Merge branch '15-client-server-protocol-needs-a-redesign' into develop

Resolve "Client-Server Protocol needs a redesign"

See merge request tobias.wach/ccats!17

Client-Server Protocol.md

@@ -1,11 +1,14 @@
 # Client-Server Protocol
 
-Protocol version: "0.1"
+Protocol version: <b>"0.2"</b>
+
+Every json message must be minimized and be followed by a newline. This rule makes receiving and parsing the messages easier because you can read until a newline comes and you will parse every json message seperately because you won't read multiple json messages from the buffer at a time.
 
 ## 1. Start a connection
 
-To start a connection you have to check the versions and verify the login.
+To start a connection you have to check the versions and verify the login or signup.
 Only if step 1.1 and 1.2 have been accomplished a usable connection is negotiated.
+You can close the connection by sending a cancel message.
 
 ### 1.1 Version check
 Client:
@@ -26,23 +29,66 @@ Server:
 
 If `accept` is `true` the connection is valid. Else the connection will be terminated after the server answered.
 
-### 1.2 Login
+
+## 1.2 Login / Signup
+
+The client is supposed to always send every field used for the login requests: `login`, `user`, `pass` and `cancel`.
+The server is supposed to always send every field used for the login answer: `accept` and `error`.
+
+### 1.2.1 Login
 Client:
 ```
 {
+	"login": true,
 	"user": string,
-	"pass": string
+	"pass": string,
+	"cancel": false
 }
 ```
 
 Server:
 ```
 {
-	"accept": bool
+	"accept": bool,
+	"error": string
+}
+```
+
+If `accept` is `true` the connection is valid and the user is logged in. Else `error` has an error string and the connection will be terminated after the server answered.
+
+### 1.2.2 Signup
+Client:
+```
+{
+	"login": false,
+	"user": string,
+	"pass": string,
+	"cancel": false
+}
+```
+
+Server:
+```
+{
+	"accept": bool,
+	"error": string
+}
+```
+
+If `accept` is `true` the connection is valid and the user is logged in and signed up. Else `error` has an error string and the connection will be terminated after the server answered.
+
+### 1.2.3 Cancel login
+Client:
+```
+{
+	"login": bool,
+	"user": string,
+	"pass": string,
+	"cancel": true
 }
 ```
 
-If `accept` is `true` the connection is valid and the user is logged in. Else the connection will be terminated after the server answered.
+After the cancel message was sent the connection will be closed.
 
 
 ## 2. Sending commands
@@ -67,31 +113,60 @@ Server:
 ```
 
 ### 2.2 List command
+List is split in two commands. `list` to request a list download and `listdata` to download the list.
+
+#### 2.2.1 list - request file list download
 Client:
 ```
 {
 	"command": "list"
 }
 ```
+Server:
+```
+{
+	"command": "list",
+	"accept": bool,
+	"items": int,
+	"chunks": int,
+	"error": string
+}
+```
 
+#### 2.2.2 listdata - download file list
+Client:
+```
+{
+	"command": "listdata",
+	"chunk": int,
+	"cancel": bool
+}
+```
 Server:
 ```
 {
-	"command": "put",
+	"command": "listdata",
+	"remaining": int,
+	"cancel": bool,
 	"names": string[],
-	"remaining": int
+	"error": string
 }
 ```
-The server loops this until all names have been sent and `remaining` hits `0`.
+The client has to request every chunk until all names have been sent and `remaining` hits `0`.
 
 
 ### 2.3 Put command
+
+Put is split in two commands. `put` to request a file upload and `putdata` to upload the data.
+
+#### 2.3.1 put - request upload
 Client:
 ```
 {
 	"command": "put",
 	"file": string,
-	"size": int
+	"size": int,
+	"chunks": int
 }
 ```
 
@@ -99,15 +174,20 @@ Server:
 ```
 {
 	"command": "put",
-	"accept": bool
+	"file": string,
+	"accept": bool,
+	"error": string
 }
 ```
-If `accept` is `true` the connection is valid and the client can start sending the file. Else the put request was rejected and is hereby canceled.
-<br /><br />
+If `accept` is `true` the connection is valid and the client can start sending the file. Else the put request was rejected and is hereby canceled. `error` should contain an error string if the request was rejected.
+
+
+#### 2.3.2 putdata - upload data
 Client:
 ```
 {
-	"command": "put",
+	"command": "putdata",
+	"file": string,
 	"data": string,
 	"remaining": int,
 	"cancel": bool
@@ -120,14 +200,21 @@ If `cancel` is `true` the file transfer will be canceled.
 Server:
 ```
 {
-	"command": "put",
+	"command": "putdata",
+	"file": string,
 	"recieved": int,
-	"cancel": bool
+	"cancel": bool,
+	"error": string
 }
 ```
-If `cancel` is `false` then cancel the upload of the file.
+If `cancel` is `true` then the upload of the file is canceled and an error message should be in `error`.
 
 ### 2.4 Get command
+
+Get is split in two commands. `get` to request a file download and `getdata` to download the data.
+
+#### 2.4.1 get - request download
+
 Client:
 ```
 {
@@ -140,33 +227,42 @@ Server:
 ```
 {
 	"command": "get",
-	"accept": bool
+	"file": string,
+	"accept": bool,
+	"chunks": int,
+	"error": string
 }
 ```
-If `accept` is `true` the connection is valid and the server can start sending the file. Else the get request was rejected and is hereby canceled.
-<br /><br />
-Server:
+If `accept` is `true` the connection is valid and the server can start sending the file. Else the get request was rejected and is hereby canceled. `error` should contain an error string if the request was rejected. `chunks` is the number of chunks of the file.
+
+#### 2.4.2 getdata - download data
+
+Client:
 ```
 {
-	"command": "get",
-	"data": string,
-	"remaining": int,
+	"command": "getdata",
+	"file": string,
+	"chunk": int,
 	"cancel": bool
 }
 ```
-`data` is a base64 string and contains a piece of the file. The server will loop this until the file is completely sent and the client has to send a received message for every chunk.
-`remaining` is a counter how many chunks will follow and the transfer is over after it hits `0`.
-If `cancel` is `true` the file transfer will be canceled.
+If `cancel` is `true` then cancel the download of the file.
 <br /><br />
-Client:
+Server:
 ```
 {
-	"command": "get",
-	"recieved": int,
-	"cancel": bool
+	"command": "getdata",
+	"file": string,
+	"data": string,
+	"remaining": int,
+	"cancel": bool,
+	"error": string
 }
 ```
-If `cancel` is `false` then cancel the download of the file.
+`data` is a base64 string and contains a piece of the file. The client must request every chunk.
+`remaining` is a counter how many chunks will follow and the transfer is over after it hits `0`.
+If `cancel` is `true` then the download of the file is canceled and an error message should be in `error`.
+
 
 ### TODO