<?php

namespace App\Database\Migrations;

use App\Support\Enrollment\DeliberationDecision;
use CodeIgniter\Database\Migration;

class AddSchoolYearTransitionEnrollmentFields extends Migration
{
    public function up()
    {
        if ($this->db->tableExists('student_decisions') && ! $this->db->fieldExists('deliberation_decision_standard', 'student_decisions')) {
            $this->forge->addColumn('student_decisions', [
                'deliberation_decision_standard' => [
                    'type'       => 'VARCHAR',
                    'constraint' => 40,
                    'null'       => true,
                    'after'      => 'decision',
                ],
            ]);
        }

        if ($this->db->tableExists('student_decisions') && $this->db->fieldExists('deliberation_decision_standard', 'student_decisions')) {
            $rows = $this->db->table('student_decisions')
                ->select('id, decision')
                ->get()
                ->getResultArray();

            foreach ($rows as $row) {
                $standard = DeliberationDecision::normalize($row['decision'] ?? null);
                if ($standard === null) {
                    continue;
                }

                $this->db->table('student_decisions')
                    ->where('id', (int) $row['id'])
                    ->update(['deliberation_decision_standard' => $standard]);
            }
        }

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

        $fields = [];
        $this->addFieldIfMissing($fields, 'source_school_year', [
            'type'       => 'VARCHAR',
            'constraint' => 20,
            'null'       => true,
            'after'      => 'school_year',
        ]);
        $this->addFieldIfMissing($fields, 'deliberation_decision', [
            'type'       => 'VARCHAR',
            'constraint' => 40,
            'null'       => true,
            'after'      => 'source_school_year',
        ]);
        $this->addFieldIfMissing($fields, 'source_grade_id', [
            'type'       => 'INT',
            'constraint' => 11,
            'unsigned'   => true,
            'null'       => true,
            'after'      => 'deliberation_decision',
        ]);
        $this->addFieldIfMissing($fields, 'assigned_grade_id', [
            'type'       => 'INT',
            'constraint' => 11,
            'unsigned'   => true,
            'null'       => true,
            'after'      => 'source_grade_id',
        ]);
        $this->addFieldIfMissing($fields, 'source_class_section_id', [
            'type'       => 'INT',
            'constraint' => 11,
            'unsigned'   => true,
            'null'       => true,
            'after'      => 'assigned_grade_id',
        ]);
        $this->addFieldIfMissing($fields, 'assigned_class_section_id', [
            'type'       => 'INT',
            'constraint' => 11,
            'unsigned'   => true,
            'null'       => true,
            'after'      => 'source_class_section_id',
        ]);
        $this->addFieldIfMissing($fields, 'placement_status', [
            'type'       => 'VARCHAR',
            'constraint' => 40,
            'null'       => true,
            'after'      => 'assigned_class_section_id',
        ]);
        $this->addFieldIfMissing($fields, 'age_reference_date', [
            'type' => 'DATE',
            'null' => true,
            'after' => 'placement_status',
        ]);
        $this->addFieldIfMissing($fields, 'age_on_reference_date', [
            'type'       => 'INT',
            'constraint' => 3,
            'null'       => true,
            'after'      => 'age_reference_date',
        ]);
        $this->addFieldIfMissing($fields, 'adult_student', [
            'type'       => 'TINYINT',
            'constraint' => 1,
            'default'    => 0,
            'after'      => 'age_on_reference_date',
        ]);
        $this->addFieldIfMissing($fields, 'parent_enrollment_allowed', [
            'type'       => 'TINYINT',
            'constraint' => 1,
            'default'    => 1,
            'after'      => 'adult_student',
        ]);
        $this->addFieldIfMissing($fields, 'student_self_enrollment_allowed', [
            'type'       => 'TINYINT',
            'constraint' => 1,
            'default'    => 0,
            'after'      => 'parent_enrollment_allowed',
        ]);
        $this->addFieldIfMissing($fields, 'exception_required', [
            'type'       => 'TINYINT',
            'constraint' => 1,
            'default'    => 0,
            'after'      => 'student_self_enrollment_allowed',
        ]);
        $this->addFieldIfMissing($fields, 'exception_reason', [
            'type' => 'TEXT',
            'null' => true,
            'after' => 'exception_required',
        ]);
        $this->addFieldIfMissing($fields, 'registration_submitted_at', [
            'type' => 'DATETIME',
            'null' => true,
            'after' => 'exception_reason',
        ]);
        $this->addFieldIfMissing($fields, 'registration_confirmed_at', [
            'type' => 'DATETIME',
            'null' => true,
            'after' => 'registration_submitted_at',
        ]);

        if ($fields !== []) {
            $this->forge->addColumn('enrollments', $fields);
        }
    }

    public function down()
    {
        if ($this->db->tableExists('student_decisions') && $this->db->fieldExists('deliberation_decision_standard', 'student_decisions')) {
            $this->forge->dropColumn('student_decisions', 'deliberation_decision_standard');
        }

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

        foreach ([
            'source_school_year',
            'deliberation_decision',
            'source_grade_id',
            'assigned_grade_id',
            'source_class_section_id',
            'assigned_class_section_id',
            'placement_status',
            'age_reference_date',
            'age_on_reference_date',
            'adult_student',
            'parent_enrollment_allowed',
            'student_self_enrollment_allowed',
            'exception_required',
            'exception_reason',
            'registration_submitted_at',
            'registration_confirmed_at',
        ] as $field) {
            if ($this->db->fieldExists($field, 'enrollments')) {
                $this->forge->dropColumn('enrollments', $field);
            }
        }
    }

    private function addFieldIfMissing(array &$fields, string $name, array $definition): void
    {
        if (! $this->db->fieldExists($name, 'enrollments')) {
            $fields[$name] = $definition;
        }
    }
}