<?php

namespace App\Models;

use App\Render\BladeRenderer;
use App\Render\MarkdownRenderer;
use App\Render\Renderer;
use App\SiteConfiguration;
use Illuminate\Contracts\Filesystem\Filesystem;
use Illuminate\Support\Facades\Storage;
use League\CommonMark\Environment\Environment;
use League\CommonMark\Extension\CommonMark\CommonMarkCoreExtension;
use League\CommonMark\Extension\FrontMatter\FrontMatterExtension;
use League\CommonMark\Extension\FrontMatter\Output\RenderedContentWithFrontMatter;
use League\CommonMark\MarkdownConverter;

use function Illuminate\Filesystem\join_paths;

// TODO: Load page's frontmatter and replace things like
// title and layout from it. Also set any default,
// values for things like layout from the config
// if they're not present on the page.
class Page
{
    public string $filename;
    public string $fileBaseName; // Name of the file with extension removed
    public string $fileExtension;
    public string $directory;
    public string $title;
    public string $slug;
    public bool $isIndex = false;
    public bool $isNestedIndex = false;
    public string $key;
    protected Filesystem $sourceDisk;
    public ?string $layout;
    public string $entityName; // The name of this page. Ex: projects/myproject = myproject
    protected string $content;
    // Collection data
    public ?string $collection = null;
    public array $collectionHierarchy = []; // All collections matched from least to most
    public array $collectionProps = [];

    public function __construct(public string $path)
    {
        $this->sourceDisk = Storage::disk('source');

        $this->filename = basename($this->path);
        $this->fileExtension = (str_ends_with($this->filename, '.blade.php')) ? 'blade.php' : pathinfo($this->filename, PATHINFO_EXTENSION);
        $this->fileExtension = str($this->fileExtension)->trim('.')->toString();
        $this->fileBaseName = str($this->filename)->remove("." . $this->fileExtension)->toString();
        $this->title = str($this->filename)->remove("." . $this->fileExtension)->title()->toString();
        $this->slug = str($this->title)->slug();
        $this->directory = dirname($this->path);
        $this->key = str($this->path)->remove("." . $this->fileExtension)->replace("/", ".")->lower()->toString();

        if ($this->fileBaseName == "index") {
            $this->isIndex = true;
            $this->isNestedIndex = true;
        }

        $this->entityName = $this->isIndex ? basename($this->directory) : $this->slug;

        $this->detectCollection();
        $this->fillAdditionalData();
    }

    public function __get($name)
    {
        if (!empty($this->$name)) {
            return $this->name;
        }
        return $this->collectionProps[$name] ?? null;
    }

    public function detectCollection()
    {
        $key_parts = explode('.', $this->key);
        $collections = SiteConfiguration::collections();
        // Turn collections into an array containing
        // the parts and the length so we can easily
        // filter likely matches.
        $collections = collect($collections)->map(function ($name) {
            $parts = explode('.', $name);
            return [
                'name' => $name,
                'parts' => $parts,
                'length' => count($parts)
            ];
        })
            ->filter(fn($col) => $col['length'] <= count($key_parts))
            ->sortBy('length');

        foreach ($collections as $c) {
            $parts = $c['parts'];
            // Get a subset of max length key parts
            $key_compare = array_slice($key_parts, 0, count($parts));
            $props = [];
            $match = true;
            foreach ($key_compare as $i => $v) {
                $check = $parts[$i];
                // Check if it's a parameter like [project_name]
                if (str($check)->isMatch('/\[[a-z_]+\]/')) {
                    $key = str($check)->remove(['[', ']'])->toString();
                    $props[$key] = $v;
                    continue;
                }

                if ($v !== $check) {
                    $match = false;
                    break;
                }
            }

            if ($match) {
                $this->collectionHierarchy[] = $c['name'];
                $this->collection = $c['name'];
                $this->collectionProps = $props;
            }
        }

        // After detecting the collection, we can also
        // determine if the file is an index in that
        // collection. Example:
        // collection = projects
        // file path = projects/myproject.md
        if (str($this->key)->remove($this->collection)->remove(".") == $this->fileBaseName) {
            $this->isIndex = true;
        }
    }

    public function applyCollectionSettings(string $collection)
    {
        $config = SiteConfiguration::getConfig()['collections'][$collection];

        $fill = ['layout'];

        foreach ($fill as $field) {
            $this->$field = $config[$field];
        }
    }

    /**
     * Grab data from the file's front matter
     * as well as the config and overwrite
     * or fill in any missing attributes.
     *
     * @return void
     */
    public function fillAdditionalData()
    {
        // Apply collection settings in a hierarchical
        // manner, with the settings from the most
        // matched collection taking precedence
        // over the least.
        foreach ($this->collectionHierarchy as $collection) {
            $this->applyCollectionSettings($collection);
        }

        // After the hierarchy, also apply settings
        // from the detected collection to be
        // safe.
        if (!empty($this->collection)) {
            $this->applyCollectionSettings($collection);
        }

        // Grab front matter data if any. Apply any settings
        // from it since it takes precedence over
        // collection settings.
        if ($this->fileExtension == 'md') {
            // Build the markdown parser
            $mdEnvironment = new Environment();
            $mdEnvironment->addExtension(new CommonMarkCoreExtension);
            $mdEnvironment->addExtension(new FrontMatterExtension);

            $parser = new MarkdownConverter($mdEnvironment);
            $parsed = $parser->convert($this->content());
            if ($parsed instanceof RenderedContentWithFrontMatter) {
                $frontMatter = $parsed->getFrontMatter();
                foreach ($frontMatter as $field => $value) {
                    $this->$field = $value;
                }
            }
        }

        // If layout is still empty just set it to main
        if (empty($this->layout)) $this->layout = 'main';
    }

    public function renderer(): Renderer
    {
        return ($this->fileExtension == 'blade.php') ? new BladeRenderer : new MarkdownRenderer;
    }

    public function render(): string
    {
        return $this->renderer()->render($this);
    }

    public function outputPath(): string
    {

        $baseDirectory = $this->directory;
        if ($this->isIndex) {
            return join_paths($baseDirectory, "index.html");
        }

        return join_paths($baseDirectory, "{$this->slug}", "index.html");
    }

    public function url(): string
    {
        $baseDirectory = $this->directory;
        if ($this->isIndex && $this->isNestedIndex) {
            return str($this->directory)->prepend("/");
        }

        return str(join_paths($baseDirectory, "{$this->slug}"))->prepend("/");
    }

    public function content(): string
    {
        if (!empty($this->content)) {
            return $this->content;
        }

        $content = Storage::disk('source')->get($this->path);
        $this->content = $content;
        return $content;
    }
}