<?php
declare(strict_types=1);

namespace Modules\Blog;

use Core\Http\Response;
use Core\Services\Auth;
use Core\Services\Database;
use Core\Views\View;
use DateTime;
use PDO;
use Throwable;

class BlogController
{
    private View $view;

    public function __construct()
    {
        $this->view = new View(__DIR__ . '/views');
    }

    public function index(): Response
    {
        $db = Database::get();
        $posts = [];
        $page = null;
        if ($db instanceof PDO) {
            $pageStmt = $db->prepare("SELECT title, content_html FROM ac_pages WHERE is_blog_index = 1 AND is_published = 1 LIMIT 1");
            $pageStmt->execute();
            $page = $pageStmt->fetch(PDO::FETCH_ASSOC) ?: null;

            $stmt = $db->prepare("
                SELECT title, slug, excerpt, published_at, featured_image_url, author_name, category, tags
                FROM ac_posts
                WHERE is_published = 1
                ORDER BY COALESCE(published_at, created_at) DESC
            ");
            $stmt->execute();
            $posts = $stmt->fetchAll(PDO::FETCH_ASSOC);
        }
        return new Response($this->view->render('site/index.php', [
            'title' => 'News',
            'posts' => $posts,
            'page' => $page,
        ]));
    }

    public function show(): Response
    {
        $slug = trim((string)($_GET['slug'] ?? ''));
        if ($slug === '') {
            return $this->notFound();
        }

        $db = Database::get();
        if (!$db instanceof PDO) {
            return $this->notFound();
        }

        $stmt = $db->prepare("
            SELECT title, content_html, published_at, featured_image_url, author_name, category, tags
            FROM ac_posts
            WHERE slug = :slug AND is_published = 1
            LIMIT 1
        ");
        $stmt->execute([':slug' => $slug]);
        $post = $stmt->fetch(PDO::FETCH_ASSOC);
        if (!$post) {
            return $this->notFound();
        }

        return new Response($this->view->render('site/show.php', [
            'title' => (string)$post['title'],
            'content_html' => (string)$post['content_html'],
            'published_at' => (string)($post['published_at'] ?? ''),
            'featured_image_url' => (string)($post['featured_image_url'] ?? ''),
            'author_name' => (string)($post['author_name'] ?? ''),
            'category' => (string)($post['category'] ?? ''),
            'tags' => (string)($post['tags'] ?? ''),
        ]));
    }

    public function adminIndex(): Response
    {
        if ($guard = $this->guard(['admin', 'manager'])) {
            return $guard;
        }
        $db = Database::get();
        $posts = [];
        if ($db instanceof PDO) {
            $stmt = $db->query("SELECT id, title, slug, author_name, is_published, published_at, updated_at FROM ac_posts ORDER BY updated_at DESC");
            $posts = $stmt ? $stmt->fetchAll(PDO::FETCH_ASSOC) : [];
        }
        return new Response($this->view->render('admin/index.php', [
            'title' => 'Posts',
            'posts' => $posts,
        ]));
    }

    public function adminEdit(): Response
    {
        if ($guard = $this->guard(['admin', 'manager'])) {
            return $guard;
        }
        $id = isset($_GET['id']) ? (int)$_GET['id'] : 0;
        $post = [
            'id' => 0,
            'title' => '',
            'slug' => '',
            'excerpt' => '',
            'featured_image_url' => '',
            'author_name' => '',
            'category' => '',
            'tags' => '',
            'content_html' => '',
            'is_published' => 0,
            'published_at' => '',
        ];

        $db = Database::get();
        if ($id > 0 && $db instanceof PDO) {
            $stmt = $db->prepare("SELECT * FROM ac_posts WHERE id = :id LIMIT 1");
            $stmt->execute([':id' => $id]);
            $row = $stmt->fetch(PDO::FETCH_ASSOC);
            if ($row) {
                $post = $row;
            }
        }

        return new Response($this->view->render('admin/edit.php', [
            'title' => $id > 0 ? 'Edit Post' : 'New Post',
            'post' => $post,
            'error' => '',
        ]));
    }

    public function adminSave(): Response
    {
        if ($guard = $this->guard(['admin', 'manager'])) {
            return $guard;
        }
        $db = Database::get();
        if (!$db instanceof PDO) {
            return new Response('', 302, ['Location' => '/admin/posts']);
        }

        $id = (int)($_POST['id'] ?? 0);
        $title = trim((string)($_POST['title'] ?? ''));
        $slug = trim((string)($_POST['slug'] ?? ''));
        $excerpt = trim((string)($_POST['excerpt'] ?? ''));
        $featuredImage = trim((string)($_POST['featured_image_url'] ?? ''));
        $authorName = trim((string)($_POST['author_name'] ?? ''));
        $category = trim((string)($_POST['category'] ?? ''));
        $tags = trim((string)($_POST['tags'] ?? ''));
        $content = (string)($_POST['content_html'] ?? '');
        $isPublished = isset($_POST['is_published']) ? 1 : 0;
        $publishedAt = trim((string)($_POST['published_at'] ?? ''));

        if ($title === '') {
            return $this->renderEditError($id, $title, $slug, $excerpt, $featuredImage, $authorName, $category, $tags, $content, $isPublished, $publishedAt, 'Title is required.');
        }

        if ($slug === '') {
            $slug = $this->slugify($title);
        } else {
            $slug = $this->slugify($slug);
        }

        if ($publishedAt !== '') {
            try {
                $dt = new DateTime($publishedAt);
                $publishedAt = $dt->format('Y-m-d H:i:s');
            } catch (Throwable $e) {
                $publishedAt = '';
            }
        }

        try {
            if ($id > 0) {
                $chk = $db->prepare("SELECT id FROM ac_posts WHERE slug = :slug AND id != :id LIMIT 1");
                $chk->execute([':slug' => $slug, ':id' => $id]);
            } else {
                $chk = $db->prepare("SELECT id FROM ac_posts WHERE slug = :slug LIMIT 1");
                $chk->execute([':slug' => $slug]);
            }
            if ($chk->fetch()) {
                return $this->renderEditError($id, $title, $slug, $excerpt, $featuredImage, $authorName, $category, $tags, $content, $isPublished, $publishedAt, 'Slug already exists.');
            }

            if ($id > 0) {
                $stmt = $db->prepare("
                    UPDATE ac_posts
                    SET title = :title, slug = :slug, excerpt = :excerpt,
                        featured_image_url = :featured_image_url, author_name = :author_name,
                        category = :category, tags = :tags, content_html = :content,
                        is_published = :published, published_at = :published_at
                    WHERE id = :id
                ");
                $stmt->execute([
                    ':title' => $title,
                    ':slug' => $slug,
                    ':excerpt' => $excerpt !== '' ? $excerpt : null,
                    ':featured_image_url' => $featuredImage !== '' ? $featuredImage : null,
                    ':author_name' => $authorName !== '' ? $authorName : null,
                    ':category' => $category !== '' ? $category : null,
                    ':tags' => $tags !== '' ? $tags : null,
                    ':content' => $content,
                    ':published' => $isPublished,
                    ':published_at' => $publishedAt !== '' ? $publishedAt : null,
                    ':id' => $id,
                ]);
            } else {
                $stmt = $db->prepare("
                    INSERT INTO ac_posts (title, slug, excerpt, featured_image_url, author_name, category, tags, content_html, is_published, published_at)
                    VALUES (:title, :slug, :excerpt, :featured_image_url, :author_name, :category, :tags, :content, :published, :published_at)
                ");
                $stmt->execute([
                    ':title' => $title,
                    ':slug' => $slug,
                    ':excerpt' => $excerpt !== '' ? $excerpt : null,
                    ':featured_image_url' => $featuredImage !== '' ? $featuredImage : null,
                    ':author_name' => $authorName !== '' ? $authorName : null,
                    ':category' => $category !== '' ? $category : null,
                    ':tags' => $tags !== '' ? $tags : null,
                    ':content' => $content,
                    ':published' => $isPublished,
                    ':published_at' => $publishedAt !== '' ? $publishedAt : null,
                ]);
            }
        } catch (Throwable $e) {
            return $this->renderEditError($id, $title, $slug, $excerpt, $featuredImage, $authorName, $category, $tags, $content, $isPublished, $publishedAt, 'Unable to save post.');
        }

        return new Response('', 302, ['Location' => '/admin/posts']);
    }

    public function adminDelete(): Response
    {
        if ($guard = $this->guard(['admin', 'manager'])) {
            return $guard;
        }
        $db = Database::get();
        if (!$db instanceof PDO) {
            return new Response('', 302, ['Location' => '/admin/posts']);
        }
        $id = (int)($_POST['id'] ?? 0);
        if ($id > 0) {
            $stmt = $db->prepare("DELETE FROM ac_posts WHERE id = :id");
            $stmt->execute([':id' => $id]);
        }
        return new Response('', 302, ['Location' => '/admin/posts']);
    }

    private function renderEditError(
        int $id,
        string $title,
        string $slug,
        string $excerpt,
        string $featuredImage,
        string $authorName,
        string $category,
        string $tags,
        string $content,
        int $isPublished,
        string $publishedAt,
        string $error
    ): Response {
        $post = [
            'id' => $id,
            'title' => $title,
            'slug' => $slug,
            'excerpt' => $excerpt,
            'featured_image_url' => $featuredImage,
            'author_name' => $authorName,
            'category' => $category,
            'tags' => $tags,
            'content_html' => $content,
            'is_published' => $isPublished,
            'published_at' => $publishedAt,
        ];
        return new Response($this->view->render('admin/edit.php', [
            'title' => $id > 0 ? 'Edit Post' : 'New Post',
            'post' => $post,
            'error' => $error,
        ]));
    }

    private function notFound(): Response
    {
        $view = new View();
        return new Response($view->render('site/404.php', [
            'title' => 'Not Found',
            'message' => 'Post not found.',
        ]), 404);
    }

    private function slugify(string $value): string
    {
        $value = strtolower(trim($value));
        $value = preg_replace('~[^a-z0-9]+~', '-', $value) ?? $value;
        $value = trim($value, '-');
        return $value !== '' ? $value : 'post';
    }

    private function guard(array $roles): ?Response
    {
        if (!Auth::check()) {
            return new Response('', 302, ['Location' => '/admin/login']);
        }
        if (!Auth::hasRole($roles)) {
            return new Response('', 302, ['Location' => '/admin']);
        }
        return null;
    }
}