<?php

namespace App\Database\Migrations;

use CodeIgniter\Database\Migration;

/**
 * Completes the family-link repair for databases that already ran the first
 * backfill before students without any household record were discovered.
 */
final class CreateMissingStudentFamilies extends Migration
{
    public function up(): void
    {
        foreach (['users', 'students', 'families', 'family_guardians', 'family_students'] as $table) {
            if (! $this->db->tableExists($table)) {
                return;
            }
        }

        $students = $this->db->query(
            "SELECT s.id AS student_id, s.parent_id, u.firstname, u.lastname
               FROM students s
               JOIN users u ON u.id = s.parent_id
          LEFT JOIN family_students fs ON fs.student_id = s.id
              WHERE fs.id IS NULL
                AND s.parent_id IS NOT NULL
                AND s.parent_id > 0
           ORDER BY s.id"
        )->getResultArray();

        foreach ($students as $student) {
            $studentId = (int) ($student['student_id'] ?? 0);
            $parentId = (int) ($student['parent_id'] ?? 0);
            if ($studentId <= 0 || $parentId <= 0) {
                continue;
            }

            $family = $this->db->query(
                "SELECT f.id
                   FROM families f
              LEFT JOIN family_guardians fg
                     ON fg.family_id = f.id
                    AND fg.user_id = ?
                  WHERE f.family_code = ? OR fg.user_id = ?
               ORDER BY (f.family_code = ?) DESC, fg.is_primary DESC, f.id ASC
                  LIMIT 1",
                [$parentId, 'FAM-' . $parentId, $parentId, 'FAM-' . $parentId]
            )->getRowArray();

            if (empty($family['id'])) {
                $parentName = trim((string) ($student['firstname'] ?? '') . ' ' . (string) ($student['lastname'] ?? ''));
                $this->db->table('families')->insert([
                    'family_code' => 'FAM-' . $parentId,
                    'household_name' => $parentName !== '' ? 'Family of ' . $parentName : 'Family of User ' . $parentId,
                    'is_active' => 1,
                ]);
                $family['id'] = (int) $this->db->insertID();
            }

            $familyId = (int) ($family['id'] ?? 0);
            if ($familyId <= 0) {
                throw new \RuntimeException('Could not create a family for parent ID ' . $parentId . '.');
            }

            $this->db->query(
                'INSERT IGNORE INTO family_guardians (family_id, user_id, relation, is_primary, receive_emails, receive_sms) VALUES (?, ?, ?, 1, 1, 0)',
                [$familyId, $parentId, 'primary']
            );
            $this->db->query(
                'INSERT IGNORE INTO family_students (family_id, student_id, is_primary_home) VALUES (?, ?, 1)',
                [$familyId, $studentId]
            );
        }
    }

    public function down(): void
    {
        // This repair is intentionally irreversible for the same reason as the
        // preceding family-membership backfill.
    }
}