package config

import (
	"testing"
	"time"

	"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()
	require.Equal(t, defaults.ShutdownTimeout, cfg.ShutdownTimeout)
	require.Equal(t, defaults.Logging.Level, cfg.Logging.Level)
	require.Equal(t, defaults.InternalHTTP, cfg.InternalHTTP)
	require.Equal(t, defaults.AdminHTTP, cfg.AdminHTTP)
	require.Equal(t, "127.0.0.1:6379", cfg.Redis.Addr)
	require.Equal(t, defaults.Redis.DB, cfg.Redis.DB)
	require.Equal(t, defaults.Redis.DomainEventsStream, cfg.Redis.DomainEventsStream)
	require.Equal(t, defaults.Redis.DomainEventsStreamMaxLen, cfg.Redis.DomainEventsStreamMaxLen)
	require.Equal(t, defaults.Telemetry, cfg.Telemetry)
}

func TestLoadFromEnvAppliesOverrides(t *testing.T) {
	t.Setenv(shutdownTimeoutEnvVar, "9s")
	t.Setenv(logLevelEnvVar, "debug")
	t.Setenv(internalHTTPAddrEnvVar, "127.0.0.1:18091")
	t.Setenv(internalHTTPReadHeaderTimeoutEnvVar, "3s")
	t.Setenv(internalHTTPRequestTimeoutEnvVar, "750ms")
	t.Setenv(adminHTTPAddrEnvVar, "127.0.0.1:19091")
	t.Setenv(adminHTTPIdleTimeoutEnvVar, "90s")
	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, "900ms")
	t.Setenv(redisKeyspacePrefixEnvVar, "user:custom:")
	t.Setenv(redisDomainEventsStreamEnvVar, "user:test_events")
	t.Setenv(redisDomainEventsStreamMaxLenEnvVar, "2048")
	t.Setenv(otelServiceNameEnvVar, "galaxy-user-stage12")
	t.Setenv(otelTracesExporterEnvVar, "otlp")
	t.Setenv(otelMetricsExporterEnvVar, "otlp")
	t.Setenv(otelExporterOTLPTracesProtocolEnvVar, "grpc")
	t.Setenv(otelExporterOTLPMetricsProtocolEnvVar, "http/protobuf")
	t.Setenv(otelStdoutTracesEnabledEnvVar, "true")
	t.Setenv(otelStdoutMetricsEnabledEnvVar, "true")

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

	require.Equal(t, 9*time.Second, cfg.ShutdownTimeout)
	require.Equal(t, "debug", cfg.Logging.Level)
	require.Equal(t, "127.0.0.1:18091", cfg.InternalHTTP.Addr)
	require.Equal(t, 3*time.Second, cfg.InternalHTTP.ReadHeaderTimeout)
	require.Equal(t, 750*time.Millisecond, cfg.InternalHTTP.RequestTimeout)
	require.Equal(t, "127.0.0.1:19091", cfg.AdminHTTP.Addr)
	require.Equal(t, 90*time.Second, cfg.AdminHTTP.IdleTimeout)
	require.Equal(t, "127.0.0.1:6380", cfg.Redis.Addr)
	require.Equal(t, "alice", cfg.Redis.Username)
	require.Equal(t, "secret", cfg.Redis.Password)
	require.Equal(t, 3, cfg.Redis.DB)
	require.True(t, cfg.Redis.TLSEnabled)
	require.Equal(t, 900*time.Millisecond, cfg.Redis.OperationTimeout)
	require.Equal(t, "user:custom:", cfg.Redis.KeyspacePrefix)
	require.Equal(t, "user:test_events", cfg.Redis.DomainEventsStream)
	require.Equal(t, int64(2048), cfg.Redis.DomainEventsStreamMaxLen)
	require.Equal(t, "galaxy-user-stage12", cfg.Telemetry.ServiceName)
	require.Equal(t, "otlp", cfg.Telemetry.TracesExporter)
	require.Equal(t, "otlp", cfg.Telemetry.MetricsExporter)
	require.Equal(t, "grpc", cfg.Telemetry.TracesProtocol)
	require.Equal(t, "http/protobuf", cfg.Telemetry.MetricsProtocol)
	require.True(t, cfg.Telemetry.StdoutTracesEnabled)
	require.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: redisTLSEnabledEnvVar, envVal: "sometimes"},
		{name: "invalid log level", envName: logLevelEnvVar, envVal: "verbose"},
		{name: "invalid int", envName: redisDBEnvVar, envVal: "db-three"},
		{name: "invalid stream max len", envName: redisDomainEventsStreamMaxLenEnvVar, envVal: "many"},
		{name: "invalid traces exporter", envName: otelTracesExporterEnvVar, envVal: "zipkin"},
		{name: "invalid metrics protocol", envName: otelExporterOTLPMetricsProtocolEnvVar, envVal: "udp"},
	}

	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)

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