<?php

if (!defined('BASEPATH')) {
    exit('No direct script access allowed');
}

class Datatables
{
    private $add_columns = [];
    private $ci;
    private $columns = [];
    private $distinct;
    private $edit_columns = [];
    private $filter = [];
    private $group_by = [];
    private $joins = [];
    private $like = [];
    private $or_where = [];
    private $select = [];
    private $table;
    private $unset_columns = [];
    private $where = [];

    /**
     * Copies an instance of CI
     */
    public function __construct()
    {
        $this->ci = &get_instance();
    }

    /**
     * Sets additional column variables for adding custom columns
     *
     * @param string $column
     * @param string $content
     * @param string $match_replacement
     * @return mixed
     */
    public function add_column($column, $content, $match_replacement = null)
    {
        $this->add_columns[$column] = ['content' => $content, 'replacement' => $this->explode(',', $match_replacement)];
        return $this;
    }

    /**
     * Generates the DISTINCT portion of the query
     *
     * @param string $column
     * @return mixed
     */
    public function distinct($column)
    {
        $this->distinct = $column;
        $this->ci->db->distinct($column);
        return $this;
    }

    /**
     * Sets additional column variables for editing columns
     *
     * @param string $column
     * @param string $content
     * @param string $match_replacement
     * @return mixed
     */
    public function edit_column($column, $content, $match_replacement)
    {
        $this->edit_columns[$column][] = ['content' => $content, 'replacement' => $this->explode(',', $match_replacement)];
        return $this;
    }

    /**
     * Generates the WHERE portion of the query
     *
     * @param mixed $key_condition
     * @param string $val
     * @param bool $backtick_protect
     * @return mixed
     */
    public function filter($key_condition, $val = null, $backtick_protect = true)
    {
        $this->filter[] = [$key_condition, $val, $backtick_protect];
        return $this;
    }

    /**
     * Generates the FROM portion of the query
     *
     * @param string $table
     * @return mixed
     */
    public function from($table)
    {
        $this->table = $table;
        return $this;
    }

    /**
     * Builds all the necessary query segments and performs the main query based on results set from chained statements
     *
     * @param string $output
     * @param string $charset
     * @return string
     */
    public function generate($output = 'json', $charset = 'UTF-8')
    {
        if ('json' == strtolower($output)) {
            $this->get_paging();
        }

        $this->get_ordering();
        $this->get_filtering();
        return $this->produce_output(strtolower($output), strtolower($charset));
    }

    /**
     * Generates a custom GROUP BY portion of the query
     *
     * @param string $val
     * @return mixed
     */
    public function group_by($val)
    {
        $this->group_by[] = $val;
        $this->ci->db->group_by($val);
        return $this;
    }

    public function group_end()
    {
        $this->ci->db->group_end();
        return $this;
    }

    public function group_start()
    {
        $this->ci->db->group_start();
        return $this;
    }

    /**
     * Generates the JOIN portion of the query
     *
     * @param string $table
     * @param string $fk
     * @param string $type
     * @return mixed
     */
    public function join($table, $fk, $type = '')
    {
        $this->joins[] = [$table, $fk, $type];
        $this->ci->db->join($table, $fk, $type);
        return $this;
    }

    /**
     * Generates a %LIKE% portion of the query
     *
     * @param mixed $key_condition
     * @param string $val
     * @param bool $backtick_protect
     * @return mixed
     */
    public function like($key_condition, $val = null, $backtick_protect = true)
    {
        $this->like[] = [$key_condition, $val, $backtick_protect];
        $this->ci->db->like($key_condition, $val, $backtick_protect);
        return $this;
    }

    /**
     * Generates the WHERE portion of the query
     *
     * @param mixed $key_condition
     * @param string $val
     * @param bool $backtick_protect
     * @return mixed
     */
    public function or_where($key_condition, $val = null, $backtick_protect = true)
    {
        $this->or_where[] = [$key_condition, $val, $backtick_protect];
        $this->ci->db->or_where($key_condition, $val, $backtick_protect);
        return $this;
    }

    /**
     * Generates the SELECT portion of the query
     *
     * @param string $columns
     * @param bool $backtick_protect
     * @return mixed
     */
    public function select($columns, $backtick_protect = true)
    {
        foreach ($this->explode(',', $columns) as $val) {
            $column = trim(preg_replace('/(.*)\s+as\s+(\w*)/i', '$2', $val));
            $this->columns[] = $column;
            $this->select[$column] = trim(preg_replace('/(.*)\s+as\s+(\w*)/i', '$1', $val));
        }

        $this->ci->db->select($columns, $backtick_protect);
        return $this;
    }

    /**
     * If you establish multiple databases in config/database.php this will allow you to
     * set the database (other than $active_group) - more info: http://ellislab.com/forums/viewthread/145901/#712942
     */
    public function set_database($db_name)
    {
        $db_data = $this->ci->load->database($db_name, true);
        $this->ci->db = $db_data;
    }

    /**
     * Unset column
     *
     * @param string $column
     * @return mixed
     */
    public function unset_column($column)
    {
        $column = explode(',', $column);
        $this->unset_columns = array_merge($this->unset_columns, $column);
        return $this;
    }

    /**
     * Generates the WHERE portion of the query
     *
     * @param mixed $key_condition
     * @param string $val
     * @param bool $backtick_protect
     * @return mixed
     */
    public function where($key_condition, $val = null, $backtick_protect = true)
    {
        $this->where[] = [$key_condition, $val, $backtick_protect];
        $this->ci->db->where($key_condition, $val, $backtick_protect);
        return $this;
    }

    /**
     * Return the difference of open and close characters
     *
     * @param string $str
     * @param string $open
     * @param string $close
     * @return string $retval
     */
    private function balanceChars($str, $open, $close)
    {
        $openCount = substr_count($str, $open);
        $closeCount = substr_count($str, $close);
        $retval = $openCount - $closeCount;
        return $retval;
    }

    /**
     * Check mDataprop
     *
     * @return bool
     */
    private function check_mDataprop()
    {
        if (!$this->ci->input->post('mDataProp_0')) {
            return false;
        }

        for ($i = 0; $i < intval($this->ci->input->post('iColumns')); $i++) {
            if (!is_numeric($this->ci->input->post('mDataProp_' . $i))) {
                return true;
            }
        }

        return false;
    }

    /**
     * Runs callback functions and makes replacements
     *
     * @param mixed $custom_val
     * @param mixed $row_data
     * @return string $custom_val['content']
     */
    private function exec_replace($custom_val, $row_data)
    {
        $replace_string = '';

        if (isset($custom_val['replacement']) && is_array($custom_val['replacement'])) {
            foreach ($custom_val['replacement'] as $key => $val) {
                $sval = preg_replace("/(?<!\w)([\'\"])(.*)\\1(?!\w)/i", '$2', trim($val));

                if (preg_match('/(\w+::\w+|\w+)\((.*)\)/i', $val, $matches) && is_callable($matches[1])) {
                    $func = $matches[1];
                    $args = preg_split("/[\s,]*\\\"([^\\\"]+)\\\"[\s,]*|" . "[\s,]*'([^']+)'[\s,]*|" . '[,]+/', $matches[2], 0, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);

                    foreach ($args as $args_key => $args_val) {
                        $args_val = preg_replace("/(?<!\w)([\'\"])(.*)\\1(?!\w)/i", '$2', trim($args_val));
                        $args[$args_key] = (in_array($args_val, $this->columns)) ? ($row_data[($this->check_mDataprop()) ? $args_val : array_search($args_val, $this->columns)]) : $args_val;
                    }

                    $replace_string = call_user_func_array($func, $args);
                } elseif (in_array($sval, $this->columns)) {
                    $replace_string = $row_data[($this->check_mDataprop()) ? $sval : array_search($sval, $this->columns)];
                } else {
                    $replace_string = $sval;
                }

                $custom_val['content'] = str_ireplace('$' . ($key + 1), $replace_string, $custom_val['content']);
            }
        }

        return $custom_val['content'];
    }

    /**
     * Explode, but ignore delimiter until closing characters are found
     *
     * @param string $delimiter
     * @param string $str
     * @param string $open
     * @param string $close
     * @return mixed $retval
     */
    private function explode($delimiter, $str, $open = '(', $close = ')')
    {
        $retval = [];
        $hold = [];
        $balance = 0;
        $parts = explode($delimiter, $str);

        foreach ($parts as $part) {
            $hold[] = $part;
            $balance += $this->balanceChars($part, $open, $close);

            if ($balance < 1) {
                $retval[] = implode($delimiter, $hold);
                $hold = [];
                $balance = 0;
            }
        }

        if (count($hold) > 0) {
            $retval[] = implode($delimiter, $hold);
        }

        return $retval;
    }

    /**
     * Compiles the select statement based on the other functions called and runs the query
     *
     * @return mixed
     */
    private function get_display_result()
    {
        return $this->ci->db->get($this->table);
    }

    /**
     * Generates a %LIKE% portion of the query
     *
     * @return mixed
     */
    private function get_filtering()
    {
        if ($this->check_mDataprop()) {
            $mColArray = $this->get_mDataprop();
        } elseif ($this->ci->input->post('sColumns')) {
            $mColArray = explode(',', $this->ci->input->post('sColumns'));
        } else {
            $mColArray = $this->columns;
        }

        $sWhere = '';
        $sSearch = $this->ci->db->escape_like_str($this->ci->input->post('sSearch'));
        $mColArray = array_values(array_diff($mColArray, $this->unset_columns));
        $columns = array_values(array_diff($this->columns, $this->unset_columns));

        if ('' != $sSearch) {
            for ($i = 0; $i < count($mColArray); $i++) {
                if ('true' == $this->ci->input->post('bSearchable_' . $i) && in_array($mColArray[$i], $columns)) {
                    $sWhere .= $this->select[$mColArray[$i]] . " LIKE '%" . $sSearch . "%' OR ";
                }
            }
        }

        $sWhere = substr_replace($sWhere, '', -3);

        if ('' != $sWhere) {
            $this->ci->db->where('(' . $sWhere . ')');
        }

        $sRangeSeparator = $this->ci->input->post('sRangeSeparator');

        for ($i = 0; $i < intval($this->ci->input->post('iColumns')); $i++) {
            if (isset($_POST['sSearch_' . $i]) && '' != $this->ci->input->post('sSearch_' . $i) && in_array($mColArray[$i], $columns)) {
                $miSearch = explode(',', $this->ci->input->post('sSearch_' . $i));

                foreach ($miSearch as $val) {
                    if (preg_match("/(<=|>=|=|<|>)(\s*)(.+)/i", trim($val), $matches)) {
                        $this->ci->db->where($this->select[$mColArray[$i]] . ' ' . $matches[1], $matches[3]);
                    } elseif (!empty($sRangeSeparator) && preg_match("/(.*)$sRangeSeparator(.*)/i", trim($val), $matches)) {
                        $rangeQuery = '';

                        if (!empty($matches[1])) {
                            $rangeQuery = 'STR_TO_DATE(' . $this->select[$mColArray[$i]] . ",'%d/%m/%y %H:%i:%s') >= STR_TO_DATE('" . $matches[1] . " 00:00:00','%d/%m/%y %H:%i:%s')";
                        }

                        if (!empty($matches[2])) {
                            $rangeQuery .= (!empty($rangeQuery) ? ' AND ' : '') . 'STR_TO_DATE(' . $this->select[$mColArray[$i]] . ",'%d/%m/%y %H:%i:%s') <= STR_TO_DATE('" . $matches[2] . " 23:59:59','%d/%m/%y %H:%i:%s')";
                        }

                        if (!empty($matches[1]) || !empty($matches[2])) {
                            $this->ci->db->where($rangeQuery);
                        }
                    } else {
                        $this->ci->db->where($this->select[$mColArray[$i]] . ' LIKE', '%' . $val . '%');
                    }
                }
            }
        }

        foreach ($this->filter as $val) {
            $this->ci->db->where($val[0], $val[1], $val[2]);
        }
    }

    /**
     * Get mDataprop order
     *
     * @return mixed
     */
    private function get_mDataprop()
    {
        $mDataProp = [];

        for ($i = 0; $i < intval($this->ci->input->post('iColumns')); $i++) {
            $mDataProp[] = $this->ci->input->post('mDataProp_' . $i);
        }

        return $mDataProp;
    }

    /**
     * Generates the ORDER BY portion of the query
     *
     * @return mixed
     */
    private function get_ordering()
    {
        if ($this->check_mDataprop()) {
            $mColArray = $this->get_mDataprop();
        } elseif ($this->ci->input->post('sColumns')) {
            $mColArray = explode(',', $this->ci->input->post('sColumns'));
        } else {
            $mColArray = $this->columns;
        }

        $mColArray = array_values(array_diff($mColArray, $this->unset_columns));
        $columns = array_values(array_diff($this->columns, $this->unset_columns));

        for ($i = 0; $i < intval($this->ci->input->post('iSortingCols')); $i++) {
            if (isset($mColArray[intval($this->ci->input->post('iSortCol_' . $i))]) && in_array($mColArray[intval($this->ci->input->post('iSortCol_' . $i))], $columns) && 'true' == $this->ci->input->post('bSortable_' . intval($this->ci->input->post('iSortCol_' . $i)))) {
                $this->ci->db->order_by($mColArray[intval($this->ci->input->post('iSortCol_' . $i))], $this->ci->input->post('sSortDir_' . $i));
            }
        }
    }

    /**
     * Generates the LIMIT portion of the query
     *
     * @return mixed
     */
    private function get_paging()
    {
        $iStart = $this->ci->input->post('iDisplayStart');
        $iLength = $this->ci->input->post('iDisplayLength');

        if ('' != $iLength && '-1' != $iLength) {
            $this->ci->db->limit($iLength, ($iStart) ? $iStart : 0);
        }
    }

    /**
     * Get result count
     *
     * @return integer
     */
    private function get_total_results($filtering = false)
    {
        if ($filtering) {
            $this->get_filtering();
        }

        foreach ($this->joins as $val) {
            $this->ci->db->join($val[0], $val[1], $val[2]);
        }

        foreach ($this->where as $val) {
            $this->ci->db->where($val[0], $val[1], $val[2]);
        }

        foreach ($this->or_where as $val) {
            $this->ci->db->or_where($val[0], $val[1], $val[2]);
        }

        foreach ($this->group_by as $val) {
            $this->ci->db->group_by($val);
        }

        foreach ($this->like as $val) {
            $this->ci->db->like($val[0], $val[1], $val[2]);
        }

        if ($this->distinct && strlen($this->distinct) > 0) {
            $this->ci->db->distinct($this->distinct);
            $this->ci->db->select($this->columns);
        }

        $query = $this->ci->db->get($this->table, null, null, false);
        return $query->num_rows();
    }

    /**
     * Workaround for json_encode's UTF-8 encoding if a different charset needs to be used
     *
     * @param mixed $result
     * @return string
     */
    private function jsonify($result = false)
    {
        if (is_null($result)) {
            return 'null';
        }

        if (false === $result) {
            return 'false';
        }

        if (true === $result) {
            return 'true';
        }

        if (is_scalar($result)) {
            if (is_float($result)) {
                return floatval(str_replace(',', '.', strval($result)));
            }

            if (is_string($result)) {
                static $jsonReplaces = [['\\', '/', '\n', '\t', '\r', '\b', '\f', '"'], ['\\\\', '\\/', '\\n', '\\t', '\\r', '\\b', '\\f', '\"']];
                return '"' . str_replace($jsonReplaces[0], $jsonReplaces[1], $result) . '"';
            }
            return $result;
        }

        $isList = true;

        for ($i = 0, reset($result); $i < count($result); $i++, next($result)) {
            if (key($result) !== $i) {
                $isList = false;
                break;
            }
        }

        $json = [];

        if ($isList) {
            foreach ($result as $value) {
                $json[] = $this->jsonify($value);
            }

            return '[' . join(',', $json) . ']';
        }
        foreach ($result as $key => $value) {
            $json[] = $this->jsonify($key) . ':' . $this->jsonify($value);
        }

        return '{' . join(',', $json) . '}';
    }

    /**
     * Builds an encoded string data. Returns JSON by default, and an array of aaData and sColumns if output is set to raw.
     *
     * @param string $output
     * @param string $charset
     * @return mixed
     */
    private function produce_output($output, $charset)
    {
        $aaData = [];
        $rResult = $this->get_display_result();

        if ('json' == $output) {
            $iTotal = $this->get_total_results();
            $iFilteredTotal = $this->get_total_results(true);
        }

        foreach ($rResult->result_array() as $row_key => $row_val) {
            $aaData[$row_key] = ($this->check_mDataprop()) ? $row_val : array_values($row_val);

            foreach ($this->add_columns as $field => $val) {
                if ($this->check_mDataprop()) {
                    $aaData[$row_key][$field] = $this->exec_replace($val, $aaData[$row_key]);
                } else {
                    $aaData[$row_key][] = $this->exec_replace($val, $aaData[$row_key]);
                }
            }

            foreach ($this->edit_columns as $modkey => $modval) {
                foreach ($modval as $val) {
                    $aaData[$row_key][($this->check_mDataprop()) ? $modkey : array_search($modkey, $this->columns)] = $this->exec_replace($val, $aaData[$row_key]);
                }
            }

            $aaData[$row_key] = array_diff_key($aaData[$row_key], ($this->check_mDataprop()) ? $this->unset_columns : array_intersect($this->columns, $this->unset_columns));

            if (!$this->check_mDataprop()) {
                $aaData[$row_key] = array_values($aaData[$row_key]);
            }
        }

        $sColumns = array_diff($this->columns, $this->unset_columns);
        $sColumns = array_merge_recursive($sColumns, array_keys($this->add_columns));

        if ('json' == $output) {
            $sOutput = [
                'sEcho'                => intval($this->ci->input->post('sEcho')),
                'iTotalRecords'        => $iTotal,
                'iTotalDisplayRecords' => $iFilteredTotal,
                'aaData'               => $aaData,
                'sColumns'             => implode(',', $sColumns),
            ];

            if ('utf-8' == $charset) {
                return json_encode($sOutput);
            }
            return $this->jsonify($sOutput);
        }
        return ['aaData' => $aaData, 'sColumns' => $sColumns];
    }
}
/* End of file Datatables.php */
/* Location: ./application/libraries/Datatables.php */
