package config

import (
	"os"
	"testing"
)

func TestLoad(t *testing.T) {
	// Save original env vars
	originalGRPCPort := os.Getenv("SERVER_GRPC_PORT")
	originalHTTPPort := os.Getenv("SERVER_HTTP_PORT")
	originalLogLevel := os.Getenv("LOG_LEVEL")
	originalLogFormat := os.Getenv("LOG_FORMAT")
	originalMetricsEnabled := os.Getenv("METRICS_ENABLED")

	// Clean up after test
	defer func() {
		os.Setenv("SERVER_GRPC_PORT", originalGRPCPort)
		os.Setenv("SERVER_HTTP_PORT", originalHTTPPort)
		os.Setenv("LOG_LEVEL", originalLogLevel)
		os.Setenv("LOG_FORMAT", originalLogFormat)
		os.Setenv("METRICS_ENABLED", originalMetricsEnabled)
	}()

	tests := []struct {
		name     string
		envVars  map[string]string
		expected Config
	}{
		{
			name:    "default values",
			envVars: map[string]string{},
			expected: Config{
				Server: ServerConfig{
					GRPCPort: "8080",
					HTTPPort: "8090",
				},
				Log: LogConfig{
					Level:  "info",
					Format: "json",
				},
				Metrics: MetricsConfig{
					Enabled: true,
				},
			},
		},
		{
			name: "custom values",
			envVars: map[string]string{
				"SERVER_GRPC_PORT": "9090",
				"SERVER_HTTP_PORT": "9091",
				"LOG_LEVEL":        "debug",
				"LOG_FORMAT":       "text",
				"METRICS_ENABLED":  "false",
			},
			expected: Config{
				Server: ServerConfig{
					GRPCPort: "9090",
					HTTPPort: "9091",
				},
				Log: LogConfig{
					Level:  "debug",
					Format: "text",
				},
				Metrics: MetricsConfig{
					Enabled: false,
				},
			},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Clear all env vars first
			os.Unsetenv("SERVER_GRPC_PORT")
			os.Unsetenv("SERVER_HTTP_PORT")
			os.Unsetenv("LOG_LEVEL")
			os.Unsetenv("LOG_FORMAT")
			os.Unsetenv("METRICS_ENABLED")

			// Set test env vars
			for key, value := range tt.envVars {
				os.Setenv(key, value)
			}

			cfg := Load()

			if cfg.Server.GRPCPort != tt.expected.Server.GRPCPort {
				t.Errorf("expected GRPCPort %s, got %s", tt.expected.Server.GRPCPort, cfg.Server.GRPCPort)
			}
			if cfg.Server.HTTPPort != tt.expected.Server.HTTPPort {
				t.Errorf("expected HTTPPort %s, got %s", tt.expected.Server.HTTPPort, cfg.Server.HTTPPort)
			}
			if cfg.Log.Level != tt.expected.Log.Level {
				t.Errorf("expected LogLevel %s, got %s", tt.expected.Log.Level, cfg.Log.Level)
			}
			if cfg.Log.Format != tt.expected.Log.Format {
				t.Errorf("expected LogFormat %s, got %s", tt.expected.Log.Format, cfg.Log.Format)
			}
			if cfg.Metrics.Enabled != tt.expected.Metrics.Enabled {
				t.Errorf("expected MetricsEnabled %t, got %t", tt.expected.Metrics.Enabled, cfg.Metrics.Enabled)
			}
		})
	}
}

func TestValidate(t *testing.T) {
	tests := []struct {
		name    string
		config  Config
		wantErr bool
	}{
		{
			name: "valid config",
			config: Config{
				Server: ServerConfig{
					GRPCPort: "8080",
					HTTPPort: "8090",
				},
				Log: LogConfig{
					Level:  "info",
					Format: "json",
				},
			},
			wantErr: false,
		},
		{
			name: "empty grpc port",
			config: Config{
				Server: ServerConfig{
					GRPCPort: "",
					HTTPPort: "8090",
				},
				Log: LogConfig{
					Level:  "info",
					Format: "json",
				},
			},
			wantErr: true,
		},
		{
			name: "same ports",
			config: Config{
				Server: ServerConfig{
					GRPCPort: "8080",
					HTTPPort: "8080",
				},
				Log: LogConfig{
					Level:  "info",
					Format: "json",
				},
			},
			wantErr: true,
		},
		{
			name: "invalid log level",
			config: Config{
				Server: ServerConfig{
					GRPCPort: "8080",
					HTTPPort: "8090",
				},
				Log: LogConfig{
					Level:  "invalid",
					Format: "json",
				},
			},
			wantErr: true,
		},
		{
			name: "invalid log format",
			config: Config{
				Server: ServerConfig{
					GRPCPort: "8080",
					HTTPPort: "8090",
				},
				Log: LogConfig{
					Level:  "info",
					Format: "invalid",
				},
			},
			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("Validate() error = %v, wantErr %v", err, tt.wantErr)
			}
		})
	}
}