<?php

namespace cx_newsletter;
use \cx_appengine\string_builder;
use \exception;

class groups_mapper
extends mapper
implements mapper_interface {
    public function create(database_item $target) : database_item {
        if ($target->has_id()) {
            throw $this->get_has_id_exception();
        }

        if ($this->exists($target)) {
            throw new exception('Group '.$target->name.' already exists.');
        }

        $converter = new group_converter();
        $converter->load_object($target);

        $result = $this->get_database()->insert(
            $this->get_tables()->groups(),
            $converter->get_array()
        );

        if ($result === false) {
            throw $this->get_exception('create');
        }

        return $this->complete(new group($this->get_database()->insert_id));
    }

    private function exists(database_item $target) : bool {
        $filter = [
            'name' => $target->name
        ];

        $result = $this->load_all($filter);

        if (empty($result)) {
            return false;
        }

        if (!$target->has_id()) {
            return true;
        }

        if ($result[0]->get_id() === $target->get_id()) {
            return false;
        }

        return true;
    }

    public function save(database_item $target) : database_item { 
        if (!$target->has_id()) {
            throw $this->get_blank_id_exception();
        }

        if ($this->exists($target)) {
            throw new exception('Group '.$target->name.' already exists.');
        }

        $converter = new group_converter();
        $converter->load_object($target);

        $condition = [];
        $condition['id'] = $target->get_id();

        $result = $this->get_database()->update(
            $this->get_tables()->groups(),
            $converter->get_array(),
            $condition
        );

        if ($result === false) {
            throw $this->get_exception('save');
        }   
        
        return $this->complete($target);
    }

    public function load_all(array $filters = [], ?int $limit = null) : array {
        $query = new string_builder();
        $query->push('select id, name ');
        $query->push('from '.$this->get_tables()->groups().' ');
        $query->push($this->parse_filters($filters));
        $query->push($this->parse_limit($limit));

        $result = $this->get_database()->get_results($query->get(), ARRAY_A);

        if ($result === null) {
            throw $this->get_exception('find');
        }

        $groups = [];
        $converter = new group_converter();

        foreach ($result as $row) {
            array_push($groups, $converter->load_array($row)->get_object());
        }

        return $groups;
    }

    public function complete(database_item $target) : database_item {
        if (!$target->has_id()) {
            throw $this->get_blank_id_exception();
        }

        $query = new string_builder();
        $query->push('select id, name ');
        $query->push('from '.$this->get_tables()->groups().' ');
        $query->push('where id=%d');

        $sql = $this->get_database()->prepare($query, $target->get_id());
        $row = $this->get_database()->get_row($sql, ARRAY_A);

        if ($row === null) {
            throw $this->get_exception('complete');
        }

        $converter = new group_converter();
        $converter->load_array($row);

        return $converter->get_object();
    }

    public function remove(database_item $target) : void {
        if (!$target->has_id()) {
            throw $this->get_blank_id_exception();
        }
        
        $result = $this->get_database()->delete(
            $this->get_tables()->groups(),
            [ 'id' => $target->get_id() ]
        );

        if ($result === false) {
            throw $this->get_exception('remove');
        }
    }

    public function count(array $filters = []) : int {
        $query = new string_builder();
        $query->push('select count(id) ');
        $query->push('from '.$this->get_tables()->groups().' ');
        $query->push($this->parse_filters($filters));

        $result = $this->get_database()->get_var($query->get());

        if ($result === null) {
            throw $this->get_exception('count');
        }

        return intval($result);
    }

    public function find(string $phrase, ?int $limit = null) : array {
        $columns = [
            'name' => '%'.$phrase.'$'
        ];

        $filters = $this->parse_filters(
            $columns,
            filter_type::like,
            filter_glue::single
        );

        $query = new string_builder();
        $query->push('select id, name ');
        $query->push('from '.$this->get_tables()->groups().' ');
        $query->push($filters);
        $query->push($this->parse_limit($limit));

        $result = $this->get_database()->get_result($query->get(), ARRAY_A);

        if ($result === null) {
            throw $this->get_exception('find');
        }

        $groups = [];
        $converter = new groups_converter();

        foreach ($result as $row) {
            array_push($groups, $converter->load_array($row)->get_object());
        }

        return $groups;
    }
}