/*
 * MinIO Cloud Storage, (C) 2019 MinIO, Inc.
 *
 * 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 cmd

import (
	"net"
	"net/http"
	"os"
	"strings"

	"github.com/minio/minio-go/pkg/set"
	"github.com/minio/minio/pkg/cpu"
	"github.com/minio/minio/pkg/disk"
	"github.com/minio/minio/pkg/madmin"
	"github.com/minio/minio/pkg/mem"

	cpuhw "github.com/shirou/gopsutil/cpu"
)

// getLocalMemUsage - returns ServerMemUsageInfo for all zones, endpoints.
func getLocalMemUsage(endpointZones EndpointZones, r *http.Request) ServerMemUsageInfo {
	var memUsages []mem.Usage
	var historicUsages []mem.Usage
	seenHosts := set.NewStringSet()
	for _, ep := range endpointZones {
		for _, endpoint := range ep.Endpoints {
			if seenHosts.Contains(endpoint.Host) {
				continue
			}
			seenHosts.Add(endpoint.Host)

			// Only proceed for local endpoints
			if endpoint.IsLocal {
				memUsages = append(memUsages, mem.GetUsage())
				historicUsages = append(historicUsages, mem.GetHistoricUsage())
			}
		}
	}
	addr := r.Host
	if globalIsDistXL {
		addr = GetLocalPeer(endpointZones)
	}
	return ServerMemUsageInfo{
		Addr:          addr,
		Usage:         memUsages,
		HistoricUsage: historicUsages,
	}
}

// getLocalCPULoad - returns ServerCPULoadInfo for all zones, endpoints.
func getLocalCPULoad(endpointZones EndpointZones, r *http.Request) ServerCPULoadInfo {
	var cpuLoads []cpu.Load
	var historicLoads []cpu.Load
	seenHosts := set.NewStringSet()
	for _, ep := range endpointZones {
		for _, endpoint := range ep.Endpoints {
			if seenHosts.Contains(endpoint.Host) {
				continue
			}
			seenHosts.Add(endpoint.Host)

			// Only proceed for local endpoints
			if endpoint.IsLocal {
				cpuLoads = append(cpuLoads, cpu.GetLoad())
				historicLoads = append(historicLoads, cpu.GetHistoricLoad())
			}
		}
	}
	addr := r.Host
	if globalIsDistXL {
		addr = GetLocalPeer(endpointZones)
	}
	return ServerCPULoadInfo{
		Addr:         addr,
		Load:         cpuLoads,
		HistoricLoad: historicLoads,
	}
}

// getLocalDrivesPerf - returns ServerDrivesPerfInfo for all zones, endpoints.
func getLocalDrivesPerf(endpointZones EndpointZones, size int64, r *http.Request) madmin.ServerDrivesPerfInfo {
	var dps []disk.Performance
	for _, ep := range endpointZones {
		for _, endpoint := range ep.Endpoints {
			// Only proceed for local endpoints
			if endpoint.IsLocal {
				if _, err := os.Stat(endpoint.Path); err != nil {
					// Since this drive is not available, add relevant details and proceed
					dps = append(dps, disk.Performance{Path: endpoint.Path, Error: err.Error()})
					continue
				}
				dp := disk.GetPerformance(pathJoin(endpoint.Path, minioMetaTmpBucket, mustGetUUID()), size)
				dp.Path = endpoint.Path
				dps = append(dps, dp)
			}
		}
	}
	addr := r.Host
	if globalIsDistXL {
		addr = GetLocalPeer(endpointZones)
	}
	return madmin.ServerDrivesPerfInfo{
		Addr: addr,
		Perf: dps,
	}
}

// getLocalCPUInfo - returns ServerCPUHardwareInfo for all zones, endpoints.
func getLocalCPUInfo(endpointZones EndpointZones, r *http.Request) madmin.ServerCPUHardwareInfo {
	var cpuHardwares []cpuhw.InfoStat
	seenHosts := set.NewStringSet()
	for _, ep := range endpointZones {
		for _, endpoint := range ep.Endpoints {
			if seenHosts.Contains(endpoint.Host) {
				continue
			}
			// Add to the list of visited hosts
			seenHosts.Add(endpoint.Host)
			// Only proceed for local endpoints
			if endpoint.IsLocal {
				cpuHardware, err := cpuhw.Info()
				if err != nil {
					return madmin.ServerCPUHardwareInfo{
						Error: err.Error(),
					}
				}
				cpuHardwares = append(cpuHardwares, cpuHardware...)
			}
		}
	}
	addr := r.Host
	if globalIsDistXL {
		addr = GetLocalPeer(endpointZones)
	}

	return madmin.ServerCPUHardwareInfo{
		Addr:    addr,
		CPUInfo: cpuHardwares,
	}
}

// getLocalNetworkInfo - returns ServerNetworkHardwareInfo for all zones, endpoints.
func getLocalNetworkInfo(endpointZones EndpointZones, r *http.Request) madmin.ServerNetworkHardwareInfo {
	var networkHardwares []net.Interface
	seenHosts := set.NewStringSet()
	for _, ep := range endpointZones {
		for _, endpoint := range ep.Endpoints {
			if seenHosts.Contains(endpoint.Host) {
				continue
			}
			// Add to the list of visited hosts
			seenHosts.Add(endpoint.Host)
			// Only proceed for local endpoints
			if endpoint.IsLocal {
				networkHardware, err := net.Interfaces()
				if err != nil {
					return madmin.ServerNetworkHardwareInfo{
						Error: err.Error(),
					}
				}
				networkHardwares = append(networkHardwares, networkHardware...)
			}
		}
	}
	addr := r.Host
	if globalIsDistXL {
		addr = GetLocalPeer(endpointZones)
	}

	return madmin.ServerNetworkHardwareInfo{
		Addr:        addr,
		NetworkInfo: networkHardwares,
	}
}

// getLocalServerProperty - returns ServerDrivesPerfInfo for only the
// local endpoints from given list of endpoints
func getLocalServerProperty(endpointZones EndpointZones, r *http.Request) madmin.ServerProperties {
	var di madmin.Disk
	var disks []madmin.Disk
	addr := r.Host
	if globalIsDistXL {
		addr = GetLocalPeer(endpointZones)
	}
	network := make(map[string]string)
	hosts := set.NewStringSet()
	for _, ep := range endpointZones {
		for _, endpoint := range ep.Endpoints {

			url := strings.Replace(endpoint.URL.String(), endpoint.Path, "", -1)
			if url == "" {
				url = r.Host
			}
			hosts.Add(url)

			// Only proceed for local endpoints
			if endpoint.IsLocal {
				url = fetchAddress(url)
				network[url] = "online"
				if _, err := os.Stat(endpoint.Path); err != nil {
					continue
				}

				diInfo, _ := disk.GetInfo(endpoint.Path)
				di.State = "ok"
				di.DrivePath = endpoint.Path
				di.TotalSpace = diInfo.Total
				di.UsedSpace = diInfo.Total - diInfo.Free
				di.Utilization = float64((diInfo.Total - diInfo.Free) / diInfo.Total * 100)
				disks = append(disks, di)
			}
		}
	}

	for host := range hosts {
		_, present := network[host]
		if !present {
			err := checkConnection(host)
			host = fetchAddress(host)
			if err != nil {
				network[host] = "offline"
			} else {
				network[host] = "online"
			}
		}
	}

	return madmin.ServerProperties{
		State:    "ok",
		Endpoint: addr,
		Uptime:   UTCNow().Sub(globalBootTime),
		Version:  Version,
		CommitID: CommitID,
		Network:  network,
		Disks:    disks,
	}
}

// Replaces http and https from address
func fetchAddress(address string) string {
	if strings.Contains(address, "http://") {
		address = strings.Replace(address, "http://", "", -1)
	} else if strings.Contains(address, "https://") {
		address = strings.Replace(address, "https://", "", -1)
	}
	return address
}