<?php

namespace App\Services;

use App\Models\Job;
use App\Models\JobCategory;
use Illuminate\Support\Str;

class SeoService
{
    /**
     * Generate meta tags for a job
     */
    public function getJobMetaTags(Job $job): array
    {
        $title = $job->title . ' at ' . $job->company . ' - JobifyGarden';
        $description = Str::limit(strip_tags($job->description), 155);
        $url = route('jobs.show', $job);

        return [
            'title' => $title,
            'description' => $description,
            'keywords' => $this->generateJobKeywords($job),
            'canonical' => $url,
            'og_title' => $job->title . ' at ' . $job->company,
            'og_description' => $description,
            'og_url' => $url,
            'og_type' => 'website',
            'og_image' => asset('images/og-default.jpg'),
            'twitter_card' => 'summary_large_image',
            'twitter_title' => $job->title . ' at ' . $job->company,
            'twitter_description' => $description,
            'twitter_image' => asset('images/twitter-card-default.jpg'),
        ];
    }

    /**
     * Generate meta tags for category page
     */
    public function getCategoryMetaTags(JobCategory $category, int $jobCount): array
    {
        $title = $category->name . ' Jobs - JobifyGarden';
        $description = "Browse {$jobCount} {$category->name} job opportunities. " . ($category->description ?? 'Find your next career in ' . $category->name . '.');
        $url = route('jobs.category', $category->slug);

        return [
            'title' => $title,
            'description' => Str::limit($description, 155),
            'keywords' => $this->generateCategoryKeywords($category),
            'canonical' => $url,
            'og_title' => $category->name . ' Jobs',
            'og_description' => Str::limit($description, 155),
            'og_url' => $url,
            'og_type' => 'website',
            'og_image' => asset('images/og-default.jpg'),
            'twitter_card' => 'summary',
            'twitter_title' => $category->name . ' Jobs',
            'twitter_description' => Str::limit($description, 155),
        ];
    }

    /**
     * Generate meta tags for homepage
     */
    public function getHomeMetaTags(int $jobCount): array
    {
        return [
            'title' => 'JobifyGarden - Find Your Dream Job | ' . number_format($jobCount) . '+ Jobs',
            'description' => 'Discover thousands of job opportunities from multiple sources. Search remote jobs, full-time positions, and more. Your next career starts here.',
            'keywords' => 'jobs, careers, employment, job search, remote jobs, full-time jobs, part-time jobs, find jobs',
            'canonical' => route('home'),
            'og_title' => 'JobifyGarden - Find Your Dream Job',
            'og_description' => 'Discover thousands of job opportunities from multiple sources. Your next career starts here.',
            'og_url' => route('home'),
            'og_type' => 'website',
            'og_image' => asset('images/og-home.jpg'),
            'twitter_card' => 'summary_large_image',
            'twitter_title' => 'JobifyGarden - Find Your Dream Job',
            'twitter_description' => 'Discover thousands of job opportunities from multiple sources.',
            'twitter_image' => asset('images/twitter-card-home.jpg'),
        ];
    }

    /**
     * Generate keywords for a job
     */
    private function generateJobKeywords(Job $job): string
    {
        $keywords = [
            $job->title,
            $job->company,
            $job->job_type,
            $job->experience_level,
        ];

        if ($job->category) {
            $keywords[] = $job->category->name;
        }

        if ($job->location) {
            $keywords[] = $job->location;
        }

        if ($job->remote_allowed) {
            $keywords[] = 'remote';
            $keywords[] = 'work from home';
        }

        return implode(', ', array_filter($keywords));
    }

    /**
     * Generate keywords for a category
     */
    private function generateCategoryKeywords(JobCategory $category): string
    {
        return implode(', ', [
            $category->name . ' jobs',
            $category->name . ' careers',
            $category->name . ' employment',
            'find ' . $category->name . ' jobs',
        ]);
    }

    /**
     * Generate JSON-LD structured data for a job
     */
    public function generateJobStructuredData(Job $job): array
    {
        $data = [
            '@context' => 'https://schema.org/',
            '@type' => 'JobPosting',
            'title' => $job->title,
            'description' => strip_tags($job->description),
            'datePosted' => $job->posted_at?->toIso8601String() ?? $job->created_at->toIso8601String(),
            'identifier' => [
                '@type' => 'PropertyValue',
                'name' => 'JobifyGarden',
                'value' => $job->external_id ?? (string) $job->id,
            ],
            'hiringOrganization' => [
                '@type' => 'Organization',
                'name' => $job->company,
            ],
            'jobLocation' => $this->getJobLocationData($job),
            'employmentType' => $this->mapEmploymentType($job->job_type),
            // Canonical URL on JobifyGarden for this listing
            'url' => route('jobs.show', $job),
        ];

        // Remote jobs: add jobLocationType per Google's spec
        if ($job->remote_allowed) {
            $data['jobLocationType'] = 'TELECOMMUTE';
        }

        if ($job->expires_at) {
            $data['validThrough'] = $job->expires_at->toIso8601String();
        }

        if ($job->salary_min || $job->salary_max) {
            $data['baseSalary'] = $this->getSalaryData($job);
        }

        if ($job->experience_level) {
            $data['experienceRequirements'] = [
                '@type' => 'OccupationalExperienceRequirements',
                'monthsOfExperience' => $this->mapExperienceLevel($job->experience_level),
            ];
        }

        if ($job->apply_url || $job->source_url) {
            $data['directApply'] = true;
            $data['applyUrl'] = $job->apply_url ?? $job->source_url;
        }

        return $data;
    }

    /**
     * Get job location data for structured data
     */
    private function getJobLocationData(Job $job): array
    {
        // For fully remote jobs with no physical location, Google requires
        // jobLocationType: TELECOMMUTE (set in parent method) and still
        // recommends providing a jobLocation with a country if known.
        // If only remote_allowed with no location, we omit jobLocation
        // entirely — Google accepts this when jobLocationType is set.
        if ($job->remote_allowed && !$job->jobLocation && !$job->location) {
            return [
                '@type' => 'Place',
                'address' => [
                    '@type' => 'PostalAddress',
                    'addressCountry' => 'US', // Default fallback; most aggregated jobs are US/global
                ],
            ];
        }

        $address = [
            '@type' => 'PostalAddress',
        ];

        if ($job->jobLocation) {
            if ($job->jobLocation->city) {
                $address['addressLocality'] = $job->jobLocation->city;
            }
            if ($job->jobLocation->state) {
                $address['addressRegion'] = $job->jobLocation->state;
            }
            if ($job->jobLocation->country) {
                $address['addressCountry'] = $job->jobLocation->country;
            }
        } elseif ($job->location) {
            $address['name'] = $job->location;
        }

        return [
            '@type' => 'Place',
            'address' => $address,
        ];
    }

    /**
     * Get salary data for structured data
     */
    private function getSalaryData(Job $job): array
    {
        $currency = $job->salary_currency ?? 'USD';

        if ($job->salary_min && $job->salary_max) {
            return [
                '@type' => 'MonetaryAmount',
                'currency' => $currency,
                'value' => [
                    '@type' => 'QuantitativeValue',
                    'minValue' => $job->salary_min,
                    'maxValue' => $job->salary_max,
                    'unitText' => 'YEAR',
                ],
            ];
        }

        $value = $job->salary_min ?? $job->salary_max;

        return [
            '@type' => 'MonetaryAmount',
            'currency' => $currency,
            'value' => [
                '@type' => 'QuantitativeValue',
                'value' => $value,
                'unitText' => 'YEAR',
            ],
        ];
    }

    /**
     * Map job type to schema.org employment type
     */
    private function mapEmploymentType(?string $jobType): string
    {
        return match ($jobType) {
            'full-time', 'full_time' => 'FULL_TIME',
            'part-time', 'part_time' => 'PART_TIME',
            'contract' => 'CONTRACTOR',
            'temporary' => 'TEMPORARY',
            'internship' => 'INTERN',
            'freelance' => 'CONTRACTOR',
            default => 'FULL_TIME',
        };
    }

    /**
     * Map experience level to months
     */
    private function mapExperienceLevel(?string $level): int
    {
        return match ($level) {
            'entry' => 0,
            'mid' => 24,
            'senior' => 60,
            'lead' => 84,
            'executive' => 120,
            default => 0,
        };
    }

    /**
     * Generate breadcrumb structured data
     */
    public function generateBreadcrumbStructuredData(array $items): array
    {
        $listItems = [];

        foreach ($items as $index => $item) {
            $listItems[] = [
                '@type' => 'ListItem',
                'position' => $index + 1,
                'name' => $item['name'],
                'item' => $item['url'],
            ];
        }

        return [
            '@context' => 'https://schema.org',
            '@type' => 'BreadcrumbList',
            'itemListElement' => $listItems,
        ];
    }
}