<?php
/**
 * NIS2 Agile - DemoSeedService
 * ----------------------------------------------------------------------------
 * Seed/reset del dataset DEMO isolato (Avatar di prodotto / formazione).
 * Clona la golden org DataCore (#151) negli org del range demo riservato:
 *   - 996001  → dataset DEMO (servito read-only via demo_jwt scope=demo:read-only)
 *   - 996002  → SANDBOX scrivibile isolata per i "prova tu" della formazione
 *
 * Idempotente: cancella e ricrea i dati del range demo. Usato da:
 *   - DemoController::resetDataset (reset tra sessioni demo / sandbox)
 *   - scripts/seed-demo-dataset.php (CLI bootstrap manuale)
 *
 * Sta sotto application/ (montata in nis2-app) così è raggiungibile sia da
 * PHP-FPM (resetDataset) sia da CLI.
 */
class DemoSeedService
{
    public const SRC_ORG = 151;                              // golden DataCore
    public const TARGETS = [
        996001 => 'DataCore Demo S.r.l.',
        996002 => 'NIS2 Sandbox Formazione S.r.l.',
    ];

    private const USERCOLS = ['owner_user_id','responsible_user_id','assigned_to','reported_by','created_by','uploaded_by','relevance_assessed_by','assessed_by','approved_by','reviewed_by','closed_by','user_id'];
    /** parent → child (FK figlio) da remappare al nuovo parent */
    private const PC = [
        ['assessments','assessment_responses','assessment_id'],
        ['risks','risk_treatments','risk_id'],
        ['incidents','incident_timeline','incident_id'],
        ['training_courses','training_assignments','course_id'],
        ['policies','policy_versions','policy_id'],
    ];
    private const SIMPLE = ['compliance_controls','suppliers','assets'];

    /**
     * Esegue il seed/reset. $targets: mappa orgId=>nome (default: entrambe).
     * @return array<int,string> esito per org ("ok uid=N" | "errore: ...")
     */
    public static function seed(?array $targets = null): array
    {
        $targets = $targets ?: self::TARGETS;
        $pdo = Database::getInstance();
        $out = [];
        $pdo->exec('SET FOREIGN_KEY_CHECKS=0');
        foreach ($targets as $T => $NAME) {
            $T = (int) $T;
            $pdo->beginTransaction();
            try {
                self::purge($pdo, $T);
                $org = Database::fetchOne('SELECT * FROM organizations WHERE id = ?', [self::SRC_ORG]);
                self::copyRow($pdo, 'organizations', $org, ['id' => $T, 'name' => $NAME], 0);

                $uid = (int) Database::insert('users', [
                    'email' => "demo-$T@nis2-demo.local", 'full_name' => "Demo NIS2 $T", 'role' => 'org_admin',
                    'password_hash' => password_hash(bin2hex(random_bytes(12)), PASSWORD_DEFAULT),
                    'is_active' => 1, 'must_change_password' => 0, 'password_version' => 1,
                ]);
                $pdo->prepare('INSERT INTO user_organizations (user_id,organization_id,role) VALUES (?,?,?)')->execute([$uid, $T, 'org_admin']);

                foreach (self::PC as [$par, $chi, $fk]) {
                    if (!self::tableExists($pdo, $par)) continue;
                    foreach (Database::fetchAll("SELECT * FROM `$par` WHERE organization_id = ? ORDER BY id", [self::SRC_ORG]) as $r) {
                        $newPar = self::copyRow($pdo, $par, $r, ['organization_id' => $T], $uid);
                        if (self::tableExists($pdo, $chi)) {
                            foreach (Database::fetchAll("SELECT * FROM `$chi` WHERE `$fk` = ? ORDER BY id", [$r['id']]) as $cr) {
                                $ov = [$fk => $newPar];
                                if (in_array('organization_id', self::cols($pdo, $chi), true)) $ov['organization_id'] = $T;
                                self::copyRow($pdo, $chi, $cr, $ov, $uid);
                            }
                        }
                    }
                }
                foreach (self::SIMPLE as $t) {
                    if (!self::tableExists($pdo, $t)) continue;
                    foreach (Database::fetchAll("SELECT * FROM `$t` WHERE organization_id = ? ORDER BY id", [self::SRC_ORG]) as $r) {
                        self::copyRow($pdo, $t, $r, ['organization_id' => $T], $uid);
                    }
                }
                $pdo->commit();
                $out[$T] = "ok (uid=$uid)";
            } catch (Throwable $ex) {
                $pdo->rollBack();
                $out[$T] = 'errore: ' . $ex->getMessage();
            }
        }
        $pdo->exec('SET FOREIGN_KEY_CHECKS=1');
        return $out;
    }

    private static function purge(PDO $pdo, int $T): void
    {
        foreach (self::PC as [$par, $chi, $fk]) {
            if (self::tableExists($pdo, $chi)) $pdo->exec("DELETE FROM `$chi` WHERE `$fk` IN (SELECT id FROM `$par` WHERE organization_id = $T)");
        }
        foreach (array_merge(array_column(self::PC, 0), self::SIMPLE) as $t) {
            if (self::tableExists($pdo, $t)) $pdo->exec("DELETE FROM `$t` WHERE organization_id = $T");
        }
        $pdo->exec("DELETE FROM user_organizations WHERE organization_id = $T");
        $pdo->exec("DELETE FROM users WHERE email = 'demo-$T@nis2-demo.local'");
        $pdo->exec("DELETE FROM organizations WHERE id = $T");
    }

    private static function cols(PDO $pdo, string $t): array
    {
        static $cache = [];
        if (!isset($cache[$t])) {
            $cache[$t] = $pdo->query("SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME='$t' ORDER BY ORDINAL_POSITION")->fetchAll(PDO::FETCH_COLUMN);
        }
        return $cache[$t];
    }

    private static function tableExists(PDO $pdo, string $t): bool
    {
        return (int) $pdo->query("SELECT COUNT(*) FROM information_schema.TABLES WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME='$t'")->fetchColumn() > 0;
    }

    /** Copia una riga in $table applicando $overrides e rimappando le colonne utente a $uid. */
    private static function copyRow(PDO $pdo, string $table, array $row, array $overrides, int $uid): int
    {
        $data = [];
        foreach (self::cols($pdo, $table) as $c) {
            if ($c === 'id') { if (array_key_exists('id', $overrides)) $data['id'] = $overrides['id']; continue; }
            if (array_key_exists($c, $overrides)) { $data[$c] = $overrides[$c]; continue; }
            $v = $row[$c] ?? null;
            if (in_array($c, self::USERCOLS, true) && $v !== null) $v = $uid;
            $data[$c] = $v;
        }
        $cl = implode(',', array_map(fn($x) => "`$x`", array_keys($data)));
        $ph = implode(',', array_fill(0, count($data), '?'));
        $pdo->prepare("INSERT INTO `$table` ($cl) VALUES ($ph)")->execute(array_values($data));
        return (int) $pdo->lastInsertId();
    }
}