package config

import (
	"os"
	"path/filepath"
	"testing"
)

func writeCreds(t *testing.T, body string) string {
	t.Helper()
	p := filepath.Join(t.TempDir(), "api_credentials.txt")
	if err := os.WriteFile(p, []byte(body), 0o600); err != nil {
		t.Fatal(err)
	}
	return p
}

// The shape the engine actually writes. This is the whole point of the file:
// on a stock install it is the ONLY place the credential exists.
func TestItReadsWhatTheEngineWrites(t *testing.T) {
	p := writeCreds(t, "username=behavision\npassword=qQTGFpetJ5Py613XwcbARQ\n")
	u, pw := EngineCredentials(p)
	if u != "behavision" || pw != "qQTGFpetJ5Py613XwcbARQ" {
		t.Fatalf("got %q / %q", u, pw)
	}
}

func TestColonSeparatedIsReadToo(t *testing.T) {
	p := writeCreds(t, "  username: behavision\n  password: hunter2\n")
	if u, pw := EngineCredentials(p); u != "behavision" || pw != "hunter2" {
		t.Fatalf("got %q / %q", u, pw)
	}
}

// A missing file is normal - an operator who set BEHAVISION_API_USER has none.
func TestAMissingFileIsNotAnError(t *testing.T) {
	if u, pw := EngineCredentials("/nope/nothing.txt"); u != "" || pw != "" {
		t.Fatalf("got %q / %q", u, pw)
	}
}

// Configured values win. Reading the file over an operator's own credential
// would silently ignore what they set.
func TestAConfiguredCredentialIsNotOverwritten(t *testing.T) {
	p := writeCreds(t, "username=generated\npassword=generated\n")
	c := Config{APIUser: "mine", APIPassword: "secret"}.WithEngineCredentials(p)
	if c.APIUser != "mine" || c.APIPassword != "secret" {
		t.Fatalf("configured credential was replaced: %q / %q", c.APIUser, c.APIPassword)
	}
}

func TestAnEmptyCredentialIsFilledIn(t *testing.T) {
	p := writeCreds(t, "username=behavision\npassword=abc\n")
	c := Config{}.WithEngineCredentials(p)
	if c.APIUser != "behavision" || c.APIPassword != "abc" {
		t.Fatalf("not filled in: %q / %q", c.APIUser, c.APIPassword)
	}
}