7443"}) {
		t.Errorf("servers = %v", c.Servers)
	}
	if c.Server != "http://10.0.0.140:7443" {
		t.Errorf("server = %q", c.Server)
	}
}

func TestTheAddressAlreadyThereStaysPreferred(t *testing.T) {
	// An operator adding a standby to an existing file expects the control
	// plane that was already working to keep being tried first.
	c := normalized(t, Config{
		Server:  "first:7443",
		Servers: []string{"second:7443", "third:7443"},
	})
	want := []string{"http://first:7443", "http://second:7443", "http://third:7443"}
	if !slices.Equal(c.Servers, want) {
		t.Errorf("servers = %v, want %v", c.Servers, want)
	}
}

func TestADuplicateAddressIsNotTriedTwiceInARow(t *testing.T) {
	// Which would look exactly like the rotation not working.
	c := normalized(t, Config{
		Server:  "a:7443",
		Servers: []string{"http://a:7443", "b:7443"},
	})
	want := []string{"http://a:7443", "http://b:7443"}
	if !slices.Equal(c.Servers, want) {
		t.Errorf("servers = %v, want %v", c.Servers, want)
	}
}

func TestEveryAddressIsCheckedAgainstTheTLSSetting(t *testing.T) {
	// The check existed for one address and has to hold for all of them: a
	// standby reached over plaintext while the leader is authenticated would
	// be a way around mutual TLS, not a fallback.
	c := Config{
		Servers: []string{"https://a:7443", "http://b:7443"},
		TLS:     tlsconf.Config{CA: "ca.pem", Cert: "c.pem", Key: "k.pem"},
	}
	err := c.normalizeServerURL()
	if err == nil {
		t.Fatal("a plaintext standby was accepted alongside TLS")
	}
	if !strings.Contains(err.Error(), "b:7443") {
		t.Errorf("the error does not say which address: %v", err)
	}
}

func TestNoServerAtAllIsStillAnError(t *testing.T) {
	c := Config{}
	if err := c.normalizeServerURL(); err == nil {
		t.Error("an agent with no control plane configured was accepted")
	}
}

func TestSchemeIsAddedPerAddress(t *testing.T) {
	c := normalized(t, Config{
		Servers: []string{"a:7443", "b:7443"},
		TLS:     tlsconf.Config{CA: "ca.pem", Cert: "c.pem", Key: "k.pem"},
	})
	for _, s := range c.Servers {
		if !strings.HasPrefix(s, "https://") {
			t.Errorf("%q did not get the secure scheme", s)
		}
	}
}