package config

import (
	"encoding/json"
	"os"
	"testing"
)

// Changing defaults could be a breaking change,
// if this needs to be modified to pass the test,
// an item should be added to the changelog.
//
// This should be maintained, as it is the primary
// interface between an app and the app framework.
var testDefaultConfig = &AppConfig{
	Environment: "development",
	Version:     getVersion(),
	Logging: &LogConfig{
		Enabled:    true,
		Level:      "info",
		Format:     LogFormatJSON,
		Output:     "stderr",
		TimeFormat: TimeFormatLong,
	},
	HTTP: &HTTPConfig{
		Enabled:      true,
		Listen:       "127.0.0.1:8080",
		LogRequests:  false,
		ReadTimeout:  "10s",
		WriteTimeout: "10s",
		IdleTimeout:  "1m",
	},
	GRPC: &GRPCConfig{
		Enabled:               false,
		Listen:                "127.0.0.1:8081",
		LogRequests:           false,
		EnableReflection:      true,
		EnableInstrumentation: true,
	},
	OTEL: &OTELConfig{
		Enabled:            true,
		PrometheusEnabled:  true,
		PrometheusPath:     "/metrics",
		StdoutEnabled:      false,
		MetricIntervalSecs: 30,
	},
}

func Test_loadConfig(t *testing.T) {
	type args struct {
		configPath string
	}
	tests := []struct {
		name    string
		args    args
		want    *AppConfig
		wantErr bool
	}{
		{
			name:    "Ensure defaults",
			args:    args{configPath: ""},
			want:    testDefaultConfig,
			wantErr: false,
		},
		{
			name: "Load from file",
			args: args{configPath: "./testdata/config.yaml"},
			want: &AppConfig{
				Name:        "test-app",
				Environment: "development",
				Version:     getVersion(),
				Logging: &LogConfig{
					Enabled:    true,
					Level:      "debug",
					Format:     LogFormatJSON,
					Output:     "stderr",
					TimeFormat: TimeFormatLong,
				},
				HTTP: &HTTPConfig{
					Enabled:      true,
					Listen:       "127.0.0.1:9090",
					LogRequests:  false,
					ReadTimeout:  "10s",
					WriteTimeout: "10s",
					IdleTimeout:  "1m",
				},
				GRPC: &GRPCConfig{
					Enabled:               false,
					Listen:                "127.0.0.1:8081",
					LogRequests:           false,
					EnableReflection:      true,
					EnableInstrumentation: true,
				},
				OTEL: &OTELConfig{
					Enabled:            true,
					PrometheusEnabled:  true,
					PrometheusPath:     "/metrics",
					StdoutEnabled:      false,
					MetricIntervalSecs: 30,
				},
			},
		},
		{
			name: "Load from env",
			args: args{configPath: ""},
			want: &AppConfig{
				Name:        "test-app-env",
				Environment: "production",
				Version:     getVersion(),
				Logging: &LogConfig{
					Enabled:    false,
					Level:      "error",
					Format:     LogFormatConsole,
					Output:     "stdout",
					TimeFormat: TimeFormatUnix,
				},
				HTTP: &HTTPConfig{
					Enabled:      false,
					Listen:       "0.0.0.0:80",
					LogRequests:  true,
					ReadTimeout:  "15s",
					WriteTimeout: "15s",
					IdleTimeout:  "2m",
				},
				GRPC: &GRPCConfig{
					Enabled:               true,
					Listen:                "0.0.0.0:443",
					LogRequests:           true,
					EnableReflection:      false,
					EnableInstrumentation: false,
				},
				OTEL: &OTELConfig{
					Enabled:            false,
					PrometheusEnabled:  false,
					PrometheusPath:     "/metricsz",
					StdoutEnabled:      true,
					MetricIntervalSecs: 60,
				},
			},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if tt.name == "Load from env" {
				os.Setenv("APP_NAME", "test-app-env")
				os.Setenv("APP_ENVIRONMENT", "production")
				os.Setenv("APP_LOG_ENABLED", "false")
				os.Setenv("APP_LOG_LEVEL", "error")
				os.Setenv("APP_LOG_FORMAT", "console")
				os.Setenv("APP_LOG_OUTPUT", "stdout")
				os.Setenv("APP_LOG_TIME_FORMAT", "unix")
				os.Setenv("APP_HTTP_ENABLED", "false")
				os.Setenv("APP_HTTP_LISTEN", "0.0.0.0:80")
				os.Setenv("APP_HTTP_LOG_REQUESTS", "true")
				os.Setenv("APP_HTTP_READ_TIMEOUT", "15s")
				os.Setenv("APP_HTTP_WRITE_TIMEOUT", "15s")
				os.Setenv("APP_HTTP_IDLE_TIMEOUT", "2m")
				os.Setenv("APP_GRPC_ENABLED", "true")
				os.Setenv("APP_GRPC_LISTEN", "0.0.0.0:443")
				os.Setenv("APP_GRPC_LOG_REQUESTS", "true")
				os.Setenv("APP_GRPC_ENABLE_REFLECTION", "false")
				os.Setenv("APP_GRPC_ENABLE_INSTRUMENTATION", "false")
				os.Setenv("APP_OTEL_ENABLED", "false")
				os.Setenv("APP_OTEL_PROMETHEUS_ENABLED", "false")
				os.Setenv("APP_OTEL_PROMETHEUS_PATH", "/metricsz")
				os.Setenv("APP_OTEL_STDOUT_ENABLED", "true")
				os.Setenv("APP_OTEL_METRIC_INTERVAL_SECS", "60")
			}
			got, err := loadConfig(tt.args.configPath)
			if (err != nil) != tt.wantErr {
				t.Errorf("loadConfig() error = %v, wantErr %v", err, tt.wantErr)
				return
			}

			// Marshal both the expected and actual structs to JSON
			gotJSON, err := json.Marshal(got)
			if err != nil {
				t.Fatalf("Failed to marshal got to JSON: %v", err)
			}
			wantJSON, err := json.Marshal(tt.want)
			if err != nil {
				t.Fatalf("Failed to marshal want to JSON: %v", err)
			}

			// Compare the JSON strings
			if string(gotJSON) != string(wantJSON) {
				t.Errorf("loadConfig() JSON = %s, want JSON = %s", string(gotJSON), string(wantJSON))
			}
		})
	}
}