package graph

import (
	"testing"
)

func TestDefaultConfig(t *testing.T) {
	config := DefaultConfig()

	if config == nil {
		t.Fatal("DefaultConfig() returned nil")
	}

	// Check default values
	if config.MaxChainLength != 5 {
		t.Errorf("MaxChainLength = %v, want 5", config.MaxChainLength)
	}

	if config.MaxPathHops != 4 {
		t.Errorf("MaxPathHops = %v, want 4", config.MaxPathHops)
	}

	if config.MaxNetworkSize != 20 {
		t.Errorf("MaxNetworkSize = %v, want 20", config.MaxNetworkSize)
	}

	if config.MinNetworkSize != 3 {
		t.Errorf("MinNetworkSize = %v, want 3", config.MinNetworkSize)
	}

	if config.DefaultResultLimit != 50 {
		t.Errorf("DefaultResultLimit = %v, want 50", config.DefaultResultLimit)
	}

	if config.MaxChainDistanceKm != 500.0 {
		t.Errorf("MaxChainDistanceKm = %v, want 500.0", config.MaxChainDistanceKm)
	}

	if config.QueryTimeoutSeconds != 30 {
		t.Errorf("QueryTimeoutSeconds = %v, want 30", config.QueryTimeoutSeconds)
	}
}

func TestConfig_Validate(t *testing.T) {
	tests := []struct {
		name    string
		config  *Config
		wantErr bool
	}{
		{
			name:    "Valid config",
			config:  DefaultConfig(),
			wantErr: false,
		},
		{
			name: "Invalid MaxChainLength",
			config: &Config{
				MaxChainLength: 0,
			},
			wantErr: true,
		},
		{
			name: "Invalid MaxPathHops",
			config: &Config{
				MaxChainLength: 5,
				MaxPathHops:    0,
			},
			wantErr: true,
		},
		{
			name: "Invalid MaxNetworkSize < MinNetworkSize",
			config: &Config{
				MaxChainLength: 5,
				MaxPathHops:    4,
				MaxNetworkSize: 2,
				MinNetworkSize: 5,
			},
			wantErr: true,
		},
		{
			name: "Invalid DefaultResultLimit",
			config: &Config{
				MaxChainLength:     5,
				MaxPathHops:        4,
				MaxNetworkSize:     20,
				MinNetworkSize:     3,
				DefaultResultLimit: 0,
			},
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			err := tt.config.Validate()
			if (err != nil) != tt.wantErr {
				t.Errorf("Config.Validate() error = %v, wantErr %v", err, tt.wantErr)
			}
		})
	}
}