### convenient object access ###

sub ALF_Object {	local($id) = @_;
	local $object = $ALF_Object{$id};
	$object? $object : $id;
}

sub ALF_Identification {	local($object) = @_;
	local $name = $ALF_Name{$object};
	local $type = $ALF_Type{$object};
	$name? $name : $type? $type : $object;
}

sub ALF_HierarchyInfoText {	local($object,$maxlevel) = @_;
	local $id = &ALF_Identification($object);
	local $parent = $object;
	local $level = 0;
	while ($level < $maxlevel) {
		$level += 1;
		$parent = $ALF_Parent{$parent};
		last unless $parent;
		$id = join('.',&ALF_Identification($parent),$id);
	}
	$id =~ s/\s//g;
	$id;
}

### create design elements ###

sub ALF_CreateCellReferences {	local($library) = @_;
	foreach $cell (&ALF_FindMatchingObjects($library,'CELL')) {
		local $ref = $ALF_Name{$cell};
		unless ($ALF_Object{$ref}) {
			$ALF_Object{$ref} = $cell;
		}
	}
}

sub ALF_CreateCellInstances {	local($design,%cell) = @_;
	local $cell_list = &CreateArray();
	foreach $key (keys %cell) {
		local $ref = $cell{$key};
		local $object = $ALF_Object{$ref};
		if ($object) {
			local $cell = &ALF_CopyObject($object,$design,$ref,$key);
			$ALF_Object{$key} = $cell;
			&AppendArray($cell_list,$cell);
		} else {
			print("# ALF Data Error: reference \47$ref\47 for key \47$key\47 not found in design \47$design\47\n");
		}
	}
	$cell_list;
}

sub ALF_CreateNodes {	local($design,@id) = @_;
	local $node_list = &CreateArray();
	foreach $id (@id) {
		local $node = &ALF_CreateNode($design,$id);
		$ALF_Object{$id} = $node;
		&AppendArray($node_list,$node);
	}
	$node_list;
}

sub ALF_CreateNode {	local($parent,$name) = @_;
	local $node = &ALF_CreateObject($parent,'NODE',$name);
	foreach $type ('DELAY','SLEWRATE','CAPACITANCE') {
		local $model = &ALF_CreateObject($node,$type);
		local $default = &ALF_CreateObject($model,'DEFAULT',undef,0);
		foreach $subtype ('RISE','FALL') {
			local $submodel = &ALF_CreateObject($model,$subtype);
			$ALF_Record{$submodel} = &CreateArray();
		}
	} $node;
}

### create design constraints ###

sub ALF_CreateConstraint {	local($node,$type,$subtype,$result,%condition) = @_;
	$node = &ALF_Object($node);
	local $model = &ALF_FindMatchingObject($node,$type);
	local $submodel = &ALF_FindMatchingObject($model,$subtype);
	local $data = &ALF_AppendRecord($ALF_Record{$submodel});
	&ALF_UpdateRecord($data,$result,%condition);
}

### create connectivity and calculation graph for nodes ###

sub ALF_CreateSum {	local($model,@nodes) = @_;
	local $type = $ALF_Type{$model};
	foreach $subtype ('RISE','FALL') {
		local $sum = &ALF_FindMatchingObject($model,$subtype);
		local @arg;
		foreach $node (@nodes) {
			local $arg = &ALF_FindMatchingObject(&ALF_FindMatchingObject($node,$type),$subtype);
			$arg[$#arg+1] = $arg if defined($arg);
		}
		if ($#arg > 0) {
			local $header = &ALF_CreateObject($sum,'HEADER');
			local @sum;
			foreach $arg (@arg) {
				local $name = &AutoName;
				local $addend = &ALF_CreateObject($header,$type,$name);
				$ALF_Link{$addend} = $arg;
				$sum[$#sum+1] = $name;
			}
			&ALF_CreateObject($sum,'EQUATION',undef,&CreateArray(split(/\s/,join(' + ',@sum))));
		} elsif ($#arg == 0) {
			$ALF_Link{$sum} = $arg[0];
		} else {
			$ALF_Value{$sum} = 0;
		}
	}
}

sub ALF_LinkNodes {	local($driver,@receivers) = @_;
	foreach $type ('DELAY','SLEWRATE') {
		foreach $receiver (@receivers) {
			local $model = &ALF_FindMatchingObject($receiver,$type);
			&ALF_CreateSum($model,$driver);
		}
	}
	&ALF_CreateSum(&ALF_FindMatchingObject($driver,'CAPACITANCE'),@receivers);
}

sub ALF_LinkNodeModel {	local($node,$type) = @_;
	$node = &ALF_Object($node);
	local $model = &ALF_FindMatchingObject($node,$type);
	if ($model) {
		foreach $subtype ('RISE','FALL') {
			local $submodel = &ALF_FindMatchingObject($model,$subtype);
			local $record = $ALF_Record{$submodel};
			$ALF_EvaluationMethod{$record} = 'sum';
		}
	}
}

### Create connectivity and calculation graph for cells ###

sub ALF_LinkCell {	local($cell,%connect) = @_;
	$cell = &ALF_Object($cell);
	print("# ALF Data Info: creating links in cell:\t",&ALF_ObjectInfoText($cell),"\n") if $ALF_Debug;
	foreach $key (keys %connect) {
		local $pin = &ALF_FindMatchingObject($cell,'PIN',$key);
		if (defined($pin)) {
			$ALF_Link{$pin} = &ALF_Object($connect{$key});
			local $pinmodel = &ALF_FindMatchingObject($pin,'CAPACITANCE');
			&ALF_LinkPinModel($pinmodel) if $pinmodel;
		} else {
			print("# ALF Data Error: no pin named $key found in cell:\t",&ALF_ObjectInfoText($cell),"\n");
		}
	}
	foreach $vector (&ALF_FindMatchingObjects($cell,'VECTOR')) {
		print("# ALF Data Info: creating links for models in vector:\t",&ALF_ObjectInfoText($vector),"\n") if $ALF_Debug;
		local $expression = $ALF_Expression{$vector};
		local $models = &CreateArray();
		&ALF_SearchForObjects($models,$vector,'ALF_IsFullArithmeticModel');
		foreach $model (&Array($models)) {
			print("# ALF Data Info: searching link for model:\t",&ALF_ObjectInfoText($model),"\n") if $ALF_Debug;
			&ALF_LinkVectorModel($model,$expression);
			local $header = &ALF_FindMatchingObject($model,'HEADER');
			foreach $arg (&Array($ALF_Children{$header})) {
				&ALF_LinkVectorModel($arg,$expression);
				print("# ALF Data Info: searching link for model argument:\t",&ALF_ObjectInfoText($arg),"\n") if $ALF_Debug;
			}
		}
	}
}

sub ALF_LinkVectorModel {	local($model,$expression) = @_;
	local $is_arg = &StringMatch($ALF_Type{$ALF_Parent{$model}},'HEADER');
	local $designation = $is_arg? 'model argument' : 'model';
	local ($pin,$node,$ref);
	if (	($pin = &ALF_FindMatchingObject($model,'PIN'))
	&&	($node = $ALF_Link{$ALF_Link{$pin}})
	&&	($ref = &ALF_FindMatchingObject($node,$ALF_Type{$model}))
	) {
		print("# ALF Data Info: pointer to link found for $designation:\t",&ALF_ObjectInfoText($model),"\n") if $ALF_Debug;
		local $edge = &ALF_FindEdgeLiteral($expression,$ALF_Value{$pin});
		local $link;
		if ($link =
			&ALF_IsRisingEdge ($edge)? &ALF_FindMatchingObject($ref,'RISE')
		:	&ALF_IsFallingEdge($edge)? &ALF_FindMatchingObject($ref,'FALL')
		: undef) {
			print("# ALF Data Info: $designation $model has link:\t",&ALF_ObjectInfoText($link),"\n") if $ALF_Debug;
			if ($is_arg) {
				$ALF_Link{$model} = $link;
			} else {
				&ALF_AppendRecord($ALF_Record{$link},$model);
			}
		} elsif ($link = &ALF_FindMatchingObject($ref,'DEFAULT')) {
			print("# ALF Data Warning: $designation $model has default link:\t",&ALF_ObjectInfoText($link),"\n");
			if ($is_arg) {
				$ALF_Link{$model} = $link;
			} else {
				&ALF_AppendRecord($ALF_Record{$link},$model);
			}
		} else {
			print("# ALF Data Error: $designation $model has no link\n");
		}
	}
}

sub ALF_LinkPinModel {	local($pin_model) = @_;
	local $node = $ALF_Link{$ALF_Parent{$pin_model}};
	local $node_model = &ALF_FindMatchingObject($node,$ALF_Type{$pin_model});
	foreach $subtype ('RISE','FALL') {
		local $found_submodel = &ALF_FindMatchingObject($pin_model,$subtype);
		local $pin_submodel = $found_submodel? $found_submodel : $pin_model;
		local $node_submodel = &ALF_FindMatchingObject($node_model,$subtype);
		&ALF_AppendRecord($ALF_Record{$node_submodel},$pin_submodel);
		print("# ALF Data Info: linking pin model\t",&ALF_ObjectInfoText($pin_submodel),"\n") if $ALF_Debug;
		print("# ALF Data Info: linked pin model $pin_submodel to node\t",&ALF_ObjectInfoText($node_submodel),"\n") if $ALF_Debug;
	}
}

### analysis engine ###

sub ALF_LibraryPreparation {	local ($library) = @_;
	print("# System Message:\tstarted library preparation\t",&DateTime,"\n");
	&ALF_FlattenObject($library);
	&ALF_CreateCellReferences($library);
	print("# System Message:\tfinished library preparation\t",&DateTime,"\n");
}

sub ALF_CircuitAnalysis {	local ($design,$ruleset,$netlist,$constraint,$method,@modeltype) = @_;
	print("# System Message:\tstarted circuit analysis\t",&DateTime,"\n");

	local ($cell_list,$node_list,$connect_list) = &Eval($netlist,$design);
	local %cell_list = &Assoc($cell_list);
	local @cell_list = &AssocKeys($cell_list);
	local @node_list = &Array($node_list);
	&ALF_CreateCellInstances($design,%cell_list); 
	&ALF_CreateNodes($design,@node_list);
	print("# System Message:\tcreated design elements   \t",&DateTime,"\n");

	&ALF_LinkObjects($ruleset,$design,'CELL','WIRE');
	print("# System Message:\tcreated internal connectivity\t",&DateTime,"\n");

	foreach $cell (@cell_list) {
		$cell = &ALF_Object($cell);
		local $connect = &AssocVal($connect_list,$ALF_Name{$cell});
		&ALF_LinkCell($cell,&Assoc($connect));
	}
	foreach $node (@node_list) {
		$node = &ALF_Object($node);
		&ALF_LinkNodeModel($node,'CAPACITANCE');
	}
	print("# System Message:\tcreated external connectivity\t",&DateTime,"\n");

	&Eval($constraint);
	print("# System Message:\tcreated evaluation constraints\t",&DateTime,"\n");

	local $models = &CreateArray();
	foreach $modeltype (@modeltype) {
		foreach $cell (@cell_list) {
			$cell = &ALF_Object($cell);
			&ALF_SearchForObjects($models,$cell,'ALF_ObjectMatch',$modeltype);
		}
	}
	print("# System Message:\tidentified evaluation targets\t",&DateTime,"\n\n");

	foreach $model (&Array($models)) {
		local $id = &ALF_HierarchyInfoText($model,5);
		local $result = &ALF_Calculate($model,$method);
		print("#\tevaluation result for model $model: $id = $result\n");
	}
	print("# System Message:\tfinished circuit analysis\t",&DateTime,"\n");
}

1;