# Client-Server Protocol

Protocol version: "0.1"

## 1. Start a connection

To start a connection you have to check the versions and verify the login.
Only if step 1.1 and 1.2 have been accomplished a usable connection is negotiated.

### 1.1 Version check
Client:
```
{
	"version": string
}
```


Server:
```
{
	"version": string,
	"accept": bool
}
```

If `accept` is `true` the connection is valid. Else the connection will be terminated after the server answered.

### 1.2 Login
Client:
```
{
	"user": string,
	"pass": string
}
```

Server:
```
{
	"accept": bool
}
```

If `accept` is `true` the connection is valid and the user is logged in. Else the connection will be terminated after the server answered.


## 2. Sending commands

Commands can be sent by the client after a connection has been negotiated (See 1).
Commands can be used unrelated to each other.

### 2.1 Status command
Client:
```
{
	"command": "status"
}
```

Server:
```
{
	"command": "status",
	"response": string
}
```

### 2.2 List command
Client:
```
{
	"command": "list"
}
```

Server:
```
{
	"command": "put",
	"names": string[],
	"remaining": int
}
```
The server loops this until all names have been sent and `remaining` hits `0`.


### 2.3 Put command
Client:
```
{
	"command": "put",
	"file": string,
	"size": int
}
```

Server:
```
{
	"command": "put",
	"accept": bool
}
```
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 />
Client:
```
{
	"command": "put",
	"data": string,
	"remaining": int,
	"cancel": bool
}
```
`data` is a base64 string and contains a piece of the file. The client will loop this until the file is completely sent and the server has to send and 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.
<br /><br />
Server:
```
{
	"command": "put",
	"recieved": int,
	"cancel": bool
}
```
If `cancel` is `false` then cancel the upload of the file.

### 2.4 Get command
Client:
```
{
	"command": "get",
	"file": string
}
```

Server:
```
{
	"command": "get",
	"accept": bool
}
```
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:
```
{
	"command": "get",
	"data": string,
	"remaining": 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.
<br /><br />
Client:
```
{
	"command": "get",
	"recieved": int,
	"cancel": bool
}
```
If `cancel` is `false` then cancel the download of the file.

### TODO


## 3. Close connection

### 3.1 Close command

Client:
```
{
	"command": "close"
}
```


Server:
```
{
	"command": "close",
	"response": "bye"
}
```