package config

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

func TestLoad(t *testing.T) {
	// Create a temporary directory for test files
	tempDir := t.TempDir()
	configPath := filepath.Join(tempDir, "test-config.yaml")

	// Create a test configuration file
	testConfig := `server:
  port: 9090
  read_timeout: 60
  write_timeout: 60
  idle_timeout: 120

proxy:
  targets:
    - name: "test-target"
      address: "http://localhost:8080"
      protocol: "http"
      weight: 1
  load_balancer: "leastconn"
  health_check_path: "/healthz"
  health_check_interval: 60

nat:
  enabled: true
  stun_server: "stun:stun.example.com:3478"
  turn_server: "turn:turn.example.com:3478"
  turn_username: "testuser"
  turn_password: "testpass"

logging:
  level: "debug"
  format: "text"
  output: "file"
  file: "/var/log/gorz.log"

monitor:
  enabled: true
  port: 8081
  path: "/stats"
  auth: true
  username: "admin"
  password: "secret"
`

	err := os.WriteFile(configPath, []byte(testConfig), 0644)
	if err != nil {
		t.Fatalf("Failed to write test config file: %v", err)
	}

	// Test loading the configuration
	cfg, err := Load(configPath)
	if err != nil {
		t.Fatalf("Failed to load configuration: %v", err)
	}

	// Verify server configuration
	if cfg.Server.Port != 9090 {
		t.Errorf("Expected port 9090, got %d", cfg.Server.Port)
	}
	if cfg.Server.ReadTimeout != 60 {
		t.Errorf("Expected read timeout 60, got %d", cfg.Server.ReadTimeout)
	}

	// Verify proxy configuration
	if cfg.Proxy.LoadBalancer != "leastconn" {
		t.Errorf("Expected load balancer 'leastconn', got %s", cfg.Proxy.LoadBalancer)
	}
	if len(cfg.Proxy.Targets) != 1 {
		t.Errorf("Expected 1 target, got %d", len(cfg.Proxy.Targets))
	}
	if cfg.Proxy.Targets[0].Name != "test-target" {
		t.Errorf("Expected target name 'test-target', got %s", cfg.Proxy.Targets[0].Name)
	}

	// Verify NAT configuration
	if !cfg.NAT.Enabled {
		t.Error("Expected NAT enabled to be true")
	}
	if cfg.NAT.STUNServer != "stun:stun.example.com:3478" {
		t.Errorf("Expected STUN server 'stun:stun.example.com:3478', got %s", cfg.NAT.STUNServer)
	}

	// Verify logging configuration
	if cfg.Logging.Level != "debug" {
		t.Errorf("Expected log level 'debug', got %s", cfg.Logging.Level)
	}
	if cfg.Logging.Output != "file" {
		t.Errorf("Expected log output 'file', got %s", cfg.Logging.Output)
	}

	// Verify monitor configuration
	if !cfg.Monitor.Enabled {
		t.Error("Expected monitor enabled to be true")
	}
	if cfg.Monitor.Port != 8081 {
		t.Errorf("Expected monitor port 8081, got %d", cfg.Monitor.Port)
	}
	if !cfg.Monitor.Auth {
		t.Error("Expected monitor auth to be true")
	}
}

func TestLoadNonexistentFile(t *testing.T) {
	_, err := Load("/nonexistent/path/config.yaml")
	if err == nil {
		t.Error("Expected error for nonexistent file, got nil")
	}
}

func TestLoadInvalidYAML(t *testing.T) {
	// Create a temporary directory for test files
	tempDir := t.TempDir()
	configPath := filepath.Join(tempDir, "invalid-config.yaml")

	// Create an invalid YAML file
	invalidYAML := `server:
  port: 8080
  read_timeout: "not a number"
`

	err := os.WriteFile(configPath, []byte(invalidYAML), 0644)
	if err != nil {
		t.Fatalf("Failed to write invalid config file: %v", err)
	}

	_, err = Load(configPath)
	if err == nil {
		t.Error("Expected error for invalid YAML, got nil")
	}
}

func TestSetDefaults(t *testing.T) {
	cfg := &Config{}

	// Apply defaults
	setDefaults(cfg)

	// Verify default server values
	if cfg.Server.Port != 8080 {
		t.Errorf("Expected default port 8080, got %d", cfg.Server.Port)
	}
	if cfg.Server.ReadTimeout != 30 {
		t.Errorf("Expected default read timeout 30, got %d", cfg.Server.ReadTimeout)
	}

	// Verify default proxy values
	if cfg.Proxy.LoadBalancer != "roundrobin" {
		t.Errorf("Expected default load balancer 'roundrobin', got %s", cfg.Proxy.LoadBalancer)
	}
	if cfg.Proxy.HealthCheckPath != "/health" {
		t.Errorf("Expected default health check path '/health', got %s", cfg.Proxy.HealthCheckPath)
	}

	// Verify default NAT values
	if cfg.NAT.Enabled {
		t.Error("Expected default NAT enabled to be false")
	}
	if cfg.NAT.STUNServer != "stun:stun.l.google.com:19302" {
		t.Errorf("Expected default STUN server 'stun:stun.l.google.com:19302', got %s", cfg.NAT.STUNServer)
	}

	// Verify default logging values
	if cfg.Logging.Level != "info" {
		t.Errorf("Expected default log level 'info', got %s", cfg.Logging.Level)
	}
	if cfg.Logging.Format != "json" {
		t.Errorf("Expected default log format 'json', got %s", cfg.Logging.Format)
	}

	// Verify default monitor values
	if !cfg.Monitor.Enabled {
		t.Error("Expected default monitor enabled to be true")
	}
	if cfg.Monitor.Port != 9090 {
		t.Errorf("Expected default monitor port 9090, got %d", cfg.Monitor.Port)
	}
}

func TestCreateDefaultConfig(t *testing.T) {
	// Create a temporary directory for test files
	tempDir := t.TempDir()
	configPath := filepath.Join(tempDir, "default-config.yaml")

	// Create default configuration
	err := CreateDefaultConfig(configPath)
	if err != nil {
		t.Fatalf("Failed to create default configuration: %v", err)
	}

	// Verify the file was created
	if _, err := os.Stat(configPath); os.IsNotExist(err) {
		t.Error("Expected config file to be created")
	}

	// Load and verify the configuration
	cfg, err := Load(configPath)
	if err != nil {
		t.Fatalf("Failed to load created configuration: %v", err)
	}

	// Verify some default values
	if cfg.Server.Port != 8080 {
		t.Errorf("Expected default port 8080, got %d", cfg.Server.Port)
	}
	if cfg.Proxy.LoadBalancer != "roundrobin" {
		t.Errorf("Expected default load balancer 'roundrobin', got %s", cfg.Proxy.LoadBalancer)
	}
	if cfg.Logging.Level != "info" {
		t.Errorf("Expected default log level 'info', got %s", cfg.Logging.Level)
	}
}

func TestCreateDefaultConfigDirectoryCreation(t *testing.T) {
	// Create a temporary directory for test files
	tempDir := t.TempDir()
	nestedDir := filepath.Join(tempDir, "nested", "directory")
	configPath := filepath.Join(nestedDir, "config.yaml")

	// Create default configuration in a nested directory
	err := CreateDefaultConfig(configPath)
	if err != nil {
		t.Fatalf("Failed to create default configuration: %v", err)
	}

	// Verify the directory was created
	if _, err := os.Stat(nestedDir); os.IsNotExist(err) {
		t.Error("Expected nested directory to be created")
	}

	// Verify the file was created
	if _, err := os.Stat(configPath); os.IsNotExist(err) {
		t.Error("Expected config file to be created")
	}
}