<?php

class DBManager extends SQLite3 {

// -----------------------------------------------------------------------------

    function __construct(string $pathOfDB) {
        $this->open($pathOfDB);
    }

// -----------------------------------------------------------------------------

    public function readContent($pageID) {

        $sql = <<<BBB
        
            select * from pages
            where pageID = "$pageID"

        BBB;

        // querySingle() 默认返回第一行第一个字段
        // 加上参数参数 true, 则返回第一行所有字段
        return $this->querySingle($sql, true);

    }

// -----------------------------------------------------------------------------

    public function writeContent(string $pageID, string $pageTitle, string $content) {

        $content = base64_encode($content);
        $sql = <<<BBB
            replace into pages (pageID, pageTitle, content)
            values ("$pageID", "$pageTitle", "$content");
        BBB;

        $this->exec($sql);

    }

// -----------------------------------------------------------------------------

    public function deletePage($pageID) {

        $sql = <<<BBB
            delete from pages
            where pageID = "$pageID"
        BBB;

        $this->exec($sql);

    }

// -----------------------------------------------------------------------------

    public function checkIfPageExists($pageID) {

        $sql = <<<BBB
            select * from pages
            where pageID = "$pageID"
        BBB;

        $arr = $this->querySingle($sql, true);

        if (count($arr) == 0) {
            return false;
        } else {
            return true;
        }

    }

// -----------------------------------------------------------------------------

    public function getAllPages() {

        $sql = <<<BBB
            select pageID, pageTitle from pages
        BBB;

        $result = $this->query($sql);

        $pages = [];
        while ($row = $result->fetchArray()) {
            $pages[] = $row;
        }

        return $pages;
        // 使用：
        // $pages[0]['pageID'], $pages[1]['pageTitle']

    }

// -----------------------------------------------------------------------------

    private function createTable() {

        $sql = <<<BBB
            CREATE TABLE pages (
                id        INTEGER PRIMARY KEY
                                  UNIQUE,
                pageID    TEXT    UNIQUE
                                  NOT NULL,
                pageTitle TEXT    NOT NULL,
                content   TEXT    NOT NULL
            );
        BBB;

        $this->exec($sql);

    }

// -----------------------------------------------------------------------------

    private function deleteTable() {

        $sql = <<<BBB
            drop table if exists pages
        BBB;

        $this->exec($sql);

    }

// -----------------------------------------------------------------------------

    public function reCreateTable() {

        $this->deleteTable();
        $this->createTable();

    }

// -----------------------------------------------------------------------------

}