<?php

namespace App\Controllers\View;

use App\Controllers\BaseController;
use App\Models\ApplicationModel;
use App\Models\JobPositionModel;
use App\Models\JobTemplateModel;
use App\Models\JobTemplateVersionModel;
use App\Services\EmailService;
use App\Services\PhoneFormatterService;

class JobPostingController extends BaseController
{
    private const ADMIN_FILTER_ROUTE = 'administrator/job-postings';
    private array $positionStatuses = ['draft', 'open', 'closed', 'filled'];
    private array $applicationStatuses = ['new', 'reviewed', 'contacted', 'rejected', 'hired'];

    protected JobTemplateModel $templates;
    protected JobTemplateVersionModel $templateVersions;
    protected JobPositionModel $positions;
    protected ApplicationModel $applications;

    public function __construct()
    {
        helper(['form', 'url', 'text']);
        $this->templates = new JobTemplateModel();
        $this->templateVersions = new JobTemplateVersionModel();
        $this->positions = new JobPositionModel();
        $this->applications = new ApplicationModel();
    }

    public function publicIndex()
    {
        return view('careers', [
            'positions' => $this->positions->openPositions(),
        ]);
    }

    public function show(string $positionId)
    {
        $position = $this->positions->where('position_id', $positionId)->where('status', 'open')->first();
        if (!$position) {
            throw \CodeIgniter\Exceptions\PageNotFoundException::forPageNotFound('Position not found');
        }

        return view('jobs/show', ['position' => $position]);
    }

    public function apply(string $positionId)
    {
        $position = $this->positions->where('position_id', $positionId)->where('status', 'open')->first();
        if (!$position) {
            throw \CodeIgniter\Exceptions\PageNotFoundException::forPageNotFound('Position not found');
        }

        return view('jobs/apply', ['position' => $position]);
    }

    public function submitApplication(string $positionId)
    {
        $position = $this->positions->where('position_id', $positionId)->where('status', 'open')->first();
        if (!$position) {
            throw \CodeIgniter\Exceptions\PageNotFoundException::forPageNotFound('Position not found');
        }

        $rules = [
            'first_name' => 'required|regex_match[/^[a-zA-Z\s-]+$/]|min_length[2]|max_length[30]',
            'last_name' => 'required|regex_match[/^[a-zA-Z\s-]+$/]|min_length[2]|max_length[30]',
            'email' => 'required|valid_email|max_length[50]',
            'phone' => 'required|regex_match[/^[\d\s\-\(\)\.]+$/]|min_length[10]|max_length[20]',
            'resume' => 'uploaded[resume]|max_size[resume,5120]|ext_in[resume,pdf,doc,docx]',
        ];
        $messages = [
            'first_name' => [
                'regex_match' => 'First name may only contain letters, spaces, and dashes.',
                'min_length' => 'First name must be at least 2 characters.',
                'max_length' => 'First name must be 30 characters or fewer.',
            ],
            'last_name' => [
                'regex_match' => 'Last name may only contain letters, spaces, and dashes.',
                'min_length' => 'Last name must be at least 2 characters.',
                'max_length' => 'Last name must be 30 characters or fewer.',
            ],
            'email' => [
                'valid_email' => 'Please enter a valid email address.',
                'max_length' => 'Email must be 50 characters or fewer.',
            ],
            'phone' => [
                'regex_match' => 'Please enter a valid 10-digit phone number, for example 123-456-7890.',
                'min_length' => 'Please enter a valid 10-digit phone number, for example 123-456-7890.',
                'max_length' => 'Please enter a valid 10-digit phone number, for example 123-456-7890.',
            ],
        ];

        if (!$this->validate($rules, $messages)) {
            return redirect()->back()->withInput()->with('errors', $this->validator->getErrors());
        }

        $formattedPhone = (new PhoneFormatterService())->formatPhoneNumber((string) $this->request->getPost('phone'));
        if ($formattedPhone === null) {
            return redirect()->back()->withInput()->with('errors', [
                'phone' => 'Please enter a valid 10-digit phone number, for example 123-456-7890.',
            ]);
        }

        $file = $this->request->getFile('resume');
        $uploadDir = WRITEPATH . 'uploads/job_applications';
        if (!is_dir($uploadDir)) {
            mkdir($uploadDir, 0755, true);
        }

        $newName = $file->getRandomName();
        $file->move($uploadDir, $newName);
        $relativePath = 'job_applications/' . $newName;

        $application = [
            'application_id' => $this->newUuid(),
            'position_id' => $position['position_id'],
            'first_name' => trim((string) $this->request->getPost('first_name')),
            'last_name' => trim((string) $this->request->getPost('last_name')),
            'email' => trim((string) $this->request->getPost('email')),
            'phone' => $formattedPhone,
            'resume_file_url' => $relativePath,
            'status' => 'new',
            'submitted_at' => utc_now(),
        ];

        if (!$this->applications->insert($application)) {
            return redirect()->back()->withInput()->with('error', 'Unable to submit application.');
        }

        $this->sendApplicationEmails($application, $position);

        return redirect()->to(site_url('careers/application-received'))->with('success', 'Application submitted.');
    }

    public function applicationReceived()
    {
        return view('jobs/received');
    }

    public function templates()
    {
        return view('jobs/admin/templates', [
            'templates' => $this->templates->orderBy('updated_at', 'DESC')->findAll(),
        ]);
    }

    public function newTemplate()
    {
        return view('jobs/admin/template_form', ['template' => null, 'versions' => []]);
    }

    public function createTemplate()
    {
        $payload = $this->templatePayload();
        if ($payload === null) {
            return redirect()->back()->withInput()->with('errors', $this->validator->getErrors());
        }

        $payload['template_id'] = $this->newUuid();
        $payload['version'] = 1;
        $payload['is_active'] = 1;
        $payload['created_by'] = $this->currentUserId();

        if (!$this->templates->insert($payload)) {
            return redirect()->back()->withInput()->with('error', 'Unable to create template.');
        }

        $this->snapshotTemplate($payload);
        return redirect()->to(site_url(self::ADMIN_FILTER_ROUTE . '/templates'))->with('success', 'Template created.');
    }

    public function editTemplate(string $templateId)
    {
        $template = $this->templates->find($templateId);
        if (!$template) {
            return redirect()->to(site_url(self::ADMIN_FILTER_ROUTE . '/templates'))->with('error', 'Template not found.');
        }

        return view('jobs/admin/template_form', [
            'template' => $template,
            'versions' => $this->templateVersions->where('template_id', $templateId)->orderBy('version', 'DESC')->findAll(),
        ]);
    }

    public function updateTemplate(string $templateId)
    {
        $template = $this->templates->find($templateId);
        if (!$template) {
            return redirect()->to(site_url(self::ADMIN_FILTER_ROUTE . '/templates'))->with('error', 'Template not found.');
        }

        $payload = $this->templatePayload();
        if ($payload === null) {
            return redirect()->back()->withInput()->with('errors', $this->validator->getErrors());
        }

        if ($this->request->getPost('save_mode') === 'new_version') {
            $payload['version'] = ((int) ($template['version'] ?? 1)) + 1;
        } else {
            $payload['version'] = (int) ($template['version'] ?? 1);
        }

        if (!$this->templates->update($templateId, $payload)) {
            return redirect()->back()->withInput()->with('error', 'Unable to update template.');
        }

        $payload['template_id'] = $templateId;
        $this->snapshotTemplate($payload);
        return redirect()->to(site_url(self::ADMIN_FILTER_ROUTE . '/templates'))->with('success', 'Template updated.');
    }

    public function archiveTemplate(string $templateId)
    {
        $this->templates->update($templateId, ['is_active' => 0]);
        return redirect()->to(site_url(self::ADMIN_FILTER_ROUTE . '/templates'))->with('success', 'Template archived.');
    }

    public function restoreTemplateVersion(string $versionId)
    {
        $version = $this->templateVersions->find($versionId);
        if (!$version) {
            return redirect()->back()->with('error', 'Template version not found.');
        }

        $payload = $this->templateVersionPayload($version);
        $payload['version'] = (int) $version['version'];
        $this->templates->update($version['template_id'], $payload);

        return redirect()->to(site_url(self::ADMIN_FILTER_ROUTE . '/templates/' . $version['template_id'] . '/edit'))->with('success', 'Template version restored.');
    }

    public function positions()
    {
        return view('jobs/admin/positions', [
            'positions' => $this->positions->openPositions(),
        ]);
    }

    public function newPosition()
    {
        $template = null;
        $templateId = (string) $this->request->getGet('template_id');
        if ($templateId !== '') {
            $template = $this->templates->find($templateId);
        }

        return view('jobs/admin/position_form', [
            'position' => $template ? $this->templateVersionPayload($template) + ['template_id' => $templateId, 'status' => 'draft'] : null,
            'statuses' => $this->positionStatuses,
            'templates' => $this->templates->where('is_active', 1)->orderBy('title', 'ASC')->findAll(),
        ]);
    }

    public function createPosition()
    {
        $payload = $this->positionPayload();
        if ($payload === null) {
            return redirect()->back()->withInput()->with('errors', $this->validator->getErrors());
        }

        $payload['position_id'] = $this->newUuid();
        $payload['posted_by'] = $this->currentUserId();

        if (!$this->positions->insert($payload)) {
            return redirect()->back()->withInput()->with('error', 'Unable to create position.');
        }

        return redirect()->to(site_url(self::ADMIN_FILTER_ROUTE . '/positions'))->with('success', 'Position created.');
    }

    public function editPosition(string $positionId)
    {
        $position = $this->positions->find($positionId);
        if (!$position) {
            return redirect()->to(site_url(self::ADMIN_FILTER_ROUTE . '/positions'))->with('error', 'Position not found.');
        }

        return view('jobs/admin/position_form', [
            'position' => $position,
            'statuses' => $this->positionStatuses,
            'templates' => $this->templates->where('is_active', 1)->orderBy('title', 'ASC')->findAll(),
        ]);
    }

    public function updatePosition(string $positionId)
    {
        $payload = $this->positionPayload();
        if ($payload === null) {
            return redirect()->back()->withInput()->with('errors', $this->validator->getErrors());
        }

        if (!$this->positions->update($positionId, $payload)) {
            return redirect()->back()->withInput()->with('error', 'Unable to update position.');
        }

        return redirect()->to(site_url(self::ADMIN_FILTER_ROUTE . '/positions'))->with('success', 'Position updated.');
    }

    public function applications()
    {
        $builder = $this->applications
            ->select('applications.*, job_positions.title AS position_title, job_positions.department')
            ->join('job_positions', 'job_positions.position_id = applications.position_id', 'left');

        $status = (string) $this->request->getGet('status');
        if (in_array($status, $this->applicationStatuses, true)) {
            $builder->where('applications.status', $status);
        }

        $positionId = (string) $this->request->getGet('position_id');
        if ($positionId !== '') {
            $builder->where('applications.position_id', $positionId);
        }

        return view('jobs/admin/applications', [
            'applications' => $builder->orderBy('submitted_at', 'DESC')->findAll(),
            'positions' => $this->positions->orderBy('title', 'ASC')->findAll(),
            'statuses' => $this->applicationStatuses,
            'selectedStatus' => $status,
            'selectedPosition' => $positionId,
        ]);
    }

    public function updateApplication(string $applicationId)
    {
        $status = (string) $this->request->getPost('status');
        if (!in_array($status, $this->applicationStatuses, true)) {
            return redirect()->back()->with('error', 'Invalid application status.');
        }

        if (!$this->applications->update($applicationId, [
            'status' => $status,
            'admin_notes' => (string) $this->request->getPost('admin_notes'),
        ])) {
            return redirect()->back()->with('error', 'Unable to update application.');
        }

        $application = $this->applications
            ->select('applications.*, job_positions.title AS position_title')
            ->join('job_positions', 'job_positions.position_id = applications.position_id', 'left')
            ->find($applicationId);

        if ($application) {
            $this->sendApplicationStatusEmail($application);
        }

        return redirect()->back()->with('success', 'Application updated.');
    }

    public function resume(string $applicationId)
    {
        $application = $this->applications->find($applicationId);
        if (!$application) {
            return redirect()->back()->with('error', 'Application not found.');
        }

        $path = WRITEPATH . 'uploads/' . ltrim((string) $application['resume_file_url'], '/');
        if (!is_file($path)) {
            return redirect()->back()->with('error', 'Resume file not found.');
        }

        return $this->response->download($path, null);
    }

    private function templatePayload(): ?array
    {
        if (!$this->validate(['title' => 'required|max_length[255]'])) {
            return null;
        }

        return $this->sharedPostingPayload();
    }

    private function positionPayload(): ?array
    {
        if (!$this->validate([
            'title' => 'required|max_length[255]',
            'status' => 'required|in_list[draft,open,closed,filled]',
        ])) {
            return null;
        }

        $payload = $this->sharedPostingPayload();
        $payload['template_id'] = $this->request->getPost('template_id') ?: null;
        $payload['status'] = (string) $this->request->getPost('status');

        return $payload;
    }

    private function sharedPostingPayload(): array
    {
        return [
            'title' => trim((string) $this->request->getPost('title')),
            'description' => trim((string) $this->request->getPost('description')),
            'department' => trim((string) $this->request->getPost('department')),
            'location' => trim((string) $this->request->getPost('location')),
            'employment_type' => trim((string) $this->request->getPost('employment_type')),
            'requirements' => trim((string) $this->request->getPost('requirements')),
        ];
    }

    private function snapshotTemplate(array $template): void
    {
        $this->templateVersions
            ->where('template_id', $template['template_id'])
            ->where('version', (int) ($template['version'] ?? 1))
            ->delete();

        $snapshot = $this->templateVersionPayload($template);
        $snapshot['version_id'] = $this->newUuid();
        $snapshot['template_id'] = $template['template_id'];
        $snapshot['version'] = (int) ($template['version'] ?? 1);
        $snapshot['saved_by'] = $this->currentUserId();
        $snapshot['saved_at'] = utc_now();

        $this->templateVersions->insert($snapshot);
    }

    private function templateVersionPayload(array $data): array
    {
        return [
            'title' => (string) ($data['title'] ?? ''),
            'description' => (string) ($data['description'] ?? ''),
            'department' => (string) ($data['department'] ?? ''),
            'location' => (string) ($data['location'] ?? ''),
            'employment_type' => (string) ($data['employment_type'] ?? ''),
            'requirements' => (string) ($data['requirements'] ?? ''),
        ];
    }

    private function sendApplicationEmails(array $application, array $position): void
    {
        $fullName = trim($application['first_name'] . ' ' . $application['last_name']);
        $body = view('emails/job_application_confirmation', [
            'name' => $fullName,
            'position' => $position,
        ]);

        try {
            (new EmailService())->send($application['email'], 'Application received: ' . $position['title'], $body, 'general');
        } catch (\Throwable $e) {
            log_message('error', 'Job application confirmation email failed: ' . $e->getMessage());
        }

        $adminRecipients = array_unique(array_filter([
            trim((string) env('JOBS_ADMIN_EMAIL', '')),
            trim((string) env('PRINCIPAL_EMAIL', '')),
        ], static fn (string $email): bool => $email !== '' && filter_var($email, FILTER_VALIDATE_EMAIL)));

        if ($adminRecipients !== []) {
            $adminBody = '<p>New application received for <strong>' . esc($position['title']) . '</strong>.</p>'
                . '<p>Applicant: ' . esc($fullName) . '<br>Email: ' . esc($application['email']) . '<br>Phone: ' . esc($application['phone']) . '</p>';

            $emailService = new EmailService();
            try {
                foreach ($adminRecipients as $adminEmail) {
                    $emailService->send($adminEmail, 'New job application: ' . $position['title'], $adminBody, 'general');
                }
            } catch (\Throwable $e) {
                log_message('error', 'Job application admin email failed: ' . $e->getMessage());
            }
        }
    }

    private function sendApplicationStatusEmail(array $application): void
    {
        $email = trim((string) ($application['email'] ?? ''));
        if ($email === '' || !filter_var($email, FILTER_VALIDATE_EMAIL)) {
            return;
        }

        $status = (string) ($application['status'] ?? '');
        $statusLabel = ucfirst(str_replace('_', ' ', $status));
        $positionTitle = (string) ($application['position_title'] ?? 'the volunteer position');
        $fullName = trim((string) (($application['first_name'] ?? '') . ' ' . ($application['last_name'] ?? '')));

        $body = view('emails/job_application_status_update', [
            'name' => $fullName !== '' ? $fullName : 'Applicant',
            'positionTitle' => $positionTitle,
            'statusLabel' => $statusLabel,
            'adminNotes' => trim((string) ($application['admin_notes'] ?? '')),
        ]);

        try {
            (new EmailService())->send($email, 'Application status update: ' . $positionTitle, $body, 'general');
        } catch (\Throwable $e) {
            log_message('error', 'Job application status email failed: ' . $e->getMessage());
        }
    }

    private function currentUserId(): ?int
    {
        $userId = (int) session()->get('user_id');
        return $userId > 0 ? $userId : null;
    }

    private function newUuid(): string
    {
        $bytes = random_bytes(16);
        $bytes[6] = chr((ord($bytes[6]) & 0x0f) | 0x40);
        $bytes[8] = chr((ord($bytes[8]) & 0x3f) | 0x80);

        return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($bytes), 4));
    }
}