<?php

namespace DoctrineMigrations;

use Doctrine\DBAL\Schema\Schema;
use Doctrine\Migrations\AbstractMigration;

final class Version20260912001200 extends AbstractMigration
{
    public function getDescription(): string
    {
        return 'Counters for the site statistics. No record per visit, no identifier, no IP address.';
    }

    public function isTransactional(): bool
    {
        return false;
    }

    public function up(Schema $schema): void
    {
        // A counter table, not a log: one row per (day, hour, path, status, referrer host) that
        // gets incremented. There is deliberately no column from which a person could follow -
        // no IP address, no identifier, not even a hashed one, because a hashed IP address is
        // still personal data. That is what makes this measurement possible without consent.
        //
        // The table is created with its indexes in one go, which is safe: the rule about adding
        // indexes only in postUp() exists because altering an existing table rebuilds it on
        // SQLite, and this table does not exist yet.
        $hits = $schema->createTable('stat_hit');
        $hits->addColumn('id', 'integer', ['autoincrement' => true]);
        $hits->addColumn('website_id', 'string', ['length' => 64]);
        $hits->addColumn('day', 'string', ['length' => 10]);
        // 0 to 23, or -1 for a day that has been compacted from hours into one row.
        $hits->addColumn('hour', 'smallint');
        $hits->addColumn('path', 'string', ['length' => 200]);
        $hits->addColumn('status', 'smallint');
        // Empty for a direct visit or a link from this site itself; a bare host otherwise.
        $hits->addColumn('referrer_host', 'string', ['length' => 100, 'default' => '']);
        $hits->addColumn('count', 'integer', ['default' => 0]);
        $hits->setPrimaryKey(['id']);
        // The counter is found by this tuple, so it has to be unique - otherwise two requests in
        // the same second would create two rows instead of incrementing one.
        $hits->addUniqueIndex(['website_id', 'day', 'hour', 'path', 'status', 'referrer_host'], 'uniq_stat_hit');
        $hits->addIndex(['website_id', 'day'], 'idx_stat_hit_day');
    }

    public function down(Schema $schema): void
    {
        // Dropping it loses the measurement and nothing else: no content, no account, no media.
        $schema->dropTable('stat_hit');
    }
}