<?php

namespace App\Services;

use CodeIgniter\Database\BaseConnection;

/**
 * Keeps the normalized family record aligned with its primary parent and
 * every current student owned by that parent.
 */
final class FamilyDataSyncService
{
    public function __construct(private readonly BaseConnection $db)
    {
    }

    public function syncForParent(int $parentId): ?int
    {
        if ($parentId <= 0) {
            return null;
        }

        foreach (['users', 'students', 'families', 'family_guardians', 'family_students'] as $table) {
            if (! $this->db->tableExists($table)) {
                return null;
            }
        }

        $parent = $this->db->table('users')
            ->select('id, firstname, lastname, cellphone, address_street, apt, city, state, zip')
            ->where('id', $parentId)
            ->get()
            ->getRowArray();
        if (! $parent) {
            return null;
        }

        $familyCode = 'FAM-' . $parentId;
        $family = $this->db->table('families')
            ->select('id')
            ->where('family_code', $familyCode)
            ->get()
            ->getRowArray();

        if (! $family) {
            $family = $this->db->table('family_guardians fg')
                ->select('fg.family_id AS id')
                ->join('families f', 'f.id = fg.family_id', 'inner')
                ->where('fg.user_id', $parentId)
                ->orderBy('fg.is_primary', 'DESC')
                ->orderBy('fg.id', 'ASC')
                ->get(1)
                ->getRowArray();
        }

        $familyData = $this->familyData($parent);
        if (! $family) {
            $this->db->table('families')->insert(['family_code' => $familyCode] + $familyData);
            $familyId = (int) $this->db->insertID();
        } else {
            $familyId = (int) ($family['id'] ?? 0);
            if ($familyId > 0) {
                $this->db->table('families')->where('id', $familyId)->update($familyData);
            }
        }

        if ($familyId <= 0) {
            throw new \RuntimeException('Family data could not be synchronized 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']
        );

        $students = $this->db->table('students')
            ->select('id')
            ->where('parent_id', $parentId)
            ->get()
            ->getResultArray();
        foreach ($students as $student) {
            $studentId = (int) ($student['id'] ?? 0);
            if ($studentId > 0) {
                $this->db->query(
                    'INSERT IGNORE INTO family_students (family_id, student_id, is_primary_home) VALUES (?, ?, 1)',
                    [$familyId, $studentId]
                );
            }
        }

        // Normally handled by the foreign key cascade; this also heals older
        // databases where that constraint was absent.
        $this->db->query(
            'DELETE fs FROM family_students fs LEFT JOIN students s ON s.id = fs.student_id WHERE fs.family_id = ? AND s.id IS NULL',
            [$familyId]
        );

        return $familyId;
    }

    private function familyData(array $parent): array
    {
        $parentName = trim((string) ($parent['firstname'] ?? '') . ' ' . (string) ($parent['lastname'] ?? ''));
        $data = [
            'household_name' => $parentName !== '' ? 'Family of ' . $parentName : 'Family of User ' . (int) $parent['id'],
            'address_line1' => trim((string) ($parent['address_street'] ?? '')),
            'address_line2' => trim((string) ($parent['apt'] ?? '')),
            'city' => trim((string) ($parent['city'] ?? '')),
            'state' => trim((string) ($parent['state'] ?? '')),
            'postal_code' => trim((string) ($parent['zip'] ?? '')),
            'primary_phone' => trim((string) ($parent['cellphone'] ?? '')),
            'is_active' => 1,
        ];
        if ($this->db->fieldExists('updated_at', 'families')) {
            $data['updated_at'] = utc_now();
        }

        return $data;
    }
}