feat: Subset stage 5: Virtual foreign keys

* Introduced virtual_references that can be used to define logical foreign keys using column names or SQL expression
* Refactored subset system and removed artifacts
* Added subset query debugging in log-level=debug
* Implemented virtual keys validation

Closes #156

internal/db/postgres/cmd/dump.go

@@ -175,8 +175,10 @@ func (d *Dump) startMainTx(ctx context.Context, conn *pgx.Conn) (pgx.Tx, error)
 }
 
 func (d *Dump) buildContextAndValidate(ctx context.Context, tx pgx.Tx) (err error) {
-	d.context, err = runtimeContext.NewRuntimeContext(ctx, tx, d.config.Dump.Transformation, d.registry,
-		d.pgDumpOptions, d.version)
+	d.context, err = runtimeContext.NewRuntimeContext(
+		ctx, tx, d.config.Dump.Transformation, d.registry, d.pgDumpOptions,
+		d.config.Dump.VirtualReferences, d.version,
+	)
 	if err != nil {
 		return fmt.Errorf("unable to build runtime context: %w", err)
 	}

internal/db/postgres/cmd/validate.go

@@ -122,8 +122,10 @@ func (v *Validate) Run(ctx context.Context) (int, error) {
 	}
 	v.config.Dump.Transformation = tablesToValidate
 
-	v.context, err = runtimeContext.NewRuntimeContext(ctx, tx, v.config.Dump.Transformation, v.registry,
-		v.pgDumpOptions, v.version)
+	v.context, err = runtimeContext.NewRuntimeContext(
+		ctx, tx, v.config.Dump.Transformation, v.registry,
+		v.pgDumpOptions, v.config.Dump.VirtualReferences, v.version,
+	)
 	if err != nil {
 		return nonZeroExitCode, fmt.Errorf("unable to build runtime context: %w", err)
 	}

internal/db/postgres/context/context.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgtype"
+	"github.com/rs/zerolog/log"
 
 	"github.com/greenmaskio/greenmask/internal/db/postgres/entries"
 	"github.com/greenmaskio/greenmask/internal/db/postgres/pgdump"
@@ -61,8 +62,9 @@ type RuntimeContext struct {
 //
 //	warnings are fatal procedure must be terminated immediately due to lack of objects required on the next step
 func NewRuntimeContext(
-	ctx context.Context, tx pgx.Tx, cfg []*domains.Table, r *transformersUtils.TransformerRegistry, opt *pgdump.Options,
-	version int,
+	ctx context.Context, tx pgx.Tx, cfg []*domains.Table,
+	r *transformersUtils.TransformerRegistry, opt *pgdump.Options,
+	vr []*domains.VirtualReference, version int,
 ) (*RuntimeContext, error) {
 	var salt []byte
 	saltHex := os.Getenv("GREENMASK_GLOBAL_SALT")
@@ -98,8 +100,14 @@ func NewRuntimeContext(
 	if err != nil {
 		return nil, fmt.Errorf("cannot get database schema: %w", err)
 	}
+	vrWarns := validateVirtualReferences(vr, tablesEntries)
+	warnings = append(warnings, vrWarns...)
+	if len(vrWarns) > 0 {
+		// if there are any warnings, we should use them in the graph build
+		vr = nil
+	}
 
-	graph, err := subset.NewGraph(ctx, tx, tablesEntries)
+	graph, err := subset.NewGraph(ctx, tx, tablesEntries, vr)
 	if err != nil {
 		return nil, fmt.Errorf("error creating graph: %w", err)
 	}
@@ -109,7 +117,7 @@ func NewRuntimeContext(
 		if err = subset.SetSubsetQueries(graph); err != nil {
 			return nil, fmt.Errorf("cannot set subset queries: %w", err)
 		}
-
+		debugQueries(tablesEntries)
 	} else {
 		// if there are no subset tables, we can sort them by size and transformation costs
 		// TODO: Implement tables ordering for subsetted tables as well
@@ -182,3 +190,16 @@ func hasSubset(tables []*entries.Table) bool {
 		return len(table.SubsetConds) > 0
 	})
 }
+
+func debugQueries(tables []*entries.Table) {
+	for _, t := range tables {
+		if t.Query == "" {
+			continue
+		}
+		log.Debug().
+			Str("Schema", t.Schema).
+			Str("Table", t.Name).
+			Msg("Debug query")
+		log.Logger.Println(t.Query)
+	}
+}

internal/db/postgres/context/virtual_references.go

@@ -0,0 +1,180 @@
+package context
+
+import (
+	"slices"
+
+	"github.com/greenmaskio/greenmask/internal/db/postgres/entries"
+	"github.com/greenmaskio/greenmask/internal/domains"
+	"github.com/greenmaskio/greenmask/pkg/toolkit"
+)
+
+func getReferencedKeys(r *domains.Reference) (res []string) {
+	for _, ref := range r.Columns {
+		if ref.Name != "" {
+			res = append(res, ref.Name)
+		} else if ref.Expression != "" {
+			res = append(res, ref.Expression)
+		}
+	}
+	return
+}
+
+func validateVirtualReferences(vrs []*domains.VirtualReference, tables []*entries.Table) (res toolkit.ValidationWarnings) {
+	for idx, vr := range vrs {
+		res = append(res, validateVirtualReference(idx, vr, tables)...)
+	}
+	return
+}
+
+func validateVirtualReference(tableIdx int, vr *domains.VirtualReference, tables []*entries.Table) (res toolkit.ValidationWarnings) {
+	if vr.Schema == "" {
+		w := toolkit.NewValidationWarning().
+			SetSeverity(toolkit.ErrorValidationSeverity).
+			SetMsg("schema is required").
+			AddMeta("TableIdx", tableIdx)
+		res = append(res, w)
+	}
+	if vr.Name == "" {
+		w := toolkit.NewValidationWarning().
+			SetSeverity(toolkit.ErrorValidationSeverity).
+			SetMsg("table name is required").
+			AddMeta("TableIdx", tableIdx)
+		res = append(res, w)
+	}
+	if len(vr.References) == 0 {
+		w := toolkit.NewValidationWarning().
+			SetMsg("virtual reference error: references are required: received empty").
+			SetSeverity(toolkit.ErrorValidationSeverity).
+			AddMeta("TableIdx", tableIdx).
+			AddMeta("TableName", vr.Name).
+			AddMeta("TableSchema", vr.Name)
+		res = append(res, w)
+	}
+
+	referencedTableIdx := slices.IndexFunc(tables, func(t *entries.Table) bool {
+		return t.Name == vr.Name && t.Schema == vr.Schema
+	})
+
+	if referencedTableIdx == -1 {
+		w := toolkit.NewValidationWarning().
+			SetSeverity(toolkit.ErrorValidationSeverity).
+			SetMsg("virtual reference error: table not found").
+			AddMeta("TableIdx", tableIdx).
+			AddMeta("TableName", vr.Name).
+			AddMeta("TableSchema", vr.Schema)
+		res = append(res, w)
+		return
+	}
+
+	fkT := tables[referencedTableIdx]
+
+	for idx, v := range vr.References {
+		var vrWarns toolkit.ValidationWarnings
+
+		primaryKeyTableIdx := slices.IndexFunc(tables, func(t *entries.Table) bool {
+			return t.Name == v.Name && t.Schema == v.Schema
+		})
+		if primaryKeyTableIdx == -1 {
+			w := toolkit.NewValidationWarning().
+				SetSeverity(toolkit.ErrorValidationSeverity).
+				SetMsg("virtual reference error: table not found").
+				AddMeta("ReferenceIdx", idx).
+				AddMeta("ReferenceName", v.Name).
+				AddMeta("ReferenceSchema", v.Schema)
+			vrWarns = append(vrWarns, w)
+			continue
+		}
+		pkT := tables[primaryKeyTableIdx]
+
+		for _, w := range validateReference(idx, v, fkT, pkT) {
+			w.AddMeta("TableIdx", tableIdx).
+				SetSeverity(toolkit.ErrorValidationSeverity).
+				AddMeta("TableName", vr.Name).
+				AddMeta("TableSchema", vr.Schema)
+			vrWarns = append(vrWarns, w)
+		}
+		res = append(res, vrWarns...)
+	}
+	return res
+}
+
+func validateReference(vrIdx int, v *domains.Reference, fkT, pkT *entries.Table) (res toolkit.ValidationWarnings) {
+	if v.Schema == "" {
+		w := toolkit.NewValidationWarning().
+			SetSeverity(toolkit.ErrorValidationSeverity).
+			SetMsg("virtual reference error: schema is required").
+			AddMeta("ReferenceIdx", vrIdx)
+		res = append(res, w)
+	}
+	if v.Name == "" {
+		w := toolkit.NewValidationWarning().
+			SetSeverity(toolkit.ErrorValidationSeverity).
+			SetMsg("virtual reference error: table name is required").
+			AddMeta("ReferenceIdx", vrIdx)
+		res = append(res, w)
+	}
+	if len(v.Columns) == 0 {
+		w := toolkit.NewValidationWarning().
+			SetSeverity(toolkit.ErrorValidationSeverity).
+			SetMsg("columns are required: received empty").
+			AddMeta("ReferenceIdx", vrIdx).
+			AddMeta("ReferenceName", v.Name).
+			AddMeta("ReferenceSchema", v.Schema)
+		res = append(res, w)
+	}
+	refCols := getReferencedKeys(v)
+	if len(refCols) != len(pkT.PrimaryKey) {
+		w := toolkit.NewValidationWarning().
+			SetSeverity(toolkit.ErrorValidationSeverity).
+			SetMsg("virtual reference error: number of columns in reference does not match primary key").
+			AddMeta("ReferenceIdx", vrIdx).
+			AddMeta("ReferencedTableColumns", refCols).
+			AddMeta("PrimaryTableColumns", pkT.PrimaryKey).
+			AddMeta("ReferenceName", v.Name).
+			AddMeta("ReferenceSchema", v.Schema)
+		res = append(res, w)
+	}
+
+	for idx, c := range v.Columns {
+		var vrWarns toolkit.ValidationWarnings
+		for _, w := range validateColumn(idx, c, fkT) {
+			w.AddMeta("ReferenceIdx", vrIdx).
+				SetSeverity(toolkit.ErrorValidationSeverity).
+				AddMeta("ReferenceName", v.Name).
+				AddMeta("ReferenceSchema", v.Schema)
+			vrWarns = append(vrWarns, w)
+		}
+		res = append(res, vrWarns...)
+	}
+
+	return res
+}
+
+func validateColumn(colIdx int, c *domains.ReferencedColumn, fkT *entries.Table) (res toolkit.ValidationWarnings) {
+	if c.Name == "" && c.Expression == "" {
+		w := toolkit.NewValidationWarning().
+			SetSeverity(toolkit.ErrorValidationSeverity).
+			SetMsg("virtual reference error: name or expression is required").
+			AddMeta("ColumnIdx", colIdx)
+		res = append(res, w)
+	}
+	if c.Name != "" && c.Expression != "" {
+		w := toolkit.NewValidationWarning().
+			SetSeverity(toolkit.ErrorValidationSeverity).
+			SetMsg("virtual reference error: name and expression are mutually exclusive").
+			AddMeta("ColumnIdx", colIdx)
+		res = append(res, w)
+	}
+	if c.Name != "" && !slices.ContainsFunc(fkT.Columns, func(column *toolkit.Column) bool {
+		return column.Name == c.Name
+	}) {
+		w := toolkit.NewValidationWarning().
+			SetSeverity(toolkit.ErrorValidationSeverity).
+			SetMsg("virtual reference error: column not found").
+			AddMeta("ColumnIdx", colIdx).
+			AddMeta("ColumnName", c.Name)
+		res = append(res, w)
+	}
+
+	return res
+}

internal/db/postgres/subset/component.go

@@ -20,7 +20,6 @@ type Component struct {
 	// Cycles
 	cycles       [][]*Edge
 	cyclesIdents map[string]struct{}
-	keys         []string
 	// groupedCycles - cycles grouped by the vertexes
 	groupedCycles map[string][]int
 	// groupedCyclesGraph - contains the mapping of the vertexes in the component to the edges in the original graph
@@ -36,11 +35,6 @@ func NewComponent(id int, componentGraph map[int][]*Edge, tables map[int]*entrie
 		cyclesIdents:   make(map[string]struct{}),
 	}
 	c.findCycles()
-	if c.hasCycle() {
-		c.keys = c.getComponentKeys()
-	} else {
-		c.keys = c.getOneTable().PrimaryKey
-	}
 	c.groupCycles()
 	c.buildCyclesGraph()
 

internal/db/postgres/subset/component_link.go

@@ -5,7 +5,7 @@ type ComponentLink struct {
 	component *Component
 }
 
-func NewComponentLink(idx int, c *Component, keys, overriddenKeys []string) *ComponentLink {
+func NewComponentLink(idx int, c *Component) *ComponentLink {
 	return &ComponentLink{
 		idx:       idx,
 		component: c,