package servlet

import (
	"context"
	"crypto/rsa"
	"encoding/json"
	"fmt"
	"sync"

	"github.com/valyala/fasthttp"

	"git.loafle.net/commons/server-go"
	"git.loafle.net/commons/server-go/socket"
	ocpc "git.loafle.net/overflow/commons-go/probe/constants"
	ocpm "git.loafle.net/overflow/commons-go/probe/model"
	og "git.loafle.net/overflow/gateway"
	"git.loafle.net/overflow/gateway/external/grpc"
	ogrs "git.loafle.net/overflow/gateway_rpc/servlet"
)

type DataServlet interface {
	ogrs.RPCServlet
}

type DataServlets struct {
	ogrs.RPCServlets

	VerifyKey *rsa.PublicKey
	SignKey   *rsa.PrivateKey

	connections sync.Map
}

func (s *DataServlets) Init(serverCtx server.ServerCtx) error {
	if err := s.RPCServlets.Init(serverCtx); nil != err {
		return err
	}

	return nil
}

func (s *DataServlets) OnStart(serverCtx server.ServerCtx) error {
	if err := s.RPCServlets.OnStart(serverCtx); nil != err {
		return err
	}

	return nil
}

func (s *DataServlets) OnStop(serverCtx server.ServerCtx) {

	s.RPCServlets.OnStop(serverCtx)
}

func (s *DataServlets) Destroy(serverCtx server.ServerCtx) {

	s.RPCServlets.Destroy(serverCtx)
}

func (s *DataServlets) Handshake(servletCtx server.ServletCtx, ctx *fasthttp.RequestCtx) (*fasthttp.ResponseHeader, error) {
	// probe key extraction
	bMethod := ctx.Request.Header.Peek(ocpc.HTTPRequestHeaderKey_Probe_Method)
	if nil == bMethod {
		return nil, fmt.Errorf("Unexpected probe method: %v", bMethod)
	}

	method := string(bMethod)

	switch method {
	case ocpc.HTTPRequestHeaderValue_Probe_Method_Connect:
	default:
		return nil, fmt.Errorf("Unexpected probe method: %s", method)
	}

	bProbeKey := ctx.Request.Header.Peek(ocpc.HTTPRequestHeaderKey_Probe_ProbeKey)
	if nil == bProbeKey {
		return nil, fmt.Errorf("Unexpected probe key : %v", bProbeKey)
	}

	probeKey := string(bProbeKey)

	grpcCTX := context.Background()
	r, err := grpc.Exec(grpcCTX, "ProbeService.readByProbeKey", probeKey)
	if nil != err {
		return nil, fmt.Errorf("grpc call Error: %s", err.Error())
	}

	probe := ocpm.Probe{}
	err = json.Unmarshal([]byte(r), probe)
	if nil != err {
		return nil, fmt.Errorf("grpc result unMarshal Error: %s", err.Error())
	}

	extHeader := &fasthttp.ResponseHeader{}
	extHeader.Add(ocpc.HTTPResponseHeaderKey_Probe_SetEncryptionKey, probe.EncryptionKey)

	servletCtx.SetAttribute(og.SessionIDKey, probe.ProbeKey)
	servletCtx.SetAttribute(og.SessionClientTypeKey, og.PROBE)
	servletCtx.SetAttribute(og.SessionTargetIDKey, probe.ProbeKey)

	return extHeader, nil
}

func (s *DataServlets) OnConnect(servletCtx server.ServletCtx, conn socket.Conn) {
	s.RPCServlets.OnConnect(servletCtx, conn)
}

func (s *DataServlets) OnDisconnect(servletCtx server.ServletCtx) {
	s.RPCServlets.OnDisconnect(servletCtx)
}