package config

import (
	"os"
	"testing"
	"time"

	"galaxy/postgres"
	"galaxy/redisconn"

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

const (
	testDSN          = "postgres://lobbyservice:lobbyservice@127.0.0.1:5432/galaxy?search_path=lobby&sslmode=disable"
	testRedisAddr    = "127.0.0.1:6379"
	testRedisSecret  = "secret"
	testUserBaseURL  = "http://user.internal:8090"
	testGMBaseURL    = "http://gm.internal:8091"
)

func TestDefaultConfig(t *testing.T) {
	t.Parallel()

	cfg := DefaultConfig()

	assert.Equal(t, 30*time.Second, cfg.ShutdownTimeout)
	assert.Equal(t, "info", cfg.Logging.Level)
	assert.Equal(t, ":8094", cfg.PublicHTTP.Addr)
	assert.Equal(t, ":8095", cfg.InternalHTTP.Addr)
	assert.Equal(t, redisconn.DefaultOperationTimeout, cfg.Redis.Conn.OperationTimeout)
	assert.Equal(t, postgres.DefaultOperationTimeout, cfg.Postgres.Conn.OperationTimeout)
	assert.Equal(t, "gm:lobby_events", cfg.Redis.GMEventsStream)
	assert.Equal(t, "runtime:start_jobs", cfg.Redis.RuntimeStartJobsStream)
	assert.Equal(t, "runtime:stop_jobs", cfg.Redis.RuntimeStopJobsStream)
	assert.Equal(t, "runtime:job_results", cfg.Redis.RuntimeJobResultsStream)
	assert.Equal(t, "notification:intents", cfg.Redis.NotificationIntentsStream)
	assert.Equal(t, time.Second, cfg.UserService.Timeout)
	assert.Equal(t, 5*time.Second, cfg.GM.Timeout)
	assert.Equal(t, 30*time.Second, cfg.EnrollmentAutomation.Interval)
	assert.Equal(t, time.Hour, cfg.PendingRegistration.Interval)
	assert.Equal(t, "galaxy-lobby", cfg.Telemetry.ServiceName)
	assert.Equal(t, "none", cfg.Telemetry.TracesExporter)
	assert.Equal(t, "none", cfg.Telemetry.MetricsExporter)
}

func TestLoadFromEnvAppliesRequiredFields(t *testing.T) {
	clearAllEnv(t)
	t.Setenv("LOBBY_REDIS_MASTER_ADDR", testRedisAddr)
	t.Setenv("LOBBY_REDIS_PASSWORD", testRedisSecret)
	t.Setenv("LOBBY_POSTGRES_PRIMARY_DSN", testDSN)
	t.Setenv("LOBBY_USER_SERVICE_BASE_URL", testUserBaseURL)
	t.Setenv("LOBBY_GM_BASE_URL", testGMBaseURL)

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

	assert.Equal(t, testRedisAddr, cfg.Redis.Conn.MasterAddr)
	assert.Equal(t, testRedisSecret, cfg.Redis.Conn.Password)
	assert.Equal(t, testDSN, cfg.Postgres.Conn.PrimaryDSN)
	assert.Equal(t, testUserBaseURL, cfg.UserService.BaseURL)
	assert.Equal(t, testGMBaseURL, cfg.GM.BaseURL)
}

func TestLoadFromEnvMissingRequiredFields(t *testing.T) {
	clearAllEnv(t)

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

func TestLoadFromEnvRejectsDeprecatedRedisVars(t *testing.T) {
	tests := []struct {
		name    string
		envName string
	}{
		{name: "TLS_ENABLED", envName: "LOBBY_REDIS_TLS_ENABLED"},
		{name: "USERNAME", envName: "LOBBY_REDIS_USERNAME"},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			clearAllEnv(t)
			t.Setenv("LOBBY_REDIS_MASTER_ADDR", testRedisAddr)
			t.Setenv("LOBBY_REDIS_PASSWORD", testRedisSecret)
			t.Setenv("LOBBY_POSTGRES_PRIMARY_DSN", testDSN)
			t.Setenv("LOBBY_USER_SERVICE_BASE_URL", testUserBaseURL)
			t.Setenv("LOBBY_GM_BASE_URL", testGMBaseURL)
			t.Setenv(tt.envName, "anything")

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

func TestLoadFromEnvOverrides(t *testing.T) {
	clearAllEnv(t)
	t.Setenv("LOBBY_REDIS_MASTER_ADDR", testRedisAddr)
	t.Setenv("LOBBY_REDIS_PASSWORD", testRedisSecret)
	t.Setenv("LOBBY_POSTGRES_PRIMARY_DSN", testDSN)
	t.Setenv("LOBBY_USER_SERVICE_BASE_URL", testUserBaseURL)
	t.Setenv("LOBBY_GM_BASE_URL", testGMBaseURL)

	t.Setenv("LOBBY_SHUTDOWN_TIMEOUT", "12s")
	t.Setenv("LOBBY_LOG_LEVEL", "debug")
	t.Setenv("LOBBY_PUBLIC_HTTP_ADDR", "127.0.0.1:9001")
	t.Setenv("LOBBY_INTERNAL_HTTP_ADDR", "127.0.0.1:9002")
	t.Setenv("LOBBY_REDIS_DB", "5")
	t.Setenv("LOBBY_REDIS_OPERATION_TIMEOUT", "300ms")
	t.Setenv("LOBBY_GM_EVENTS_STREAM", "alt:gm_events")
	t.Setenv("LOBBY_NOTIFICATION_INTENTS_STREAM", "alt:intents")
	t.Setenv("LOBBY_ENROLLMENT_AUTOMATION_INTERVAL", "45s")
	t.Setenv("LOBBY_RACE_NAME_EXPIRATION_INTERVAL", "15m")
	t.Setenv("OTEL_SERVICE_NAME", "galaxy-lobby-test")

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

	assert.Equal(t, 12*time.Second, cfg.ShutdownTimeout)
	assert.Equal(t, "debug", cfg.Logging.Level)
	assert.Equal(t, "127.0.0.1:9001", cfg.PublicHTTP.Addr)
	assert.Equal(t, "127.0.0.1:9002", cfg.InternalHTTP.Addr)
	assert.Equal(t, 5, cfg.Redis.Conn.DB)
	assert.Equal(t, 300*time.Millisecond, cfg.Redis.Conn.OperationTimeout)
	assert.Equal(t, "alt:gm_events", cfg.Redis.GMEventsStream)
	assert.Equal(t, "alt:intents", cfg.Redis.NotificationIntentsStream)
	assert.Equal(t, 45*time.Second, cfg.EnrollmentAutomation.Interval)
	assert.Equal(t, 15*time.Minute, cfg.PendingRegistration.Interval)
	assert.Equal(t, "galaxy-lobby-test", cfg.Telemetry.ServiceName)
}

func TestLoadFromEnvInvalidDuration(t *testing.T) {
	clearAllEnv(t)
	t.Setenv("LOBBY_REDIS_MASTER_ADDR", testRedisAddr)
	t.Setenv("LOBBY_REDIS_PASSWORD", testRedisSecret)
	t.Setenv("LOBBY_POSTGRES_PRIMARY_DSN", testDSN)
	t.Setenv("LOBBY_USER_SERVICE_BASE_URL", testUserBaseURL)
	t.Setenv("LOBBY_GM_BASE_URL", testGMBaseURL)
	t.Setenv("LOBBY_SHUTDOWN_TIMEOUT", "not-a-duration")

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

func TestPublicHTTPConfigValidate(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name    string
		mutate  func(*PublicHTTPConfig)
		wantErr string
	}{
		{name: "ok", mutate: func(*PublicHTTPConfig) {}},
		{name: "empty addr", mutate: func(cfg *PublicHTTPConfig) { cfg.Addr = "" }, wantErr: "addr must not be empty"},
		{name: "malformed addr", mutate: func(cfg *PublicHTTPConfig) { cfg.Addr = "not-an-addr" }, wantErr: "must use host:port"},
		{name: "zero read header", mutate: func(cfg *PublicHTTPConfig) { cfg.ReadHeaderTimeout = 0 }, wantErr: "read header timeout"},
		{name: "zero read", mutate: func(cfg *PublicHTTPConfig) { cfg.ReadTimeout = 0 }, wantErr: "read timeout"},
		{name: "zero idle", mutate: func(cfg *PublicHTTPConfig) { cfg.IdleTimeout = 0 }, wantErr: "idle timeout"},
	}

	for _, tt := range tests {
		tt := tt
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			cfg := DefaultConfig().PublicHTTP
			tt.mutate(&cfg)

			err := cfg.Validate()
			if tt.wantErr == "" {
				require.NoError(t, err)
				return
			}
			require.Error(t, err)
			require.Contains(t, err.Error(), tt.wantErr)
		})
	}
}

func TestInternalHTTPConfigValidate(t *testing.T) {
	t.Parallel()

	cfg := DefaultConfig().InternalHTTP
	require.NoError(t, cfg.Validate())

	cfg.Addr = "bogus"
	err := cfg.Validate()
	require.Error(t, err)
	require.Contains(t, err.Error(), "must use host:port")
}

func TestRedisConfigValidate(t *testing.T) {
	t.Parallel()

	base := DefaultConfig().Redis
	base.Conn.MasterAddr = testRedisAddr
	base.Conn.Password = testRedisSecret
	require.NoError(t, base.Validate())

	tests := []struct {
		name    string
		mutate  func(*RedisConfig)
		wantErr string
	}{
		{name: "empty master addr", mutate: func(cfg *RedisConfig) { cfg.Conn.MasterAddr = "" }, wantErr: "master addr"},
		{name: "empty password", mutate: func(cfg *RedisConfig) { cfg.Conn.Password = "" }, wantErr: "password"},
		{name: "negative db", mutate: func(cfg *RedisConfig) { cfg.Conn.DB = -1 }, wantErr: "must not be negative"},
		{name: "zero op timeout", mutate: func(cfg *RedisConfig) { cfg.Conn.OperationTimeout = 0 }, wantErr: "operation timeout"},
		{name: "empty gm stream", mutate: func(cfg *RedisConfig) { cfg.GMEventsStream = "" }, wantErr: "gm events stream"},
		{name: "zero gm block", mutate: func(cfg *RedisConfig) { cfg.GMEventsReadBlockTimeout = 0 }, wantErr: "gm events read block timeout"},
		{name: "empty start jobs", mutate: func(cfg *RedisConfig) { cfg.RuntimeStartJobsStream = "" }, wantErr: "runtime start jobs"},
		{name: "empty stop jobs", mutate: func(cfg *RedisConfig) { cfg.RuntimeStopJobsStream = "" }, wantErr: "runtime stop jobs"},
		{name: "empty job results", mutate: func(cfg *RedisConfig) { cfg.RuntimeJobResultsStream = "" }, wantErr: "runtime job results"},
		{name: "zero job block", mutate: func(cfg *RedisConfig) { cfg.RuntimeJobResultsReadBlockTimeout = 0 }, wantErr: "runtime job results read block"},
		{name: "empty intents", mutate: func(cfg *RedisConfig) { cfg.NotificationIntentsStream = "" }, wantErr: "notification intents"},
	}

	for _, tt := range tests {
		tt := tt
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			cfg := base
			tt.mutate(&cfg)
			err := cfg.Validate()
			require.Error(t, err)
			require.Contains(t, err.Error(), tt.wantErr)
		})
	}
}

func TestPostgresConfigValidate(t *testing.T) {
	t.Parallel()

	base := DefaultConfig().Postgres
	base.Conn.PrimaryDSN = testDSN
	require.NoError(t, base.Validate())

	bad := base
	bad.Conn.PrimaryDSN = ""
	require.ErrorContains(t, bad.Validate(), "primary DSN")
}

func TestUserServiceConfigValidate(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name    string
		cfg     UserServiceConfig
		wantErr string
	}{
		{name: "ok", cfg: UserServiceConfig{BaseURL: "http://x:1", Timeout: time.Second}},
		{name: "empty base url", cfg: UserServiceConfig{Timeout: time.Second}, wantErr: "base url must not be empty"},
		{name: "ftp scheme", cfg: UserServiceConfig{BaseURL: "ftp://x", Timeout: time.Second}, wantErr: "absolute http"},
		{name: "zero timeout", cfg: UserServiceConfig{BaseURL: "http://x:1"}, wantErr: "timeout must be positive"},
	}

	for _, tt := range tests {
		tt := tt
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			err := tt.cfg.Validate()
			if tt.wantErr == "" {
				require.NoError(t, err)
				return
			}
			require.Error(t, err)
			require.Contains(t, err.Error(), tt.wantErr)
		})
	}
}

func TestGMConfigValidate(t *testing.T) {
	t.Parallel()

	require.NoError(t, GMConfig{BaseURL: "https://gm:443", Timeout: time.Second}.Validate())

	require.ErrorContains(t, GMConfig{Timeout: time.Second}.Validate(), "base url must not be empty")
	require.ErrorContains(t, GMConfig{BaseURL: "http://gm", Timeout: 0}.Validate(), "timeout must be positive")
}

func TestEnrollmentAutomationConfigValidate(t *testing.T) {
	t.Parallel()

	require.NoError(t, EnrollmentAutomationConfig{Interval: time.Second}.Validate())
	require.ErrorContains(t, EnrollmentAutomationConfig{}.Validate(), "interval must be positive")
}

func TestPendingRegistrationConfigValidate(t *testing.T) {
	t.Parallel()

	require.NoError(t, PendingRegistrationConfig{Interval: time.Hour}.Validate())
	require.ErrorContains(t, PendingRegistrationConfig{}.Validate(), "race name expiration interval must be positive")
}

func TestTelemetryConfigValidate(t *testing.T) {
	t.Parallel()

	require.NoError(t, TelemetryConfig{TracesExporter: "none", MetricsExporter: "none"}.Validate())
	require.ErrorContains(t, TelemetryConfig{TracesExporter: "weird", MetricsExporter: "none"}.Validate(), "unsupported traces exporter")
	require.ErrorContains(t, TelemetryConfig{TracesExporter: "none", MetricsExporter: "weird"}.Validate(), "unsupported metrics exporter")
	require.ErrorContains(t, TelemetryConfig{TracesExporter: "none", MetricsExporter: "none", TracesProtocol: "ws"}.Validate(), "OTLP traces protocol")
	require.ErrorContains(t, TelemetryConfig{TracesExporter: "none", MetricsExporter: "none", MetricsProtocol: "ws"}.Validate(), "OTLP metrics protocol")
}

func TestConfigValidateLogLevel(t *testing.T) {
	t.Parallel()

	cfg := DefaultConfig()
	cfg.Redis.Conn.MasterAddr = testRedisAddr
	cfg.Redis.Conn.Password = testRedisSecret
	cfg.Postgres.Conn.PrimaryDSN = testDSN
	cfg.UserService.BaseURL = "http://u:1"
	cfg.GM.BaseURL = "http://gm:1"
	require.NoError(t, cfg.Validate())

	cfg.Logging.Level = "bogus"
	err := cfg.Validate()
	require.Error(t, err)
	require.Contains(t, err.Error(), "slog level")
}

// clearAllEnv unsets every environment variable the config package reads so
// tests can configure their expected values explicitly.
func clearAllEnv(t *testing.T) {
	t.Helper()

	envVars := []string{
		shutdownTimeoutEnvVar,
		logLevelEnvVar,
		publicHTTPAddrEnvVar,
		publicHTTPReadHeaderTimeoutEnvVar,
		publicHTTPReadTimeoutEnvVar,
		publicHTTPIdleTimeoutEnvVar,
		internalHTTPAddrEnvVar,
		internalHTTPReadHeaderTimeoutEnvVar,
		internalHTTPReadTimeoutEnvVar,
		internalHTTPIdleTimeoutEnvVar,
		"LOBBY_REDIS_MASTER_ADDR",
		"LOBBY_REDIS_REPLICA_ADDRS",
		"LOBBY_REDIS_PASSWORD",
		"LOBBY_REDIS_DB",
		"LOBBY_REDIS_OPERATION_TIMEOUT",
		"LOBBY_REDIS_TLS_ENABLED",
		"LOBBY_REDIS_USERNAME",
		"LOBBY_POSTGRES_PRIMARY_DSN",
		"LOBBY_POSTGRES_REPLICA_DSNS",
		"LOBBY_POSTGRES_OPERATION_TIMEOUT",
		"LOBBY_POSTGRES_MAX_OPEN_CONNS",
		"LOBBY_POSTGRES_MAX_IDLE_CONNS",
		"LOBBY_POSTGRES_CONN_MAX_LIFETIME",
		gmEventsStreamEnvVar,
		gmEventsReadBlockTimeoutEnvVar,
		runtimeStartJobsStreamEnvVar,
		runtimeJobResultsStreamEnvVar,
		runtimeJobResultsReadBlockTimeoutEnv,
		notificationIntentsStreamEnvVar,
		userServiceBaseURLEnvVar,
		userServiceTimeoutEnvVar,
		gmBaseURLEnvVar,
		gmTimeoutEnvVar,
		enrollmentAutomationIntervalEnvVar,
		raceNameDirectoryBackendEnvVar,
		raceNameExpirationIntervalEnvVar,
		otelServiceNameEnvVar,
		otelTracesExporterEnvVar,
		otelMetricsExporterEnvVar,
		otelExporterOTLPProtocolEnvVar,
		otelExporterOTLPTracesProtocolEnvVar,
		otelExporterOTLPMetricsProtocolEnvVar,
		otelStdoutTracesEnabledEnvVar,
		otelStdoutMetricsEnabledEnvVar,
	}

	for _, name := range envVars {
		// t.Setenv registers a Cleanup that restores the pre-test value.
		// Unsetenv after enrolling the cleanup leaves the variable unset for
		// the duration of the test while still restoring prior state on exit.
		t.Setenv(name, "")
		require.NoError(t, os.Unsetenv(name))
	}
}