Code to facilitate #1123

app/Http/Middleware/Installer.php

@@ -0,0 +1,86 @@
+<?php
+
+namespace FireflyIII\Http\Middleware;
+
+use Closure;
+use DB;
+use FireflyConfig;
+use FireflyIII\Exceptions\FireflyException;
+use Illuminate\Database\QueryException;
+use Log;
+
+/**
+ * Class Installer
+ */
+class Installer
+{
+    /**
+     * Handle an incoming request.
+     *
+     * @throws FireflyException
+     *
+     * @param  \Illuminate\Http\Request $request
+     * @param  \Closure                 $next
+     *
+     * @return mixed
+     */
+    public function handle($request, Closure $next)
+    {
+        $url = $request->url();
+        $strpos = stripos($url, '/install');
+        if (!($strpos === false)) {
+            return $next($request);
+        }
+
+        // no tables present?
+        try {
+            DB::table('users')->count();
+        } catch (QueryException $e) {
+            $message = $e->getMessage();
+            Log::error('Access denied: ' . $message);
+            if ($this->isAccessDenied($message)) {
+                throw new FireflyException('It seems your database configuration is not correct. Please verify the username and password in your .env file.');
+            }
+            if ($this->noTablesExist($message)) {
+                // redirect to UpdateController
+                Log::warning('There are no Firefly III tables present. Redirect to migrate routine.');
+
+                return response()->redirectTo(route('installer.migrate'));
+            }
+            throw new FireflyException(sprintf('Could not access the database: %s', $message));
+        }
+
+        // older version in config than database?
+        $configVersion = intval(config('firefly.db_version'));
+        $dbVersion     = intval(FireflyConfig::get('db_version', 1)->data);
+        if ($configVersion > $dbVersion) {
+            Log::warning(sprintf(
+                'The current installed version (%d) is older than the required version (%d). Redirect to migrate routine.', $dbVersion, $configVersion
+            ));
+
+            // redirect to migrate routine:
+            return response()->redirectTo(route('installer.migrate'));
+        }
+        return $next($request);
+    }
+
+    /**
+     * @param string $message
+     *
+     * @return bool
+     */
+    protected function isAccessDenied(string $message): bool
+    {
+        return !(stripos($message, 'Access denied') === false);
+    }
+
+    /**
+     * @param string $message
+     *
+     * @return bool
+     */
+    protected function noTablesExist(string $message): bool
+    {
+        return !(stripos($message, 'Base table or view not found') === false);
+    }
+}