<?php

namespace App\Commands;

use App\Support\Enrollment\DeliberationDecision;
use CodeIgniter\CLI\BaseCommand;
use CodeIgniter\CLI\CLI;
use CodeIgniter\Database\BaseConnection;

class EnrollmentDataAuditCommand extends BaseCommand
{
    protected $group = 'Registration';
    protected $name = 'registration:enrollment-data-audit';
    protected $description = 'Audit withdrawn terminology normalization and duplicate enrollment rows per student/year.';
    protected $usage = 'php spark registration:enrollment-data-audit [--school-year=2026-2027] [--json]';
    protected $options = [
        '--school-year' => 'Optional school year filter for duplicate enrollment detection.',
        '--json' => 'Print machine-readable JSON.',
    ];

    private BaseConnection $db;

    public function run(array $params)
    {
        $this->db = \Config\Database::connect();
        $schoolYear = trim((string) (CLI::getOption('school-year') ?? ''));

        $report = [
            'generated_at' => date('Y-m-d H:i:s'),
            'school_year_filter' => $schoolYear !== '' ? $schoolYear : null,
            'withdrawn_normalization' => $this->auditWithdrawnValues(),
            'duplicate_enrollments' => $this->auditDuplicateEnrollments($schoolYear),
        ];

        if (CLI::getOption('json') !== null) {
            CLI::write(json_encode($report, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES));

            return;
        }

        CLI::write('Enrollment Data Audit', 'green');
        CLI::newLine();
        CLI::write('Withdrawn / misspelling findings: ' . count($report['withdrawn_normalization']), 'yellow');
        foreach ($report['withdrawn_normalization'] as $row) {
            CLI::write(sprintf(
                '  [%s] %s.%s = %s',
                $row['table'],
                $row['column'],
                $row['id'] ?? $row['student_id'] ?? '?',
                $row['value']
            ));
        }
        CLI::newLine();
        CLI::write('Duplicate enrollment groups: ' . count($report['duplicate_enrollments']), 'yellow');
        foreach ($report['duplicate_enrollments'] as $group) {
            CLI::write(sprintf(
                '  student=%d year=%s rows=%d ids=[%s]',
                $group['student_id'],
                $group['school_year'],
                $group['row_count'],
                implode(',', $group['enrollment_ids'])
            ));
        }
    }

    /**
     * @return list<array<string, mixed>>
     */
    private function auditWithdrawnValues(): array
    {
        $findings = [];
        $patterns = ['widthrawan', 'widthrwan', 'withdraw'];

        if ($this->db->tableExists('enrollments')) {
            $rows = $this->db->table('enrollments')
                ->select('id, student_id, school_year, enrollment_status')
                ->get()
                ->getResultArray();
            foreach ($rows as $row) {
                $status = strtolower(trim((string) ($row['enrollment_status'] ?? '')));
                foreach ($patterns as $pattern) {
                    if ($status === $pattern || str_contains($status, $pattern)) {
                        $findings[] = [
                            'table' => 'enrollments',
                            'column' => 'enrollment_status',
                            'id' => (int) ($row['id'] ?? 0),
                            'student_id' => (int) ($row['student_id'] ?? 0),
                            'school_year' => (string) ($row['school_year'] ?? ''),
                            'value' => (string) ($row['enrollment_status'] ?? ''),
                            'recommended' => 'withdrawn',
                        ];
                    }
                }
            }
        }

        if ($this->db->tableExists('student_decisions')) {
            $rows = $this->db->table('student_decisions')
                ->select('id, student_id, school_year, decision, deliberation_decision_standard')
                ->get()
                ->getResultArray();
            foreach ($rows as $row) {
                foreach (['decision', 'deliberation_decision_standard'] as $column) {
                    $raw = (string) ($row[$column] ?? '');
                    $normalized = DeliberationDecision::normalize($raw);
                    if ($raw !== '' && $normalized === DeliberationDecision::WITHDRAWN && strtoupper($raw) !== DeliberationDecision::WITHDRAWN) {
                        $findings[] = [
                            'table' => 'student_decisions',
                            'column' => $column,
                            'id' => (int) ($row['id'] ?? 0),
                            'student_id' => (int) ($row['student_id'] ?? 0),
                            'school_year' => (string) ($row['school_year'] ?? ''),
                            'value' => $raw,
                            'recommended' => DeliberationDecision::WITHDRAWN,
                        ];
                    }
                }
            }
        }

        return $findings;
    }

    /**
     * @return list<array<string, mixed>>
     */
    private function auditDuplicateEnrollments(string $schoolYear): array
    {
        if (! $this->db->tableExists('enrollments')) {
            return [];
        }

        $builder = $this->db->table('enrollments')
            ->select('student_id, school_year, COUNT(*) AS row_count, GROUP_CONCAT(id ORDER BY updated_at DESC, id DESC) AS enrollment_ids', false)
            ->groupBy('student_id, school_year')
            ->having('row_count >', 1);

        if ($schoolYear !== '') {
            $builder->where('school_year', $schoolYear);
        }

        $groups = [];
        foreach ($builder->get()->getResultArray() as $row) {
            $ids = array_values(array_filter(array_map('intval', explode(',', (string) ($row['enrollment_ids'] ?? '')))));
            $groups[] = [
                'student_id' => (int) ($row['student_id'] ?? 0),
                'school_year' => (string) ($row['school_year'] ?? ''),
                'row_count' => (int) ($row['row_count'] ?? 0),
                'enrollment_ids' => $ids,
            ];
        }

        return $groups;
    }
}