<?php

namespace ProcessMaker\Traits;

use ProcessMaker\Query\Expression;

use ProcessMaker\Query\Traits\PMQL;

use Illuminate\Database\Eloquent\Builder;

trait ExtendedPMQL

{

use PMQL {

PMQL::scopePMQL as parentScopePMQL;

}

/**

* PMQL scope that extends the standard PMQL scope by supporting any custom

* aliases specified in the model.

*

* @param \Illuminate\Database\Eloquent\Builder $builder

* @param string $query

* @param callable $callback

*

* @return mixed

*/

public function scopePMQL(Builder $builder, string $query, callable $callback = null)

{

if (! $callback) {

// If a callback isn't passed to the scope, we handle it here

return $this->parentScopePMQL($builder, $query, function($expression) use ($builder) {

return $this->handle($expression, $builder);

});

} else {

// If a callback is passed to the scope, we skip handling it here

return $this->parentScopePMQL($builder, $query, $callback);

}

}

/**

* Callback function to check for and handle any field aliases, value

* aliases, or field wildcards specified in the given model.

*

* @param \ProcessMaker\Query\Expression $expression

* @param \Illuminate\Database\Eloquent\Builder $builder

*

* @return mixed

*/

private function handle(Expression $expression, Builder $builder)

{

// Setup our needed variables

$field = $expression->field->field();

$model = $builder->getModel();

if (is_string($field)) {

// Check the type of our value; set as string if possible

if (is_a($expression->value, 'ProcessMaker\\Query\\LiteralValue')) {

$value = $expression->value->value();

} else {

$value = $expression->value;

}

// Title case our field name so we can suffix it to our method names

$fieldMethodName = ucfirst(strtolower($field));

// A field alias specifies that a field name used in a PMQL query

// translates to a different field name in our database.

$method = "fieldAlias{$fieldMethodName}";

if (method_exists($model, $method)) {

return $expression->field->setField($model->{$method}());

}

// A value alias specifies that a value must be parsed by a callback

// function if its field name matches a specific word.

$method = "valueAlias{$fieldMethodName}";

if (method_exists($model, $method)) {

return $model->{$method}($value, $expression, $builder);

}

// A field wildcard passes any fields not caught by a field or value

// alias to a callback function for any needed processing. If the

// callback returns void, the PMQL is parsed as if there is

// no callback.

$method = "fieldWildcard";

if (method_exists($model, $method)) {

return $model->{$method}($value, $expression, $builder);

}

}

}

}