// Copyright (C) 2014-2018 Goodrain Co., Ltd.
// RAINBOND, Application Management Platform

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version. For any non-GPL usage of Rainbond,
// one or multiple Commercial Licenses authorized by Goodrain Co., Ltd.
// must be obtained first.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.

package server

import (
	"context"
	"crypto/tls"
	"crypto/x509"
	"io/ioutil"
	"log"
	"net/http"
	_ "net/http/pprof" // Register handlers for the dedicated diagnostics server.
	"os"
	"strings"
	"time"

	"github.com/goodrain/rainbond/api/api_routers/gateway"
	"github.com/goodrain/rainbond/api/handler"
	"github.com/goodrain/rainbond/config/configs"
	"github.com/goodrain/rainbond/config/configs/rbdcomponent"
	k8scomponent "github.com/goodrain/rainbond/pkg/component/k8s"
	promcomponent "github.com/goodrain/rainbond/pkg/component/prom"
	"github.com/goodrain/rainbond/pkg/gogo"
	"github.com/goodrain/rainbond/pkg/interceptors"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	_ "k8s.io/component-base/metrics/prometheus/version" // Register Kubernetes build-version metrics.

	"github.com/goodrain/rainbond/util"

	"github.com/goodrain/rainbond/api/api_routers/doc"
	"github.com/goodrain/rainbond/api/api_routers/license"
	"github.com/goodrain/rainbond/api/metric"
	"github.com/goodrain/rainbond/api/proxy"

	"github.com/goodrain/rainbond/api/api_routers/version2"
	"github.com/goodrain/rainbond/api/api_routers/websocket"

	apimiddleware "github.com/goodrain/rainbond/api/middleware"

	"github.com/go-chi/chi"
	"github.com/go-chi/chi/middleware"
	"github.com/sirupsen/logrus"
)

// Manager apiserver
type Manager struct {
	ctx             context.Context
	cancel          context.CancelFunc
	stopChan        chan struct{}
	r               *chi.Mux
	prometheusProxy proxy.Proxy
	exporter        *metric.Exporter
	LogConfig       *configs.LogConfig
	WebSocket       *configs.WebSocketConfig
	APIConfig       *rbdcomponent.APIConfig
}

// NewManager newManager
func NewManager() *Manager {
	config := configs.Default()
	ctx, cancel := context.WithCancel(context.Background())
	manager := &Manager{
		ctx:       ctx,
		cancel:    cancel,
		stopChan:  make(chan struct{}),
		LogConfig: config.LogConfig,
		WebSocket: config.WebSocketConfig,
		APIConfig: config.APIConfig,
	}
	r := chi.NewRouter()
	manager.r = r
	manager.SetMiddleware()
	return manager
}

// SetMiddleware set api meddleware
func (m *Manager) SetMiddleware() {
	r := m.r
	r.Use(m.RequestMetric)
	r.Use(middleware.RequestID)
	//Sets a http.Request's RemoteAddr to either X-Forwarded-For or X-Real-IP
	r.Use(middleware.RealIP)
	//Logs the start and end of each request with the elapsed processing time
	if m.LogConfig.LoggerFile != "" {
		logerFile, err := os.OpenFile(m.LogConfig.LoggerFile, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0644)
		if err != nil {
			logrus.Errorf("open logger file %s error %s", m.LogConfig.LoggerFile, err.Error())
			r.Use(middleware.DefaultLogger)
		} else {
			requestLog := middleware.RequestLogger(&middleware.DefaultLogFormatter{Logger: log.New(logerFile, "", log.LstdFlags)})
			r.Use(requestLog)
		}
	} else {
		r.Use(middleware.DefaultLogger)
	}
	//Gracefully absorb panics and prints the stack trace
	r.Use(interceptors.Recoverer)
	//request time out
	r.Use(interceptors.Timeout(time.Second * 5))
	//simple authz
	if os.Getenv("TOKEN") != "" {
		r.Use(apimiddleware.FullToken)
	}
	//simple api version
	r.Use(apimiddleware.APIVersion)
	r.Use(apimiddleware.Proxy)
}

// Start manager
func (m *Manager) Start() error {
	return gogo.Go(func(ctx context.Context) error {
		m.Do()
		logrus.Info("start api router success.")
		return nil
	})
}

// Do do
func (m *Manager) Do() {
	for {
		select {
		case <-m.ctx.Done():
			return
		default:
			m.Run()
		}
	}
}

// Stop manager
func (m *Manager) Stop() error {
	logrus.Info("api router is stopped.")
	m.cancel()
	return nil
}

// Run run
func (m *Manager) Run() {
	v2R := &version2.V2{}
	m.Metric()
	if m.APIConfig.Debug {
		util.ProfilerSetup(m.r)
	}
	m.r.Get("/monitor", func(res http.ResponseWriter, req *http.Request) {
		res.WriteHeader(http.StatusOK)
		res.Write([]byte("ok"))
	})
	m.r.Mount("/v2/proxy-pass/gateway/{tenant_name}", gateway.Routes())
	m.r.Mount("/api-gateway/v1/{tenant_name}", gateway.Routes())

	m.r.Mount("/v2", v2R.Routes())
	m.r.Mount("/", doc.Routes())
	m.r.Mount("/license", license.Routes())
	m.r.Get("/kubernetes/dashboard", m.KuberntesDashboardAPI)
	//prometheus单节点代理
	m.r.Get("/api/v1/query", m.PrometheusAPI)
	m.r.Get("/api/v1/query_range", m.PrometheusAPI)
	m.r.Get("/api/v1/alerts", m.PrometheusAPI)
	//开启对浏览器的websocket服务和文件服务

	_ = gogo.Go(func(ctx context.Context) error {
		websocketRouter := chi.NewRouter()
		websocketRouter.Mount("/", websocket.Routes())
		websocketRouter.Mount("/logs", websocket.LogRoutes())
		websocketRouter.Mount("/app", websocket.AppRoutes())
		websocketRouter.Mount("/package_build", websocket.PackageBuildRoutes())
		websocketRouter.Mount("/helm_install", websocket.HelmInstallRegionStatus())
		// 共享存储的文件操作路由
		websocketRouter.Mount("/v2/file-operate", websocket.FileOperateRoutes())
		// 语言包处理
		websocketRouter.Mount("/lg_pack_operate", websocket.LongVersionRoutes())
		if m.WebSocket.WebsocketSSL {
			logrus.Infof("websocket listen on (HTTPs) %s", m.WebSocket.WebsocketAddr)
			logrus.Fatal(http.ListenAndServeTLS(m.WebSocket.WebsocketAddr, m.WebSocket.WebsocketCertFile, m.WebSocket.WebsocketKeyFile, websocketRouter))
		} else {
			logrus.Infof("websocket listen on (HTTP) %s", m.WebSocket.WebsocketAddr)
			logrus.Fatal(http.ListenAndServe(m.WebSocket.WebsocketAddr, websocketRouter))
		}
		return nil
	})

	// api ssl
	if m.APIConfig.APISSL {
		_ = gogo.Go(func(ctx context.Context) error {
			pool := x509.NewCertPool()
			caCrt, err := ioutil.ReadFile(m.APIConfig.APICaFile)
			if err != nil {
				logrus.Fatal("ReadFile ca err:", err)
				return err
			}
			pool.AppendCertsFromPEM(caCrt)
			s := &http.Server{
				Addr:    m.APIConfig.APIAddrSSL,
				Handler: m.r,
				TLSConfig: &tls.Config{
					ClientCAs:  pool,
					ClientAuth: tls.RequireAndVerifyClientCert,
				},
			}
			logrus.Infof("api listen on (HTTPs) %s", m.APIConfig.APIAddrSSL)
			logrus.Fatal(s.ListenAndServeTLS(m.APIConfig.APICertFile, m.APIConfig.APIKeyFile))
			return nil
		})
	}
	_ = gogo.Go(func(ctx context.Context) error {
		healthzRouter := chi.NewRouter()
		healthzRouter.Get("/healthz", func(res http.ResponseWriter, req *http.Request) {
			res.WriteHeader(http.StatusOK)
			res.Write([]byte("ok"))
		})
		logrus.Infof("health check listen on (HTTP) %s", m.APIConfig.APIHealthzAddr)
		logrus.Fatal(http.ListenAndServe(m.APIConfig.APIHealthzAddr, healthzRouter))
		return nil
	})
	go func() {
		http.ListenAndServe(":6789", nil)
	}()
	// api
	logrus.Infof("api listen on (HTTP) %s", m.APIConfig.APIAddr)
	logrus.Fatal(http.ListenAndServe(m.APIConfig.APIAddr, m.r))
}

// PrometheusAPI prometheus api 代理
func (m *Manager) PrometheusAPI(w http.ResponseWriter, r *http.Request) {
	handler.GetPrometheusProxy().Proxy(w, r)
}

// KuberntesDashboardAPI proxy traffix to kubernetes dashboard
func (m *Manager) KuberntesDashboardAPI(w http.ResponseWriter, r *http.Request) {
	handler.GetKubernetesDashboardProxy().Proxy(w, r)
}

// Metric prometheus metric
func (m *Manager) Metric() {
	exporter := metric.NewExporter()
	m.exporter = exporter
	prometheus.MustRegister(exporter)
	kube, monitor := k8scomponent.Default(), promcomponent.Default()
	if kube != nil && monitor != nil {
		collector, err := metric.NewAPIServerCollector(kube.Clientset, kube.RestConfig, monitor.PrometheusCli)
		if err != nil {
			logrus.WithError(err).Warning("API server request-counter collector unavailable")
		} else {
			prometheus.MustRegister(collector)
		}
	}
	m.r.Handle("/metrics", promhttp.Handler())
}

// RequestMetric request metric midd
func (m *Manager) RequestMetric(next http.Handler) http.Handler {
	fn := func(w http.ResponseWriter, r *http.Request) {
		ww := middleware.NewWrapResponseWriter(w, r.ProtoMajor)
		defer func() {
			path := r.RequestURI
			if strings.Index(r.RequestURI, "?") > -1 {
				path = r.RequestURI[:strings.Index(r.RequestURI, "?")]
			}
			m.exporter.RequestInc(ww.Status(), path)
		}()
		next.ServeHTTP(ww, r)
	}
	return http.HandlerFunc(fn)
}