<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use App\Models\AuditLog;
use App\Models\Page;
use App\Services\SiteRevalidationService;
use Illuminate\Http\Request;

class PageController extends Controller
{
    public function __construct()
    {
        $this->middleware('can:view_pages')->only(['index', 'show']);
        $this->middleware('can:create_pages')->only(['create', 'store']);
        $this->middleware('can:edit_pages')->only(['edit', 'update']);
        $this->middleware('can:delete_pages')->only(['destroy']);
        $this->middleware('can:publish_pages')->only(['publish']);
    }

    public function index()
    {
        $pages = Page::with(['creator', 'parent'])
            ->topLevel()
            ->orderBy('sort_order')
            ->get();

        // Also load child pages
        $pages->load('children');

        return view('admin.pages.index', compact('pages'));
    }

    public function create()
    {
        $parentPages = Page::topLevel()->orderBy('sort_order')->get();

        return view('admin.pages.create', compact('parentPages'));
    }

    public function store(Request $request)
    {
        $validated = $request->validate([
            'title' => 'required|string|max:255',
            'slug' => 'nullable|string|max:255|unique:pages,slug',
            'content' => 'required|string',
            'template' => 'nullable|string|max:255',
            'status' => 'required|in:draft,published',
            'meta_description' => 'nullable|string|max:500',
            'parent_id' => 'nullable|exists:pages,id',
            'sort_order' => 'nullable|integer',
        ]);

        $page = Page::create([
            'title' => $validated['title'],
            'slug' => $validated['slug'] ?? null,
            'content' => $validated['content'],
            'template' => $validated['template'] ?? null,
            'status' => $validated['status'],
            'meta_description' => $validated['meta_description'] ?? null,
            'parent_id' => $validated['parent_id'] ?? null,
            'sort_order' => $validated['sort_order'] ?? 0,
            'published_at' => $validated['status'] === 'published' ? now() : null,
            'created_by_user_id' => auth()->id(),
            'last_updated_by_user_id' => auth()->id(),
        ]);

        AuditLog::create([
            'user_id' => auth()->id(),
            'action' => 'page.created',
            'description' => "建立頁面：{$page->title} (狀態：{$page->getStatusLabel()})",
            'ip_address' => request()->ip(),
        ]);

        if ($validated['status'] === 'published') {
            SiteRevalidationService::revalidatePage($page->slug);
        }

        return redirect()
            ->route('admin.pages.show', $page)
            ->with('status', '頁面已成功建立');
    }

    public function show(Page $page)
    {
        $page->load(['creator', 'lastUpdatedBy', 'parent', 'children']);

        return view('admin.pages.show', compact('page'));
    }

    public function edit(Page $page)
    {
        $parentPages = Page::topLevel()
            ->where('id', '!=', $page->id)
            ->orderBy('sort_order')
            ->get();

        return view('admin.pages.edit', compact('page', 'parentPages'));
    }

    public function update(Request $request, Page $page)
    {
        $validated = $request->validate([
            'title' => 'required|string|max:255',
            'slug' => 'nullable|string|max:255|unique:pages,slug,'.$page->id,
            'content' => 'required|string',
            'template' => 'nullable|string|max:255',
            'status' => 'required|in:draft,published',
            'meta_description' => 'nullable|string|max:500',
            'parent_id' => 'nullable|exists:pages,id',
            'sort_order' => 'nullable|integer',
        ]);

        $updateData = [
            'title' => $validated['title'],
            'content' => $validated['content'],
            'template' => $validated['template'] ?? null,
            'status' => $validated['status'],
            'meta_description' => $validated['meta_description'] ?? null,
            'parent_id' => $validated['parent_id'] ?? null,
            'sort_order' => $validated['sort_order'] ?? 0,
            'last_updated_by_user_id' => auth()->id(),
        ];

        if (! empty($validated['slug']) && $validated['slug'] !== $page->slug) {
            $updateData['slug'] = $validated['slug'];
        }

        if ($validated['status'] === 'published' && ! $page->published_at) {
            $updateData['published_at'] = now();
        }

        $page->update($updateData);

        AuditLog::create([
            'user_id' => auth()->id(),
            'action' => 'page.updated',
            'description' => "更新頁面：{$page->title}",
            'ip_address' => request()->ip(),
        ]);

        if ($page->isPublished()) {
            SiteRevalidationService::revalidatePage($page->slug);
        }

        return redirect()
            ->route('admin.pages.show', $page)
            ->with('status', '頁面已成功更新');
    }

    public function destroy(Page $page)
    {
        if ($page->children()->count() > 0) {
            return back()->with('error', '此頁面下仍有子頁面，無法刪除');
        }

        $title = $page->title;
        $slug = $page->slug;
        $wasPublished = $page->isPublished();
        $page->delete();

        AuditLog::create([
            'user_id' => auth()->id(),
            'action' => 'page.deleted',
            'description' => "刪除頁面：{$title}",
            'ip_address' => request()->ip(),
        ]);

        if ($wasPublished) {
            SiteRevalidationService::revalidatePage($slug);
        }

        return redirect()
            ->route('admin.pages.index')
            ->with('status', '頁面已成功刪除');
    }

    public function publish(Page $page)
    {
        if ($page->isPublished()) {
            return back()->with('error', '此頁面已經發布');
        }

        $page->publish(auth()->user());

        AuditLog::create([
            'user_id' => auth()->id(),
            'action' => 'page.published',
            'description' => "發布頁面：{$page->title}",
            'ip_address' => request()->ip(),
        ]);

        SiteRevalidationService::revalidatePage($page->slug);

        return back()->with('status', '頁面已成功發布');
    }
}