<?php

namespace App\Repositories;

use App\Models\Job;
use Illuminate\Contracts\Pagination\LengthAwarePaginator;
use Illuminate\Database\Eloquent\Collection;

class JobRepository
{
    /**
     * Get all active jobs with pagination
     */
    public function getActiveJobs(int $perPage = 15): LengthAwarePaginator
    {
        return Job::with(['source', 'category', 'jobLocation'])
            ->active()
            ->latest('posted_at')
            ->paginate($perPage);
    }

    /**
     * Find a job by ID
     */
    public function find(int $id): ?Job
    {
        return Job::with(['source', 'category', 'jobLocation'])->find($id);
    }

    /**
     * Get jobs by category
     */
    public function getByCategory(int $categoryId, int $perPage = 15): LengthAwarePaginator
    {
        return Job::with(['source', 'category', 'jobLocation'])
            ->active()
            ->where('job_category_id', $categoryId)
            ->latest('posted_at')
            ->paginate($perPage);
    }

    /**
     * Get jobs by location
     */
    public function getByLocation(int $locationId, int $perPage = 15): LengthAwarePaginator
    {
        return Job::with(['source', 'category', 'jobLocation'])
            ->active()
            ->where('job_location_id', $locationId)
            ->latest('posted_at')
            ->paginate($perPage);
    }

    /**
     * Get remote jobs
     */
    public function getRemoteJobs(int $perPage = 15): LengthAwarePaginator
    {
        return Job::with(['source', 'category', 'jobLocation'])
            ->active()
            ->remote()
            ->latest('posted_at')
            ->paginate($perPage);
    }

    /**
     * Get recent jobs (last N days)
     */
    public function getRecentJobs(int $days = 7, int $perPage = 15): LengthAwarePaginator
    {
        return Job::with(['source', 'category', 'jobLocation'])
            ->active()
            ->where(function ($query) use ($days) {
                $query->where('posted_at', '>=', now()->subDays($days))
                      ->orWhere(function ($q) use ($days) {
                          $q->whereNull('posted_at')
                            ->where('created_at', '>=', now()->subDays($days));
                      });
            })
            ->latest('posted_at')
            ->paginate($perPage);
    }

    /**
     * Get jobs by experience level
     */
    public function getByExperienceLevel(string $level, int $perPage = 15): LengthAwarePaginator
    {
        return Job::with(['source', 'category', 'jobLocation'])
            ->active()
            ->experienceLevel($level)
            ->latest('posted_at')
            ->paginate($perPage);
    }

    /**
     * Get jobs by type
     */
    public function getByJobType(string $type, int $perPage = 15): LengthAwarePaginator
    {
        return Job::with(['source', 'category', 'jobLocation'])
            ->active()
            ->ofType($type)
            ->latest('posted_at')
            ->paginate($perPage);
    }

    /**
     * Get similar jobs (same category, exclude current)
     */
    public function getSimilarJobs(Job $job, int $limit = 5): Collection
    {
        return Job::with(['source', 'category', 'jobLocation'])
            ->active()
            ->where('id', '!=', $job->id)
            ->where('job_category_id', $job->job_category_id)
            ->latest('posted_at')
            ->limit($limit)
            ->get();
    }

    /**
     * Get featured jobs (most recent from diverse sources)
     */
    public function getFeaturedJobs(int $limit = 10): Collection
    {
        // First, build a subquery with window function
        $subQuery = \DB::table('jobs')
            ->selectRaw('jobs.*, ROW_NUMBER() OVER (PARTITION BY job_source_id ORDER BY posted_at DESC) as rn')
            ->whereNull('deleted_at')
            ->where(function ($query) {
                $query->whereNull('expires_at')
                      ->orWhere('expires_at', '>', now());
            });

        // Then query from that subquery filtering by rn
        // Use withoutGlobalScopes to prevent SoftDeletes from adding WHERE clause
        return Job::withoutGlobalScopes()
            ->with(['source', 'category', 'jobLocation'])
            ->fromSub($subQuery, 'ranked_jobs')
            ->whereRaw('ranked_jobs.rn <= 2')
            ->orderBy('posted_at', 'desc')
            ->limit($limit)
            ->get();
    }

    /**
     * Get job statistics
     */
    public function getStatistics(): array
    {
        $total = Job::count();
        $active = Job::active()->count();
        $remote = Job::active()->remote()->count();
        $recentlyAdded = Job::where('created_at', '>=', now()->subDays(7))->count();

        $topCategories = Job::active()
            ->select('job_category_id', \DB::raw('COUNT(*) as count'))
            ->whereNotNull('job_category_id')
            ->groupBy('job_category_id')
            ->orderBy('count', 'desc')
            ->limit(5)
            ->with('category')
            ->get();

        return [
            'total_jobs' => $total,
            'active_jobs' => $active,
            'remote_jobs' => $remote,
            'recently_added' => $recentlyAdded,
            'top_categories' => $topCategories,
        ];
    }

    /**
     * Create a new job
     */
    public function create(array $data): Job
    {
        return Job::create($data);
    }

    /**
     * Update a job
     */
    public function update(Job $job, array $data): bool
    {
        return $job->update($data);
    }

    /**
     * Delete a job
     */
    public function delete(Job $job): bool
    {
        return $job->delete();
    }

    /**
     * Get jobs count by source
     */
    public function getCountBySource(): Collection
    {
        return Job::with('source')
            ->select('job_source_id', \DB::raw('COUNT(*) as count'))
            ->groupBy('job_source_id')
            ->orderBy('count', 'desc')
            ->get();
    }
}