<?php

namespace App\Database\Migrations;

use CodeIgniter\Database\Migration;

class CreateDoctorSpecializations extends Migration
{
    public function up(): void
    {
        $this->forge->addField([
            'id'   => ['type' => 'INT', 'unsigned' => true, 'auto_increment' => true],
            'name' => ['type' => 'VARCHAR', 'constraint' => 100],
        ]);
        $this->forge->addKey('id', true);
        $this->forge->addUniqueKey('name');
        $this->forge->createTable('specializations', true);

        $this->forge->addField([
            'id'                => ['type' => 'INT', 'unsigned' => true, 'auto_increment' => true],
            'doctor_id'         => ['type' => 'INT', 'unsigned' => true],
            'specialization_id' => ['type' => 'INT', 'unsigned' => true],
        ]);
        $this->forge->addKey('id', true);
        $this->forge->addKey('doctor_id');
        $this->forge->addKey('specialization_id');
        $this->forge->addUniqueKey(['doctor_id', 'specialization_id']);
        $this->forge->createTable('doctor_specializations', true);

        $db = \Config\Database::connect();

        if (! $db->tableExists('doctors')) {
            return;
        }

        $doctors = $db->table('doctors')
            ->select('id, specialization')
            ->where('specialization IS NOT NULL')
            ->where('specialization !=', '')
            ->get()
            ->getResultArray();

        foreach ($doctors as $doctor) {
            $rawNames = explode(',', (string) $doctor['specialization']);
            $names    = [];

            foreach ($rawNames as $name) {
                $name = trim($name);
                if ($name !== '' && ! in_array($name, $names, true)) {
                    $names[] = $name;
                }
            }

            foreach ($names as $name) {
                $existing = $db->table('specializations')->where('name', $name)->get()->getRowArray();

                if ($existing) {
                    $specializationId = (int) $existing['id'];
                } else {
                    $db->table('specializations')->insert(['name' => $name]);
                    $specializationId = (int) $db->insertID();
                }

                $pivotExists = $db->table('doctor_specializations')
                    ->where('doctor_id', (int) $doctor['id'])
                    ->where('specialization_id', $specializationId)
                    ->countAllResults() > 0;

                if (! $pivotExists) {
                    $db->table('doctor_specializations')->insert([
                        'doctor_id'         => (int) $doctor['id'],
                        'specialization_id' => $specializationId,
                    ]);
                }
            }
        }
    }

    public function down(): void
    {
        $this->forge->dropTable('doctor_specializations', true);
        $this->forge->dropTable('specializations', true);
    }
}