package server

import (
	"encoding/json"
	"errors"
	"fmt"
	"net/http"

	"github.com/go-zoo/bone"
	"github.com/kubernetes-incubator/cri-o/libkpod/sandbox"
	"github.com/kubernetes-incubator/cri-o/oci"
	"github.com/sirupsen/logrus"
)

// ContainerInfo stores information about containers
type ContainerInfo struct {
	Name        string            `json:"name"`
	Pid         int               `json:"pid"`
	Image       string            `json:"image"`
	CreatedTime int64             `json:"created_time"`
	Labels      map[string]string `json:"labels"`
	Annotations map[string]string `json:"annotations"`
	LogPath     string            `json:"log_path"`
	Root        string            `json:"root"`
	Sandbox     string            `json:"sandbox"`
	IP          string            `json:"ip_address"`
}

// CrioInfo stores information about the crio daemon
type CrioInfo struct {
	StorageDriver string `json:"storage_driver"`
	StorageRoot   string `json:"storage_root"`
	CgroupDriver  string `json:"cgroup_driver"`
}

func (s *Server) getInfo() CrioInfo {
	return CrioInfo{
		StorageDriver: s.config.Config.Storage,
		StorageRoot:   s.config.Config.Root,
		CgroupDriver:  s.config.Config.CgroupManager,
	}
}

var (
	errCtrNotFound     = errors.New("container not found")
	errCtrStateNil     = errors.New("container state is nil")
	errSandboxNotFound = errors.New("sandbox for container not found")
)

func (s *Server) getContainerInfo(id string, getContainerFunc func(id string) *oci.Container, getInfraContainerFunc func(id string) *oci.Container, getSandboxFunc func(id string) *sandbox.Sandbox) (ContainerInfo, error) {
	ctr := getContainerFunc(id)
	if ctr == nil {
		ctr = getInfraContainerFunc(id)
		if ctr == nil {
			return ContainerInfo{}, errCtrNotFound
		}
	}
	// TODO(mrunalp): should we call UpdateStatus()?
	ctrState := ctr.State()
	if ctrState == nil {
		return ContainerInfo{}, errCtrStateNil
	}
	sb := getSandboxFunc(ctr.Sandbox())
	if sb == nil {
		logrus.Debugf("can't find sandbox %s for container %s", ctr.Sandbox(), id)
		return ContainerInfo{}, errSandboxNotFound
	}
	return ContainerInfo{
		Name:        ctr.Name(),
		Pid:         ctrState.Pid,
		Image:       ctr.Image(),
		CreatedTime: ctrState.Created.UnixNano(),
		Labels:      ctr.Labels(),
		Annotations: ctr.Annotations(),
		Root:        ctr.MountPoint(),
		LogPath:     ctr.LogPath(),
		Sandbox:     ctr.Sandbox(),
		IP:          sb.IP(),
	}, nil

}

// GetInfoMux returns the mux used to serve info requests
func (s *Server) GetInfoMux() *bone.Mux {
	mux := bone.New()

	mux.Get("/info", http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		ci := s.getInfo()
		js, err := json.Marshal(ci)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		w.Write(js)
	}))

	mux.Get("/containers/:id", http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		containerID := bone.GetValue(req, "id")
		ci, err := s.getContainerInfo(containerID, s.GetContainer, s.getInfraContainer, s.getSandbox)
		if err != nil {
			switch err {
			case errCtrNotFound:
				http.Error(w, fmt.Sprintf("can't find the container with id %s", containerID), http.StatusNotFound)
			case errCtrStateNil:
				http.Error(w, fmt.Sprintf("can't find container state for container with id %s", containerID), http.StatusInternalServerError)
			case errSandboxNotFound:
				http.Error(w, fmt.Sprintf("can't find the sandbox for container id %s", containerID), http.StatusNotFound)
			default:
				http.Error(w, err.Error(), http.StatusInternalServerError)
			}
			return
		}
		js, err := json.Marshal(ci)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		w.Write(js)
	}))

	return mux
}