package compat

import (
	"fmt"
	"net/http"
	"os"
	goRuntime "runtime"
	"strings"
	"time"

	"github.com/containers/common/pkg/config"
	"github.com/containers/common/pkg/sysinfo"
	"github.com/containers/image/v5/pkg/sysregistriesv2"
	"github.com/containers/podman/v4/libpod"
	"github.com/containers/podman/v4/libpod/define"
	"github.com/containers/podman/v4/pkg/api/handlers"
	"github.com/containers/podman/v4/pkg/api/handlers/utils"
	api "github.com/containers/podman/v4/pkg/api/types"
	"github.com/containers/podman/v4/pkg/rootless"
	docker "github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/registry"
	"github.com/docker/docker/api/types/swarm"
	"github.com/google/uuid"
	log "github.com/sirupsen/logrus"
)

func GetInfo(w http.ResponseWriter, r *http.Request) {
	// 200 ok
	// 500 internal
	runtime := r.Context().Value(api.RuntimeKey).(*libpod.Runtime)

	infoData, err := runtime.Info()
	if err != nil {
		utils.Error(w, http.StatusInternalServerError, fmt.Errorf("failed to obtain system memory info: %w", err))
		return
	}

	configInfo, err := runtime.GetConfig()
	if err != nil {
		utils.Error(w, http.StatusInternalServerError, fmt.Errorf("failed to obtain runtime config: %w", err))
		return
	}
	versionInfo, err := define.GetVersion()
	if err != nil {
		utils.Error(w, http.StatusInternalServerError, fmt.Errorf("failed to obtain podman versions: %w", err))
		return
	}
	stateInfo := getContainersState(runtime)
	sysInfo := sysinfo.New(true)

	// FIXME: Need to expose if runtime supports Checkpointing
	// liveRestoreEnabled := criu.CheckForCriu() && configInfo.RuntimeSupportsCheckpoint()

	info := &handlers.Info{
		Info: docker.Info{
			Architecture:       goRuntime.GOARCH,
			BridgeNfIP6tables:  !sysInfo.BridgeNFCallIP6TablesDisabled,
			BridgeNfIptables:   !sysInfo.BridgeNFCallIPTablesDisabled,
			CPUCfsPeriod:       sysInfo.CPUCfsPeriod,
			CPUCfsQuota:        sysInfo.CPUCfsQuota,
			CPUSet:             sysInfo.Cpuset,
			CPUShares:          sysInfo.CPUShares,
			CgroupDriver:       configInfo.Engine.CgroupManager,
			ClusterAdvertise:   "",
			ClusterStore:       "",
			ContainerdCommit:   docker.Commit{},
			Containers:         infoData.Store.ContainerStore.Number,
			ContainersPaused:   stateInfo[define.ContainerStatePaused],
			ContainersRunning:  stateInfo[define.ContainerStateRunning],
			ContainersStopped:  stateInfo[define.ContainerStateStopped] + stateInfo[define.ContainerStateExited],
			Debug:              log.IsLevelEnabled(log.DebugLevel),
			DefaultRuntime:     configInfo.Engine.OCIRuntime,
			DockerRootDir:      infoData.Store.GraphRoot,
			Driver:             infoData.Store.GraphDriverName,
			DriverStatus:       getGraphStatus(infoData.Store.GraphStatus),
			ExperimentalBuild:  true,
			GenericResources:   nil,
			HTTPProxy:          getEnv("http_proxy"),
			HTTPSProxy:         getEnv("https_proxy"),
			ID:                 uuid.New().String(),
			IPv4Forwarding:     !sysInfo.IPv4ForwardingDisabled,
			Images:             infoData.Store.ImageStore.Number,
			IndexServerAddress: "",
			InitBinary:         "",
			InitCommit:         docker.Commit{},
			Isolation:          "",
			KernelMemoryTCP:    false,
			KernelVersion:      infoData.Host.Kernel,
			Labels:             nil,
			LiveRestoreEnabled: false,
			LoggingDriver:      "",
			MemTotal:           infoData.Host.MemTotal,
			MemoryLimit:        sysInfo.MemoryLimit,
			NCPU:               goRuntime.NumCPU(),
			NEventsListener:    0,
			NFd:                getFdCount(),
			NGoroutines:        goRuntime.NumGoroutine(),
			Name:               infoData.Host.Hostname,
			NoProxy:            getEnv("no_proxy"),
			OSType:             goRuntime.GOOS,
			OSVersion:          infoData.Host.Distribution.Version,
			OomKillDisable:     sysInfo.OomKillDisable,
			OperatingSystem:    infoData.Host.Distribution.Distribution,
			PidsLimit:          sysInfo.PidsLimit,
			Plugins: docker.PluginsInfo{
				Volume:  infoData.Plugins.Volume,
				Network: infoData.Plugins.Network,
				Log:     infoData.Plugins.Log,
			},
			ProductLicense:  "Apache-2.0",
			RegistryConfig:  getServiceConfig(runtime),
			RuncCommit:      docker.Commit{},
			Runtimes:        getRuntimes(configInfo),
			SecurityOptions: getSecOpts(sysInfo),
			ServerVersion:   versionInfo.Version,
			SwapLimit:       sysInfo.SwapLimit,
			Swarm: swarm.Info{
				LocalNodeState: swarm.LocalNodeStateInactive,
			},
			SystemStatus: nil,
			SystemTime:   time.Now().Format(time.RFC3339Nano),
			Warnings:     []string{},
		},
		BuildahVersion:     infoData.Host.BuildahVersion,
		CPURealtimePeriod:  sysInfo.CPURealtimePeriod,
		CPURealtimeRuntime: sysInfo.CPURealtimeRuntime,
		CgroupVersion:      strings.TrimPrefix(infoData.Host.CgroupsVersion, "v"),
		Rootless:           rootless.IsRootless(),
		SwapFree:           infoData.Host.SwapFree,
		SwapTotal:          infoData.Host.SwapTotal,
		Uptime:             infoData.Host.Uptime,
	}
	utils.WriteResponse(w, http.StatusOK, info)
}

func getServiceConfig(runtime *libpod.Runtime) *registry.ServiceConfig {
	var indexConfs map[string]*registry.IndexInfo

	regs, err := sysregistriesv2.GetRegistries(runtime.SystemContext())
	if err == nil {
		indexConfs = make(map[string]*registry.IndexInfo, len(regs))
		for _, reg := range regs {
			mirrors := make([]string, len(reg.Mirrors))
			for i, mirror := range reg.Mirrors {
				mirrors[i] = mirror.Location
			}
			indexConfs[reg.Prefix] = &registry.IndexInfo{
				Name:    reg.Prefix,
				Mirrors: mirrors,
				Secure:  !reg.Insecure,
			}
		}
	} else {
		log.Warnf("failed to get registries configuration: %v", err)
		indexConfs = make(map[string]*registry.IndexInfo)
	}

	return &registry.ServiceConfig{
		AllowNondistributableArtifactsCIDRs:     make([]*registry.NetIPNet, 0),
		AllowNondistributableArtifactsHostnames: make([]string, 0),
		InsecureRegistryCIDRs:                   make([]*registry.NetIPNet, 0),
		IndexConfigs:                            indexConfs,
		Mirrors:                                 make([]string, 0),
	}
}

func getGraphStatus(storeInfo map[string]string) [][2]string {
	graphStatus := make([][2]string, 0, len(storeInfo))
	for k, v := range storeInfo {
		graphStatus = append(graphStatus, [2]string{k, v})
	}
	return graphStatus
}

func getSecOpts(sysInfo *sysinfo.SysInfo) []string {
	var secOpts []string
	if sysInfo.AppArmor {
		secOpts = append(secOpts, "name=apparmor")
	}
	if sysInfo.Seccomp {
		// FIXME: get profile name...
		secOpts = append(secOpts, fmt.Sprintf("name=seccomp,profile=%s", "default"))
	}
	return secOpts
}

func getRuntimes(configInfo *config.Config) map[string]docker.Runtime {
	runtimes := map[string]docker.Runtime{}
	for name, paths := range configInfo.Engine.OCIRuntimes {
		runtimes[name] = docker.Runtime{
			Path: paths[0],
			Args: nil,
		}
	}
	return runtimes
}

func getFdCount() (count int) {
	count = -1
	if entries, err := os.ReadDir("/proc/self/fd"); err == nil {
		count = len(entries)
	}
	return
}

// Just ignoring Container errors here...
func getContainersState(r *libpod.Runtime) map[define.ContainerStatus]int {
	states := map[define.ContainerStatus]int{}
	ctnrs, err := r.GetAllContainers()
	if err == nil {
		for _, ctnr := range ctnrs {
			state, err := ctnr.State()
			if err != nil {
				continue
			}
			states[state]++
		}
	}
	return states
}

func getEnv(value string) string {
	if v, exists := os.LookupEnv(strings.ToUpper(value)); exists {
		return v
	}
	if v, exists := os.LookupEnv(strings.ToLower(value)); exists {
		return v
	}
	return ""
}