<?php namespace App\Services\Utils;
/**
 * Copyright 2019 OpenStack Foundation
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 **/

use Illuminate\Support\Facades\Log;
use Iterator;
/**
 * Class CSVReader
 * @package App\Services\Utils
 */
final class CSVReader implements Iterator {

    private $position = 0;
    /**
     * @var array
     */
    private $lines = [];
    /**
     * @var array
     */
    private $header = [];

    /**
     * CSVReader constructor.
     * @param array $header
     * @param array $lines
     */
    private function __construct(array $header, array $lines)
    {
        $this->header = $header;
        $this->lines  = $lines;
    }

    /**
     * @param string $content
     * @return array
     */
    public static function buildFrom(string $content):CSVReader
    {
        Log::debug(sprintf("CSVReader::buildFrom content %s", $content));
        $data    = str_getcsv($content,"\n"  );
        Log::debug(sprintf("CSVReader::buildFrom data %s", json_encode($data)));
        $idx     = 0;
        $header  = [];
        $lines   = [];
        foreach($data as $row)
        {
            $row = str_getcsv($row, ",");
            Log::debug(sprintf("CSVReader::buildFrom row %s", json_encode($row)));
            ++$idx;
            if($idx === 1) {

                foreach($row as $idx => $val){
                    // check the encoding of the header values
                    if(mb_detect_encoding($val) == 'UTF-8')
                        $val = iconv('utf-8', 'ascii//TRANSLIT', $val);
                    $header[] = $val;
                }
                continue;
            }
            $line  = [];
            if(count($row) != count($header)) continue;
            for($i = 0; $i < count($header); $i++){
                $line[$header[$i]] = trim($row[$i]);
            }
            $lines[] = $line;

        } //parse the items in rows
        return new CSVReader($header, $lines);
    }

    /**
     * @param string $colName
     * @return bool
     */
    public function hasColumn(string $colName):bool {
        if(mb_detect_encoding($colName) == 'UTF-8')
            $colName = iconv('utf-8', 'ascii//TRANSLIT', $colName);
        return in_array(trim($colName), $this->header);
    }

    /**
     * Return the current element
     * @link https://php.net/manual/en/iterator.current.php
     * @return mixed Can return any type.
     * @since 5.0.0
     */
    public function current()
    {
        return $this->lines[$this->position];
    }

    /**
     * Move forward to next element
     * @link https://php.net/manual/en/iterator.next.php
     * @return void Any returned value is ignored.
     * @since 5.0.0
     */
    public function next()
    {
        ++$this->position;
    }

    /**
     * Return the key of the current element
     * @link https://php.net/manual/en/iterator.key.php
     * @return mixed scalar on success, or null on failure.
     * @since 5.0.0
     */
    public function key()
    {
        return $this->position;
    }

    /**
     * Checks if current position is valid
     * @link https://php.net/manual/en/iterator.valid.php
     * @return boolean The return value will be casted to boolean and then evaluated.
     * Returns true on success or false on failure.
     * @since 5.0.0
     */
    public function valid()
    {
        return isset($this->lines[$this->position]);
    }

    /**
     * Rewind the Iterator to the first element
     * @link https://php.net/manual/en/iterator.rewind.php
     * @return void Any returned value is ignored.
     * @since 5.0.0
     */
    public function rewind()
    {
        $this->position = 0;
    }
}