<?php

namespace App\Services;

use PDO;
use RuntimeException;

final class TenantRegistrationService
{
    public function __construct(
        private readonly PDO $pdo,
        private readonly AuditService $audit
    ) {
    }

    public function register(array $input): string
    {
        $name = trim((string) ($input['tenant_name'] ?? ''));
        $slug = $this->slugify((string) ($input['tenant_slug'] ?? $name));
        $ownerName = trim((string) ($input['owner_name'] ?? ''));
        $ownerEmail = mb_strtolower(trim((string) ($input['owner_email'] ?? '')));
        $ownerPassword = (string) ($input['owner_password'] ?? '');
        $plan = (string) ($input['plan'] ?? 'starter');
        $defaultPriceCents = max(50, (int) round(((float) ($input['default_price_eur'] ?? 1.20)) * 100));

        if ($name === '' || $slug === '' || $ownerName === '' || $ownerEmail === '' || $ownerPassword === '') {
            throw new RuntimeException('Bitte alle Pflichtfelder ausfuellen.');
        }

        if (!filter_var($ownerEmail, FILTER_VALIDATE_EMAIL)) {
            throw new RuntimeException('Die E-Mail-Adresse ist ungueltig.');
        }

        if (mb_strlen($ownerPassword) < 12) {
            throw new RuntimeException('Das Passwort muss mindestens 12 Zeichen lang sein.');
        }

        $allowedPlans = ['starter', 'team', 'business'];

        if (!in_array($plan, $allowedPlans, true)) {
            $plan = 'starter';
        }

        $existingTenant = $this->pdo->prepare('SELECT id FROM tenants WHERE slug = :slug LIMIT 1');
        $existingTenant->execute(['slug' => $slug]);

        if ($existingTenant->fetchColumn()) {
            throw new RuntimeException('Der gewuenschte Kurzname ist bereits vergeben.');
        }

        $existingUser = $this->pdo->prepare('SELECT id FROM users WHERE email = :email LIMIT 1');
        $existingUser->execute(['email' => $ownerEmail]);

        if ($existingUser->fetchColumn()) {
            throw new RuntimeException('Die E-Mail-Adresse ist bereits vorhanden. Fuer weitere Tenants bitte spaeter Einladungen nutzen.');
        }

        $now = gmdate('Y-m-d H:i:s');

        $this->pdo->beginTransaction();

        try {
            $userInsert = $this->pdo->prepare(
                'INSERT INTO users (full_name, email, password_hash, platform_role)
                 VALUES (:full_name, :email, :password_hash, "user")'
            );
            $userInsert->execute([
                'full_name' => $ownerName,
                'email' => $ownerEmail,
                'password_hash' => secure_password_hash($ownerPassword),
            ]);
            $userId = (int) $this->pdo->lastInsertId();

            $tenantInsert = $this->pdo->prepare(
                'INSERT INTO tenants (name, slug, plan, status, created_at)
                 VALUES (:name, :slug, :plan, "active", :created_at)'
            );
            $tenantInsert->execute([
                'name' => $name,
                'slug' => $slug,
                'plan' => $plan,
                'created_at' => $now,
            ]);
            $tenantId = (int) $this->pdo->lastInsertId();

            $membershipInsert = $this->pdo->prepare(
                'INSERT INTO tenant_memberships (tenant_id, user_id, role, status)
                 VALUES (:tenant_id, :user_id, "owner", "active")'
            );
            $membershipInsert->execute([
                'tenant_id' => $tenantId,
                'user_id' => $userId,
            ]);

            $settingsInsert = $this->pdo->prepare(
                'INSERT INTO tenant_settings (
                    tenant_id,
                    currency_code,
                    default_product_price_cents,
                    allow_self_service,
                    allow_paper_lists,
                    allow_rfid
                ) VALUES (
                    :tenant_id,
                    "EUR",
                    :default_product_price_cents,
                    1,
                    1,
                    0
                )'
            );
            $settingsInsert->execute([
                'tenant_id' => $tenantId,
                'default_product_price_cents' => $defaultPriceCents,
            ]);

            $memberInsert = $this->pdo->prepare(
                'INSERT INTO members (tenant_id, user_id, display_name, email, status)
                 VALUES (:tenant_id, :user_id, :display_name, :email, "active")'
            );
            $memberInsert->execute([
                'tenant_id' => $tenantId,
                'user_id' => $userId,
                'display_name' => $ownerName,
                'email' => $ownerEmail,
            ]);

            $sourceInsert = $this->pdo->prepare(
                'INSERT INTO capture_sources (tenant_id, code, name, channel, is_system)
                 VALUES (:tenant_id, :code, :name, :channel, 1)'
            );

            foreach ([
                ['digital_self', 'Digitale Selbstbuchung', 'digital'],
                ['paper_sheet', 'Papierliste / Nacherfassung', 'paper'],
                ['admin_backoffice', 'Backoffice-Buchung', 'admin'],
                ['rfid_reader', 'RFID-Geraet', 'rfid'],
            ] as [$code, $sourceName, $channel]) {
                $sourceInsert->execute([
                    'tenant_id' => $tenantId,
                    'code' => $code,
                    'name' => $sourceName,
                    'channel' => $channel,
                ]);
            }

            foreach ([
                ['Kaffee', $defaultPriceCents],
                ['Espresso', $defaultPriceCents],
                ['Tee', max(80, $defaultPriceCents - 20)],
            ] as [$productName, $priceCents]) {
                $productInsert = $this->pdo->prepare(
                    'INSERT INTO products (tenant_id, name, sku, is_active)
                     VALUES (:tenant_id, :name, :sku, 1)'
                );
                $productInsert->execute([
                    'tenant_id' => $tenantId,
                    'name' => $productName,
                    'sku' => strtolower(str_replace(' ', '-', $productName)),
                ]);
                $productId = (int) $this->pdo->lastInsertId();

                $priceInsert = $this->pdo->prepare(
                    'INSERT INTO product_prices (tenant_id, product_id, price_cents, valid_from)
                     VALUES (:tenant_id, :product_id, :price_cents, :valid_from)'
                );
                $priceInsert->execute([
                    'tenant_id' => $tenantId,
                    'product_id' => $productId,
                    'price_cents' => $priceCents,
                    'valid_from' => $now,
                ]);
            }

            $this->pdo->commit();
        } catch (\Throwable $throwable) {
            $this->pdo->rollBack();
            throw $throwable;
        }

        $this->audit->log($tenantId, $userId, 'tenant.registered', 'tenant', $tenantId, 'success', [
            'plan' => $plan,
            'slug' => $slug,
        ]);

        return $slug;
    }

    private function slugify(string $value): string
    {
        $value = mb_strtolower($value);
        $value = preg_replace('/[^a-z0-9]+/u', '-', $value) ?? '';
        $value = trim($value, '-');

        return $value;
    }
}