package main

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

func TestLoadConfig_Defaults(t *testing.T) {
	// Ensure env vars don't leak in from the host.
	for _, k := range []string{"ECS_GATEWAY_URL", "ECS_GATEWAY_CA", "ECS_REGION",
		"ECS_CLUSTER", "ECS_ACCESS_KEY", "ECS_SECRET_KEY", "ECS_IMDS_BASE",
		"ECS_CONTAINERD_SOCKET", "ECS_HEARTBEAT_INTERVAL", "ECS_POLL_INTERVAL"} {
		t.Setenv(k, "")
	}
	cfg := loadConfig(filepath.Join(t.TempDir(), "absent.env"))
	if cfg.GatewayCA != defaultGatewayCA {
		t.Errorf("GatewayCA = %q, want default", cfg.GatewayCA)
	}
	if cfg.IMDSBase != defaultIMDSBase {
		t.Errorf("IMDSBase = %q, want default", cfg.IMDSBase)
	}
	if cfg.ContainerdSocket != defaultContainerdSocket {
		t.Errorf("ContainerdSocket = %q, want default", cfg.ContainerdSocket)
	}
	if cfg.ClusterName != "default" {
		t.Errorf("ClusterName = %q, want default", cfg.ClusterName)
	}
	if cfg.Heartbeat != defaultHeartbeat {
		t.Errorf("Heartbeat = %v, want %v", cfg.Heartbeat, defaultHeartbeat)
	}
	if cfg.PollInterval != defaultPollInterval {
		t.Errorf("PollInterval = %v, want %v", cfg.PollInterval, defaultPollInterval)
	}
}

func TestLoadConfig_FileThenEnvOverride(t *testing.T) {
	dir := t.TempDir()
	envFile := filepath.Join(dir, "agent.env")
	body := "# comment\nECS_GATEWAY_URL=https://gw.file\nECS_REGION=us-west-2\nECS_CLUSTER=prod\n"
	if err := os.WriteFile(envFile, []byte(body), 0o600); err != nil {
		t.Fatal(err)
	}
	t.Setenv("ECS_GATEWAY_URL", "https://gw.env")
	t.Setenv("ECS_ACCESS_KEY", "AKIAENV")

	cfg := loadConfig(envFile)
	if cfg.GatewayURL != "https://gw.env" {
		t.Errorf("GatewayURL = %q, want env override", cfg.GatewayURL)
	}
	if cfg.Region != "us-west-2" {
		t.Errorf("Region = %q, want from file", cfg.Region)
	}
	if cfg.ClusterName != "prod" {
		t.Errorf("ClusterName = %q, want from file", cfg.ClusterName)
	}
	if cfg.AccessKey != "AKIAENV" {
		t.Errorf("AccessKey = %q, want env", cfg.AccessKey)
	}
}

func TestLoadConfig_HeartbeatOverride(t *testing.T) {
	t.Setenv("ECS_HEARTBEAT_INTERVAL", "5s")
	if cfg := loadConfig(filepath.Join(t.TempDir(), "absent.env")); cfg.Heartbeat != 5*time.Second {
		t.Errorf("Heartbeat = %v, want 5s", cfg.Heartbeat)
	}
	// Garbage value falls back to the default, not zero.
	t.Setenv("ECS_HEARTBEAT_INTERVAL", "not-a-duration")
	if cfg := loadConfig(filepath.Join(t.TempDir(), "absent.env")); cfg.Heartbeat != defaultHeartbeat {
		t.Errorf("Heartbeat = %v, want default on bad value", cfg.Heartbeat)
	}
}