<?php

namespace App\Http\Controllers;

use App\Actions\BbcodeFormatter;
use App\Models\Post;
use App\Models\Thread;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Storage;

class PostController extends Controller
{
    public function index(Request $request): JsonResponse
    {
        $query = Post::query()->withoutTrashed()->with([
            'user' => fn ($query) => $query
                ->withCount(['posts', 'threads', 'thanksGiven', 'thanksReceived'])
                ->with(['rank', 'roles']),
            'attachments.extension',
            'attachments.group',
        ]);

        $threadParam = $request->query('thread');
        if (is_string($threadParam)) {
            $threadId = $this->parseIriId($threadParam);
            if ($threadId !== null) {
                $query->where('thread_id', $threadId);
            }
        }

        $posts = $query
            ->oldest('created_at')
            ->get()
            ->map(fn (Post $post) => $this->serializePost($post));

        return response()->json($posts);
    }

    public function store(Request $request): JsonResponse
    {
        $data = $request->validate([
            'body' => ['required', 'string'],
            'thread' => ['required', 'string'],
        ]);

        $threadId = $this->parseIriId($data['thread']);
        $thread = Thread::findOrFail($threadId);

        $post = Post::create([
            'thread_id' => $thread->id,
            'user_id' => $request->user()?->id,
            'body' => $data['body'],
        ]);

        $post->loadMissing([
            'user' => fn ($query) => $query
                ->withCount(['posts', 'threads', 'thanksGiven', 'thanksReceived'])
                ->with(['rank', 'roles']),
            'attachments.extension',
            'attachments.group',
        ]);

        return response()->json($this->serializePost($post), 201);
    }

    public function destroy(Request $request, Post $post): JsonResponse
    {
        $post->deleted_by = $request->user()?->id;
        $post->save();
        $post->delete();

        return response()->json(null, 204);
    }

    private function parseIriId(?string $value): ?int
    {
        if (!$value) {
            return null;
        }

        if (preg_match('#/threads/(\d+)$#', $value, $matches)) {
            return (int) $matches[1];
        }

        if (is_numeric($value)) {
            return (int) $value;
        }

        return null;
    }

    private function serializePost(Post $post): array
    {
        $attachments = $post->relationLoaded('attachments') ? $post->attachments : collect();
        $bodyHtml = $this->renderBody($post->body, $attachments);
        return [
            'id' => $post->id,
            'body' => $post->body,
            'body_html' => $bodyHtml,
            'thread' => "/api/threads/{$post->thread_id}",
            'user_id' => $post->user_id,
            'user_name' => $post->user?->name,
            'user_avatar_url' => $post->user?->avatar_path
                ? Storage::url($post->user->avatar_path)
                : null,
            'user_posts_count' => ($post->user?->posts_count ?? 0) + ($post->user?->threads_count ?? 0),
            'user_created_at' => $post->user?->created_at?->toIso8601String(),
            'user_location' => $post->user?->location,
            'user_thanks_given_count' => $post->user?->thanks_given_count ?? 0,
            'user_thanks_received_count' => $post->user?->thanks_received_count ?? 0,
            'user_rank_name' => $post->user?->rank?->name,
            'user_rank_badge_type' => $post->user?->rank?->badge_type,
            'user_rank_badge_text' => $post->user?->rank?->badge_text,
            'user_rank_badge_url' => $post->user?->rank?->badge_image_path
                ? Storage::url($post->user->rank->badge_image_path)
                : null,
            'user_rank_color' => $post->user?->rank?->color,
            'user_group_color' => $this->resolveGroupColor($post->user),
            'created_at' => $post->created_at?->toIso8601String(),
            'updated_at' => $post->updated_at?->toIso8601String(),
            'attachments' => $post->relationLoaded('attachments')
                ? $attachments
                    ->map(fn ($attachment) => [
                        'id' => $attachment->id,
                        'group' => $attachment->group ? [
                            'id' => $attachment->group->id,
                            'name' => $attachment->group->name,
                        ] : null,
                        'original_name' => $attachment->original_name,
                        'extension' => $attachment->extension,
                        'mime_type' => $attachment->mime_type,
                        'size_bytes' => $attachment->size_bytes,
                        'download_url' => "/api/attachments/{$attachment->id}/download",
                        'created_at' => $attachment->created_at?->toIso8601String(),
                    ])
                    ->values()
                : [],
        ];
    }

    private function renderBody(string $body, $attachments): string
    {
        $replaced = $this->replaceAttachmentTags($body, $attachments);
        return BbcodeFormatter::format($replaced);
    }

    private function replaceAttachmentTags(string $body, $attachments): string
    {
        if (!$attachments || count($attachments) === 0) {
            return $body;
        }

        $map = [];
        foreach ($attachments as $attachment) {
            $name = strtolower($attachment->original_name ?? '');
            if ($name !== '') {
                $map[$name] = [
                    'url' => "/api/attachments/{$attachment->id}/download",
                    'mime' => $attachment->mime_type ?? '',
                ];
            }
        }

        if (!$map) {
            return $body;
        }

        return preg_replace_callback('/\\[attachment\\](.+?)\\[\\/attachment\\]/i', function ($matches) use ($map) {
            $rawName = trim($matches[1]);
            $key = strtolower($rawName);
            if (!array_key_exists($key, $map)) {
                return $matches[0];
            }
            $entry = $map[$key];
            $url = $entry['url'];
            $mime = $entry['mime'] ?? '';
            if (str_starts_with($mime, 'image/')) {
                return "[img]{$url}[/img]";
            }
            return "[url={$url}]{$rawName}[/url]";
        }, $body) ?? $body;
    }

    private function resolveGroupColor(?\App\Models\User $user): ?string
    {
        if (!$user) {
            return null;
        }

        $roles = $user->roles;
        if (!$roles) {
            return null;
        }

        foreach ($roles->sortBy('name') as $role) {
            if (!empty($role->color)) {
                return $role->color;
            }
        }

        return null;
    }
}