<?php  namespace Filebase;

use Filebase\SortLogic;

class QueryLogic
{

    /**
    * $database
    *
    * \Filebase\Database
    */
    protected $database;

    /**
    * $predicate
    *
    * \Filebase\Predicate
    */
    protected $predicate;


    /**
    * $cache
    *
    * \Filebase\Cache
    */
    protected $cache = false;

    /**
    * __construct
    *
    */
    public function __construct(Database $database)
    {
        $this->database  = $database;
        $this->predicate = new Predicate();

        if ($this->database->getConfig()->cache===true)
        {
            $this->cache = new Cache($this->database);
        }
    }

    /**
    * loadDocuments
    *
    */
    private function loadDocuments()
    {
        $predicates = $this->predicate->get();

        if ($this->cache===false)
        {
            $this->documents = $this->database->findAll(true,false);
            return $this;
        }

        $this->cache->setKey(json_encode($predicates));

        if ($cached_documents = $this->cache->get())
        {
            $this->documents = $cached_documents;

            $this->sort();
            $this->offsetLimit();
            return $this;
        }
        $this->documents = $this->database->findAll(true,false);
        return $this;
    }

    /**
    * run
    *
    */
    public function run()
    {
        $predicates = $this->predicate->get();
        $this->documents  = [];
        $cached_documents = false;

        if (empty($predicates))
        {
            $predicates = 'findAll';
        }

        $this->loadDocuments();

        if ($predicates !== 'findAll')
        {
            $this->documents = $this->filter($this->documents, $predicates);
        }

        if ($this->cache !== false)
        {
            if ($cached_documents === false)
            {
                $dsave = [];
                foreach($this->documents as $document)
                {
                    $dsave[] = $document->getId();
                }

                $this->cache->store($dsave);
            }
        }

        $this->sort();
        $this->offsetLimit();

        if (is_array($this->fields) && !empty($this->fields))
        {
            foreach($this->documents as $index => $document)
            {
                $fields = [];
                foreach($this->fields as $fieldTarget)
                {
                    $fields[ $fieldTarget ] = $document->field($fieldTarget);
                }

                $this->documents[$index] = $fields;
            }
        }

        return $this;
    }

    /**
    * filter
    *
    */
    protected function filter($documents, $predicates)
    {
        $results = [];

        $org_docs = $documents;

        if (isset($predicates['and']) && !empty($predicates['and']))
        {
            foreach($predicates['and'] as $predicate)
            {
                list($field, $operator, $value) = $predicate;

                $documents = array_values(array_filter($documents, function ($document) use ($field, $operator, $value) {
                    return $this->match($document, $field, $operator, $value);
                }));

                $results = $documents;
            }
        }

        if (isset($predicates['or']) && !empty($predicates['or']))
        {
            foreach($predicates['or'] as $predicate)
            {
                list($field, $operator, $value) = $predicate;

                $documents = array_values(array_filter($org_docs, function ($document) use ($field, $operator, $value) {
                    return $this->match($document, $field, $operator, $value);
                }));

                $results = array_unique(array_merge($results, $documents), SORT_REGULAR);
            }
        }

        return $results;
    }

    /**
    * offsetLimit
    *
    */
    protected function offsetLimit()
    {
        if ($this->limit != 0 || $this->offset != 0)
        {
            $this->documents = array_slice($this->documents, $this->offset, $this->limit);
        }
    }

    /**
    * sort
    *
    */
    protected function sort()
    {
        if ($this->orderBy[0] == '')
        {
            return false;
        }

        $sortlogic = new SortLogic($this->orderBy, $this->sortBy, 0);
        usort($this->documents, [$sortlogic, 'sort']);
    }

    /**
    * match
    *
    */
    public function match($document, $field, $operator, $value)
    {
        $d_value = $document->field($field);

        switch (true)
        {
            case ($operator === '=' && $d_value == $value):
                return true;
            case ($operator === '==' && $d_value == $value):
                return true;
            case ($operator === '===' && $d_value === $value):
                return true;
            case ($operator === '!=' && $d_value != $value):
                return true;
            case ($operator === '!==' && $d_value !== $value):
                return true;
            case (strtoupper($operator) === 'NOT' && $d_value != $value):
                return true;
            case ($operator === '>'  && $d_value >  $value):
                return true;
            case ($operator === '>=' && $d_value >= $value):
                return true;
            case ($operator === '<'  && $d_value <  $value):
                return true;
            case ($operator === '<=' && $d_value <= $value):
                return true;
            case (strtoupper($operator) === 'LIKE' && preg_match('/'.$value.'/is',$d_value)):
                return true;
            case (strtoupper($operator) === 'NOT LIKE' && !preg_match('/'.$value.'/is',$d_value)):
                return true;
            case (strtoupper($operator) === 'IN' && in_array($d_value, (array) $value)):
                return true;
            case (strtoupper($operator) === 'IN' && in_array($value, (array) $d_value)):
                return true;
            case (strtoupper($operator) === 'REGEX' && preg_match($value, $d_value)):
                return true;
            default:
                return false;
        }

    }

}