/*
Copyright 2015 The Kubernetes Authors All rights reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package main

import (
	"github.com/ghodss/yaml"

	"github.com/kubernetes/deployment-manager/common"
	"github.com/kubernetes/deployment-manager/expandybird/expander"
	"github.com/kubernetes/deployment-manager/registry"
	"github.com/kubernetes/deployment-manager/util"

	"archive/tar"
	"bytes"
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"net/http"
	"net/url"
	"os"
	"path"
	"regexp"
	"strconv"
	"strings"
	"time"
)

var (
	deployment_name   = flag.String("name", "", "Name of deployment, used for deploy and update commands (defaults to template name)")
	stdin             = flag.Bool("stdin", false, "Reads a configuration from the standard input")
	properties        = flag.String("properties", "", "Properties to use when deploying a template (e.g., --properties k1=v1,k2=v2)")
	template_registry = flag.String("registry", "github.com/kubernetes/application-dm-templates", "Registry (github.com/owner/repo)")
	service           = flag.String("service", "http://localhost:8001/api/v1/proxy/namespaces/dm/services/manager-service:manager", "URL for deployment manager")
	binary            = flag.String("binary", "../expandybird/expansion/expansion.py", "Path to template expansion binary")
	timeout           = flag.Int("timeout", 10, "Time in seconds to wait for response")
	regex_string      = flag.String("regex", "", "Regular expression to filter the templates listed in a template registry")
	apitoken          = flag.String("apitoken", "", "Github api token that overrides GITHUB_API_TOKEN environment variable")
)

var commands = []string{
	"expand \t\t\t Expands the supplied configuration(s)",
	"deploy \t\t\t Deploys the named template or the supplied configuration(s)",
	"list \t\t\t Lists the deployments in the cluster",
	"get \t\t\t Retrieves the supplied deployment",
	"manifest \t\t\t Lists manifests for deployment or retrieves the supplied manifest in the form (deployment[/manifest])",
	"delete \t\t\t Deletes the supplied deployment",
	"update \t\t\t Updates a deployment using the supplied configuration(s)",
	"deployed-types \t\t Lists the types deployed in the cluster",
	"deployed-instances \t Lists the instances of the named type deployed in the cluster",
	"templates \t\t Lists the templates in a given template registry",
	"describe \t\t Describes the named template in a given template registry",
}

var usage = func() {
	message := "Usage: %s [<flags>] <command> [(<template-name> | <deployment-name> | (<configuration> [<import1>...<importN>]))]\n"
	fmt.Fprintf(os.Stderr, message, os.Args[0])
	fmt.Fprintln(os.Stderr, "Commands:")
	for _, command := range commands {
		fmt.Fprintln(os.Stderr, command)
	}

	fmt.Fprintln(os.Stderr)
	fmt.Fprintln(os.Stderr, "Flags:")
	flag.PrintDefaults()
	fmt.Fprintln(os.Stderr)
	fmt.Fprintln(os.Stderr, "--stdin requires a file name and either the file contents or a tar archive containing the named file.")
	fmt.Fprintln(os.Stderr, "        a tar archive may include any additional files referenced directly or indirectly by the named file.")
	panic("\n")
}

// TODO(jackgr): Move all registry related operations to the server side.
var registryProvider registry.RegistryProvider

func getRegistryProvider() registry.RegistryProvider {
	if registryProvider == nil {
		rs := registry.NewInmemRegistryService()
		_, err := rs.GetByURL(*template_registry)
		if err != nil {
			r := newRegistry(*template_registry)
			if err := rs.Create(r); err != nil {
				panic(fmt.Errorf("cannot configure registry at %s: %s", r.URL, err))
			}
		}

		cp := registry.NewInmemCredentialProvider()
		if *apitoken == "" {
			*apitoken = os.Getenv("DM_GITHUB_API_TOKEN")
		}

		if *apitoken != "" {
			credential := common.RegistryCredential{
				APIToken: common.APITokenCredential(*apitoken),
			}
			if err := cp.SetCredential("default", &credential); err != nil {
				panic(fmt.Errorf("cannot set credential at %s: %s", "default", err))
			}
		}

		registryProvider = registry.NewRegistryProvider(rs, nil, cp)
	}

	return registryProvider
}

func newRegistry(URL string) *common.Registry {
	tFormat := fmt.Sprintf("%s;%s", common.VersionedRegistry, common.CollectionRegistry)
	return &common.Registry{
		Name:           util.TrimURLScheme(URL),
		Type:           common.GithubRegistryType,
		URL:            URL,
		Format:         common.RegistryFormat(tFormat),
		CredentialName: "default",
	}
}

func getGithubRegistry() registry.Registry {
	provider := getRegistryProvider()
	git, err := provider.GetRegistryByShortURL(*template_registry)
	if err != nil {
		panic(fmt.Errorf("cannot open registry %s: %s", *template_registry, err))
	}

	return git
}

func main() {
	defer func() {
		result := recover()
		if result != nil {
			log.Fatalln(result)
		}
	}()

	execute()
	os.Exit(0)
}

func execute() {
	flag.Parse()
	args := flag.Args()
	if len(args) < 1 {
		fmt.Fprintln(os.Stderr, "No command supplied")
		usage()
	}

	switch args[0] {
	case "templates":
		var regex *regexp.Regexp
		if *regex_string != "" {
			var err error
			regex, err = regexp.Compile(*regex_string)
			if err != nil {
				panic(fmt.Errorf("cannot compile regular expression %s: %s", *regex_string, err))
			}
		}

		git := getGithubRegistry()
		types, err := git.ListTypes(regex)
		if err != nil {
			panic(fmt.Errorf("cannot list templates in registry %s: %s", *template_registry, err))
		}

		for _, t := range types {
			fmt.Printf("%s\n", t.String())
			urls, err := git.GetDownloadURLs(t)
			if err != nil {
				panic(fmt.Errorf("cannot get download urls for %s: %s", t, err))
			}

			for _, downloadURL := range urls {
				fmt.Printf("\t%s\n", downloadURL)
			}
		}
	case "describe":
		describeType(args)
	case "expand":
		template := loadTemplate(args)
		callService("expand", "POST", "expand configuration", marshalTemplate(template))
	case "deploy":
		template := loadTemplate(args)
		action := fmt.Sprintf("deploy configuration named %s", template.Name)
		callService("deployments", "POST", action, marshalTemplate(template))
	case "list":
		callService("deployments", "GET", "list deployments", nil)
	case "get":
		if len(args) < 2 {
			fmt.Fprintln(os.Stderr, "No deployment name supplied")
			usage()
		}

		path := fmt.Sprintf("deployments/%s", args[1])
		action := fmt.Sprintf("get deployment named %s", args[1])
		callService(path, "GET", action, nil)
	case "manifest":
		msg := "Must specify manifest in the form <deployment>/<manifest> or <deployment> to list."
		if len(args) < 2 {
			fmt.Fprintln(os.Stderr, msg)
			usage()
		}

		s := strings.Split(args[1], "/")
		ls := len(s)
		if ls < 1 || ls > 2 {
			fmt.Fprintln(os.Stderr, fmt.Sprintf("Invalid manifest (%s), %s", args[1], msg))
			usage()
		}

		path := fmt.Sprintf("deployments/%s/manifests", s[0])
		if ls == 2 {
			path = path + fmt.Sprintf("/%s", s[1])
		}

		action := fmt.Sprintf("get manifest %s", args[1])
		callService(path, "GET", action, nil)
	case "delete":
		if len(args) < 2 {
			fmt.Fprintln(os.Stderr, "No deployment name supplied")
			usage()
		}

		path := fmt.Sprintf("deployments/%s", args[1])
		action := fmt.Sprintf("delete deployment named %s", args[1])
		callService(path, "DELETE", action, nil)
	case "update":
		template := loadTemplate(args)
		path := fmt.Sprintf("deployments/%s", template.Name)
		action := fmt.Sprintf("delete deployment named %s", template.Name)
		callService(path, "PUT", action, marshalTemplate(template))
	case "deployed-types":
		callService("types", "GET", "list deployed types", nil)
	case "deployed-instances":
		if len(args) < 2 {
			fmt.Fprintln(os.Stderr, "No type name supplied")
			usage()
		}

		tUrls := getDownloadURLs(args[1])
		var tUrl = ""
		if len(tUrls) == 0 {
			// Type is most likely a primitive.
			tUrl = args[1]
		} else {
			// TODO(vaikas): Support packages properly.
			tUrl = tUrls[0]
		}
		path := fmt.Sprintf("types/%s/instances", url.QueryEscape(tUrl))
		action := fmt.Sprintf("list deployed instances of type %s", tUrl)
		callService(path, "GET", action, nil)
	default:
		usage()
	}
}

func callService(path, method, action string, reader io.ReadCloser) {
	u := fmt.Sprintf("%s/%s", *service, path)

	resp := callHttp(u, method, action, reader)
	var j interface{}
	if err := json.Unmarshal([]byte(resp), &j); err != nil {
		panic(fmt.Errorf("Failed to parse JSON response from service: %s", resp))
	}

	y, err := yaml.Marshal(j)
	if err != nil {
		panic(fmt.Errorf("Failed to serialize JSON response from service: %s", resp))
	}

	fmt.Println(string(y))
}

func callHttp(path, method, action string, reader io.ReadCloser) string {
	request, err := http.NewRequest(method, path, reader)
	request.Header.Add("Content-Type", "application/json")

	client := http.Client{
		Timeout: time.Duration(time.Duration(*timeout) * time.Second),
	}

	response, err := client.Do(request)
	if err != nil {
		panic(fmt.Errorf("cannot %s: %s\n", action, err))
	}

	defer response.Body.Close()
	body, err := ioutil.ReadAll(response.Body)
	if err != nil {
		panic(fmt.Errorf("cannot %s: %s\n", action, err))
	}

	if response.StatusCode < http.StatusOK ||
		response.StatusCode >= http.StatusMultipleChoices {
		message := fmt.Sprintf("status code: %d status: %s : %s", response.StatusCode, response.Status, body)
		panic(fmt.Errorf("cannot %s: %s\n", action, message))
	}

	return string(body)
}

// describeType prints the schema for a type specified by either a
// template URL or a fully qualified registry type name (e.g.,
// <type-name>:<version>)
func describeType(args []string) {
	if len(args) != 2 {
		fmt.Fprintln(os.Stderr, "No type name or URL supplied")
		usage()
	}

	tUrls := getDownloadURLs(args[1])
	if len(tUrls) == 0 {
		panic(fmt.Errorf("Invalid type name, must be a template URL or in the form \"<type-name>:<version>\": %s", args[1]))
	}

	schemaUrl := tUrls[0] + ".schema"
	fmt.Println(callHttp(schemaUrl, "GET", "get schema for type ("+tUrls[0]+")", nil))
}

// getDownloadURLs returns URLs or empty list if a primitive type.
func getDownloadURLs(tName string) []string {
	qName := path.Join(*template_registry, tName)
	provider := getRegistryProvider()
	result, err := registry.GetDownloadURLs(provider, qName)
	if err != nil {
		panic(fmt.Errorf("cannot get URLs for %s: %s\n", tName, err))
	}

	return result
}

func loadTemplate(args []string) *common.Template {
	var template *common.Template
	var err error
	if len(args) < 2 {
		fmt.Fprintln(os.Stderr, "No template name or configuration(s) supplied")
		usage()
	}

	if *stdin {
		if len(args) < 2 {
			usage()
		}

		input, err := ioutil.ReadAll(os.Stdin)
		if err != nil {
			panic(err)
		}

		r := bytes.NewReader(input)
		template, err = expander.NewTemplateFromArchive(args[1], r, args[2:])
		if err != nil {
			if err != tar.ErrHeader {
				panic(err)
			}

			r := bytes.NewReader(input)
			template, err = expander.NewTemplateFromReader(args[1], r, args[2:])
			if err != nil {
				panic(fmt.Errorf("cannot create configuration from supplied arguments: %s\n", err))
			}
		}
	} else {
		if len(args) < 3 {
			if t, err := registry.ParseType(args[1]); err == nil {
				template = buildTemplateFromType(t)
			} else {
				template, err = expander.NewTemplateFromRootTemplate(args[1])
			}
		} else {
			template, err = expander.NewTemplateFromFileNames(args[1], args[2:])
		}

		if err != nil {
			panic(fmt.Errorf("cannot create configuration from supplied arguments: %s\n", err))
		}
	}

	// Override name if set from flags.
	if *deployment_name != "" {
		template.Name = *deployment_name
	}

	return template
}

func buildTemplateFromType(t registry.Type) *common.Template {
	props := make(map[string]interface{})
	if *properties != "" {
		plist := strings.Split(*properties, ",")
		for _, p := range plist {
			ppair := strings.Split(p, "=")
			if len(ppair) != 2 {
				panic(fmt.Errorf("--properties must be in the form \"p1=v1,p2=v2,...\": %s\n", p))
			}

			// support ints
			// TODO: needs to support other types.
			i, err := strconv.Atoi(ppair[1])
			if err != nil {
				props[ppair[0]] = ppair[1]
			} else {
				props[ppair[0]] = i
			}
		}
	}

	// Name the deployment after the type name.
	name := fmt.Sprintf("%s:%s", t.Name, t.GetVersion())

	config := common.Configuration{Resources: []*common.Resource{&common.Resource{
		Name:       name,
		Type:       getDownloadURLs(t.String())[0],
		Properties: props,
	}}}

	y, err := yaml.Marshal(config)
	if err != nil {
		panic(fmt.Errorf("error: %s\ncannot create configuration for deployment: %v\n", err, config))
	}

	return &common.Template{
		Name:    name,
		Content: string(y),
		// No imports, as this is a single type from repository.
	}
}

func marshalTemplate(template *common.Template) io.ReadCloser {
	j, err := json.Marshal(template)
	if err != nil {
		panic(fmt.Errorf("cannot deploy configuration %s: %s\n", template.Name, err))
	}

	return ioutil.NopCloser(bytes.NewReader(j))
}

func getRandomName() string {
	return fmt.Sprintf("manifest-%d", time.Now().UTC().UnixNano())
}