<?php
namespace App\Http\Controllers;

use App\Models\Category;
use App\Models\CodeExample;
use App\Models\Course;
use App\Models\CssCode;
use App\Models\Developer;
use App\Models\Page;
use App\Models\Post;
use App\Models\Project;
use App\Models\Service;
use App\Models\Tag;
use Carbon\Carbon;
use Illuminate\Support\Facades\View;

class SitemapController extends Controller
{
    public $lastUpdatedAt = null;

    public function index()
    {
        $categories = $this->getCategories();
        $tags = $this->getTags();

        $articles = array_merge(
            $this->getAllPages(),
            $this->getAllPosts($categories, $tags),
            $this->getAllCodeExaples($categories, $tags),
            $this->getAllUsers(),
            $this->getAllServices(),
            $this->getAllDesigns(),
            $this->getAllProjects(),
            $this->getAllCourses(),
            $this->getAllRootGenericPages()
        );

        // Unique the array by loc.
        $articles = collect($articles)->unique('loc')->toArray();

        // Filter out also if lastmod or loc is empty
        $articles = array_filter($articles, function ($article) {
            return !empty($article['loc']) && !empty($article['lastmod']);
        });

        $content = '';
        $content .= '<?xml version="1.0" encoding="UTF-8"?>' . "\n";
        $content .= '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">' . "\n";
        foreach ($articles as $article) {
            $url = strip_tags($article['loc']); // Strip HTML tags from the URL

            // Filter out non-UTF-8 characters, see https://stackoverflow.com/a/1401710/3958494
            $url = str_replace('&', '&amp;', $url);
            $url = preg_replace('/[^\x20-\x7E]/', '', $url);


            $content .= "\t" . '<url>' . "\n";
            $content .= "\t\t" . '<loc>' . $url . '</loc>' . "\n";
            $content .= "\t\t" . '<lastmod>' . $article['lastmod'] . '</lastmod>' . "\n";
            $content .= "\t\t" . '<changefreq>weekly</changefreq>' . "\n";
            $content .= "\t\t" . '<priority>0.8</priority>' . "\n";
            $content .= "\t" . '</url>' . "\n";
        }
        $content .= '</urlset>';

        return response($content)
            ->withHeaders([
                'Content-Type' => 'text/xml'
            ]);
    }

    public function getCategories()
    {
        return Category::select('slug', 'updated_at')->get();
    }

    public function getTags()
    {
        return Tag::select('slug', 'updated_at')->get();
    }

    public function setLastUpdatedAt($lastUpdatedAt): void
    {
        if ($this->lastUpdatedAt == null) {
            $this->lastUpdatedAt = $lastUpdatedAt;
        } else {
            if ($lastUpdatedAt > $this->lastUpdatedAt) {
                $this->lastUpdatedAt = $lastUpdatedAt;
            }
        }

        if ($this->lastUpdatedAt == null) {
            $this->lastUpdatedAt = now();
        }

        $this->lastUpdatedAt = Carbon::parse($this->lastUpdatedAt)->tz('UTC')->toAtomString();
    }

    /**
     * @return <[loc, lastmod]>
     */
    public function getAllPosts($categories, $tags, $where = null): array
    {
        $query = Post::select('slug', 'updated_at', 'post_or_tutorial');

        if ($where) {
            $query->where($where);
        }

        $posts = $query->get();

        $data = [];
        $posts->map(function ($post) use (&$data) {
            $type = $post->post_or_tutorial == 0 ? 'blog/' : 'tutorials/';
            $data[] = [
                'loc' => url($type . $post->slug),
                'lastmod' => $post->updated_at->tz('UTC')->toAtomString(),
            ];
        });

        $this->setLastUpdatedAt($posts->max('updated_at'));

        $data[] = [
            'loc' => url('blog'),
            'lastmod' => $this->lastUpdatedAt,
        ];

        $data[] = [
            'loc' => url('tutorials'),
            'lastmod' => $this->lastUpdatedAt,
        ];

        $data[] = [
            'loc' => url('tutorials-center'),
            'lastmod' => $this->lastUpdatedAt,
        ];

        $data[] = [
            'loc' => url('search-tutorial'),
            'lastmod' => $this->lastUpdatedAt,
        ];

        $data[] = [
            'loc' => url('playlists'),
            'lastmod' => $this->lastUpdatedAt,
        ];

        foreach ($categories as $category) {
            $data[] = [
                'loc' => url('tutorials/category/' . $category->slug),
                'lastmod' => $this->lastUpdatedAt,
            ];
            $data[] = [
                'loc' => url('blog/category/' . $category->slug),
                'lastmod' => $this->lastUpdatedAt,
            ];
        }

        foreach ($tags as $tag) {
            $data[] = [
                'loc' => url('tutorials/tag/' . $tag->slug),
                'lastmod' => $this->lastUpdatedAt,
            ];
            $data[] = [
                'loc' => url('blog/tag/' . $tag->slug),
                'lastmod' => $this->lastUpdatedAt,
            ];
        }

        return $data;
    }

    /**
     * @return <[loc, lastmod]>
     */
    public function getAllCodeExaples(): array
    {
        $data = [];
        $codeExamples = CodeExample::select('slug', 'updated_at')->get();
        $codeExamples->map(function ($codeExample) use (&$data) {
            $codeExample->slug = 'example/' . $codeExample->slug;
            $data[] = [
                'loc' => url($codeExample->slug),
                'lastmod' => $codeExample->updated_at->tz('UTC')->toAtomString(),
            ];
        });

        $this->setLastUpdatedAt($codeExamples->max('updated_at'));

        $data[] = [
            'loc' => url('codes'),
            'lastmod' => $this->lastUpdatedAt,
        ];

        $data[] = [
            'loc' => url('codes/run/code'),
            'lastmod' => $this->lastUpdatedAt,
        ];

        return $data;
    }

    /**
     * @return <[loc, lastmod]>
     */
    public function getAllPages(): array
    {
        $data = [];
        $pages = Page::select('slug', 'updated_at')->get();
        $pages->map(function ($page) use (&$data) {
            $data[] = [
                'loc' => url('page/' . $page->slug),
                'lastmod' => $page->updated_at->tz('UTC')->toAtomString(),
            ];
        });

        $this->setLastUpdatedAt($pages->max('updated_at'));

        return $data;
    }

    /**
     * @return <[loc, lastmod]>
     */
    public function getAllUsers(): array
    {
        $data = [];
        $users = Developer::select('username', 'updated_at')->get();
        $users->map(function ($user) use (&$data) {
            $data[] = [
                'loc' => url('users/' . $user->username),
                'lastmod' => $user->updated_at->tz('UTC')->toAtomString(),
            ];
        });

        return $data;
    }

    /**
     * @return <[loc, lastmod]>
     */
    public function getAllServices(): array
    {
        $data = [];
        $services = Service::select('slug', 'updated_at')->get();
        $services->map(function ($service) use (&$data) {
            $data[] = [
                'loc' => url('services/' . $service->slug),
                'lastmod' => $service->updated_at->tz('UTC')->toAtomString(),
            ];
        });

        return $data;
    }

    /**
     * @return <[loc, lastmod]>
     */
    public function getAllDesigns(): array
    {
        $data = [];

        // Get all frameworks
        $frameworks = ['tailwind', 'bootstrap'];
        $cssCodes = CssCode::select('framework', 'slug', 'updated_at')->get();

        foreach ($frameworks as $framework) {
            $frameworkCSSCodes = collect($cssCodes)->where('framework', $framework);

            foreach ($frameworkCSSCodes as $cssCode) {
                $data[] = [
                    'loc' => url('design/' . $cssCode->framework . '/' . $cssCode->slug),
                    'lastmod' => $cssCode->updated_at->tz('UTC')->toAtomString(),
                ];
                $data[] = [
                    'loc' => url('design/' . $cssCode->framework . '/' . $cssCode->slug . '/view'),
                    'lastmod' => $cssCode->updated_at->tz('UTC')->toAtomString(),
                ];
                $this->setLastUpdatedAt($cssCode->updated_at);
            }

            $data[] = [
                'loc' => url('design/' . $framework),
                'lastmod' => $this->lastUpdatedAt,
            ];

            $data[] = [
                'loc' => url('design'),
                'lastmod' => $this->lastUpdatedAt,
            ];
        }

        return $data;
    }

    /**
     * @return <[loc, lastmod]>
     */
    public function getAllProjects(): array
    {
        $data = [];

        // Get all projects
        $projects = Project::select('slug', 'updated_at')->get();
        $projects->map(function ($project) use (&$data) {
            $data[] = [
                'loc' => url('portfolio/' . $project->slug),
                'lastmod' => $project->updated_at->tz('UTC')->toAtomString(),
            ];
        });

        return $data;
    }

    /**
     * @return <[loc, lastmod]>
     */
    public function getAllCourses(): array
    {
        $data = [];
        $lastUpdatedAt = null;

        // Get all courses
        $courses = Course::select('slug', 'updated_at')->get();
        $courses->map(function ($course) use (&$data, &$lastUpdatedAt) {
            $data[] = [
                'loc' => url('course/' . $course->slug),
                'lastmod' => $course->updated_at->tz('UTC')->toAtomString(),
            ];

            $lastUpdatedAt = $course->updated_at->tz('UTC')->toAtomString();
        });

        $data[] = [
            'loc' => url('course'),
            'lastmod' => $lastUpdatedAt,
        ];

        return $data;
    }

    /**
     * @return <[loc, lastmod]>
     */
    public function getAllRootGenericPages(): array
    {
        $data[] = [
            'loc' => url('/'),
            'lastmod' => $this->lastUpdatedAt,
        ];

        $data[] = [
            'loc' => url('about-us'),
            'lastmod' => $this->lastUpdatedAt,
        ];

        $data[] = [
            'loc' => url('contact'),
            'lastmod' => $this->lastUpdatedAt,
        ];

        return $data;
    }
}