Started work on attachments

Created base models and started user-facing controls.

app/Http/Controllers/FileController.php

@@ -0,0 +1,91 @@
+<?php
+
+namespace BookStack\Http\Controllers;
+
+use BookStack\Exceptions\FileUploadException;
+use BookStack\File;
+use BookStack\Page;
+use BookStack\Repos\PageRepo;
+use BookStack\Services\FileService;
+use Illuminate\Http\Request;
+
+use BookStack\Http\Requests;
+
+class FileController extends Controller
+{
+    protected $fileService;
+    protected $file;
+    protected $pageRepo;
+
+    /**
+     * FileController constructor.
+     * @param FileService $fileService
+     * @param File $file
+     * @param PageRepo $pageRepo
+     */
+    public function __construct(FileService $fileService, File $file, PageRepo $pageRepo)
+    {
+        $this->fileService = $fileService;
+        $this->file = $file;
+        $this->pageRepo = $pageRepo;
+    }
+
+
+    /**
+     * Endpoint at which files are uploaded to.
+     * @param Request $request
+     */
+    public function upload(Request $request)
+    {
+        // TODO - Add file upload permission check
+        // TODO - ensure user has permission to edit relevant page.
+        // TODO - ensure uploads are deleted on page delete.
+
+        $this->validate($request, [
+            'uploaded_to' => 'required|integer|exists:pages,id'
+        ]);
+
+        $uploadedFile = $request->file('file');
+        $pageId = $request->get('uploaded_to');
+
+        try {
+            $file = $this->fileService->saveNewUpload($uploadedFile, $pageId);
+        } catch (FileUploadException $e) {
+            return response($e->getMessage(), 500);
+        }
+
+        return response()->json($file);
+    }
+
+    /**
+     * Get the files for a specific page.
+     * @param $pageId
+     * @return mixed
+     */
+    public function getFilesForPage($pageId)
+    {
+        // TODO - check view permission on page?
+        $page = $this->pageRepo->getById($pageId);
+        return response()->json($page->files);
+    }
+
+    /**
+     * Update the file sorting.
+     * @param $pageId
+     * @param Request $request
+     * @return mixed
+     */
+    public function sortFilesForPage($pageId, Request $request)
+    {
+        $this->validate($request, [
+            'files' => 'required|array',
+            'files.*.id' => 'required|integer',
+        ]);
+        $page = $this->pageRepo->getById($pageId);
+        $files = $request->get('files');
+        $this->fileService->updateFileOrderWithinPage($files, $pageId);
+        return response()->json(['message' => 'File order updated']);
+    }
+
+
+}