package processor

import (
	"context"
	"os"
	"testing"

	"github.com/google/uuid"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"

	"apskel-pos-be/internal/constants"
	"apskel-pos-be/internal/entities"
	"apskel-pos-be/internal/repository"
)

type auditRepoFake struct{ rows []entities.AuditLog }

func (f *auditRepoFake) Insert(_ context.Context, e *entities.AuditLog) error {
	f.rows = append(f.rows, *e)
	return nil
}

func (f *auditRepoFake) ListByEntity(context.Context, uuid.UUID, string, uuid.UUID, int) ([]entities.AuditLog, error) {
	return f.rows, nil
}

func validAuditEntry() AuditEntry {
	return AuditEntry{
		OrganizationID: uuid.New(),
		ActorType:      constants.AuditActorUser,
		ActorID:        ptr(uuid.New()),
		EntityType:     constants.AuditEntityGame,
		EntityID:       uuid.New(),
		Action:         "STATUS_CHANGED",
		Before:         map[string]string{"status": "DRAFT"},
		After:          map[string]string{"status": "ACTIVE"},
		Source:         constants.AuditSourceAdminAPI,
	}
}

func TestAuditLogger_RecordsSnapshotsAsJSON(t *testing.T) {
	repo := &auditRepoFake{}
	l := NewAuditLogger(repo)
	require.NoError(t, l.Record(context.Background(), validAuditEntry()))

	created := validAuditEntry()
	created.ActorType, created.ActorID = constants.AuditActorSystem, nil
	var nothing *entities.Game
	created.Before = nothing
	require.NoError(t, l.Record(context.Background(), created))

	require.Len(t, repo.rows, 2)
	assert.JSONEq(t, `{"status": "DRAFT"}`, string(repo.rows[0].Before))
	assert.JSONEq(t, `{"status": "ACTIVE"}`, string(repo.rows[0].After))
	assert.Nil(t, repo.rows[1].Before, "a nil pointer is stored as NULL, not as JSON null")
}

func TestAuditLogger_RejectsIncompleteEntries(t *testing.T) {
	for name, mutate := range map[string]func(*AuditEntry){
		"no organization":    func(e *AuditEntry) { e.OrganizationID = uuid.Nil },
		"unknown actor type": func(e *AuditEntry) { e.ActorType = "ROBOT" },
		"USER without actor": func(e *AuditEntry) { e.ActorID = nil },
		"no entity type":     func(e *AuditEntry) { e.EntityType = " " },
		"no entity id":       func(e *AuditEntry) { e.EntityID = uuid.Nil },
		"no action":          func(e *AuditEntry) { e.Action = "" },
		"no source":          func(e *AuditEntry) { e.Source = "" },
		"unmarshallable":     func(e *AuditEntry) { e.After = func() {} },
	} {
		repo := &auditRepoFake{}
		e := validAuditEntry()
		mutate(&e)
		err := NewAuditLogger(repo).Record(context.Background(), e)
		assert.ErrorIs(t, err, ErrInvalidAuditEntry, name)
		assert.Empty(t, repo.rows, name)
	}
}

// An audit row commits and rolls back with the change it records. Needs
// TEST_DATABASE_URL; see internal/repository/wallet_repository_test.go.
func TestAuditLogger_AgainstPostgres(t *testing.T) {
	dsn := os.Getenv("TEST_DATABASE_URL")
	if dsn == "" {
		t.Skip("TEST_DATABASE_URL not set")
	}
	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)})
	require.NoError(t, err)
	org := uuid.New()
	t.Cleanup(func() { db.Exec(`DELETE FROM audit_logs WHERE organization_id = ?`, org) })

	repo := repository.NewAuditLogRepository(db)
	l := NewAuditLogger(repo)
	txm := repository.NewTxManager(db)
	entry := func(entityID uuid.UUID) AuditEntry {
		e := validAuditEntry()
		e.OrganizationID, e.EntityID, e.Reason = org, entityID, ptr("promo")
		return e
	}
	ctx := context.Background()

	committed, rolledBack := uuid.New(), uuid.New()
	require.NoError(t, txm.WithTransaction(ctx, func(ctx context.Context) error {
		return l.Record(ctx, entry(committed))
	}))
	failure := assert.AnError
	err = txm.WithTransaction(ctx, func(ctx context.Context) error {
		require.NoError(t, l.Record(ctx, entry(rolledBack)))
		return failure
	})
	require.ErrorIs(t, err, failure)

	rows, err := repo.ListByEntity(ctx, org, constants.AuditEntityGame, committed, 10)
	require.NoError(t, err)
	require.Len(t, rows, 1)
	assert.Equal(t, "STATUS_CHANGED", rows[0].Action)
	assert.JSONEq(t, `{"status": "DRAFT"}`, string(rows[0].Before))
	assert.JSONEq(t, `{"status": "ACTIVE"}`, string(rows[0].After))
	assert.Equal(t, "promo", *rows[0].Reason)
	assert.False(t, rows[0].CreatedAt.IsZero())

	rows, err = repo.ListByEntity(ctx, org, constants.AuditEntityGame, rolledBack, 10)
	require.NoError(t, err)
	assert.Empty(t, rows, "a rolled back change leaves no audit row")

	assert.ErrorIs(t, l.Record(ctx, entry(uuid.New())), repository.ErrAuditTxRequired)
}