<?php
namespace LatinizeUrl;

use Exception;
use ExtensionRegistry;
use Title;
use User;
use MediaWiki\MediaWikiServices;

class Utils {
    private static $dbr = null;
    private static $dbw = null;
    private static $cache = null;

    public static function initMasterDb(){
        if(!self::$dbw){
            self::$dbw = wfGetDB(DB_MASTER);
        }
    }

    public static function initReplicaDb(){
        if(!self::$dbr){
            self::$dbr = wfGetDB(DB_REPLICA);
        }
    }

    public static function initCache(){
        if(!self::$cache){
            self::$cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
        }
    }

    public static function slugExists($slug, $excludeUrl = null){
        if($excludeUrl){
            self::initReplicaDb();

            $cond = [
                'slug' => $slug,
            ];
            $cond['url'] = ['!', self::$dbr->addQuotes($excludeUrl)];
            
            $res = self::$dbr->selectField('url_slug', 'COUNT(*)', $cond, __METHOD__);
            return intval($res) > 0;
        } else {
            return self::getTitleTextBySlug($slug) !== false;
        }
    }

    public static function slugUrlExists($url){
        return self::getTitleTextBySlugUrl($url) !== false;
    }

    public static function titleSlugExists($title){
        return self::getSlugByTitle($title) !== false;
    }

    public static function getTitleBySlug($slug, $namespace = NS_MAIN){
        if($slug instanceof Title){
            $namespace = $slug->getNamespace();
            $slug = $slug->getText();
        }

        $titleText = self::getTitleTextBySlug($slug);
        if($titleText){
            return Title::newFromText($titleText, $namespace);
        } else {
            return false;
        }
    }

    public static function getTitleBySlugUrl($url, $namespace = NS_MAIN){
        if($url instanceof Title){
            $namespace = $url->getNamespace();
            $url = $url->getText();
        }

        $titleText = self::getTitleTextBySlugUrl($url);
        if($titleText){
            return Title::newFromText($titleText, $namespace);
        } else {
            return false;
        }
    }

    public static function getTitleTextBySlug($slug){
        self::initCache();
        self::initReplicaDb();

        return self::$cache->getWithSetCallback(
            self::$cache->makeKey('slug2title', $slug),
            self::$cache::TTL_MINUTE * 10,
            function() use($slug){
                $res = self::$dbr->select('url_slug', ['title'], [
                    'slug' => $slug,
                ], __METHOD__, [
                    'LIMIT' => 1,
                ]);
                if($res->numRows() > 0){
                    $data = $res->fetchRow();
                    return $data['title'];
                } else {
                    return false;
                }
            }
        );
    }

    public static function getTitleTextBySlugUrl($url){
        self::initCache();
        self::initReplicaDb();

        return self::$cache->getWithSetCallback(
            self::$cache->makeKey('slugurl2title', $url),
            self::$cache::TTL_MINUTE * 10,
            function() use($url){
                $res = self::$dbr->select('url_slug', ['title'], [
                    'url' => $url,
                ], __METHOD__, [
                    'LIMIT' => 1,
                ]);
                if($res->numRows() > 0){
                    $data = $res->fetchRow();
                    return $data['title'];
                } else {
                    return false;
                }
            }
        );
    }

    public static function getSlugByTitle($title){
        if($title instanceof Title){
            $title = $title->getText();
        }

        self::initCache();
        self::initReplicaDb();

        return self::$cache->getWithSetCallback(
            self::$cache->makeKey('title2slug', $title),
            self::$cache::TTL_MINUTE * 10,
            function() use($title){
                $res = self::$dbr->select('url_slug', ['slug'], [
                    'title' => $title,
                ], __METHOD__, [
                    'LIMIT' => 1,
                ]);
                if($res->numRows() > 0){
                    $data = $res->fetchRow();
                    return $data['slug'];
                } else {
                    return false;
                }
            }
        );
    }

    public static function getSlugUrlByTitle($title){
        if($title instanceof Title){
            $title = $title->getText();
        }

        self::initCache();
        self::initReplicaDb();

        return self::$cache->getWithSetCallback(
            self::$cache->makeKey('title2slugurl', $title),
            self::$cache::TTL_MINUTE * 10,
            function() use($title){
                $res = self::$dbr->select('url_slug', ['url'], [
                    'title' => $title,
                ], __METHOD__, [
                    'LIMIT' => 1,
                ]);
                if($res->numRows() > 0){
                    $data = $res->fetchRow();
                    return $data['url'];
                } else {
                    return false;
                }
            }
        );
    }

    public static function addTitleSlugMap($title, $slug, $latinize = [], $custom = 0){
        if(self::titleSlugExists($title)){
            throw new Exception("Title slug map already exists: " . $title);
        }
        self::initMasterDb();
        
        $exists = self::slugExists($slug);

        if($exists){
            $url = $slug . '-id';
        } else {
            $url = $slug;
        }

        self::$dbw->insert('url_slug', array(
            'title' => $title,
            'slug' => $slug,
            'url' => $url,
            'show_id' => $exists,
            'is_custom' => $custom,
            'latinize' => json_encode($latinize),
        ), __METHOD__);
        $lastId = self::$dbw->insertId();
        if($exists){
            $url = $slug . '-' . $lastId;
            self::$dbw->update('url_slug', [
                'url' => $url,
            ], [
                'id' => intval($lastId),
            ], __METHOD__);
        }
        return $url;
    }

    public static function updateTitleSlugMap($title, $slug, $latinize = [], $custom = 0){
        if(!self::titleSlugExists($title)){
            throw new Exception("Title slug map not exists: " . $title);
        }
        self::initMasterDb();
        self::initReplicaDb();

        $res = self::$dbr->selectRow('url_slug', ['id', 'slug', 'url', 'show_id'], [
            'title' => $title,
        ], __METHOD__);
        
        $mapId = intval($res->id);
        $oldSlug = $res->slug;
        $oldUrl = $res->url;

        if($oldSlug == $slug) return $oldUrl;

        $exists = self::slugExists($slug, $slug);
        if($exists){
            $url = $slug . '-' . strval($mapId);
        } else {
            $url = $slug;
        }

        $data = [
            'slug' => $slug,
            'url' => $url,
            'show_id' => $exists ? 1 : 0,
            'is_custom' => $custom,
        ];
        if(!empty($latinize)){
            $data['latinize'] = json_encode($latinize);
        }

        self::$dbw->update('url_slug', $data, [
            'id' => $mapId,
        ], __METHOD__);

        self::$cache->delete(self::$cache->makeKey('slug2title', $oldSlug));
        self::$cache->delete(self::$cache->makeKey('slugurl2title', $oldUrl));
        self::$cache->delete(self::$cache->makeKey('title2slug', $title));
        self::$cache->delete(self::$cache->makeKey('title2slugurl', $title));
        return $url;
    }

    public static function replaceTitleSlugMap($title, $slug, $latinize = [], $custom = 0){
        if(self::titleSlugExists($title)){
            return self::updateTitleSlugMap($title, $slug, $latinize, $custom);
        } else {
            return self::addTitleSlugMap($title, $slug, $latinize, $custom);
        }
    }

    public static function removeTitleSlugMap($title){
        self::initMasterDb();

        if(self::titleSlugExists($title)){
            $oldData = self::$dbr->selectRow('url_slug', ['slug', 'url'], [
                'title' => $title,
            ], __METHOD__);

            self::$dbr->delete('url_slug', [
                'title' => $title,
            ]);
            
            self::$cache->delete(self::$cache->makeKey('slug2title', $oldData->slug));
            self::$cache->delete(self::$cache->makeKey('slugurl2title', $oldData->url));
            self::$cache->delete(self::$cache->makeKey('title2slug', $title));
            self::$cache->delete(self::$cache->makeKey('title2slugurl', $title));
            return true;
        } else {
            return true;
        }
    }

    public static function hasUserEditedPage(Title $title, User $user){
        self::initReplicaDb();
        if(!$user->getId()) return false;
        $matchRecords = self::$dbr->selectField('revision', 'COUNT(*)', [
            'rev_page' => $title->getArticleID(),
            'rev_user' => $user->getId(),
        ], __METHOD__);
        $matchRecords = intval($matchRecords);
        return $matchRecords > 0;
    }

    public static function encodeUriComponent($str){
        return implode("/", array_map("urlencode", explode("/", $str)));
    }

    public static function getVersion(){
        return ExtensionRegistry::getInstance()->getAllThings()['LatinizeUrl']['version'];
    }
}