package cmd

import (
	"fmt"
	"time"
	"regexp"
	"strings"
)

/********************************************************************************
 * List all snapshots jails have
 *******************************************************************************/
func ListJailsSnapshots(args []string) {
	var jailNames []string
	var snapshots []Snapshot
	
	if len(args) > 0 {
		for _, a := range args {
			jailNames = append(jailNames, a)
		}
	} 
	
	if len(jailNames) == 0 || len(args) == 0 {
		for _, j := range gJails {
			snapshots = append(snapshots, listJailSnapshots(j)...)
		}
	} else {
		for _, cj := range gJails {
			for _, jn := range jailNames {
				if strings.EqualFold(cj.Name, jn) {
					snapshots = append(snapshots, listJailSnapshots(cj)...)
				}
			}
		}
	}
	displaySnapshotsFields(snapshots, []string{"Jailname","Name","Creation","Referenced","Used"})
}


/********************************************************************************
 * List all snapshots a jail have
 *******************************************************************************/
func listJailSnapshots(jail Jail) []Snapshot {
	var snapshots []Snapshot
	
	// 1. List all datasets
	// TODO : Include mounted filesystems?
	rs := strings.Split(jail.RootPath, "/")
	rootDataset := fmt.Sprintf("%s%s", jail.Zpool, strings.Join(rs[:len(rs)-1], "/"))
	cmd := fmt.Sprintf("zfs list -r -H -o name,mountpoint,used,referenced,creation -t snapshot %s", rootDataset)
	out, err := executeCommand(cmd)
	if err != nil {
		fmt.Printf("Error: %s\n", err.Error())
		return snapshots
	}
	
	dateLayout := "Mon Jan _2 15:04 2006"
	loc, _ := time.LoadLocation(gTimeZone)
	
	for _, line := range strings.Split(out, "\n") {
		if len(line) > 0 {
			ls := strings.Split(line, "\t")
			// Parse creation date so we can use it to sort snapshots
			creationts, err := time.ParseInLocation(dateLayout, ls[4], loc)
			if err != nil {
				fmt.Println("Error while parsing date %s:", ls[4], err)
				return snapshots
			}
			// Get subdir to append to snapshot name
			subdir := strings.Replace(strings.Split(ls[0], "@")[0], rootDataset, "", 1)
			
			snapshots = append(snapshots, Snapshot{Dsname: ls[0],
				Name: fmt.Sprintf("%s%s", strings.Split(ls[0], "@")[1], subdir),
				Jailname: jail.Name,
				Mountpoint: ls[1],
				Used: ls[2],
				Referenced: ls[3],
				Creation: creationts})
		}
	}
	
	// Sort snapshots by creation date
	ss := initSnapshotSortStruct()
	SnapshotsOrderedBy(ss.CreationInc).Sort(snapshots)
	
	return snapshots
}


/********************************************************************************
 * Create snapshot for jail(s)
 *******************************************************************************/
func CreateJailSnapshot(args []string) {
	var jailNames []string
	
	if len(args) > 0 {
		for _, a := range args {
			jailNames = append(jailNames, a)
		}
	} 
	
	for _, cj := range gJails {
		for _, jn := range jailNames {
			if strings.EqualFold(cj.Name, jn) {
				createJailSnapshot(cj)
			}
		}
	}
}

/********************************************************************************
 * Create snapshot for a jail
 *******************************************************************************/
func createJailSnapshot(jail Jail) error {
	rs := strings.Split(jail.RootPath, "/")
	rootDataset := fmt.Sprintf("%s%s", jail.Zpool, strings.Join(rs[:len(rs)-1], "/"))
	cmd := fmt.Sprintf("zfs snapshot -r %s@%s", rootDataset, gSnapshotName)

	_, err := executeCommand(cmd)
	if err != nil {
		fmt.Printf("Error creating snapshot %s@%s: %s\n", rootDataset, gSnapshotName, err.Error())
		return err
	}
	fmt.Printf("Snapshot %s@%s created\n", rootDataset, gSnapshotName)
	
	return nil
}

/********************************************************************************
 * Delete snapshot for jail(s)
 *******************************************************************************/
func DeleteJailSnapshot(args []string) {
	var jailNames []string
	
	if len(args) > 0 {
		for _, a := range args {
			jailNames = append(jailNames, a)
		}
	} 
	
	for _, cj := range gJails {
		for _, jn := range jailNames {
			if strings.EqualFold(cj.Name, jn) {
				deleteJailSnapshot(cj)
			}
		}
	}
}

/********************************************************************************
 * Delete snapshot for a jail
 *******************************************************************************/
func deleteJailSnapshot(jail Jail) error {
	var snaptodel []string
	
	// Get all recursive snapshots
	rs := strings.Split(jail.RootPath, "/")
	rootDataset := fmt.Sprintf("%s%s", jail.Zpool, strings.Join(rs[:len(rs)-1], "/"))
	cmd := fmt.Sprintf("zfs list -r -H -o name -t snapshot %s", rootDataset)
	out, err := executeCommand(cmd)
	if err != nil {
		fmt.Printf("Error: listing snapshots: %s\n", err.Error())
		return nil
	}
	
	for _, line := range strings.Split(out, "\n") {
		if len(line) > 0 {
			ls := strings.Split(line, "@")
			
			matched, _ := regexp.Match(fmt.Sprintf("^%s(\\/.*)?$", gSnapshotName), []byte(ls[1]))
			if matched {
				snaptodel = append(snaptodel, strings.Join(ls, "@"))
			}
		}
	}
	
	for _, s := range snaptodel {
		cmd := fmt.Sprintf("zfs destroy %s", s)
		_, err := executeCommand(cmd)
		if err != nil {
			fmt.Printf("Error deleting snapshot %s: %s\n", s, err.Error())
			return nil
		}
		fmt.Printf("Snapshot %s deleted\n", s)
	}
	
	return nil
}