package main

import (
    "fmt"
    "github.com/weilinks/gotcp"
    "github.com/weilinks/gotcp/message"
)

func main() {
    // Create a new server with options.
    s := easytcp.NewServer(&easytcp.ServerOption{
        Packer: easytcp.NewDefaultPacker(), // use default packer
        Codec:  nil,                        // don't use codec
    })

    // Register a route with message's ID.
    // The `DefaultPacker` treats id as int,
    // so when we add routes or return response, we should use int.
    s.AddRoute(1001, func(c easytcp.Context) {
        // acquire request
        req := c.Request()

        // do things...
        fmt.Printf("[server] request received | id: %d; size: %d; data: %s\n", req.ID, len(req.Data), req.Data)

        // set response
        c.SetResponseMessage(&message.Entry{
            ID:   1002,
            Data: []byte("copy that"),
        })
    })

    // Set custom logger (optional).
    easytcp.SetLogger(lg)

    // Add global middlewares (optional).
    s.Use(recoverMiddleware)

    // Set hooks (optional).
    s.OnSessionCreate = func(session easytcp.Session) {...}
    s.OnSessionClose = func(session easytcp.Session) {...}

    // Set not-found route handler (optional).
    s.NotFoundHandler(handler)

    // Listen and serve.
    if err := s.Serve(":5896"); err != nil && err != server.ErrServerStopped {
        fmt.Println("serve error: ", err.Error())
    }
}

// Create a new server with options.
s := easytcp.NewServer(&easytcp.ServerOption{
    Packer: easytcp.NewDefaultPacker(), // use default packer
    Codec:  &easytcp.JsonCodec{},       // use JsonCodec
})

// Register a route with message's ID.
// The `DefaultPacker` treats id as int,
// so when we add routes or return response, we should use int.
s.AddRoute(1001, func(c easytcp.Context) {
    // decode request data and bind to `reqData`
    var reqData map[string]interface{}
    if err := c.Bind(&reqData); err != nil {
        // handle err
    }

    // do things...
    respId := 1002
    respData := map[string]interface{}{
        "success": true,
        "feeling": "Great!",
    }

    // encode response data and set to `c`
    if err := c.SetResponse(respId, respData); err != nil {
        // handle err
    }
})

s.AddRoute(reqID, func(c easytcp.Context) {
    // acquire request
    req := c.Request()

    // do things...
    fmt.Printf("[server] request received | id: %d; size: %d; data: %s\n", req.ID, len(req.Data), req.Data)

    // set response
    c.SetResponseMessage(&message.Entry{
        ID:   respID,
        Data: []byte("copy that"),
    })
})

// register global middlewares.
// global middlewares are prior than per-route middlewares, they will be invoked first
s.Use(recoverMiddleware, logMiddleware, ...)

// register middlewares for one route
s.AddRoute(reqID, handler, middleware1, middleware2)

// a middleware looks like:
var exampleMiddleware easytcp.MiddlewareFunc = func(next easytcp.HandlerFunc) easytcp.HandlerFunc {
    return func(c easytcp.Context) {
        // do things before...
        next(c)
        // do things after...
    }
}

s := easytcp.NewServer(&easytcp.ServerOption{
    Packer: new(MyPacker), // this is optional, the default one is DefaultPacker
})

// CustomPacker is a custom packer, implements Packer interafce.
// Treats Packet format as `size(2)id(2)data(n)`
type CustomPacker struct{}

func (p *CustomPacker) bytesOrder() binary.ByteOrder {
    return binary.BigEndian
}

func (p *CustomPacker) Pack(entry *message.Entry) ([]byte, error) {
    size := len(entry.Data) // only the size of data.
    buffer := make([]byte, 2 2 size)
    p.bytesOrder().PutUint16(buffer[:2], uint16(size))
    p.bytesOrder().PutUint16(buffer[2:4], entry.ID.(uint16))
    copy(buffer[4:], entry.Data)
    return buffer, nil
}

func (p *CustomPacker) Unpack(reader io.Reader) (*message.Entry, error) {
    headerBuffer := make([]byte, 2 2)
    if _, err := io.ReadFull(reader, headerBuffer); err != nil {
        return nil, fmt.Errorf("read size and id err: %s", err)
    }
    size := p.bytesOrder().Uint16(headerBuffer[:2])
    id := p.bytesOrder().Uint16(headerBuffer[2:])

    data := make([]byte, size)
    if _, err := io.ReadFull(reader, data); err != nil {
        return nil, fmt.Errorf("read data err: %s", err)
    }

    entry := &message.Entry{
        // since entry.ID is type of uint16, we need to use uint16 as well when adding routes.
        // eg: server.AddRoute(uint16(123), ...)
        ID:   id,
        Data: data,
    }
    entry.Set("theWholeLength", 2 2 size) // we can set our custom kv data here.
    // c.Request().Get("theWholeLength")  // and get them in route handler.
    return entry, nil
}

s := easytcp.NewServer(&easytcp.ServerOption{
    Codec: &easytcp.JsonCodec{}, // this is optional. The JsonCodec is a built-in codec
})

s.AddRoute(reqID, func(c easytcp.Context) {
    var reqData map[string]interface{}
    if err := c.Bind(&reqData); err != nil { // here we decode message data and bind to reqData
        // handle error...
    }
    req := c.Request()
    fmt.Printf("[server] request received | id: %d; size: %d; data-decoded: % v\n", req.ID, len(req.Data), reqData)
    respData := map[string]string{"key": "value"}
    if err := c.SetResponse(respID, respData); err != nil {
        // handle error...
    }
})