<?php

declare(strict_types=1);

namespace App\Http\Controllers\Api\Certificates;

use App\Http\Controllers\Api\Core\BaseApiController;
use App\Models\Configuration;
use App\Services\Certificates\CertificatePdfService;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Http\Response;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;

class CertificateController extends BaseApiController
{
    public function __construct()
    {
        parent::__construct();
    }

    /**
     * GET /api/v1/administrator/certificates/form-options
     */
    public function formOptions(Request $request): JsonResponse
    {
        $schoolYearParam = $request->query('school_year');
        if ($schoolYearParam !== null) {
            $schoolYear = trim((string) $schoolYearParam);
        } else {
            try {
                $schoolYear = trim((string) (Configuration::getConfig('school_year') ?? ''));
            } catch (\Throwable) {
                $schoolYear = '';
            }
        }
        $classSectionId = $request->query('class_section_id');

        try {
            $classSections = DB::table('classSection')
                ->select('class_section_id', 'class_section_name')
                ->orderBy('class_section_name', 'ASC')
                ->get()
                ->map(fn ($r) => (array) $r)
                ->all();
        } catch (\Throwable $e) {
            Log::error('Certificate formOptions class query failed: ' . $e->getMessage());
            return $this->error('Failed to load classes: ' . $e->getMessage(), 500);
        }

        $students = [];
        if ($classSectionId) {
            try {
                $studentQuery = DB::table('student_class as sc')
                    ->select('s.id', 's.firstname', 's.lastname', 'cs.class_section_name as grade')
                    ->join('students as s', 's.id', '=', 'sc.student_id')
                    ->join('classSection as cs', 'cs.class_section_id', '=', 'sc.class_section_id')
                    ->where('sc.class_section_id', (int) $classSectionId)
                    ->where('s.is_active', 1)
                    ->orderBy('s.lastname')
                    ->orderBy('s.firstname');

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

                $students = $studentQuery->get()->map(fn ($r) => (array) $r)->all();
            } catch (\Throwable $e) {
                Log::error('Certificate formOptions student query failed: ' . $e->getMessage());
                return $this->error('Failed to load students: ' . $e->getMessage(), 500);
            }
        }

        return $this->success([
            'class_sections'    => $classSections,
            'students'          => $students,
            'school_year'       => $schoolYear,
            'selected_class_id' => $classSectionId,
        ]);
    }

    /**
     * POST /api/v1/administrator/certificates/generate
     */
    public function generate(Request $request): Response|JsonResponse
    {
        $studentIds     = $request->input('student_ids', []);
        $certDate       = trim((string) ($request->input('cert_date') ?? date('m/d/Y')));
        $classSectionId = $request->input('class_section_id');

        if (empty($studentIds) || !is_array($studentIds)) {
            return $this->error('Please select at least one student.', 422);
        }

        $studentIds = array_values(array_filter(array_map('intval', $studentIds)));
        $certDate   = preg_replace('/[^0-9\/\-]/', '', $certDate) ?? date('m/d/Y');

        if (empty($studentIds)) {
            return $this->error('Invalid student selection.', 422);
        }

        $students = [];
        foreach ($studentIds as $id) {
            $row = null;

            if ($classSectionId) {
                $row = DB::table('student_class as sc')
                    ->select('s.id', 's.firstname', 's.lastname', 'cs.class_section_name as grade')
                    ->join('students as s', 's.id', '=', 'sc.student_id')
                    ->join('classSection as cs', 'cs.class_section_id', '=', 'sc.class_section_id')
                    ->where('sc.class_section_id', (int) $classSectionId)
                    ->where('s.id', $id)
                    ->first();
            }

            if (!$row) {
                $row = DB::table('students')
                    ->select('id', 'firstname', 'lastname', 'registration_grade as grade')
                    ->where('id', $id)
                    ->first();
            }

            if ($row) {
                $students[] = (array) $row;
            }
        }

        if (empty($students)) {
            return $this->error('No valid students found.', 422);
        }

        try {
            $pdfService = app(CertificatePdfService::class);
            $pdfContent = $pdfService->generate($students, $certDate);
        } catch (\Throwable $e) {
            Log::error('Certificate PDF generation failed: ' . $e->getMessage(), ['exception' => $e]);
            return $this->error('Failed to generate certificates.', 500);
        }

        $filename = 'Certificates_' . date('Ymd_His') . '.pdf';

        return response($pdfContent, 200, [
            'Content-Type'        => 'application/pdf',
            'Content-Disposition' => 'inline; filename="' . $filename . '"',
        ]);
    }

    private function currentSchoolYear(): string
    {
        return trim((string) (Configuration::getConfig('school_year') ?? ''));
    }
}