<?hh // strict

namespace Facebook\HackCodegen;

/**

* For a given ModelSchema, this class generates code for a class

* that will allow to read the data from a database and store it

* in the object.

*/

class ModelGenerator {

public function __construct(

private \ModelSchema $schema,

) {}

private function getSchemaName(): string {

$ref = new \ReflectionClass($this->schema);

$name = $ref->getShortName();

return Str::endsWith($name, 'Schema')

? Str::substr($name, 0, -6)

: $name;

}

public function generate(): void {

$class = codegen_class($this->getSchemaName())

->setIsFinal()

->setConstructor($this->getConstructor())

->addMethod($this->getLoad())

->addMethods($this->getGetters())

->setHasManualMethodSection();

codegen_file(dirname(__FILE__).'/../models/'.$this->getSchemaName().'.php')

->addClass($class)

->save();

}

private function getConstructor(): CodegenConstructor {

return codegen_constructor()

->setPrivate()

->addParameter('private Map<string, mixed> $data');

}

private function getLoad(): CodegenMethod {

$body = hack_builder()

->addLine(

'$result = DB::queryFirstRow("SELECT * FROM %s WHERE %s=%%s", $id);',

$this->schema->getTableName(),

$this->schema->getIdField()

)

->startIfBlock('!$result')

->addReturn('null')

->endIfBlock()

->addReturn('new %s(new Map($result))', $this->getSchemaName());

return codegen_method('load')

->setIsStatic()

->addParameter('int $id')

->setReturnType('?'.$this->getSchemaName())

->setBody($body->getCode());

}

private function getGetters(): Vector<CodegenMethod> {

$methods = Vector {};

foreach ($this->schema->getFields() as $name => $field) {

$return_type = $field->getType();

$data = '$this->data[\''.$field->getDbColumn().'\']';

$return_data = $data;

if ($return_type == 'DateTime') {

$return_data = 'new DateTime('.$data.')';

} else {

$return_data = "($return_type) $data";

}

if ($field->isOptional()) {

$return_type = '?'.$return_type;

$builder = hack_builder();

if ($field->isManual()) {

$builder->beginManualSection($name);

}

$builder->addWithSuggestedLineBreaks(

"return isset($data)\t? $return_data\t: null;",

);

if ($field->isManual()) {

$builder->endManualSection();

}

$body = $builder->getCode();

} else {

$body = 'return '.$return_data.';';

}

$methods[] = codegen_method('get'.$name)

->setReturnType($return_type)

->setBody($body);

}

return $methods;

}

}