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# SOLEC protocol specification

* Payload can contain multiple numeric types or binary data in a single frame
* Numeric types are big endian
* Numeric types names are same as in [Go](https://go.dev/ref/spec#Numeric_types)
* See [test payload](#Test) for an example of complex data structure

## Frame

| Type     | Description    |
|----------|----------------|
| `uint8`  | Payload type   |
| `uint16` | Payload length |
| `[]any`  | Payload        |


## Data types

### Numeric types

* `uint8`
* `uint16`
* `uint32`
* `uint64`

### `binary`

| Type   | Description    |
|--------|----------------|
| uint16 | Data length    |
| binary | Data           |

### `string`

UTF-8 encoded string encapsulated in `bianry` type.

### `time`

[Unix timestamp](https://en.wikipedia.org/wiki/Unix_time) stored in `uint16`.
Timezone is always UTC.

# Payloads

## Payload prefixes

| Type | Name         |
|------|--------------|
| 0x01 | Handshake    |
| 0x02 | Ping         |
| 0x03 | Pong         |
| 0x04 | Message      |
| 0xFF | Test         |

## Payload types

### Handshake

| Type   | Name                | Description                                              |
|--------|---------------------|----------------------------------------------------------|
| uint8 | ProtocolVersionMajor | Bumped if changes are incompatible with previous version |
| uint8 | PrococolVersionMinor | Bumber if changes are backwards compatible               |


### Ping

Can be send by client or server. Receiver shoudl reply with `Pong`.

### Pong

Reply to `ping`.

| Type   | Name | Description             |
|--------|------|-------------------------|
| uint64 | Time | Set just before sending |

### Test

Used for testing purposes. Can change at any time.

| Type   | Name  | Description |
|--------|-------|-------------|
| uint8  | Num1  |             |
| time   | Time1 |             |
| string | Str1  |             |
| uint16 | Num2  |             |
| binary | Bin1  |             |
| uint32 | Num3  |             |
| string | Str2  |             |
| uint64 | Num4  |             |