// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0

package client

import (
	"fmt"
	"net"
	"net/rpc"
	"time"

	"github.com/hashicorp/nomad/client/config"
	"github.com/hashicorp/nomad/client/fingerprint"
	"github.com/hashicorp/nomad/client/servers"
	"github.com/hashicorp/nomad/client/serviceregistration/mock"
	agentconsul "github.com/hashicorp/nomad/command/agent/consul"
	"github.com/hashicorp/nomad/helper/pluginutils/catalog"
	"github.com/hashicorp/nomad/helper/pluginutils/singleton"
	"github.com/hashicorp/nomad/helper/pool"
	"github.com/hashicorp/nomad/helper/testlog"
	testing "github.com/mitchellh/go-testing-interface"
)

// TestClient creates an in-memory client for testing purposes and returns a
// cleanup func to shutdown the client and remove the alloc and state dirs.
//
// There is no need to override the AllocDir or StateDir as they are randomized
// and removed in the returned cleanup function. If they are overridden in the
// callback then the caller still must run the returned cleanup func.
func TestClient(t testing.T, cb func(c *config.Config)) (*Client, func() error) {
	return TestClientWithRPCs(t, cb, nil)
}

func TestClientWithRPCs(t testing.T, cb func(c *config.Config), rpcs map[string]interface{}) (*Client, func() error) {
	conf, cleanup := config.TestClientConfig(t)

	// Tighten the fingerprinter timeouts (must be done in client package
	// to avoid circular dependencies)
	if conf.Options == nil {
		conf.Options = make(map[string]string)
	}
	conf.Options[fingerprint.TightenNetworkTimeoutsConfig] = "true"

	logger := testlog.HCLogger(t)
	conf.Logger = logger

	if cb != nil {
		cb(conf)
	}

	// Set the plugin loaders
	if conf.PluginLoader == nil {
		conf.PluginLoader = catalog.TestPluginLoaderWithOptions(t, "", conf.Options, nil)
	}
	if conf.PluginSingletonLoader == nil {
		conf.PluginSingletonLoader = singleton.NewSingletonLoader(logger, conf.PluginLoader)
	}
	mockCatalog := agentconsul.NewMockCatalog(logger)
	mockService := mock.NewServiceRegistrationHandler(logger)
	client, err := NewClient(conf, mockCatalog, nil, mockService, rpcs)
	if err != nil {
		cleanup()
		t.Fatalf("err: %v", err)
	}
	return client, func() error {
		ch := make(chan error)

		go func() {
			defer close(ch)

			// Shutdown client
			err := client.Shutdown()
			if err != nil {
				ch <- fmt.Errorf("failed to shutdown client: %v", err)
			}

			// Call TestClientConfig cleanup
			cleanup()
		}()

		select {
		case e := <-ch:
			return e
		case <-time.After(1 * time.Minute):
			return fmt.Errorf("timed out while shutting down client")
		}
	}
}

// TestRPCOnlyClient is a client that only pings to establish a connection
// with the server and then returns mock RPC responses for those interfaces
// passed in the `rpcs` parameter. Useful for testing client RPCs from the
// server. Returns the Client, a shutdown function, and any error.
func TestRPCOnlyClient(t testing.T, srvAddr net.Addr, rpcs map[string]interface{}) (*Client, func() error, error) {
	var err error
	conf, cleanup := config.TestClientConfig(t)

	client := &Client{config: conf, logger: testlog.HCLogger(t)}
	client.servers = servers.New(client.logger, client.shutdownCh, client)

	client.rpcServer = rpc.NewServer()
	for name, rpc := range rpcs {
		client.rpcServer.RegisterName(name, rpc)
	}

	client.connPool = pool.NewPool(testlog.HCLogger(t), 10*time.Second, 10, nil)

	cancelFunc := func() error {
		ch := make(chan error)

		go func() {
			defer close(ch)
			client.connPool.Shutdown()
			client.shutdownGroup.Wait()
			cleanup()
		}()

		select {
		case <-ch:
			return nil
		case <-time.After(1 * time.Minute):
			return fmt.Errorf("timed out while shutting down client")
		}
	}

	go client.rpcConnListener()

	_, err = client.SetServers([]string{srvAddr.String()})
	if err != nil {
		return nil, cancelFunc, fmt.Errorf("could not set servers: %v", err)
	}
	client.shutdownGroup.Go(client.registerAndHeartbeat)

	return client, cancelFunc, nil
}
