package store

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"os"
	"strings"
	"sync"
	"testing"
	"time"

	"yovision/sense/internal/device"
)

const (
	postgresTestDSNEnv      = "YOVISION_TEST_POSTGRES_DSN"
	postgresTestAdminDSNEnv = "YOVISION_TEST_POSTGRES_ADMIN_DSN"
)

func TestPostgresInvalidDSNDoesNotLeakInput(t *testing.T) {
	secret := "do-not-echo-this-value"
	_, err := OpenPostgres(context.Background(), "postgres://sense:"+secret+"@%zz")
	if err == nil {
		t.Fatal("invalid PostgreSQL DSN was accepted")
	}
	if strings.Contains(err.Error(), secret) {
		t.Fatal("PostgreSQL configuration error leaked DSN input")
	}
}

func TestOpenRepositoryRejectsUnknownDriver(t *testing.T) {
	_, err := OpenRepository(context.Background(), "mysql", "unused")
	if err == nil {
		t.Fatal("unknown repository driver was accepted")
	}
}

func TestPostgresDefaultAndMaximumQuota(t *testing.T) {
	store, admin := openPostgresTestStore(t)
	ctx := context.Background()
	insertBellSite(t, admin, "tenant-default", "site-default", 0)
	for index := 1; index <= device.DefaultVideoChannels; index++ {
		if err := store.CreateDevice(ctx, videoDevice(index, "tenant-default", "site-default")); err != nil {
			t.Fatalf("create default channel %d: %v", index, err)
		}
	}
	radar := device.Device{
		ID: "radar-default", TenantID: "tenant-default", SiteID: "site-default",
		SerialNumber: "radar-default", Name: "Radar", Modality: device.ModalityRadar,
		Capabilities: []device.Capability{device.CapabilityTelemetry},
		DesiredState: device.DesiredEnabled, ActualState: device.ActualPending,
	}
	if err := store.CreateDevice(ctx, radar); err != nil {
		t.Fatalf("non-video device must not consume video quota: %v", err)
	}
	err := store.CreateDevice(ctx, videoDevice(17, "tenant-default", "site-default"))
	var quotaError *device.QuotaExceededError
	if !errors.As(err, &quotaError) || quotaError.Limit != 16 {
		t.Fatalf("expected default quota error, got %v", err)
	}

	insertBellSite(t, admin, "tenant-max", "site-max", 128)
	for index := 1; index <= device.MaximumVideoChannels; index++ {
		if err := store.CreateDevice(ctx, videoDevice(index+1000, "tenant-max", "site-max")); err != nil {
			t.Fatalf("create maximum channel %d: %v", index, err)
		}
	}
	err = store.CreateDevice(ctx, videoDevice(1129, "tenant-max", "site-max"))
	if !errors.As(err, &quotaError) || quotaError.Limit != 128 {
		t.Fatalf("expected maximum quota error, got %v", err)
	}
}

func TestPostgresConcurrentAdmissionCannotExceedQuota(t *testing.T) {
	store, admin := openPostgresTestStore(t)
	insertBellSite(t, admin, "tenant", "site", 1)
	ctx := context.Background()
	start := make(chan struct{})
	errorsFound := make(chan error, 2)
	var wait sync.WaitGroup
	for index := 1; index <= 2; index++ {
		wait.Add(1)
		go func(index int) {
			defer wait.Done()
			<-start
			errorsFound <- store.CreateDevice(ctx, videoDevice(index, "tenant", "site"))
		}(index)
	}
	close(start)
	wait.Wait()
	close(errorsFound)
	var succeeded, rejected int
	for err := range errorsFound {
		if err == nil {
			succeeded++
			continue
		}
		var quotaError *device.QuotaExceededError
		if errors.As(err, &quotaError) {
			rejected++
			continue
		}
		t.Fatalf("unexpected concurrent admission error: %v", err)
	}
	if succeeded != 1 || rejected != 1 {
		t.Fatalf("expected one success and one quota rejection, got success=%d rejected=%d", succeeded, rejected)
	}
}

func TestPostgresProjectionFailureAndRollbackFailClosed(t *testing.T) {
	store, admin := openPostgresTestStore(t)
	ctx := context.Background()
	err := store.CreateDevice(ctx, videoDevice(1, "missing-tenant", "missing-site"))
	if !errors.Is(err, ErrQuotaProjectionUnavailable) {
		t.Fatalf("missing projection must fail closed, got %v", err)
	}

	insertBellSite(t, admin, "tenant", "site", 2)
	if _, err := store.db.ExecContext(ctx, `INSERT INTO sense.site_quota_projection_state(
		tenant_id, site_id, source_version, synced_at
	) VALUES ('tenant', 'site', 99, clock_timestamp())`); err != nil {
		t.Fatal(err)
	}
	err = store.CreateDevice(ctx, videoDevice(2, "tenant", "site"))
	if !errors.Is(err, ErrQuotaProjectionInvalid) {
		t.Fatalf("projection version rollback must fail closed, got %v", err)
	}
	var devices int
	if err := store.db.QueryRowContext(ctx, `SELECT COUNT(*) FROM sense.devices`).Scan(&devices); err != nil {
		t.Fatal(err)
	}
	if devices != 0 {
		t.Fatalf("failed admissions must not persist devices, got %d", devices)
	}
}

func TestPostgresLowerQuotaDoesNotDisableAndEnableStillChecks(t *testing.T) {
	store, admin := openPostgresTestStore(t)
	ctx := context.Background()
	insertBellSite(t, admin, "tenant", "site", 2)
	for index := 1; index <= 2; index++ {
		if err := store.CreateDevice(ctx, videoDevice(index, "tenant", "site")); err != nil {
			t.Fatal(err)
		}
	}
	disabled := videoDevice(3, "tenant", "site")
	disabled.DesiredState = device.DesiredDisabled
	if err := store.CreateDevice(ctx, disabled); err != nil {
		t.Fatal(err)
	}
	if _, err := admin.ExecContext(ctx, `UPDATE bell.sites SET max_video_channels = 1
		WHERE tenant_id = 'tenant' AND id = 'site'`); err != nil {
		t.Fatal(err)
	}
	for index := 1; index <= 2; index++ {
		value, err := store.GetDevice(ctx, fmt.Sprintf("camera-%03d", index))
		if err != nil {
			t.Fatal(err)
		}
		if value.DesiredState != device.DesiredEnabled {
			t.Fatalf("quota decrease disabled existing device %d", index)
		}
	}
	err := store.SetDesiredState(ctx, "camera-003", device.DesiredEnabled)
	var quotaError *device.QuotaExceededError
	if !errors.As(err, &quotaError) || quotaError.Limit != 1 {
		t.Fatalf("new enable after quota decrease must be rejected, got %v", err)
	}
}

func TestPostgresTenantIsolationAndConvergenceParity(t *testing.T) {
	store, admin := openPostgresTestStore(t)
	ctx := context.Background()
	insertBellSite(t, admin, "tenant-a", "site", 1)
	insertBellSite(t, admin, "tenant-b", "site", 1)
	left := videoDevice(1, "tenant-a", "site")
	right := videoDevice(2, "tenant-b", "site")
	right.SerialNumber = left.SerialNumber
	if err := store.CreateDevice(ctx, left); err != nil {
		t.Fatal(err)
	}
	if err := store.CreateDevice(ctx, right); err != nil {
		t.Fatal(err)
	}
	now := time.Date(2026, 8, 7, 0, 0, 0, 0, time.UTC)
	if err := store.MarkReconciled(ctx, left.ID, 1, now); err != nil {
		t.Fatal(err)
	}
	if err := store.UpdateActualState(ctx, left.ID, device.ActualOnline, now); err != nil {
		t.Fatal(err)
	}
	snapshot, err := store.ConvergenceSnapshot(ctx)
	if err != nil {
		t.Fatal(err)
	}
	if snapshot.Total != 2 || snapshot.Unconverged != 1 {
		t.Fatalf("unexpected convergence snapshot: %+v", snapshot)
	}
	if err := store.RequestReconcile(ctx, left.ID, now.Add(time.Second)); err != nil {
		t.Fatal(err)
	}
	snapshot, err = store.ConvergenceSnapshot(ctx)
	if err != nil {
		t.Fatal(err)
	}
	if snapshot.Unconverged != 2 {
		t.Fatalf("runtime reconcile request was not persisted: %+v", snapshot)
	}
}

func TestPostgresRecordsQuotaSourceVersion(t *testing.T) {
	store, admin := openPostgresTestStore(t)
	ctx := context.Background()
	insertBellSite(t, admin, "tenant", "site", 2)
	if err := store.CreateDevice(ctx, videoDevice(1, "tenant", "site")); err != nil {
		t.Fatal(err)
	}
	var firstVersion int64
	if err := store.db.QueryRowContext(ctx, `SELECT quota_source_version
		FROM sense.devices WHERE id = 'camera-001'`).Scan(&firstVersion); err != nil {
		t.Fatal(err)
	}
	if _, err := admin.ExecContext(ctx, `UPDATE bell.sites SET name = name
		WHERE tenant_id = 'tenant' AND id = 'site'`); err != nil {
		t.Fatal(err)
	}
	second := videoDevice(2, "tenant", "site")
	if err := store.CreateDevice(ctx, second); err != nil {
		t.Fatal(err)
	}
	var secondVersion int64
	if err := store.db.QueryRowContext(ctx, `SELECT quota_source_version
		FROM sense.devices WHERE id = 'camera-002'`).Scan(&secondVersion); err != nil {
		t.Fatal(err)
	}
	if firstVersion != 1 || secondVersion != 2 {
		t.Fatalf("expected recorded projection versions 1 and 2, got %d and %d", firstVersion, secondVersion)
	}
}

func TestPostgresReconcilePortParity(t *testing.T) {
	store, admin := openPostgresTestStore(t)
	ctx := context.Background()
	insertBellSite(t, admin, "tenant", "site", 1)
	if err := store.CreateDevice(ctx, videoDevice(1, "tenant", "site")); err != nil {
		t.Fatal(err)
	}
	now := time.Now().UTC()
	due, err := store.ListDueReconcile(ctx, now.Add(time.Second), 10)
	if err != nil || len(due) != 1 || len(due[0].Device.Capabilities) != 2 {
		t.Fatalf("unexpected due reconcile list: values=%+v error=%v", due, err)
	}
	enabled, err := store.ListEnabledVideoDevices(ctx, 10)
	if err != nil || len(enabled) != 1 || enabled[0].ID != "camera-001" {
		t.Fatalf("unexpected enabled video list: values=%+v error=%v", enabled, err)
	}
	if err := store.SetDesiredState(ctx, "camera-001", device.DesiredEnabled); err != nil {
		t.Fatal(err)
	}
	value, err := store.GetDevice(ctx, "camera-001")
	if err != nil || value.Generation != 1 {
		t.Fatalf("idempotent desired state changed generation: value=%+v error=%v", value, err)
	}
	nextAttempt := now.Add(time.Minute)
	if err := store.MarkReconcileFailure(ctx, "camera-001", 1, nextAttempt, "test_failure", now); err != nil {
		t.Fatal(err)
	}
	due, err = store.ListDueReconcile(ctx, now.Add(30*time.Second), 10)
	if err != nil || len(due) != 0 {
		t.Fatalf("backoff device became due early: values=%+v error=%v", due, err)
	}
	due, err = store.ListDueReconcile(ctx, now.Add(2*time.Minute), 10)
	if err != nil || len(due) != 1 || due[0].FailureCount != 1 {
		t.Fatalf("backoff device did not become due: values=%+v error=%v", due, err)
	}
	value, err = store.GetDevice(ctx, "camera-001")
	if err != nil || value.ActualState != device.ActualFailed {
		t.Fatalf("reconcile failure did not persist actual state: value=%+v error=%v", value, err)
	}
}

func TestPostgresOpenRejectsOverprivilegedRuntimeRole(t *testing.T) {
	_, admin := openPostgresTestStore(t)
	ctx := context.Background()
	if _, err := admin.ExecContext(ctx,
		`GRANT UPDATE ON bell.site_quota_v1 TO yovision_t009_sense`); err != nil {
		t.Fatal(err)
	}
	defer func() {
		_, _ = admin.ExecContext(context.Background(),
			`REVOKE UPDATE ON bell.site_quota_v1 FROM yovision_t009_sense`)
	}()
	value, err := OpenPostgres(ctx, os.Getenv(postgresTestDSNEnv))
	if value != nil {
		_ = value.Close()
		t.Fatal("overprivileged runtime role was accepted")
	}
	if err == nil || !strings.Contains(err.Error(), "privilege boundary") {
		t.Fatalf("expected privilege-boundary error, got %v", err)
	}
}

func openPostgresTestStore(t *testing.T) (*Postgres, *sql.DB) {
	t.Helper()
	dsn := os.Getenv(postgresTestDSNEnv)
	adminDSN := os.Getenv(postgresTestAdminDSNEnv)
	if dsn == "" || adminDSN == "" {
		t.Skip("PostgreSQL integration DSNs are not configured")
	}
	admin, err := sql.Open("pgx", adminDSN)
	if err != nil {
		t.Fatal(err)
	}
	if err := admin.PingContext(context.Background()); err != nil {
		admin.Close()
		t.Fatal("connect PostgreSQL test administrator")
	}
	if _, err := admin.ExecContext(context.Background(), `TRUNCATE
		sense.device_capabilities,
		sense.reconcile_state,
		sense.devices,
		sense.site_quota_projection_state,
		bell.sites CASCADE`); err != nil {
		admin.Close()
		t.Fatal(err)
	}
	store, err := OpenPostgres(context.Background(), dsn)
	if err != nil {
		admin.Close()
		t.Fatal(err)
	}
	t.Cleanup(func() {
		_ = store.Close()
		_ = admin.Close()
	})
	return store, admin
}

func insertBellSite(t *testing.T, admin *sql.DB, tenantID, siteID string, quota int) {
	t.Helper()
	query := `INSERT INTO bell.sites(tenant_id, id, name, max_video_channels)
		VALUES ($1, $2, $3, $4)`
	arguments := []any{tenantID, siteID, "Test Site", quota}
	if quota == 0 {
		query = `INSERT INTO bell.sites(tenant_id, id, name) VALUES ($1, $2, $3)`
		arguments = arguments[:3]
	}
	if _, err := admin.ExecContext(context.Background(), query, arguments...); err != nil {
		t.Fatal(err)
	}
}