package cmd

import (
	"os"
	"fmt"
	//"log"
	"sync"
	"errors"
	"regexp"
	"os/exec"
	//"reflect"
	"strconv"
	"strings"
	
	log "github.com/sirupsen/logrus"
)

// TODO : Use SYS_RCTL_GET_RACCT syscall
func removeRctlRules(jail string, rules []string) error {
	var cmd []string

	if len(rules) == 0 {
		rules[0] = ""
	}

	for _, r := range rules {
		if gUseSudo {
			cmd = append(cmd, "sudo")
		}
		cmd = append(cmd, "/usr/bin/rctl")
		cmd = append(cmd, "-r")
		cmd = append(cmd, fmt.Sprintf("jail:%s:%s", jail, r))

		// TODO : Log in another channel than stdout (will scramble display)
		//log.Println(fmt.Sprintf("Removing all rules for jail %s: %s", jail, cmd))

		//out, err := exec.Command(cmd[0], cmd[1:]...).Output()
		_, err := exec.Command(cmd[0], cmd[1:]...).Output()
		return err
	}

	return nil
}

// TODO: Validate with  >1 dataset
func umountAndUnjailZFS(jail *Jail) error {
	var ds []string

	// Make sure we have a string array
	ds = append(ds, jail.Config.Jail_zfs_dataset)

	for _, zd := range ds {
		// 1. Get dataset and childs
		cmd := fmt.Sprintf("zfs list -H -r -o name -S name %s", zd)
		out, err := executeCommand(cmd)
		if err != nil {
			fmt.Printf(fmt.Sprintf("ERROR listing dataset %s\n", zd))
			os.Exit(1)
		}
		for _, c := range strings.Split(out, "\n") {
			if len(c) == 0 {
				continue
			}
			fmt.Printf("Unmounting dataset %s: ", c)
			cmd := fmt.Sprintf("zfs umount %s", c)
			_, err := executeCommandInJail(jail, cmd)
			if err != nil {
				return err
			}
			fmt.Printf("OK\n")
		}
	}

	// 2. Unjail dataset from the host
	cmd := fmt.Sprintf("zfs unjail %s %s", jail.InternalName, ds[len(ds)-1])
	_, err := executeCommand(cmd)
	if err != nil {
		fmt.Printf("ERROR unjailing %s: %s\n", ds[len(ds)-1], err.Error())
		return err
	}

	return nil
}

func destroyVNetInterfaces(jail *Jail) error {
	for _, i := range strings.Split(jail.Config.Ip4_addr, ",") {
		iname := fmt.Sprintf("%s.%d", strings.Split(i, "|")[0], jail.JID)
		fmt.Printf("%s: ", iname)
		_, err := executeCommand(fmt.Sprintf("ifconfig %s destroy", iname))
		//_, err := executeScript(fmt.Sprintf("ifconfig %s destroy >/dev/null 2>&1", iname))
		if err != nil {
			return err
		} else {
			fmt.Printf("OK\n")
		}
	}

	return nil
}

// Jails copy the ruleset referenced as "devfs_ruleset" when starting, getting a new devsf_ruleset ID.
// This new ID can be obtained with 'jls -j $JID devfs_ruleset'
// This is the ID which needs to be removed. Original ID referenced is json should not be deleted
//  or else it will require a restart of "devfs" service.
// But, stoppign the jail already removes this >1000 ID.
// So no need to call this function.
func deleteDevfsRuleset(ruleset int) error {
	cmd := "devfs rule showsets"
	out, err := executeCommand(cmd)
	if err != nil {
		return errors.New(fmt.Sprintf("ERROR listing rulesets: %s", err.Error()))
	}
	
	rs := strconv.Itoa(ruleset)
	for _, r := range strings.Split(out, "\n") {
		if r == rs {
			cmd := fmt.Sprintf("devfs rule -s %d delset", ruleset)
			_, err := executeCommand(cmd)
			return err
		}
	}

	return nil
}

func umountJailFsFromHost(jail *Jail, mountpoint string) error {
	cmd := "mount -p"
	out, err := executeCommand(cmd)
	if err != nil {
		return errors.New(fmt.Sprintf("Error executing mount: %s", err.Error()))
	}

	remSpPtrn := regexp.MustCompile(`\s+`)
	for _, l := range strings.Split(out, "\n") {
		f := strings.Split(remSpPtrn.ReplaceAllString(l, " "), " ")
		if len(f) > 2 {
			if strings.EqualFold(f[1], fmt.Sprintf("%s%s", jail.RootPath, mountpoint)) {
				cmd = fmt.Sprintf("umount %s%s", jail.RootPath, mountpoint)
				_, err := executeCommand(cmd)
				if err != nil {
					return errors.New(fmt.Sprintf("Error umounting %s%s: %s", jail.RootPath, mountpoint, err.Error()))
				}
				return nil
			}
		}
	}

	return nil
}

// Internal usage only
func stopJail(jail *Jail) error {
	cmd := "jail -q"

	// Test if conf file exist (iocage created)
	cf := fmt.Sprintf("/var/run/jail.%s.conf", jail.InternalName)
	file, err := os.Open(cf)
	if err != nil {
		file.Close()
		cmd = fmt.Sprintf("%s -f %s", cmd, cf)
	}
	cmd = fmt.Sprintf("%s -r %s", cmd, jail.InternalName)

	_, err = executeCommand(cmd)
	if err != nil {
		return err
	}

	return nil
}

// Stop all running jails by reverse priority
// Parallelize up to gMaxThreads
// Only parallelize same priority level jails
func StopAllRunningJails() {
	var stopList []Jail
	var wg *sync.WaitGroup
	var curThNb int
	var curPri int
	
	// Get boot enabled jails
	for _, j := range gJails {
		if j.Running == true {
			stopList = append(stopList, j)
		}
	}
	
	// Order by priority
	js := initJailSortStruct()
	fct, _, err := getStructFieldValue(js, "Config.PriorityDec")
	if err != nil {
		log.Errorf("ERROR getting JailSort struct field \"Config.PriorityDec\"\n")
		return
	}
	JailsOrderedBy(fct.Interface().(jailLessFunc)).Sort(stopList)


	wg = new(sync.WaitGroup)
	curThNb = 0
	for i, j := range stopList {
		jFullName := fmt.Sprintf("%s/%s", j.Datastore, j.Name)
		log.Debugf("Stopping %s with priority %s\n", jFullName, j.Config.Priority)
		jailPri, err := strconv.Atoi(j.Config.Priority)
		if err != nil {
			panic(fmt.Sprintf("Invalid format for Priority (Jail %s)\n", jFullName))
		}

		if (curThNb >= gMaxThreads || i == 0) {
			// FIXME : Use a pool instead of waiting for all threads to run a new one
			wg.Wait()
			curThNb = 0
			
			wg.Add(1)
			curThNb++
			curPri = jailPri
			go func(jailFullName string) {
				defer wg.Done()
				StopJail([]string{jailFullName})
			}(jFullName)
		} else {
			if (curPri == jailPri) {
				wg.Add(1)
				curThNb++
				go func(jailFullName string) {
					defer wg.Done()
					StopJail([]string{jailFullName})
				}(jFullName)
			} else {
				wg.Wait()
				curThNb = 0
			
				wg.Add(1)
				curThNb++
				curPri = jailPri
				go func(jailFullName string) {
					defer wg.Done()
					StopJail([]string{jailFullName})
				}(jFullName)
			}
		}
	}
	wg.Wait()
}

/*
	Stop jail:
		Remove rctl rules
		Execute prestop if set (jailhost perimeter)
		Execute stop if set (inside jail)
		Umount ZFS dataset from inside jail
		Unjail ZFS dataset from jailhost
		If VNet
			Delete VNet interface on host
		Delete devfs ruleset
		Effectively stop jail process
		Umount all mountpoints from $jail/fstab
		Umount proc if set
		Umount linprocfs if set
		Umount fdescfs if set
		Umount devfs if set

	Use setfib for each command

	Shouldnt rctl rules be removed last, when jail is stopped?
*/
func StopJail(args []string) {
	// Current jail were stopping
	var cj *Jail
	var err error

	for _, a := range args {
		// Check if jail exist and is distinctly named
		cj, err = getJailFromArray(a, []string{"jail"}, gJails)
		if err != nil {
			fmt.Printf("Error getting jail: %s\n", err)
			continue
		}

		if cj.Running == false {
			fmt.Printf("Jail %s is not running!\n", cj.Name)
			continue
		}

		fmt.Printf("> Stopping jail %s\n", cj.Name)

		// Get and write new release into config.json
		updateVersion(cj)

		out, err := executeCommand(fmt.Sprintf("rctl jail:%s", cj.InternalName))
		if err == nil && len(out) > 0 {
			fmt.Printf("  > Remove RCTL rules:\n")
			err := removeRctlRules(cj.InternalName, []string{""})
			if err != nil {
				fmt.Printf("ERROR: %s\n", err.Error())
			} else {
				fmt.Printf("  > Remove RCTL rules: OK\n")
			}
		}

		if len(cj.Config.Exec_prestop) > 0 {
			fmt.Printf("  > Execute pre-stop:\n")
			_, err := executeCommand(cj.Config.Exec_prestop)
			if err != nil {
				fmt.Printf("ERROR: %s\n", err.Error())
			} else {
				fmt.Printf("  > Execute pre-stop: OK\n")
			}
		}

		if len(cj.Config.Exec_stop) > 0 {
			fmt.Printf("  > Execute stop:\n")
			_, err := executeCommandInJail(cj, cj.Config.Exec_stop)
			if err != nil {
				fmt.Printf("ERROR: %s\n", err.Error())
			} else {
				fmt.Printf("  > Execute stop: OK\n")
			}
		}

		if cj.Config.Jail_zfs > 0 {
			fmt.Printf("  > Umount jailed ZFS:\n")
			err := umountAndUnjailZFS(cj)
			if err != nil {
				fmt.Printf("ERROR: %s\n", err.Error())
			} else {
				fmt.Printf("  > Umount jailed ZFS: OK\n")
			}
		}

		if cj.Config.Vnet > 0 && len(cj.Config.Ip4_addr) > 0 {
			fmt.Printf("  > Destroy VNet interfaces:\n")
			err := destroyVNetInterfaces(cj)
			if err != nil {
				fmt.Printf("ERROR: %s\n", err.Error())
			} else {
				fmt.Printf("  > Destroy VNet interfaces: OK\n")
			}
		}

		fmt.Printf("  > Remove devfs ruleset %d: \n", cj.Devfs_ruleset)
		err = deleteDevfsRuleset(cj.Devfs_ruleset)
		if err != nil {
			fmt.Printf("ERROR: %s\n", err.Error())
		} else {
			fmt.Printf("  > Remove devfsruleset %d: OK\n", cj.Devfs_ruleset)
		}

		fmt.Printf("  > Stop jail %s:\n", cj.Name)
		err = stopJail(cj)
		if err != nil {
			fmt.Printf("ERROR: %s\n", err.Error())
		} else {
			fmt.Printf("  > Stop jail %s: OK\n", cj.Name)
		}

		if cj.Config.Mount_procfs > 0 {
			fmt.Printf("  > Umount procfs:\n")
			err := umountJailFsFromHost(cj, "/proc")
			if err != nil {
				fmt.Printf("ERROR: %s\n", err.Error())
			} else {
				fmt.Printf("  > Umount procfs: OK\n")
			}
		}

		if cj.Config.Mount_linprocfs > 0 {
			fmt.Printf("  > Umount linprocfs:\n")
			err := umountJailFsFromHost(cj, "/compat/linux/proc")
			if err != nil {
				fmt.Printf("ERROR: %s\n", err.Error())
			} else {
				fmt.Printf("  > Umount linprocfs: OK\n")
			}
		}

		// FIXME: /dev/fd is mounted even with Mount_fdescfs = 0 ?!
		//if cj.Config.Mount_fdescfs > 0 {
			fmt.Printf("  > Umount fdescfs:\n")
			err = umountJailFsFromHost(cj, "/dev/fd")
			if err != nil {
				fmt.Printf("ERROR: %s\n", err.Error())
			} else {
				fmt.Printf("  > Umount fdescfs: OK\n")
			}
		//}

		if cj.Config.Mount_devfs > 0 {
			fmt.Printf("  > Umount devfs:\n")
			err := umountJailFsFromHost(cj, "/dev")
			if err != nil {
				fmt.Printf("ERROR: %s\n", err.Error())
			} else {
				fmt.Printf("  > Umount devfs: OK\n")
			}
		}

		// Remove local mounts from $JAIL/fstab
		fstab := strings.Replace(cj.ConfigPath, "config.json", "fstab", 1)
		mounts, err := getFstab(fstab)
		if err != nil {
			fmt.Printf("ERROR: %s\n", err.Error())
		}
		if len(mounts) > 0 {
			fmt.Printf("  > Umount mountpoints from %s\n", fstab)
			errs := 0
			for _, m := range mounts {
				err = umountJailFsFromHost(cj, m.Mountpoint)
				if err != nil {
					fmt.Printf("ERROR: %s\n", err.Error())
					errs += 1
				}
			}
			if errs == 0 {
				fmt.Printf("  > Umount mountpoints from %s: OK\n", fstab)
			}
		}

		// TODO: Execute poststop
		if len(cj.Config.Exec_poststop) > 0 {
			fmt.Printf("  > Execute post-stop:\n")
			_, err := executeCommand(cj.Config.Exec_poststop)
			if err != nil {
				fmt.Printf("ERROR: %s\n", err.Error())
			} else {
				fmt.Printf("  > Execute post-stop: OK\n")
			}
		}

		// Remove parameter file
		pfile := fmt.Sprintf("/var/run/jail.%s.conf", cj.InternalName)
		if err = os.Remove(pfile); err != nil {
			fmt.Printf("Error deleting parameter file %s\n", pfile)
		}

		// We need this to get a reference to cj.Running (bc cj.Running is just a copy of value in the scope of StopJail())
		for i, j := range gJails {
			if strings.EqualFold(j.Name, cj.Name) && strings.EqualFold(j.Datastore, cj.Datastore) {
				if err = setStructFieldValue(&gJails[i], "Running", "false"); err != nil {
					fmt.Printf("ERROR: setting Running property to false: %s\n", err.Error())
				}
				if err = setStructFieldValue(&gJails[i], "JID", "0"); err != nil {
					fmt.Printf("ERROR: setting JID property to 0: %s\n", err.Error())
				}
				if err = setStructFieldValue(&gJails[i], "InternalName", ""); err != nil {
					fmt.Printf("ERROR: clearing InternalName property: %s\n", err.Error())
				}
				if err = setStructFieldValue(&gJails[i], "Devfs_ruleset", "0"); err != nil {
					fmt.Printf("ERROR: setting Devfs_ruleset property to 0: %s\n", err.Error())
				}
			}
		}
		writeConfigToDisk(cj, false)

	}
}