package admin

import (
	"context"
	"crypto/rand"
	"fmt"
	"git.wamblee.org/converge/pkg/comms"
	"git.wamblee.org/converge/pkg/models"
	"git.wamblee.org/converge/pkg/testsupport"
	"github.com/stretchr/testify/suite"
	"io"
	"net/http"
	"strings"
	"testing"
	"time"
)

// test cases
//
// Agent only: verify state, verify agentregistration message
// - Connect single agent
// - Connect agent, connect second agent with duplicate id
//    -> new id taken out
// - Connect more than 100 agents with the same id
//   -> 101th agents gets error
//
// Client connected to agent: Verify clientConnection and agentCOnnection, verify state, verify clientInfo message.
// - Connect agent + connect client with mmtching id
// - Connect agent + connect client with wrong id
//
// Overall:
// - Connect agent, connect 2 clients
// - Connect multiple agents and clients

type AdminTestSuite struct {
	suite.Suite

	ctx         context.Context
	cancelFunc  context.CancelFunc
	pprofServer *http.Server

	admin   *Admin
	hostKey []byte
}

func (s *AdminTestSuite) createPipe() (io.ReadWriteCloser, io.ReadWriteCloser) {
	bitpipe := testsupport.NewInmemoryConnection(s.ctx, "inmemory", 10)
	return bitpipe.Front(), bitpipe.Back()
}

func (s *AdminTestSuite) SetupSuite() {
	s.pprofServer = testsupport.StartPprof("")
}

func (s *AdminTestSuite) TearDownSuite() {
	testsupport.StopPprof(s.ctx, s.pprofServer)
}

func (s *AdminTestSuite) SetupTest() {
	ctx, cancelFunc := testsupport.CreateTestContext(context.Background(), 10*time.Second)
	s.ctx = ctx
	s.cancelFunc = cancelFunc

	s.admin = NewAdmin()
	s.hostKey = make([]byte, 100)
	s.NotNil(rand.Read(s.hostKey))
}

func (suite *AdminTestSuite) TearDownTest() {
}

func TestAdminTestSuite(t *testing.T) {
	suite.Run(t, &AdminTestSuite{})
}

type AddAgentResult struct {
	agentConn *agentConnection
	err       error
}

type AgentRegisterResult struct {
	registration comms.AgentRegistration
	err          error
}

func (s *AdminTestSuite) agentRegisters(requestedPublicId, assignedPublicId string) (AddAgentResult, AgentRegisterResult) {
	agentRW, serverRW := s.createPipe()
	res := testsupport.RunAndWait(
		&s.Suite,
		func() any {
			agentConn, err := s.addAgent(requestedPublicId, assignedPublicId, serverRW)
			return AddAgentResult{
				agentConn: agentConn,
				err:       err,
			}
		},
		func() any {
			res := s.agentRegistration(assignedPublicId, agentRW)
			if assignedPublicId != "" {
				s.Nil(res.err)
				s.True(res.registration.Ok)
				s.Equal(s.hostKey, res.registration.HostPrivateKey)
			}
			return res
		})
	return res[0].(AddAgentResult), res[1].(AgentRegisterResult)
}

func (s *AdminTestSuite) Test_AgentRegisters() {
	res, _ := s.agentRegisters("abc", "abc")
	s.Nil(res.err)
	agentConn := res.agentConn
	state := s.admin.CreateNotifification()
	s.Equal(1, len(state.Agents))
	s.Equal(0, len(state.Clients))
	s.Equal(agentConn.Info, state.Agents[agentConn.Info.Guid])
}

func (s *AdminTestSuite) Test_ManyAgentsRegister() {
	N := 10
	agentRegistrations := make([]testsupport.TestFunction, N)
	for i := range N {
		publicId := fmt.Sprintf("abc%d", i)
		agentRegistrations[i] = func() any {
			res, _ := s.agentRegisters(publicId, publicId)
			s.Nil(res.err)
			return res.agentConn
		}
	}
	res := testsupport.RunAndWait(
		&s.Suite,
		agentRegistrations...)
	state := s.admin.CreateNotifification()
	s.Equal(len(res), len(state.Agents))
	s.Equal(0, len(state.Clients))
	for _, entry := range res {
		agentConn := entry.(*agentConnection)
		s.Equal(agentConn.Info, state.Agents[agentConn.Info.Guid])
	}
}

func (s *AdminTestSuite) Test_agentDuplicateId() {
	res, _ := s.agentRegisters("abc", "abc")
	s.Nil(res.err)
	for i := range 100 {
		res, _ = s.agentRegisters("abc", fmt.Sprintf("abc-%d", i))
		s.Nil(res.err)
	}
	res, agentSideResult := s.agentRegisters("abc", "")
	s.NotNil(res.err)
	// verify it is the correct error an dnot an id mismatch.
	s.True(strings.Contains(res.err.Error(), "could not allocate a new unique id"))
	s.False(agentSideResult.registration.Ok)
}

func (s *AdminTestSuite) agentRegistration(expectedPublicId string, agentRW io.ReadWriteCloser) AgentRegisterResult {
	// verify registration message received
	agentRegistration, err := comms.ReceiveRegistrationMessage(agentRW)
	if err != nil {
		return AgentRegisterResult{err: err}
	}
	commChannel, err := comms.NewCommChannel(comms.Agent, agentRW)
	if err != nil {
		return AgentRegisterResult{registration: agentRegistration, err: err}
	}
	s.NotNil(commChannel)
	return AgentRegisterResult{registration: agentRegistration, err: nil}
}

func (s *AdminTestSuite) addAgent(publicId string, assignedPublicId string, serverRW io.ReadWriteCloser) (*agentConnection, error) {
	agentConn, err := s.admin.AddAgent(
		s.hostKey, models.RendezVousId(publicId), comms.EnvironmentInfo{},
		serverRW)
	if err != nil {
		return nil, err
	}
	s.Equal(assignedPublicId, string(agentConn.Info.PublicId))
	return agentConn, nil
}