--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Lib/IMPL/SQL/Schema/Traits.pm	Mon Nov 09 01:39:31 2009 +0300
@@ -0,0 +1,270 @@
+package IMPL::SQL::Schema::Traits;
+use strict;
+use base qw(IMPL::Object IMPL::Object::Autofill);
+use IMPL::Class::Property;
+use IMPL::Class::Property::Direct;
+
+use constant {
+    STATE_NORMAL => 0,
+    STATE_UPDATED => 1,
+    STATE_CREATED => 2,
+    STATE_REMOVED => 3,
+    STATE_PENDING => 4
+} ;
+
+BEGIN {
+    public _direct property SrcSchema => prop_none;
+    public _direct property DstSchema => prop_none;
+    public _direct property PendingActions => prop_get;
+    public _direct property TableInfo => prop_get;
+    public _direct property Handler => prop_get;
+    public _direct property TableMap => prop_none;
+    public _direct property KeepTables => prop_all;
+}
+
+__PACKAGE__->PassThroughArgs;
+
+sub CTOR {
+    my $this = shift;
+    
+    $this->{$SrcSchema} or die new IMPL::InvalidArgumentException('A source schema is required');
+    $this->{$DstSchema} or die new IMPL::InvalidArgumentException('A destination schema is required');
+    $this->{$Handler} or die new IMPL::InvalidArgumentException('A handler is required to produce the update batch');
+    
+    $this->{$TableInfo} = {};
+    $this->{$PendingActions} = [];
+    
+}
+
+sub UpdateTable {
+    my ($this,$srcTable) = @_;
+    
+    return 1 if $this->{$TableInfo}->{$srcTable->Name}->{'processed'};
+    
+    my $dstTableName = $this->{$TableMap}->{$srcTable->Name} ? $this->{$TableMap}->{$srcTable->Name} : $srcTable->Name;
+    my $dstTable = $this->{$DstSchema}->Tables->{$dstTableName};
+    
+    $this->{$TableInfo}->{$srcTable->Name}->{'processed'} = 1;
+    
+    if (not $dstTable) {
+        $this->DropTable($srcTable) if not $this->{$KeepTables};
+        return 1;
+    }
+    
+    if ( not grep {$srcTable->Column($_->Name)} $dstTable->Columns ) {
+        
+        $this->{$TableInfo}->{$srcTable->Name}->{'NewName'} = $dstTable->Name if $srcTable->Name ne $dstTable->Name;
+        
+        $this->DropTable($srcTable);
+        $this->CreateTable($dstTable);
+        
+        return 1;
+    }
+    
+    if ($srcTable->Name ne $dstTableName) {
+        $this->RenameTable($srcTable,$dstTableName);
+    }
+    
+    my %dstConstraints = %{$dstTable->Constraints};
+    
+    foreach my $srcConstraint (values %{$srcTable->Constraints}) {
+        if (my $dstConstraint = delete $dstConstraints{$srcConstraint->Name}) {
+            $this->UpdateConstraint($srcConstraint,$dstConstraint);
+        } else {
+            $this->DropConstraint($srcConstraint);
+        }
+    }
+    
+    my $i = 0;
+    my %dstColumns = map { $_->Name, $i++} $dstTable->Columns ;
+    
+    # сначала удаляем столбцы
+    # потом добавляем недостающие и изменяем столбцы в нужном порядке
+    
+    my @columnsToUpdate;
+    
+    foreach my $srcColumn ($srcTable->Columns) {
+        if (defined (my $dstColumnIndex = delete $dstColumns{$srcColumn->Name})) {
+            push @columnsToUpdate, { Action => 'update', ColumnSrc => $srcColumn, ColumnDst => $dstTable->ColumnAt($dstColumnIndex), NewPosition => $dstColumnIndex};
+        } else {
+            $this->DropColumn($srcTable,$srcColumn);
+        }
+    }
+    push @columnsToUpdate, map { {Action => 'add', ColumnDst => $dstTable->ColumnAt($_), NewPosition => $_} } values %dstColumns;
+    
+    foreach my $action (sort {$a->{'NewPosition'} <=> $b->{'NewPosition'}} @columnsToUpdate ) {
+        if ($action->{'Action'} eq 'update') {
+            $this->UpdateColumn($srcTable,@$action{'ColumnSrc','ColumnDst'},$dstTable,$action->{'NewPosition'}); # change type and position
+        }elsif ($action->{'Action'} eq 'add') {
+            $this->AddColumn($srcTable,$action->{'ColumnDst'},$dstTable,$action->{'NewPosition'}); # add at specified position
+        }
+    }
+    
+    foreach my $dstConstraint (values %dstConstraints) {
+        $this->AddConstraint($dstConstraint);
+    }
+    
+    $this->{$TableInfo}{$srcTable->Name}{'State'} = STATE_UPDATED;
+}
+
+sub UpdateConstraint {
+    my ($this,$src,$dst) = @_;
+    
+    if (not ConstraintEquals($src,$dst)) {
+        if (UNIVERSAL::isa($src,'IMPL::SQL::Schema::Constraint::PrimaryKey')) {
+            $this->UpdateTable($_->Table) foreach values %{$src->ConnectedFK};
+        }
+        $this->DropConstraint($src);
+        $this->AddConstraint($dst);
+    } else {
+        $this->{$TableInfo}->{$this->MapTableName($src->Table->Name)}->{'Constraints'}->{$src->Name} = STATE_UPDATED;
+    }
+}
+
+sub ConstraintEquals {
+    my ($src,$dst) = @_;
+    
+    ref $src eq ref $dst or return 0;
+    
+    my @dstColumns = $dst->Columns;
+    scalar(@{$src->Columns}) == scalar(@{$dst->Columns}) and not grep { my $column = shift @dstColumns; not $column->isSame($_) } $src->Columns or return 0;
+    
+    not UNIVERSAL::isa($src,'IMPL::SQL::Schema::Constraint::ForeignKey') or ConstraintEquals($src->ReferencedPrimaryKey,$dst->ReferencedPrimaryKey) or return 0;
+    
+    1;
+}
+
+sub UpdateSchema {
+    my ($this) = @_;
+    
+    my %Updated = map { $this->UpdateTable($_); $this->MapTableName($_->Name) , 1; } values %{$this->{$SrcSchema}->Tables ? $this->{$SrcSchema}->Tables : {} };
+    
+    $this->CreateTable($_) foreach grep {not $Updated{$_->Name}} values %{$this->{$DstSchema}->Tables};
+    
+    $this->ProcessPendingActions();
+}
+
+sub RenameTable {
+    my ($this,$tblSrc,$tblDstName) = @_;
+    
+    $this->{$Handler}->AlterTableRename($tblSrc->Name,$tblDstName);
+    $this->{$TableInfo}->{$tblSrc->Name}->{'NewName'} = $tblDstName;
+}
+
+sub MapTableName {
+    my ($this,$srcName) = @_;
+    
+    $this->{$TableInfo}->{$srcName}->{'NewName'} ? $this->{$TableInfo}->{$srcName}->{'NewName'} : $srcName;
+}
+
+sub DropTable {
+    my ($this,$tbl) = @_;
+    
+    if ($tbl->PrimaryKey) {
+        $this->UpdateTable($_->Table) foreach values %{$tbl->PrimaryKey->ConnectedFK};
+    }
+    
+    $this->{$Handler}->DropTable($this->MapTableName($tbl->Name));
+    $this->{$TableInfo}{$this->MapTableName($tbl->Name)}{'State'} = STATE_REMOVED;
+    $this->{$TableInfo}{$this->MapTableName($tbl->Name)}{'Constraints'} = {map {$_,STATE_REMOVED} keys %{$tbl->Constraints}};
+    $this->{$TableInfo}{$this->MapTableName($tbl->Name)}{'Columns'} = {map { $_->Name, STATE_REMOVED} $tbl->Columns};
+    
+    return 1;
+}
+
+sub CreateTable {
+    my ($this,$tbl) = @_;
+    
+    # создаем таблицу, кроме внешних ключей
+    $this->{$Handler}->CreateTable($tbl,skip_foreign_keys => 1);
+    
+    $this->{$TableInfo}->{$tbl->Name}->{'State'} = STATE_CREATED;
+    
+    $this->{$TableInfo}->{$tbl->Name}->{'Columns'} = {map { $_->Name, STATE_CREATED } $tbl->Columns};
+    $this->{$TableInfo}->{$tbl->Name}->{'Constraints'} = {map {$_->Name, STATE_CREATED} grep { not UNIVERSAL::isa($_,'IMPL::SQL::Schema::Constraint::ForeignKey') } values %{$tbl->Constraints}};
+    
+    $this->AddConstraint($_) foreach grep { UNIVERSAL::isa($_,'IMPL::SQL::Schema::Constraint::ForeignKey') } values %{$tbl->Constraints};
+    
+    return 1;
+}
+
+sub AddColumn {
+    my ($this,$tblSrc,$column,$tblDst,$pos) = @_;
+    
+    $this->{$Handler}->AlterTableAddColumn($this->MapTableName($tblSrc->Name),$column,$tblDst,$pos);
+    $this->{$TableInfo}->{$this->MapTableName($tblSrc->Name)}->{'Columns'}->{$column->Name} = STATE_CREATED;
+    
+    return 1;
+}
+
+sub DropColumn {
+    my ($this,$tblSrc,$column) = @_;
+    $this->{$Handler}->AlterTableDropColumn($this->MapTableName($tblSrc->Name),$column->Name);
+    $this->{$TableInfo}->{$this->MapTableName($tblSrc->Name)}->{'Columns'}->{$column->Name} = STATE_REMOVED;
+    
+    return 1;
+}
+
+sub UpdateColumn {
+    my ($this,$tblSrc,$srcColumn,$dstColumn,$tblDst,$pos) = @_;
+    
+    if ($srcColumn->isSame($dstColumn) and $pos < @{$tblSrc->Columns} and $tblSrc->ColumnAt($pos) == $srcColumn) {
+        $this->{$TableInfo}->{$this->MapTableName($tblSrc->Name)}->{'Columns'}->{$dstColumn->Name} = STATE_UPDATED;
+        return 1;
+    }
+    
+    $this->{$Handler}->AlterTableChangeColumn($this->MapTableName($tblSrc->Name),$dstColumn,$tblDst,$pos);
+    $this->{$TableInfo}->{$this->MapTableName($tblSrc->Name)}->{'Columns'}->{$dstColumn->Name} = STATE_UPDATED;
+    
+    return 1;
+}
+
+sub DropConstraint {
+    my ($this,$constraint) = @_;
+    
+    $this->{$Handler}->AlterTableDropConstraint($this->MapTableName($constraint->Table->Name),$constraint);
+    $this->{$TableInfo}->{$constraint->Table->Name}->{'Constraints'}->{$constraint->Name} = STATE_REMOVED;
+    
+    return 1;
+}
+
+sub IfUndef {
+    my ($value,$default) = @_;
+    
+    return defined $value ? $value : $default;
+}
+
+sub AddConstraint {
+    my ($this,$constraint) = @_;
+    
+    # перед добавлением ограничения нужно убедиться в том, что созданы все необходимые столбцы и сопутствующие
+    # ограничения (например первичные ключи)
+    
+    my $pending;
+    
+    $pending = grep { my $column = $_; not grep { IfUndef($this->{$TableInfo}{$constraint->Table->Name}{'Columns'}{$column->Name}, STATE_NORMAL) == $_ } (STATE_UPDATED, STATE_CREATED) } $constraint->Columns;
+    
+    if ($pending) {
+        push @{$this->{$PendingActions}},{Action => \&AddConstraint, Args => [$constraint]};
+        return 2;
+    } else {
+        if (UNIVERSAL::isa($constraint,'IMPL::SQL::Schema::Constraint::ForeignKey')) {
+            if (not grep { IfUndef($this->{$TableInfo}{$constraint->ReferencedPrimaryKey->Table->Name}{'Constraints'}{$constraint->ReferencedPrimaryKey->Name},STATE_NORMAL) == $_} (STATE_UPDATED, STATE_CREATED)) {
+                push @{$this->{$PendingActions}},{Action => \&AddConstraint, Args => [$constraint]};
+                return 2;
+            }
+        }
+        $this->{$Handler}->AlterTableAddConstraint($constraint->Table->Name,$constraint);
+        $this->{$TableInfo}->{$constraint->Table->Name}->{'Constraints'}->{$constraint->Name} = STATE_CREATED;
+    }
+}
+
+sub ProcessPendingActions {
+    my ($this) = @_;
+    
+    while (my $action = shift @{$this->{$PendingActions}}) {
+        $action->{'Action'}->($this,@{$action->{'Args'}});
+    }
+}
+
+1;