package inventory

import (
	"errors"
	"fmt"
	"log"
	"path"
	"strconv"
	"time"

	ctx "golang.org/x/net/context"

	"github.com/rook/rook/pkg/util"
	"github.com/rook/rook/pkg/util/exec"

	etcd "github.com/coreos/etcd/client"
)

const (
	HeartbeatKey        = "heartbeat"
	disksKey            = "disks"
	processorsKey       = "cpu"
	networkKey          = "net"
	memoryKey           = "mem"
	locationKey         = "location"
	heartbeatTtlSeconds = 60 * 60
	publicIpAddressKey  = "publicIp"
	privateIpAddressKey = "privateIp"
)

var (
	HeartbeatTtlDuration = time.Duration(heartbeatTtlSeconds) * time.Second
)

func DiscoverHardware(nodeID string, etcdClient etcd.KeysAPI, executor exec.Executor) error {
	nodeConfigKey := GetNodeConfigKey(nodeID)
	if err := discoverDisks(nodeConfigKey, etcdClient, executor); err != nil {
		return err
	}

	// TODO: discover more hardware properties

	return nil
}

// gets the key under which all node hardware/config will be stored
func GetNodeConfigKey(nodeID string) string {
	return path.Join(NodesConfigKey, nodeID)
}

// Load all the nodes' infrastructure configuration
func loadNodeConfig(etcdClient etcd.KeysAPI) (map[string]*NodeConfig, error) {
	nodesConfig := make(map[string]*NodeConfig)

	// Load the node configuration keys
	nodeInfo, err := etcdClient.Get(ctx.Background(), NodesConfigKey, &etcd.GetOptions{Recursive: true})
	if err != nil && !util.IsEtcdKeyNotFound(err) {
		return nil, fmt.Errorf("failed to get the node config. %v", err)
	}
	if nodeInfo == nil || nodeInfo.Node == nil {
		return nodesConfig, nil
	}

	// verbose: log.Printf("Discovered %d nodes", len(nodeInfo.Node.Nodes))

	for _, etcdNode := range nodeInfo.Node.Nodes {
		nodeConfig := &NodeConfig{}
		nodeID := util.GetLeafKeyPath(etcdNode.Key)

		// get all the config information for the current node
		err = loadHardwareConfig(nodeID, nodeConfig, etcdNode)
		if err != nil {
			log.Printf("failed to parse hardware config for node %s, %v", etcdNode, err)
			return nil, err
		}

		nodesConfig[nodeID] = nodeConfig
	}

	return nodesConfig, nil
}

func loadNodeHealth(etcdClient etcd.KeysAPI, nodes map[string]*NodeConfig) error {
	// set the default health info on all the nodes
	for _, node := range nodes {
		// If no heartbeat is found, set the age to one year
		node.HeartbeatAge = time.Hour * 24 * 365
	}

	// Load the node configuration keys
	healthInfo, err := etcdClient.Get(ctx.Background(), NodesHealthKey, &etcd.GetOptions{Recursive: true})
	if err != nil && !util.IsEtcdKeyNotFound(err) {
		return fmt.Errorf("failed to get the node health key. %v", err)
	}
	if healthInfo == nil || healthInfo.Node == nil {
		// no node health found
		return nil
	}

	for _, health := range healthInfo.Node.Nodes {
		nodeID := util.GetLeafKeyPath(health.Key)

		var nodeConfig *NodeConfig
		var ok bool
		if nodeConfig, ok = nodes[nodeID]; !ok {
			log.Printf("found health but no config for node %s", nodeID)
			continue
		}

		err := loadSingleNodeHealth(nodeConfig, health)
		if err != nil {
			return fmt.Errorf("failed to load health for node %s. %v", nodeID, err)
		}
	}

	return nil
}

func loadSingleNodeHealth(node *NodeConfig, health *etcd.Node) error {

	for _, prop := range health.Nodes {
		switch util.GetLeafKeyPath(prop.Key) {
		case HeartbeatKey:
			node.HeartbeatAge = HeartbeatTtlDuration - (time.Duration(prop.TTL) * time.Second)
			// verbose: log.Printf("Node %s has age of %s", node.IPAddress, node.HeartbeatAge.String())
		default:
			return fmt.Errorf("unknown node health key %s", prop.Key)
		}
	}

	return nil
}

// Set the IP address for a node
func SetIPAddress(etcdClient etcd.KeysAPI, nodeId, publicIP, privateIP string) error {
	err := setConfigProperty(etcdClient, nodeId, publicIpAddressKey, publicIP)
	if err != nil {
		return err
	}

	return setConfigProperty(etcdClient, nodeId, privateIpAddressKey, privateIP)
}

func SetLocation(etcdClient etcd.KeysAPI, nodeId, location string) error {
	return setConfigProperty(etcdClient, nodeId, locationKey, location)
}

func setConfigProperty(etcdClient etcd.KeysAPI, nodeId, keyName, val string) error {
	key := path.Join(GetNodeConfigKey(nodeId), keyName)
	_, err := etcdClient.Set(ctx.Background(), key, val, nil)

	return err
}

func loadHardwareConfig(nodeId string, nodeConfig *NodeConfig, nodeInfo *etcd.Node) error {
	if nodeInfo == nil || nodeInfo.Nodes == nil {
		return errors.New("hardware info missing")
	}

	for _, nodeConfigRoot := range nodeInfo.Nodes {
		key := util.GetLeafKeyPath(nodeConfigRoot.Key)
		var err error
		switch key {
		case disksKey:
			err = loadDisksConfig(nodeConfig, nodeConfigRoot)

		case processorsKey:
			err = loadProcessorsConfig(nodeConfig, nodeConfigRoot)

		case memoryKey:
			err = loadMemoryConfig(nodeConfig, nodeConfigRoot)

		case networkKey:
			err = loadNetworkConfig(nodeConfig, nodeConfigRoot)

		case publicIpAddressKey:
			err = loadSimpleConfigStringProperty(&(nodeConfig.PublicIP), nodeConfigRoot, "Public IP")

		case privateIpAddressKey:
			err = loadSimpleConfigStringProperty(&(nodeConfig.PrivateIP), nodeConfigRoot, "Private IP")

		case locationKey:
			err = loadSimpleConfigStringProperty(&(nodeConfig.Location), nodeConfigRoot, "Location")

		default:
			log.Printf("unexpected hardware component: %s, skipping...", nodeConfigRoot)
		}

		if err != nil {
			log.Printf("failed to load %s config for node %s, %v", key, nodeId, err)
			return err
		}
	}

	return nil
}

func loadDisksConfig(nodeConfig *NodeConfig, disksRootNode *etcd.Node) error {
	numDisks := 0
	if disksRootNode.Nodes != nil {
		numDisks = len(disksRootNode.Nodes)
	}

	nodeConfig.Disks = make([]DiskConfig, numDisks)

	// iterate over all disks from etcd
	for i, diskInfo := range disksRootNode.Nodes {
		disk, err := getDiskInfo(diskInfo)
		if err != nil {
			log.Printf("Failed to get disk. err=%v", err)
			return err
		}

		nodeConfig.Disks[i] = *disk

	}

	return nil
}

func loadProcessorsConfig(nodeConfig *NodeConfig, procsRootNode *etcd.Node) error {
	numProcs := 0
	if procsRootNode.Nodes != nil {
		numProcs = len(procsRootNode.Nodes)
	}

	nodeConfig.Processors = make([]ProcessorConfig, numProcs)

	// iterate over all processors from etcd
	for i, procInfo := range procsRootNode.Nodes {
		proc := ProcessorConfig{}
		if procID, err := strconv.ParseUint(util.GetLeafKeyPath(procInfo.Key), 10, 32); err != nil {
			return err
		} else {
			proc.ID = uint(procID)
		}

		// iterate over all properties of the processor
		for _, procProperty := range procInfo.Nodes {
			procPropertyName := util.GetLeafKeyPath(procProperty.Key)
			switch procPropertyName {
			case ProcPhysicalIDKey:
				if phsyicalId, err := strconv.ParseUint(procProperty.Value, 10, 32); err != nil {
					return err
				} else {
					proc.PhysicalID = uint(phsyicalId)
				}
			case ProcSiblingsKey:
				if siblings, err := strconv.ParseUint(procProperty.Value, 10, 32); err != nil {
					return err
				} else {
					proc.Siblings = uint(siblings)
				}
			case ProcCoreIDKey:
				if coreId, err := strconv.ParseUint(procProperty.Value, 10, 32); err != nil {
					return err
				} else {
					proc.CoreID = uint(coreId)
				}
			case ProcNumCoresKey:
				if numCores, err := strconv.ParseUint(procProperty.Value, 10, 32); err != nil {
					return err
				} else {
					proc.NumCores = uint(numCores)
				}
			case ProcSpeedKey:
				if speed, err := strconv.ParseFloat(procProperty.Value, 64); err != nil {
					return err
				} else {
					proc.Speed = speed
				}
			case ProcBitsKey:
				if numBits, err := strconv.ParseUint(procProperty.Value, 10, 32); err != nil {
					return err
				} else {
					proc.Bits = uint(numBits)
				}
			default:
				log.Printf("unknown processor property key %s, skipping", procPropertyName)
			}
		}

		nodeConfig.Processors[i] = proc
	}

	return nil
}

func loadMemoryConfig(nodeConfig *NodeConfig, memoryRootNode *etcd.Node) error {
	mem := MemoryConfig{}
	for _, memProperty := range memoryRootNode.Nodes {
		memPropertyName := util.GetLeafKeyPath(memProperty.Key)
		switch memPropertyName {
		case MemoryTotalSizeKey:
			if size, err := strconv.ParseUint(memProperty.Value, 10, 64); err != nil {
				return err
			} else {
				mem.TotalSize = size
			}
		default:
			log.Printf("unknown memory property key %s, skipping", memPropertyName)
		}
	}

	nodeConfig.Memory = mem
	return nil
}

func loadNetworkConfig(nodeConfig *NodeConfig, networkRootNode *etcd.Node) error {
	numNics := 0
	if networkRootNode.Nodes != nil {
		numNics = len(networkRootNode.Nodes)
	}

	nodeConfig.NetworkAdapters = make([]NetworkConfig, numNics)

	// iterate over all network adapters from etcd
	for i, netInfo := range networkRootNode.Nodes {
		net := NetworkConfig{}
		net.Name = util.GetLeafKeyPath(netInfo.Key)

		// iterate over all properties of the network adapter
		for _, netProperty := range netInfo.Nodes {
			netPropertyName := util.GetLeafKeyPath(netProperty.Key)
			switch netPropertyName {
			case NetworkIPv4AddressKey:
				net.IPv4Address = netProperty.Value
			case NetworkIPv6AddressKey:
				net.IPv6Address = netProperty.Value
			case NetworkSpeedKey:
				if netProperty.Value == "" {
					net.Speed = 0
				} else if speed, err := strconv.ParseUint(netProperty.Value, 10, 64); err != nil {
					return err
				} else {
					net.Speed = speed
				}
			default:
				log.Printf("unknown network adapter property key %s, skipping", netPropertyName)
			}
		}

		nodeConfig.NetworkAdapters[i] = net
	}

	return nil
}

func loadSimpleConfigStringProperty(cfgField *string, cfgNode *etcd.Node, propName string) error {
	if cfgNode.Dir {
		return fmt.Errorf("%s node '%s' is a directory, but it's expected to be a key", propName, cfgNode.Key)
	}
	*cfgField = cfgNode.Value
	return nil
}