package cmd

import (
	"os"
	"fmt"
	"strings"

	"github.com/spf13/viper"
	log "github.com/sirupsen/logrus"
)

/********************************************************************************
 * Initialize datastore(s) /iocage, /iocage/jails
 * Put defaults.json,
 * Update it with hostid, interfaces, and maybe other necessary fields
 * Initialize bridge
 *******************************************************************************/
func InitGoCage(args []string) {
	// Create datastores
	for _, dstore := range viper.GetStringSlice("datastore") {
		log.Debugf("Ranging over %v\n", dstore)
		dset, err := zfsGetDatasetByMountpoint(dstore)
		if err != nil && strings.HasSuffix(err.Error(), "No such file or directory\"") {
			if len(gZPool) == 0 {
				log.Errorf("Datastore mountpoint \"%s\" does not exist. Specify a pool if you want to create it.", dstore)
				return
			}
			// Create dataset /iocage
			rootDSName := fmt.Sprintf("%s%s", gZPool, dstore)
			log.Debugf("Creating dataset %s mounted on %s\n", rootDSName, dstore)
			if err = zfsCreateDataset(rootDSName, dstore, ""); err != nil {
				log.Errorf("Error creating dataset %s: %v\n", rootDSName, err)
				return
			}
			// Create /iocage/jail, releases, templates
			for _, l := range []string{"jails","releases","templates"} {
				cds := fmt.Sprintf("%s/%s", rootDSName, l)
				cmp := fmt.Sprintf("%s/%s", dstore, l)
				log.Debugf("Creating dataset %s mounted on %s\n", cds, cmp)
				if err = zfsCreateDataset(cds, cmp, ""); err != nil {
					log.Errorf("Error creating dataset %s: %v\n", cds, err)
					return
				}
			}
			
			// Create /iocage/defaults.json
			exists, err := doFileExist(fmt.Sprintf("%s/defaults.json", dstore))
			if err != nil {
				log.Errorf("Error checking defaults.json: %v\n", err)
				return
			}
			if !exists {
				if err = createDefaultsJson(dstore, gBridge); err != nil {
					log.Errorf("%v\n", err)
				}
			}
		} else if err != nil {
			log.Errorf("Error checking datastore existence: %v\n", err)
			return
		} else {
			log.Debugf("Datastore dataset exist: %s\n", dset)
		}
	}
	// Check and create bridge
	// FIXME: What if bridge name is invalid, as we already wrote it in defaults.json in dstore loop?
	if len(gBridge) > 0 && len(gInterface) > 0 {
		if err := initBridge(); err != nil {
			log.Errorf("%v\n", err)
		}
	}
}

func createDefaultsJson(rootDirectory string, bridge string) error {
	hostid, err := os.ReadFile("/etc/hostid")
	if err != nil {
		log.Fatalf("Unable to read /etc/hostid: %v\n", err)
	}
	json := strings.Replace(gDefaultsJson, "TO-BE-REPLACED-WITH-HOSTID", strings.Trim(string(hostid), "\n"), 1)
	json = strings.Replace(json, "TO-BE-REPLACED-WITH-BRIDGE", bridge, 1)
	if err := os.WriteFile(fmt.Sprintf("%s/defaults.json", rootDirectory), []byte(json), 0640); err != nil {
		log.Fatal(err)
	}
	
	return nil
}

func createInterface(iface string) error {
	log.Debugf("creating interface \"%s\"\n", iface)
	cmd := fmt.Sprintf("/sbin/ifconfig %s create", iface)
	_, err := executeCommand(cmd)
	if err != nil {
		return err
	}
	return nil
}

func bringUpInterface(iface string) error {
	log.Debugf("bringing up interface \"%s\"\n", iface)
	cmd := fmt.Sprintf("/sbin/ifconfig %s up", iface)
	_, err := executeCommand(cmd)
	if err != nil {
		return err
	}
	return nil
}

func addMemberToBridge(bridge string, iface string) error {
	log.Debugf("adding member interface \"%s\" to bridge \"%s\"\n", iface, bridge)
	cmd := fmt.Sprintf("/sbin/ifconfig %s addm %s", bridge, iface)
	_, err := executeCommand(cmd)
	if err != nil {
		return err
	}
	return nil
}

func initBridge() error {
	hostInt, err := gJailHost.GetInterfaces()
	if err != nil {
		return fmt.Errorf("Error listing interfaces: %v\n", err)
	}
	if !isStringInArray(hostInt, gInterface) {
		return fmt.Errorf("Interface not found: %s\n", gInterface)
	}
	if !isStringInArray(hostInt, gBridge) {
		if err := createInterface(gBridge); err != nil {
			return fmt.Errorf("Error creating bridge: %v\n", err)
		}
		if err := bringUpInterface(gBridge); err != nil {
			return fmt.Errorf("Error bringing up bridge: %v\n", err)
		}
		log.Infof("bridge was created, but it won't persist reboot. Configure rc.conf to persist. See https://docs.freebsd.org/en/books/handbook/advanced-networking/#network-bridging\n")
		log.Infof("It is strongly suggested you move interface %s IP to bridge %s\n", gInterface, gBridge)
	}
	// FIXME: Need to check if not already member
	members, err := getBridgeMembers(gBridge)
	if err != nil {
		return fmt.Errorf("Error getting bridge members: %v\n", err)
	}
	
	// Return if interface already member of the bridge
	for _, m := range members {
		log.Debugf("Bridge member: %s\n", m)
		if strings.EqualFold(m, gInterface) {
			return nil
		}
	}
	if err := addMemberToBridge(gBridge, gInterface); err != nil {
		return fmt.Errorf("Error adding interface to bridge: %v\n", err)
	}

	return nil
}