chore: move the go code into a subfolder

apps/api/internal/command/preparation/command.go

@@ -0,0 +1,79 @@
+package preparation
+
+import (
+	"context"
+
+	"github.com/zitadel/zitadel/internal/eventstore"
+	"github.com/zitadel/zitadel/internal/zerrors"
+)
+
+// Validation of the input values of the command and if correct returns
+// the function to create commands or if not valid an error
+type Validation func() (CreateCommands, error)
+
+// CreateCommands builds the commands
+// the filter param is an extended version of the eventstore filter method
+// it filters for events including the commands on the current context
+type CreateCommands func(context.Context, FilterToQueryReducer) ([]eventstore.Command, error)
+
+// FilterToQueryReducer is an abstraction of the eventstore method
+type FilterToQueryReducer func(ctx context.Context, queryFactory *eventstore.SearchQueryBuilder) ([]eventstore.Event, error)
+
+var (
+	//ErrNotExecutable is thrown if no command creator was created
+	ErrNotExecutable = zerrors.ThrowInvalidArgument(nil, "PREPA-pH70n", "Errors.Internal")
+)
+
+// PrepareCommands checks the passed validations and if ok creates the commands
+//
+// Deprecated: filter causes unneeded allocation. Use [eventstore.FilterToQueryReducer] instead.
+func PrepareCommands(ctx context.Context, filter FilterToQueryReducer, validations ...Validation) (cmds []eventstore.Command, err error) {
+	commanders, err := validate(validations)
+	if err != nil {
+		return nil, err
+	}
+	return create(ctx, filter, commanders)
+}
+
+func validate(validations []Validation) ([]CreateCommands, error) {
+	creators := make([]CreateCommands, 0, len(validations))
+
+	for _, validate := range validations {
+		cmds, err := validate()
+		if err != nil {
+			return nil, err
+		}
+		creators = append(creators, cmds)
+	}
+
+	if len(creators) == 0 {
+		return nil, ErrNotExecutable
+	}
+	return creators, nil
+}
+
+func create(ctx context.Context, filter FilterToQueryReducer, commanders []CreateCommands) (cmds []eventstore.Command, err error) {
+	for _, command := range commanders {
+		cmd, err := command(ctx, transactionFilter(filter, cmds))
+		if err != nil {
+			return nil, err
+		}
+		cmds = append(cmds, cmd...)
+	}
+
+	return cmds, nil
+}
+
+func transactionFilter(filter FilterToQueryReducer, commands []eventstore.Command) FilterToQueryReducer {
+	return func(ctx context.Context, query *eventstore.SearchQueryBuilder) ([]eventstore.Event, error) {
+		events, err := filter(ctx, query)
+		if err != nil {
+			return nil, err
+		}
+		matches := query.Matches(commands...)
+		for _, command := range matches {
+			events = append(events, command.(eventstore.Event))
+		}
+		return events, nil
+	}
+}