// Copyright 2016 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// The following enables go generate to generate the doc.go file.
//go:generate go run $JIRI_ROOT/release/go/src/v.io/x/lib/cmdline/testdata/gendoc.go . -help

package main

import (
	"fmt"
	"io/ioutil"
	"os/exec"
	"strings"

	"v.io/v23"
	"v.io/v23/context"
	"v.io/v23/security"

	"v.io/x/lib/cmdline"
	"v.io/x/ref/lib/signals"
	"v.io/x/ref/lib/v23cmd"
	_ "v.io/x/ref/runtime/factories/roaming"
	"v.io/x/ref/services/allocator"
	"v.io/x/ref/services/cluster"
)

var (
	nameFlag                string
	serverNameFlag          string
	serverNameRootFlag      string
	deploymentTemplateFlag  string
	globalAdminsFlag        string
	maxInstancesFlag        int
	maxInstancesPerUserFlag int
	diskSizeFlag            string
	gcloudBinFlag           string
	kubectlBinFlag          string
	vkubeBinFlag            string
	vkubeCfgFlag            string
	clusterAgentFlag        string
	blessingSecretFlag      string
	monitoringKeyFileFlag   string

	// HTTP flags.
	assetsFlag              string
	httpAddrFlag            string
	externalURLFlag         string
	oauthCredsFileFlag      string
	secureCookiesFlag       bool
	dashboardGCMMetricFlag  string
	dashboardGCMProjectFlag string
	staticAssetsPrefixFlag  string

	cmdRoot = &cmdline.Command{
		Runner: v23cmd.RunnerFunc(runAllocator),
		Name:   "allocatord",
		Short:  "Runs the allocator service",
		Long:   "Runs the allocator service",
	}
)

const (
	serverNameFlagName     = "server-name"
	serverNameRootFlagName = "server-name-root"
	oauthCredsFileFlagName = "oauth-client-creds-file"
	gcloudFlagName         = "gcloud"
	kubectlFlagName        = "kubectl"
	vkubeFlagName          = "vkube"
)

func main() {
	cmdRoot.Flags.StringVar(&nameFlag, "name", "", "Name to publish for this service.")
	cmdRoot.Flags.StringVar(&serverNameFlag, serverNameFlagName, "", "Name of the servers to allocate. This name is part of the published names in the Vanadium namespace and the names of the Deployments in Kubernetes.")
	cmdRoot.Flags.StringVar(&serverNameRootFlag, serverNameRootFlagName, "", "Namespace root for allocated servers to use when publishing in the Vanadium namespace.  If not set, the namespace root of the allocator server is used.")
	cmdRoot.Flags.StringVar(&deploymentTemplateFlag, "deployment-template", "", "The template for the deployment of the servers to allocate.")
	cmdRoot.Flags.StringVar(&globalAdminsFlag, "global-admins", "", "A comma-separated list of blessing patterns that have access to all the server instances.")
	cmdRoot.Flags.IntVar(&maxInstancesFlag, "max-instances", 10, "The maximum total number of server instances to create.")
	cmdRoot.Flags.IntVar(&maxInstancesPerUserFlag, "max-instances-per-user", 1, "The maximum number of server instances to create per user.")
	cmdRoot.Flags.StringVar(&diskSizeFlag, "server-disk-size", "50GB", "The size of the persistent disk to allocate with the servers.")
	cmdRoot.Flags.StringVar(&gcloudBinFlag, gcloudFlagName, "gcloud", "The gcloud binary to use.")
	cmdRoot.Flags.StringVar(&kubectlBinFlag, kubectlFlagName, "kubectl", "The kubectl binary to use.")
	cmdRoot.Flags.StringVar(&vkubeBinFlag, vkubeFlagName, "vkube", "The vkube binary to use.")
	cmdRoot.Flags.StringVar(&vkubeCfgFlag, "vkube-cfg", "vkube.cfg", "The vkube.cfg to use.")
	cmdRoot.Flags.StringVar(&clusterAgentFlag, "cluster-agent", "", "The address of the cluster-agent.")
	cmdRoot.Flags.StringVar(&blessingSecretFlag, "blessings-secret-file", "", "If set, this file contains the secret to present to the cluster-agent to get the base blessings for the allocated servers.")
	cmdRoot.Flags.StringVar(&assetsFlag, "assets", "", "If set, the directory containing assets (template definitions, css, javascript files etc.) to use in the web interface. If not set, compiled-in assets will be used instead.")
	cmdRoot.Flags.StringVar(&httpAddrFlag, "http-addr", "", "Address on which the HTTP server listens on.  If empty, no HTTP server is started.")
	cmdRoot.Flags.StringVar(&externalURLFlag, "external-url", "", "Public URL for the HTTP server.  Must be specified if --http-addr is specified.")
	cmdRoot.Flags.StringVar(&monitoringKeyFileFlag, "monitoring-key-file", "", "The path to the service account's JSON credentials file.")
	cmdRoot.Flags.StringVar(&oauthCredsFileFlag, oauthCredsFileFlagName, "", "JSON-encoded file containing Google Oauth2 client ID and secret (https://developers.google.com/identity/protocols/OAuth2#basicsteps), as well as the HMAC cookie signing key")
	cmdRoot.Flags.BoolVar(&secureCookiesFlag, "secure-cookies", true, "Whether to use only secure cookies.  Should be true unless running the server without TLS for testing.")
	cmdRoot.Flags.StringVar(&dashboardGCMMetricFlag, "dashboard-gcm-metric", "", "The metric name used to get data from GCM to render dashboard charts.")
	cmdRoot.Flags.StringVar(&dashboardGCMProjectFlag, "dashboard-gcm-project", "", "The project name used to get data from GCM to render dashboard charts.")
	cmdRoot.Flags.StringVar(&staticAssetsPrefixFlag, "static-assets-prefix", "", "Host serving the web assets.")
	cmdline.HideGlobalFlagsExcept()
	cmdline.Main(cmdRoot)
}

func checkFlags(ctx *context.T, env *cmdline.Env) error {
	if nameRoot(ctx) == "" {
		return env.UsageErrorf("--%s not specified, and no default namespace root found", serverNameRootFlagName)
	}
	for f, b := range map[string]string{gcloudFlagName: gcloudBinFlag, kubectlFlagName: kubectlBinFlag, vkubeFlagName: vkubeBinFlag} {
		if _, err := exec.LookPath(b); err != nil {
			return env.UsageErrorf("--%s binary %s not found: %v", f, b, err)
		}
	}
	return nil
}

func runAllocator(ctx *context.T, env *cmdline.Env, args []string) error {
	if err := checkFlags(ctx, env); err != nil {
		return err
	}

	var (
		baseBlessings     security.Blessings
		baseBlessingNames []string
	)
	if clusterAgentFlag == "" || blessingSecretFlag == "" {
		fmt.Fprintln(env.Stderr, "WARNING: Using self-blessed blessings for allocated servers")
		const selfName = "allocator"
		var err error
		if baseBlessings, err = v23.GetPrincipal(ctx).BlessSelf(selfName); err != nil {
			return err
		}
		baseBlessingNames = []string{selfName}
	} else {
		secret, err := ioutil.ReadFile(blessingSecretFlag)
		if err != nil {
			return err
		}
		baseBlessings, err = cluster.ClusterAgentClient(clusterAgentFlag).SeekBlessings(ctx, strings.TrimSpace(string(secret)))
		if err != nil {
			return err
		}
		baseBlessingNames = security.BlessingNames(v23.GetPrincipal(ctx), baseBlessings)
	}

	ctx, server, err := v23.WithNewServer(
		ctx,
		nameFlag,
		allocator.AllocatorServer(&allocatorImpl{baseBlessings, baseBlessingNames}),
		security.AllowEveryone(),
	)
	if err != nil {
		return err
	}
	ah, err := newAssetsHelper(assetsFlag)
	if err != nil {
		return err
	}
	ctx.Infof("Listening on: %v", server.Status().Endpoints)
	if httpAddrFlag != "" {
		if oauthCredsFileFlag == "" {
			return env.UsageErrorf("--%s must be provided", oauthCredsFileFlagName)
		}
		oauthCreds, err := clientCredsFromFile(oauthCredsFileFlag)
		if err != nil {
			return err
		}
		cleanup := startHTTP(ctx, httpArgs{
			addr:                httpAddrFlag,
			externalURL:         externalURLFlag,
			dashboardGCMMetric:  dashboardGCMMetricFlag,
			dashboardGCMProject: dashboardGCMProjectFlag,
			monitoringKeyFile:   monitoringKeyFileFlag,
			oauthCreds:          oauthCreds,
			serverName:          serverNameFlag,
			secureCookies:       secureCookiesFlag,
			baseBlessings:       baseBlessings,
			baseBlessingNames:   baseBlessingNames,
			staticAssetsPrefix:  staticAssetsPrefixFlag,
			assets:              ah,
		})
		defer cleanup()
	}
	<-signals.ShutdownOnSignals(ctx)
	return nil
}