<?php

namespace system\library\database\driver;

use system\library\database\ifs\DatabaseIfs;
use system\library\exception\DatabaseException;

/**
 * Mysqli数据库驱动
 *
 * @author topnuomi 2018年11月20日
 */
class MySQLi implements DatabaseIfs {

    private static $instance;

    private $link;

    private $sql;

    public static function instance() {
        if (!self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    private function __construct() {
    }

    /**
     * 连接数据库
     * @param array $config
     * @return $this
     * @throws \Exception
     */
    public function connect($config) {
        $link = $this->link = @mysqli_connect($config['host'], $config['user'], $config['passwd'], $config['dbname']);
        if ($link === false) {
            throw new DatabaseException(mysqli_connect_error());
        }
        mysqli_query($link, 'set names ' . $config['charset']);
        return $this;
    }

    /**
     * @param string $table
     * @param array $data
     * @return int|string
     * @throws \Exception
     */
    public function insert($table, $data) {
        // TODO Auto-generated method stub
        if (count($data) == count($data, 1)) { // 一维数组
            $query = 'insert into ' . $table;
            $field = ' (' . implode(',', array_keys($data)) . ')';
            $value = array_values($data);
            $value = '(' . implode(',', $this->checkNull($value)) . ')';
            $this->sql = $query .= $field . ' values ' . $value . ';';
            $this->query($query);
        } else { // 二维数组
            foreach ($data as $key => $value) {
                $query = 'insert into ' . $table;
                $allField = ' (' . implode(',', array_keys($value)) . ')';
                $allValue = array_values($value);
                $allValue = '(' . implode(',', $this->checkNull($value)) . ')';
                $this->sql = $query .= $allField . ' values ' . $allValue . ';';
                $this->query($query);
            }
        }
        return mysqli_insert_id($this->link);
    }

    /**
     * @param string $table
     * @param array $join
     * @param array|string $on
     * @param array|string $where
     * @param string $order
     * @param string $limit
     * @param array $data
     * @return int
     * @throws \Exception
     */
    public function update($table, $join, $on, $where, $order, $limit, $data) {
        // TODO Auto-generated method stub
        $join = $this->processJoin($join, $on);
        $where = $this->processWhere($where);
        $order = $this->processOrder($order);
        $limit = $this->processLimit($limit);
        $query = 'update ' . $table . "{$join} set ";
        $updateData = [];
        foreach ($data as $key => $value) {
            if (!is_numeric($value) && !$value) {
                $value = 'NULL';
            } else {
                $value = '\'' . mysqli_real_escape_string($this->link, $value) . '\'';
            }
            $updateData[] = $key . '=' . $value;
        }
        $this->sql = $query .= implode(',', $updateData) . "{$where}{$order}{$limit}";
        $this->query($query);
        return mysqli_affected_rows($this->link);
    }

    /**
     * @param string $table
     * @param $distinct
     * @param array|string $field
     * @param array $join
     * @param array|string $on
     * @param array|string $where
     * @param string $order
     * @return array|null
     * @throws \Exception
     */
    public function find($table, $distinct, $field, $join, $on, $where, $order) {
        // TODO Auto-generated method stub
        $join = $this->processJoin($join, $on);
        $distinct = $this->processDistinct($distinct);
        if ($distinct) {
            $field = $distinct;
        } else {
            $field = $this->processField($field);
        }
        $where = $this->processWhere($where);
        $order = $this->processOrder($order);
        $this->sql = "select {$field} from $table{$join}{$where}{$order} limit 1";
        $result = $this->query($this->sql);
        return mysqli_fetch_assoc($result);
    }

    /**
     * @param string $table
     * @param $distinct
     * @param array|string $field
     * @param array $join
     * @param array|string $on
     * @param array|string $where
     * @param string $order
     * @param string $limit
     * @return array|null
     * @throws \Exception
     */
    public function select($table, $distinct, $field, $join, $on, $where, $order, $limit) {
        // TODO Auto-generated method stub
        $join = $this->processJoin($join, $on);
        $distinct = $this->processDistinct($distinct);
        if ($distinct) {
            $field = $distinct;
        } else {
            $field = $this->processField($field);
        }
        $where = $this->processWhere($where);
        $order = $this->processOrder($order);
        $limit = $this->processLimit($limit);
        $this->sql = "select {$field} from {$table}{$join}{$where}{$order}{$limit}";
        $result = $this->query($this->sql);
        return mysqli_fetch_all($result, MYSQLI_ASSOC);
    }

    /**
     * @param array|string $effect
     * @param string $table
     * @param array $join
     * @param array|string $on
     * @param array|string $where
     * @param string $order
     * @param string $limit
     * @return int
     * @throws \Exception
     */
    public function delete($effect, $table, $join, $on, $where, $order, $limit) {
        // TODO Auto-generated method stub
        $effect = $this->effect($effect);
        $join = $this->processJoin($join, $on);
        $where = $this->processWhere($where);
        $order = $this->processOrder($order);
        $limit = $this->processLimit($limit);
        $this->sql = "delete{$effect} from $table{$join}{$where}{$order}{$limit}";
        $this->query($this->sql);
        return mysqli_affected_rows($this->link);
    }

    /**
     * 获取表结构
     * @param $table
     * @return array|bool|null
     * @throws \Exception
     */
    public function tableDesc($table) {
        $sql = 'desc ' . $table;
        if (!$result = $this->query($sql)) {
            return false;
        }
        $data = mysqli_fetch_all($result, MYSQLI_ASSOC);
        return $data;
    }

    /**
     * @param $table
     * @param $field
     * @param $join
     * @param $on
     * @param $where
     * @return mixed
     * @throws \Exception
     */
    public function count($table, $field, $join, $on, $where) {
        $field = $this->processField($field);
        $join = $this->processJoin($join, $on);
        $where = $this->processWhere($where);
        $this->sql = "select count({$field}) from $table{$join}{$where}";
        $result = $this->query($this->sql);
        $count = mysqli_fetch_array($result);
        return $count[0];
    }

    /**
     * 公共方法
     * @param $table
     * @param $field
     * @param $join
     * @param $on
     * @param $where
     * @param $type
     * @return bool
     * @throws \Exception
     */
    public function common($table, $distinct, $field, $join, $on, $where, $type) {
        $distinct = $this->processDistinct($distinct);
        if ($distinct) {
            $field = $distinct;
        } else {
            $field = $this->processField($field);
        }
        $join = $this->processJoin($join, $on);
        $where = $this->processWhere($where);
        $this->sql = "select {$type}({$field}) from {$table}{$join}{$where}";
        $result = $this->query($this->sql);
        $data = mysqli_fetch_array($result);
        if (isset($data[0])) {
            return $data[0];
        } else {
            return false;
        }
    }

    /**
     * 执行SQL
     * @param string $query
     * @return bool|\mysqli_result
     * @throws \Exception
     */
    public function query($query) {
        $result = mysqli_query($this->link, $query);
        if (!$result)
            throw new DatabaseException(mysqli_error($this->link));
        // $this->writeLogs($result, $query);
        return $result;
    }

    /**
     * 获取执行的最后一条SQL
     *
     * @return string
     */
    public function sql() {
        return trim($this->sql, ' ');
    }

    public function effect($effect) {
        if ($effect) {
            if (is_array($effect)) {
                $effect = implode(',', $effect);
            }
            return ' ' . $effect;
        }
        return '';
    }

    private function processDistinct($distinct) {
        if ($distinct) {
            if (is_array($distinct)) {
                $distinct = implode(',', $distinct);
            }
            return 'distinct ' . $distinct;
        }
        return '';
    }

    /**
     * 组合字段
     *
     * @param string|array $field
     * @return string
     */
    private function processField($field) {
        if (!$field) {
            $field = '*';
        } else if (is_array($field)) {
            $field = implode(',', $field);
        }
        return $field;
    }

    /**
     * 组合where条件
     *
     * @param array $array
     * @param string $glue
     * @return string
     */
    private function processWhere(array $array, $glue = 'and') {
        $where = [];
        foreach ($array as $value) {
            if (empty($value)) continue;
            if (is_array($value)) {
                foreach ($value as $key => $val) {
                    if (is_array($val)) {
                        switch (strtolower($val[0])) {
                            case 'in':
                                $arr_ = explode(',', $val[1]);
                                $str = '';
                                for ($i = 0; $i < count($arr_); $i++) {
                                    $str .= (($i != 0) ? ',' : '') . $this->checkNull(trim($arr_[$i]));
                                }
                                $where[] = $key . ' ' . $val[0] . ' (' . $str . ')';
                                break;
                            case 'like':
                                $where[] = $key . ' ' . $val[0] . ' \'%' . $val[1] . '%\'';
                                break;
                            default:
                                $where[] = $key . ' ' . $val[0] . ' ' . $this->checkNull($val[1]);
                        }
                    } else {
                        $val = $this->checkNull($val);
                        $where[] = $key . '=' . $val;
                    }
                }
            } else {
                $where[] = $value;
            }
        }
        if (empty($where)) {
            return '';
        } else {
            return ' where ' . implode(' ' . $glue . ' ', $where);
        }
    }

    /**
     * 组合order
     *
     * @param string $order
     * @return string
     */
    private function processOrder($order = '') {
        if ($order) {
            $order = ' order by ' . $order;
        }
        return $order;
    }

    /**
     * 组合limit
     *
     * @param string $limit
     * @return string
     */
    private function processLimit($limit = '') {
        if ($limit) {
            if (is_array($limit)) {
                $limit = ' limit ' . implode(',', $limit);
            } else {
                $limit = ' limit ' . $limit;
            }
        }
        return $limit;
    }

    /**
     * 链接多表（join on）
     *
     * @param array $data
     * @param string|array $on
     * @return string
     */
    public function processJoin($data, $on) {
        $join = [];
        for ($i = 0; $i < count($data); $i++) {
            if (is_array($on[$i])) {
                $pieces = [];
                foreach ($on[$i] as $key => $value) {
                    $pieces[] = $key . ' = ' . $value;
                }
                $onString = implode(' and ', $pieces);
            } else {
                $onString = $on[$i];
            }
            $join[] = $data[$i][0] . ' join ' . $data[$i][1] . ($data[$i][2] ? ' as ' . $data[$i][2] : '') . ' on ' . $onString;
        }
        if (!empty($join)) {
            return ' ' . implode(' ', $join);
        }
        return '';
    }

    /**
     * 检查并处理空值
     *
     * @param array|string $array
     * @return array
     */
    private function checkNull($value) {
        if (is_array($value)) {
            foreach ($value as $k => $v) {
                if (!is_numeric($v) && !$v) {
                    $value[$k] = 'NULL';
                } else {
                    $value[$k] = '\'' . mysqli_real_escape_string($this->link, $v) . '\'';
                }
            }
        } else {
            if (!is_numeric($value) && !$value) {
                $value = 'NULL';
            } else {
                $value = '\'' . mysqli_real_escape_string($this->link, $value) . '\'';
            }
        }
        return $value;
    }

    public function writeLogs($result, $query) {
        if (DEBUG) {
            $error = '';
            if (!$result) {
                $error = mysqli_error($this->link);
            }
            $nowTime = date('Y-m-d H:i:s', time());
            $content = <<<EOF
[{$nowTime}] SQL: {$query} {$error}\n
EOF;
            file_put_contents(BASEDIR . '/system/logs/db_logs.txt', $content, FILE_APPEND);
        }
    }

    /**
     * 关闭数据库连接
     *
     * {@inheritdoc}
     *
     * @see \system\library\database\ifs\DatabaseIfs::close()
     */
    public function close() {
        if ($this->link) {
            if (mysqli_close($this->link)) {
                return true;
            }
            return false;
        }
        return true;
    }

    /**
     */
    public function __destruct() {
        $this->close();
    }
}