<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use App\Models\Announcement;
use App\Models\AuditLog;
use Illuminate\Http\Request;

class AnnouncementController extends Controller
{
    public function __construct()
    {
        $this->middleware('can:view_announcements')->only(['index', 'show']);
        $this->middleware('can:create_announcements')->only(['create', 'store']);
        $this->middleware('can:edit_announcements')->only(['edit', 'update']);
        $this->middleware('can:delete_announcements')->only(['destroy']);
        $this->middleware('can:publish_announcements')->only(['publish', 'archive']);
    }

    /**
     * Display a listing of announcements
     */
    public function index(Request $request)
    {
        $query = Announcement::with(['creator', 'lastUpdatedBy'])
            ->orderByDesc('is_pinned')
            ->orderByDesc('created_at');

        // Filter by status
        if ($request->filled('status')) {
            $query->where('status', $request->status);
        }

        // Filter by access level
        if ($request->filled('access_level')) {
            $query->where('access_level', $request->access_level);
        }

        // Filter by pinned
        if ($request->filled('pinned')) {
            $query->where('is_pinned', $request->pinned === 'yes');
        }

        // Search
        if ($request->filled('search')) {
            $search = $request->search;
            $query->where(function($q) use ($search) {
                $q->where('title', 'like', "%{$search}%")
                  ->orWhere('content', 'like', "%{$search}%");
            });
        }

        $announcements = $query->paginate(20);

        // Statistics
        $stats = [
            'total' => Announcement::count(),
            'draft' => Announcement::draft()->count(),
            'published' => Announcement::published()->count(),
            'archived' => Announcement::archived()->count(),
            'pinned' => Announcement::pinned()->count(),
        ];

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

    /**
     * Show the form for creating a new announcement
     */
    public function create()
    {
        return view('admin.announcements.create');
    }

    /**
     * Store a newly created announcement
     */
    public function store(Request $request)
    {
        $validated = $request->validate([
            'title' => 'required|string|max:255',
            'content' => 'required|string',
            'access_level' => 'required|in:public,members,board,admin',
            'published_at' => 'nullable|date',
            'expires_at' => 'nullable|date|after:published_at',
            'is_pinned' => 'boolean',
            'display_order' => 'nullable|integer',
            'save_action' => 'required|in:draft,publish',
        ]);

        $announcement = Announcement::create([
            'title' => $validated['title'],
            'content' => $validated['content'],
            'access_level' => $validated['access_level'],
            'status' => $validated['save_action'] === 'publish' ? Announcement::STATUS_PUBLISHED : Announcement::STATUS_DRAFT,
            'published_at' => $validated['save_action'] === 'publish' ? ($validated['published_at'] ?? now()) : null,
            'expires_at' => $validated['expires_at'] ?? null,
            'is_pinned' => $validated['is_pinned'] ?? false,
            'display_order' => $validated['display_order'] ?? 0,
            'created_by_user_id' => auth()->id(),
            'last_updated_by_user_id' => auth()->id(),
        ]);

        // Audit log
        AuditLog::create([
            'user_id' => auth()->id(),
            'action' => 'announcement.created',
            'description' => "建立公告：{$announcement->title} (狀態：{$announcement->getStatusLabel()})",
            'ip_address' => request()->ip(),
        ]);

        $message = $validated['save_action'] === 'publish' ? '公告已成功發布' : '公告已儲存為草稿';

        return redirect()
            ->route('admin.announcements.show', $announcement)
            ->with('status', $message);
    }

    /**
     * Display the specified announcement
     */
    public function show(Announcement $announcement)
    {
        // Check if user can view this announcement
        if (!$announcement->canBeViewedBy(auth()->user())) {
            abort(403, '您沒有權限查看此公告');
        }

        $announcement->load(['creator', 'lastUpdatedBy']);

        // Increment view count if viewing published announcement
        if ($announcement->isPublished()) {
            $announcement->incrementViewCount();
        }

        return view('admin.announcements.show', compact('announcement'));
    }

    /**
     * Show the form for editing the specified announcement
     */
    public function edit(Announcement $announcement)
    {
        // Check if user can edit this announcement
        if (!$announcement->canBeEditedBy(auth()->user())) {
            abort(403, '您沒有權限編輯此公告');
        }

        return view('admin.announcements.edit', compact('announcement'));
    }

    /**
     * Update the specified announcement
     */
    public function update(Request $request, Announcement $announcement)
    {
        // Check if user can edit this announcement
        if (!$announcement->canBeEditedBy(auth()->user())) {
            abort(403, '您沒有權限編輯此公告');
        }

        $validated = $request->validate([
            'title' => 'required|string|max:255',
            'content' => 'required|string',
            'access_level' => 'required|in:public,members,board,admin',
            'published_at' => 'nullable|date',
            'expires_at' => 'nullable|date|after:published_at',
            'is_pinned' => 'boolean',
            'display_order' => 'nullable|integer',
        ]);

        $announcement->update([
            'title' => $validated['title'],
            'content' => $validated['content'],
            'access_level' => $validated['access_level'],
            'published_at' => $validated['published_at'],
            'expires_at' => $validated['expires_at'] ?? null,
            'is_pinned' => $validated['is_pinned'] ?? false,
            'display_order' => $validated['display_order'] ?? 0,
            'last_updated_by_user_id' => auth()->id(),
        ]);

        // Audit log
        AuditLog::create([
            'user_id' => auth()->id(),
            'action' => 'announcement.updated',
            'description' => "更新公告：{$announcement->title}",
            'ip_address' => request()->ip(),
        ]);

        return redirect()
            ->route('admin.announcements.show', $announcement)
            ->with('status', '公告已成功更新');
    }

    /**
     * Remove the specified announcement (soft delete)
     */
    public function destroy(Announcement $announcement)
    {
        // Check if user can delete this announcement
        if (!$announcement->canBeEditedBy(auth()->user())) {
            abort(403, '您沒有權限刪除此公告');
        }

        $title = $announcement->title;
        $announcement->delete();

        // Audit log
        AuditLog::create([
            'user_id' => auth()->id(),
            'action' => 'announcement.deleted',
            'description' => "刪除公告：{$title}",
            'ip_address' => request()->ip(),
        ]);

        return redirect()
            ->route('admin.announcements.index')
            ->with('status', '公告已成功刪除');
    }

    /**
     * Publish a draft announcement
     */
    public function publish(Announcement $announcement)
    {
        // Check permission
        if (!auth()->user()->can('publish_announcements')) {
            abort(403, '您沒有權限發布公告');
        }

        // Check if user can edit this announcement
        if (!$announcement->canBeEditedBy(auth()->user())) {
            abort(403, '您沒有權限發布此公告');
        }

        if ($announcement->isPublished()) {
            return back()->with('error', '此公告已經發布');
        }

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

        // Audit log
        AuditLog::create([
            'user_id' => auth()->id(),
            'action' => 'announcement.published',
            'description' => "發布公告：{$announcement->title}",
            'ip_address' => request()->ip(),
        ]);

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

    /**
     * Archive an announcement
     */
    public function archive(Announcement $announcement)
    {
        // Check permission
        if (!auth()->user()->can('publish_announcements')) {
            abort(403, '您沒有權限歸檔公告');
        }

        // Check if user can edit this announcement
        if (!$announcement->canBeEditedBy(auth()->user())) {
            abort(403, '您沒有權限歸檔此公告');
        }

        if ($announcement->isArchived()) {
            return back()->with('error', '此公告已經歸檔');
        }

        $announcement->archive(auth()->user());

        // Audit log
        AuditLog::create([
            'user_id' => auth()->id(),
            'action' => 'announcement.archived',
            'description' => "歸檔公告：{$announcement->title}",
            'ip_address' => request()->ip(),
        ]);

        return back()->with('status', '公告已成功歸檔');
    }

    /**
     * Pin an announcement
     */
    public function pin(Request $request, Announcement $announcement)
    {
        // Check permission
        if (!auth()->user()->can('edit_announcements')) {
            abort(403, '您沒有權限置頂公告');
        }

        // Check if user can edit this announcement
        if (!$announcement->canBeEditedBy(auth()->user())) {
            abort(403, '您沒有權限置頂此公告');
        }

        $validated = $request->validate([
            'display_order' => 'nullable|integer',
        ]);

        $announcement->pin($validated['display_order'] ?? 0, auth()->user());

        // Audit log
        AuditLog::create([
            'user_id' => auth()->id(),
            'action' => 'announcement.pinned',
            'description' => "置頂公告：{$announcement->title}",
            'ip_address' => request()->ip(),
        ]);

        return back()->with('status', '公告已成功置頂');
    }

    /**
     * Unpin an announcement
     */
    public function unpin(Announcement $announcement)
    {
        // Check permission
        if (!auth()->user()->can('edit_announcements')) {
            abort(403, '您沒有權限取消置頂公告');
        }

        // Check if user can edit this announcement
        if (!$announcement->canBeEditedBy(auth()->user())) {
            abort(403, '您沒有權限取消置頂此公告');
        }

        $announcement->unpin(auth()->user());

        // Audit log
        AuditLog::create([
            'user_id' => auth()->id(),
            'action' => 'announcement.unpinned',
            'description' => "取消置頂公告：{$announcement->title}",
            'ip_address' => request()->ip(),
        ]);

        return back()->with('status', '公告已取消置頂');
    }
}