<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use App\Models\JobPost;
use App\Models\JobApplication;
use App\Models\Worker;
use App\Models\User;
use Illuminate\Support\Facades\Validator;

class WorkerJobController extends Controller
{
    /**
     * API to list available jobs.
     * GET /api/workers/jobs
     */
    public function listJobs(Request $request)
    {
        $jobs = JobPost::where('status', 'active')
            ->with(['employer.employerProfile'])
            ->latest()
            ->get()
            ->map(function ($job) {
                return [
                    'id' => $job->id,
                    'title' => $job->title,
                    'location' => $job->location,
                    'salary' => (int) $job->salary,
                    'workers_needed' => $job->workers_needed,
                    'job_type' => $job->job_type,
                    'start_date' => $job->start_date ? $job->start_date->format('Y-m-d') : null,
                    'description' => $job->description,
                    'requirements' => $job->requirements,
                    'company_name' => $job->employer->employerProfile->company_name ?? 'Private Sponsor',
                    'posted_by' => $job->employer->name ?? 'Private Sponsor',
                    'posted_at' => $job->created_at->toIso8601String(),
                ];
            });

        return response()->json([
            'success' => true,
            'data' => [
                'jobs' => $jobs
            ]
        ]);
    }

    /**
     * API to retrieve job details.
     * GET /api/workers/jobs/{id}
     */
    public function jobDetails($id)
    {
        $job = JobPost::where('status', 'active')
            ->with(['employer.employerProfile'])
            ->find($id);

        if (!$job) {
            return response()->json([
                'success' => false,
                'message' => 'Job not found.'
            ], 404);
        }

        return response()->json([
            'success' => true,
            'data' => [
                'job' => [
                    'id' => $job->id,
                    'title' => $job->title,
                    'location' => $job->location,
                    'salary' => (int) $job->salary,
                    'workers_needed' => $job->workers_needed,
                    'job_type' => $job->job_type,
                    'start_date' => $job->start_date ? $job->start_date->format('Y-m-d') : null,
                    'description' => $job->description,
                    'requirements' => $job->requirements,
                    'company_name' => $job->employer->employerProfile->company_name ?? 'Private Sponsor',
                    'posted_by' => $job->employer->name ?? 'Private Sponsor',
                    'posted_at' => $job->created_at->toIso8601String(),
                ]
            ]
        ]);
    }

    /**
     * API for workers to apply for a job.
     * POST /api/workers/jobs/{id}/apply
     */
    public function applyJob(Request $request, $id)
    {
        /** @var Worker $worker */
        $worker = $request->attributes->get('worker');

        $job = JobPost::where('status', 'active')->find($id);

        if (!$job) {
            return response()->json([
                'success' => false,
                'message' => 'Job not found.'
            ], 404);
        }

        // Prevent duplicate applications
        $exists = JobApplication::where('worker_id', $worker->id)
            ->where('job_id', $job->id)
            ->exists();

        if ($exists) {
            return response()->json([
                'success' => false,
                'message' => 'You have already applied for this job.'
            ], 409);
        }

        $application = JobApplication::create([
            'worker_id' => $worker->id,
            'job_id' => $job->id,
            'status' => 'applied'
        ]);

        return response()->json([
            'success' => true,
            'message' => 'Successfully applied for the job.',
            'data' => [
                'application' => $application
            ]
        ], 201);
    }

    /**
     * API for workers to view their applied jobs.
     * GET /api/workers/applied-jobs
     */
    public function appliedJobs(Request $request)
    {
        /** @var Worker $worker */
        $worker = $request->attributes->get('worker');

        $applications = JobApplication::where('worker_id', $worker->id)
            ->with(['jobPost.employer.employerProfile'])
            ->latest()
            ->get()
            ->map(function ($app) {
                $job = $app->jobPost;
                return [
                    'application_id' => $app->id,
                    'status' => $app->status,
                    'applied_at' => $app->created_at->toIso8601String(),
                    'job' => $job ? [
                        'id' => $job->id,
                        'title' => $job->title,
                        'location' => $job->location,
                        'salary' => (int) $job->salary,
                        'job_type' => $job->job_type,
                        'company_name' => $job->employer->employerProfile->company_name ?? 'Private Sponsor',
                        'posted_by' => $job->employer->name ?? 'Private Sponsor',
                    ] : null
                ];
            });

        return response()->json([
            'success' => true,
            'data' => [
                'applications' => $applications
            ]
        ]);
    }

    private function checkJobAccess($employerId)
    {
        $sub = \Illuminate\Support\Facades\DB::table('subscriptions')
            ->where('user_id', $employerId)
            ->where('status', 'active')
            ->latest('id')
            ->first();

        $planId = $sub ? $sub->plan_id : 'basic';
        return $planId !== 'basic';
    }

    /**
     * API for employers to list their jobs.
     * GET /api/employers/jobs
     */
    public function employerListJobs(Request $request)
    {
        /** @var User $employer */
        $employer = $request->attributes->get('employer');

        if (!$this->checkJobAccess($employer->id)) {
            return response()->json([
                'success' => false,
                'message' => 'Your current plan does not support the Job Apply module. Please upgrade to a Premium plan to access this feature.'
            ], 403);
        }

        $jobs = JobPost::where('employer_id', $employer->id)
            ->with(['applications'])
            ->latest()
            ->get()
            ->map(function ($job) {
                return [
                    'id' => $job->id,
                    'title' => $job->title,
                    'location' => $job->location,
                    'salary' => (int) $job->salary,
                    'workers_needed' => $job->workers_needed,
                    'job_type' => $job->job_type,
                    'start_date' => $job->start_date ? $job->start_date->format('Y-m-d') : null,
                    'description' => $job->description,
                    'requirements' => $job->requirements,
                    'applied_count' => $job->applications->count(),
                    'posted_at' => $job->created_at->toIso8601String(),
                    'status' => $job->status,
                ];
            });

        return response()->json([
            'success' => true,
            'data' => [
                'jobs' => $jobs
            ]
        ]);
    }

    /**
     * API for employers to create a job.
     * POST /api/employers/jobs
     */
    public function employerCreateJob(Request $request)
    {
        /** @var User $employer */
        $employer = $request->attributes->get('employer');

        if (!$this->checkJobAccess($employer->id)) {
            return response()->json([
                'success' => false,
                'message' => 'Your current plan does not support the Job Apply module. Please upgrade to a Premium plan to access this feature.'
            ], 403);
        }

        $validator = Validator::make($request->all(), [
            'title' => 'required|string|max:255',
            'workers_needed' => 'required|integer|min:1',
            'location' => 'required|string|max:255',
            'salary' => 'required|numeric|min:0',
            'job_type' => 'required|string|in:Full Time,Part Time,Contract',
            'start_date' => 'required|date',
            'description' => 'required|string|max:1000',
            'requirements' => 'nullable|string',
        ]);

        if ($validator->fails()) {
            return response()->json([
                'success' => false,
                'message' => 'Validation error.',
                'errors' => $validator->errors()
            ], 422);
        }

        $job = JobPost::create([
            'employer_id' => $employer->id,
            'title' => $request->title,
            'workers_needed' => $request->workers_needed,
            'job_type' => $request->job_type,
            'location' => $request->location,
            'salary' => $request->salary,
            'start_date' => $request->start_date,
            'description' => $request->description,
            'requirements' => $request->requirements,
            'status' => 'active',
        ]);

        return response()->json([
            'success' => true,
            'message' => 'Job posted successfully.',
            'data' => [
                'job' => [
                    'id' => $job->id,
                    'title' => $job->title,
                    'location' => $job->location,
                    'salary' => (int) $job->salary,
                    'workers_needed' => $job->workers_needed,
                    'job_type' => $job->job_type,
                    'start_date' => $job->start_date ? $job->start_date->format('Y-m-d') : null,
                    'description' => $job->description,
                    'requirements' => $job->requirements,
                    'posted_at' => $job->created_at->toIso8601String(),
                    'status' => $job->status,
                ]
            ]
        ], 201);
    }

    /**
     * API for employers to retrieve details of a specific job.
     * GET /api/employers/jobs/{id}
     */
    public function employerJobDetail(Request $request, $id)
    {
        /** @var User $employer */
        $employer = $request->attributes->get('employer');

        if (!$this->checkJobAccess($employer->id)) {
            return response()->json([
                'success' => false,
                'message' => 'Your current plan does not support the Job Apply module. Please upgrade to a Premium plan to access this feature.'
            ], 403);
        }

        $job = JobPost::where('employer_id', $employer->id)
            ->with(['applications'])
            ->find($id);

        if (!$job) {
            return response()->json([
                'success' => false,
                'message' => 'Job not found or unauthorized.'
            ], 404);
        }

        return response()->json([
            'success' => true,
            'data' => [
                'job' => [
                    'id' => $job->id,
                    'title' => $job->title,
                    'location' => $job->location,
                    'salary' => (int) $job->salary,
                    'workers_needed' => $job->workers_needed,
                    'job_type' => $job->job_type,
                    'start_date' => $job->start_date ? $job->start_date->format('Y-m-d') : null,
                    'description' => $job->description,
                    'requirements' => $job->requirements,
                    'applied_count' => $job->applications->count(),
                    'posted_at' => $job->created_at->toIso8601String(),
                    'status' => $job->status,
                ]
            ]
        ]);
    }

    /**
     * API for employers to update a specific job.
     * POST /api/employers/jobs/{id}/update
     */
    public function employerUpdateJob(Request $request, $id)
    {
        /** @var User $employer */
        $employer = $request->attributes->get('employer');

        if (!$this->checkJobAccess($employer->id)) {
            return response()->json([
                'success' => false,
                'message' => 'Your current plan does not support the Job Apply module. Please upgrade to a Premium plan to access this feature.'
            ], 403);
        }

        $job = JobPost::where('employer_id', $employer->id)->find($id);

        if (!$job) {
            return response()->json([
                'success' => false,
                'message' => 'Job not found or unauthorized.'
            ], 404);
        }

        $validator = Validator::make($request->all(), [
            'title' => 'required|string|max:255',
            'workers_needed' => 'required|integer|min:1',
            'location' => 'required|string|max:255',
            'salary' => 'required|numeric|min:0',
            'job_type' => 'required|string|in:Full Time,Part Time,Contract',
            'start_date' => 'required|date',
            'description' => 'required|string|max:1000',
            'requirements' => 'nullable|string',
            'status' => 'required|string|in:active,closed,draft',
        ]);

        if ($validator->fails()) {
            return response()->json([
                'success' => false,
                'message' => 'Validation error.',
                'errors' => $validator->errors()
            ], 422);
        }

        $job->update([
            'title' => $request->title,
            'workers_needed' => $request->workers_needed,
            'job_type' => $request->job_type,
            'location' => $request->location,
            'salary' => $request->salary,
            'start_date' => $request->start_date,
            'description' => $request->description,
            'requirements' => $request->requirements,
            'status' => strtolower($request->status),
        ]);

        return response()->json([
            'success' => true,
            'message' => 'Job updated successfully.',
            'data' => [
                'job' => [
                    'id' => $job->id,
                    'title' => $job->title,
                    'location' => $job->location,
                    'salary' => (int) $job->salary,
                    'workers_needed' => $job->workers_needed,
                    'job_type' => $job->job_type,
                    'start_date' => $job->start_date ? $job->start_date->format('Y-m-d') : null,
                    'description' => $job->description,
                    'requirements' => $job->requirements,
                    'posted_at' => $job->created_at->toIso8601String(),
                    'status' => $job->status,
                ]
            ]
        ]);
    }

    /**
     * API for employers to delete a job.
     * DELETE /api/employers/jobs/{id}
     */
    public function employerDeleteJob(Request $request, $id)
    {
        /** @var User $employer */
        $employer = $request->attributes->get('employer');

        if (!$this->checkJobAccess($employer->id)) {
            return response()->json([
                'success' => false,
                'message' => 'Your current plan does not support the Job Apply module. Please upgrade to a Premium plan to access this feature.'
            ], 403);
        }

        $job = JobPost::where('employer_id', $employer->id)->find($id);

        if (!$job) {
            return response()->json([
                'success' => false,
                'message' => 'Job not found or unauthorized.'
            ], 404);
        }

        $job->delete();

        return response()->json([
            'success' => true,
            'message' => 'Job deleted successfully.'
        ]);
    }

    /**
     * API for employers to view applicants for each job.
     * GET /api/employers/jobs/{id}/applicants
     */
    public function employerJobApplicants(Request $request, $id)
    {
        /** @var User $employer */
        $employer = $request->attributes->get('employer');

        if (!$this->checkJobAccess($employer->id)) {
            return response()->json([
                'success' => false,
                'message' => 'Your current plan does not support the Job Apply module. Please upgrade to a Premium plan to access this feature.'
            ], 403);
        }

        $job = JobPost::where('employer_id', $employer->id)->find($id);

        if (!$job) {
            return response()->json([
                'success' => false,
                'message' => 'Job not found or unauthorized.'
            ], 404);
        }

        $query = JobApplication::where('job_id', $job->id)
            ->with(['worker.skills']);

        // Search filter: name, nationality
        if ($request->filled('search')) {
            $search = $request->search;
            $query->whereHas('worker', function($q) use ($search) {
                $q->where('name', 'like', "%{$search}%")
                  ->orWhere('nationality', 'like', "%{$search}%");
            });
        }

        // Status filter
        if ($request->filled('status')) {
            $query->where('status', strtolower($request->status));
        }

        $sortBy = $request->input('sort_by', 'created_at');
        $sortOrder = $request->input('sort_order', 'desc');

        if ($sortBy === 'created_at' || $sortBy === 'applied_at') {
            $query->orderBy('created_at', $sortOrder === 'asc' ? 'asc' : 'desc');
        }

        $applicants = $query->get()->map(function ($app) use ($employer) {
            $w = $app->worker;
            if (!$w) return null;

            // Check if worker is saved in Saved Workers (Shortlist)
            $isSaved = \App\Models\Shortlist::where('employer_id', $employer->id)
                ->where('worker_id', $w->id)
                ->exists();

            return [
                'application_id' => $app->id,
                'status' => $app->status,
                'notes' => $app->notes,
                'status_history' => $app->status_history ?: [],
                'applied_at' => $app->created_at->toIso8601String(),
                'is_saved' => $isSaved,
                'worker' => [
                    'id' => $w->id,
                    'name' => $w->name,
                    'nationality' => $w->nationality,
                    'salary' => (int) $w->salary,
                    'preferred_location' => $w->preferred_location,
                    'preferred_job_type' => $w->preferred_job_type,
                    'visa_status' => $w->visa_status,
                    'experience' => $w->experience,
                    'skills' => $w->skills->pluck('name')->toArray(),
                ]
            ];
        })->filter()->values();

        return response()->json([
            'success' => true,
            'data' => [
                'job' => [
                    'id' => $job->id,
                    'title' => $job->title,
                ],
                'applicants' => $applicants
            ]
        ]);
    }

    /**
     * API for employers to update application status.
     * POST /api/employers/applications/{id}/status
     */
    public function employerUpdateApplicationStatus(Request $request, $id)
    {
        /** @var User $employer */
        $employer = $request->attributes->get('employer');

        if (!$this->checkJobAccess($employer->id)) {
            return response()->json([
                'success' => false,
                'message' => 'Your current plan does not support the Job Apply module. Please upgrade to a Premium plan to access this feature.'
            ], 403);
        }

        $validator = Validator::make($request->all(), [
            'status' => 'required|string|in:applied,shortlisted,contacted,interview scheduled,interview_scheduled,selected,rejected,hired',
            'notes' => 'nullable|string',
        ]);

        if ($validator->fails()) {
            return response()->json([
                'success' => false,
                'message' => 'Validation error.',
                'errors' => $validator->errors()
            ], 422);
        }

        $application = JobApplication::where('id', $id)
            ->whereHas('jobPost', function($q) use ($employer) {
                $q->where('employer_id', $employer->id);
            })->first();

        if (!$application) {
            return response()->json([
                'success' => false,
                'message' => 'Job application not found or unauthorized.'
            ], 404);
        }

        $dbStatus = strtolower($request->status);

        // Contact Limit check: if moving to 'shortlisted', 'contacted', 'interview_scheduled', 'selected', 'hired' for the first time
        $contactStatuses = ['shortlisted', 'contacted', 'interview_scheduled', 'selected', 'hired'];
        if (in_array($dbStatus, $contactStatuses)) {
            if (!User::canContactWorker($employer->id, $application->worker_id)) {
                $activeSub = \App\Models\Subscription::where('user_id', $employer->id)->where('status', 'active')->first();
                $planId = $activeSub ? $activeSub->plan_id : 'basic';
                $plan = \App\Models\Plan::find($planId);
                $maxContacts = $plan ? $plan->max_contact_people : 10;

                return response()->json([
                    'success' => false,
                    'message' => 'You have reached your contacted workers limit of ' . $maxContacts . ' under your active plan. Please upgrade or renew your subscription to contact more workers.'
                ], 403);
            }
        }

        $notes = $request->input('notes');

        // Update application status & history
        $history = $application->status_history ?: [];
        $history[] = [
            'status' => $dbStatus,
            'timestamp' => now()->toIso8601String(),
            'notes' => $notes,
        ];

        $updateData = [
            'status' => $dbStatus,
            'status_history' => $history,
        ];

        if ($notes !== null) {
            $updateData['notes'] = $notes;
        }

        $application->update($updateData);

        // If shortlisted, automatically add to Saved Workers (Shortlist table) if not already saved
        if ($dbStatus === 'shortlisted') {
            $exists = \App\Models\Shortlist::where('employer_id', $employer->id)
                ->where('worker_id', $application->worker_id)
                ->exists();
            if (!$exists) {
                \App\Models\Shortlist::create([
                    'employer_id' => $employer->id,
                    'worker_id' => $application->worker_id,
                ]);
            }
        }

        // If hired, also update worker status
        if ($dbStatus === 'hired') {
            if ($application->worker) {
                $application->worker->update(['status' => 'Hired']);
            }
            // Create/update the JobOffer record to satisfy the Worker Employer List API
            \App\Models\JobOffer::updateOrCreate(
                [
                    'employer_id' => $employer->id,
                    'worker_id' => $application->worker_id,
                ],
                [
                    'work_date' => $application->jobPost->start_date ?? now(),
                    'location' => $application->jobPost->location ?? 'Dubai',
                    'salary' => $application->jobPost->salary ?? 0,
                    'status' => 'accepted',
                    'notes' => $application->notes ?? 'Hired through Job Application',
                ]
            );
        } elseif ($dbStatus === 'rejected') {
            if ($application->worker) {
                $application->worker->update(['status' => 'active']);
            }
        }

        // Trigger notifications
        $this->triggerStatusNotification($application, $dbStatus);

        return response()->json([
            'success' => true,
            'message' => 'Application status updated successfully.',
            'data' => [
                'application' => $application->fresh()
            ]
        ]);
    }

    /**
     * API for workers to view details of a specific job application.
     * GET /api/workers/applied-jobs/{id}
     */
    public function appliedJobDetail(Request $request, $id)
    {
        /** @var Worker $worker */
        $worker = $request->attributes->get('worker');

        $application = JobApplication::where('worker_id', $worker->id)
            ->with(['jobPost.employer.employerProfile'])
            ->find($id);

        if (!$application) {
            return response()->json([
                'success' => false,
                'message' => 'Application not found.'
            ], 404);
        }

        $job = $application->jobPost;

        return response()->json([
            'success' => true,
            'data' => [
                'application' => [
                    'id' => $application->id,
                    'status' => $application->status,
                    'status_history' => $application->status_history ?: [],
                    'applied_at' => $application->created_at->toIso8601String(),
                    'job' => $job ? [
                        'id' => $job->id,
                        'title' => $job->title,
                        'location' => $job->location,
                        'salary' => (int) $job->salary,
                        'job_type' => $job->job_type,
                        'description' => $job->description,
                        'requirements' => $job->requirements,
                        'company_name' => $job->employer->employerProfile->company_name ?? 'Private Sponsor',
                        'posted_by' => $job->employer->name ?? 'Private Sponsor',
                        'posted_at' => $job->created_at->toIso8601String(),
                    ] : null
                ]
            ]
        ]);
    }

    /**
     * API for workers to withdraw their job application.
     * POST /api/workers/applied-jobs/{id}/withdraw
     */
    public function withdrawApplication(Request $request, $id)
    {
        /** @var Worker $worker */
        $worker = $request->attributes->get('worker');

        $application = JobApplication::where('worker_id', $worker->id)->find($id);

        if (!$application) {
            return response()->json([
                'success' => false,
                'message' => 'Application not found.'
            ], 404);
        }

        if (strtolower($application->status) !== 'applied') {
            return response()->json([
                'success' => false,
                'message' => 'You can only withdraw applications that are still in "Applied" status.'
            ], 400);
        }

        $application->delete();

        return response()->json([
            'success' => true,
            'message' => 'Application successfully withdrawn.'
        ]);
    }

    /**
     * Dispatch FCM Push Notification.
     */
    private function triggerStatusNotification($application, $status)
    {
        $worker = $application->worker;
        $job = $application->jobPost;
        $employer = $job ? $job->employer : null;

        // When a new application is submitted: notify employer
        if ($status === 'applied') {
            if ($employer && $employer->fcm_token) {
                \App\Services\FCMService::sendPushNotification(
                    $employer->fcm_token,
                    "New Job Application",
                    "A candidate has applied for your job: " . ($job->title ?? 'Job Post'),
                    [
                        'type' => 'new_job_application',
                        'job_id' => $job->id,
                        'application_id' => $application->id,
                    ]
                );
            }
            return;
        }

        // When status is updated: notify worker
        if ($worker && $worker->fcm_token) {
            $title = "Job Application Update";
            $body = "";
            switch (strtolower($status)) {
                case 'shortlisted':
                    $body = "You have been shortlisted for the job: " . ($job->title ?? 'Job Post');
                    break;
                case 'contacted':
                    $body = "An employer wants to contact you regarding the job: " . ($job->title ?? 'Job Post');
                    break;
                case 'interview scheduled':
                case 'interview_scheduled':
                    $body = "An interview has been scheduled for the job: " . ($job->title ?? 'Job Post');
                    break;
                case 'selected':
                    $body = "Congratulations! You have been selected for the job: " . ($job->title ?? 'Job Post');
                    break;
                case 'rejected':
                    $body = "Your application for the job: " . ($job->title ?? 'Job Post') . " has been reviewed and rejected.";
                    break;
                case 'hired':
                    $body = "Congratulations! You have been hired for the job: " . ($job->title ?? 'Job Post');
                    break;
                default:
                    $body = "Your application status for the job: " . ($job->title ?? 'Job Post') . " has changed to " . ucfirst($status);
                    break;
            }

            \App\Services\FCMService::sendPushNotification(
                $worker->fcm_token,
                $title,
                $body,
                [
                    'type' => 'job_application_status_update',
                    'job_id' => $job->id ?? '',
                    'application_id' => $application->id,
                    'status' => $status,
                ]
            );
        }
    }
}