package config

import (
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestLoadFromEnvUsesDefaults(t *testing.T) {
	t.Setenv(redisAddrEnvVar, "127.0.0.1:6379")

	cfg, err := LoadFromEnv()
	require.NoError(t, err)

	defaults := DefaultConfig()
	assert.Equal(t, defaults.ShutdownTimeout, cfg.ShutdownTimeout)
	assert.Equal(t, defaults.Logging.Level, cfg.Logging.Level)
	assert.Equal(t, defaults.PublicHTTP, cfg.PublicHTTP)
	assert.Equal(t, defaults.InternalHTTP, cfg.InternalHTTP)
	assert.Equal(t, "127.0.0.1:6379", cfg.Redis.Addr)
	assert.Equal(t, defaults.Redis.DB, cfg.Redis.DB)
	assert.Equal(t, defaults.Redis.OperationTimeout, cfg.Redis.OperationTimeout)
	assert.Equal(t, defaults.UserService, cfg.UserService)
	assert.Equal(t, defaults.MailService, cfg.MailService)
	assert.Equal(t, defaults.Telemetry.ServiceName, cfg.Telemetry.ServiceName)
	assert.Equal(t, defaults.Telemetry.TracesExporter, cfg.Telemetry.TracesExporter)
	assert.Equal(t, defaults.Telemetry.MetricsExporter, cfg.Telemetry.MetricsExporter)
	assert.False(t, cfg.Telemetry.StdoutTracesEnabled)
	assert.False(t, cfg.Telemetry.StdoutMetricsEnabled)
}

func TestLoadFromEnvAppliesOverrides(t *testing.T) {
	t.Setenv(shutdownTimeoutEnvVar, "9s")
	t.Setenv(logLevelEnvVar, "debug")
	t.Setenv(publicHTTPAddrEnvVar, "127.0.0.1:18080")
	t.Setenv(internalHTTPAddrEnvVar, "127.0.0.1:18081")
	t.Setenv(redisAddrEnvVar, "127.0.0.1:6380")
	t.Setenv(redisUsernameEnvVar, "alice")
	t.Setenv(redisPasswordEnvVar, "secret")
	t.Setenv(redisDBEnvVar, "3")
	t.Setenv(redisTLSEnabledEnvVar, "true")
	t.Setenv(redisOperationTimeoutEnvVar, "750ms")
	t.Setenv(userServiceModeEnvVar, "rest")
	t.Setenv(userServiceBaseURLEnvVar, "http://127.0.0.1:19090")
	t.Setenv(userServiceRequestTimeoutEnvVar, "900ms")
	t.Setenv(mailServiceModeEnvVar, "rest")
	t.Setenv(mailServiceBaseURLEnvVar, "http://127.0.0.1:19091")
	t.Setenv(mailServiceRequestTimeoutEnvVar, "950ms")
	t.Setenv(otelServiceNameEnvVar, "custom-authsession")
	t.Setenv(otelTracesExporterEnvVar, "otlp")
	t.Setenv(otelMetricsExporterEnvVar, "otlp")
	t.Setenv(otelExporterOTLPProtocolEnvVar, "grpc")
	t.Setenv(otelStdoutTracesEnabledEnvVar, "true")
	t.Setenv(otelStdoutMetricsEnabledEnvVar, "true")

	cfg, err := LoadFromEnv()
	require.NoError(t, err)

	assert.Equal(t, 9*time.Second, cfg.ShutdownTimeout)
	assert.Equal(t, "debug", cfg.Logging.Level)
	assert.Equal(t, "127.0.0.1:18080", cfg.PublicHTTP.Addr)
	assert.Equal(t, "127.0.0.1:18081", cfg.InternalHTTP.Addr)
	assert.Equal(t, "127.0.0.1:6380", cfg.Redis.Addr)
	assert.Equal(t, "alice", cfg.Redis.Username)
	assert.Equal(t, "secret", cfg.Redis.Password)
	assert.Equal(t, 3, cfg.Redis.DB)
	assert.True(t, cfg.Redis.TLSEnabled)
	assert.Equal(t, 750*time.Millisecond, cfg.Redis.OperationTimeout)
	assert.Equal(t, UserServiceConfig{
		Mode:           "rest",
		BaseURL:        "http://127.0.0.1:19090",
		RequestTimeout: 900 * time.Millisecond,
	}, cfg.UserService)
	assert.Equal(t, MailServiceConfig{
		Mode:           "rest",
		BaseURL:        "http://127.0.0.1:19091",
		RequestTimeout: 950 * time.Millisecond,
	}, cfg.MailService)
	assert.Equal(t, "custom-authsession", cfg.Telemetry.ServiceName)
	assert.Equal(t, "otlp", cfg.Telemetry.TracesExporter)
	assert.Equal(t, "otlp", cfg.Telemetry.MetricsExporter)
	assert.Equal(t, "grpc", cfg.Telemetry.TracesProtocol)
	assert.Equal(t, "grpc", cfg.Telemetry.MetricsProtocol)
	assert.True(t, cfg.Telemetry.StdoutTracesEnabled)
	assert.True(t, cfg.Telemetry.StdoutMetricsEnabled)
}

func TestLoadFromEnvRejectsInvalidValues(t *testing.T) {
	tests := []struct {
		name    string
		envName string
		envVal  string
	}{
		{name: "invalid duration", envName: shutdownTimeoutEnvVar, envVal: "later"},
		{name: "invalid bool", envName: otelStdoutTracesEnabledEnvVar, envVal: "sometimes"},
		{name: "invalid log level", envName: logLevelEnvVar, envVal: "verbose"},
		{name: "invalid traces protocol", envName: otelExporterOTLPTracesProtocolEnvVar, envVal: "udp"},
		{name: "invalid user service mode", envName: userServiceModeEnvVar, envVal: "grpc"},
		{name: "invalid user service timeout", envName: userServiceRequestTimeoutEnvVar, envVal: "never"},
		{name: "invalid mail service mode", envName: mailServiceModeEnvVar, envVal: "grpc"},
		{name: "invalid mail service timeout", envName: mailServiceRequestTimeoutEnvVar, envVal: "never"},
	}

	for _, tt := range tests {
		tt := tt

		t.Run(tt.name, func(t *testing.T) {
			t.Setenv(redisAddrEnvVar, "127.0.0.1:6379")
			t.Setenv(tt.envName, tt.envVal)
			if tt.envName == otelExporterOTLPTracesProtocolEnvVar {
				t.Setenv(otelTracesExporterEnvVar, "otlp")
			}

			_, err := LoadFromEnv()
			require.Error(t, err)
			assert.Contains(t, err.Error(), tt.envName)
		})
	}
}

func TestLoadFromEnvRejectsInvalidRESTUserServiceConfiguration(t *testing.T) {
	t.Setenv(redisAddrEnvVar, "127.0.0.1:6379")
	t.Setenv(userServiceModeEnvVar, "rest")

	t.Run("missing base url", func(t *testing.T) {
		_, err := LoadFromEnv()
		require.Error(t, err)
		assert.Contains(t, err.Error(), userServiceBaseURLEnvVar)
	})

	t.Run("non positive timeout", func(t *testing.T) {
		t.Setenv(userServiceBaseURLEnvVar, "http://127.0.0.1:19090")
		t.Setenv(userServiceRequestTimeoutEnvVar, "0s")

		_, err := LoadFromEnv()
		require.Error(t, err)
		assert.Contains(t, err.Error(), userServiceRequestTimeoutEnvVar)
	})
}

func TestLoadFromEnvRejectsInvalidRESTMailServiceConfiguration(t *testing.T) {
	t.Setenv(redisAddrEnvVar, "127.0.0.1:6379")
	t.Setenv(mailServiceModeEnvVar, "rest")

	t.Run("missing base url", func(t *testing.T) {
		_, err := LoadFromEnv()
		require.Error(t, err)
		assert.Contains(t, err.Error(), mailServiceBaseURLEnvVar)
	})

	t.Run("non positive timeout", func(t *testing.T) {
		t.Setenv(mailServiceBaseURLEnvVar, "http://127.0.0.1:19091")
		t.Setenv(mailServiceRequestTimeoutEnvVar, "0s")

		_, err := LoadFromEnv()
		require.Error(t, err)
		assert.Contains(t, err.Error(), mailServiceRequestTimeoutEnvVar)
	})
}