package raid

import (
	"fmt"
	"os"
	"os/exec"
	"strconv"
	"strings"
)

/*
	mdadm manager

	This script handles the interaction with mdadm
*/

type StorageDeviceMeta struct {
	Name       string
	Size       int64
	RO         bool
	DevType    string
	MountPoint string
}

// List all the storage device in the system, set minSize to 0 for no filter
func (m *Manager) ListAllStorageDevices(minSize int64) ([]*StorageDeviceMeta, error) {
	cmd := exec.Command("sudo", "lsblk", "-b")

	output, err := cmd.CombinedOutput()
	if err != nil {
		return nil, fmt.Errorf("lsblk error: %v", err)
	}

	// Split the output into lines
	lines := strings.Split(string(output), "\n")

	var devices []*StorageDeviceMeta

	// Parse each line to extract device information
	for _, line := range lines[1:] { // Skip the header line
		fields := strings.Fields(line)
		if len(fields) < 7 {
			continue
		}

		size, err := strconv.ParseInt(fields[3], 10, 64)
		if err != nil {
			return nil, fmt.Errorf("error parsing device size: %v", err)
		}

		ro := fields[4] == "1"

		device := &StorageDeviceMeta{
			Name:       fields[0],
			Size:       size,
			RO:         ro,
			DevType:    fields[5],
			MountPoint: fields[6],
		}

		// Filter devices based on minimum size
		if size >= minSize {
			devices = append(devices, device)
		}
	}

	return devices, nil
}

// Return the uuid of the disk by its path name (e.g. /dev/sda)
func (m *Manager) GetDiskUUIDByPath(devicePath string) (string, error) {
	cmd := exec.Command("sudo", "blkid", devicePath)

	output, err := cmd.CombinedOutput()
	if err != nil {
		return "", fmt.Errorf("blkid error: %v", err)
	}

	// Parse the output to extract the UUID
	fields := strings.Fields(string(output))
	for _, field := range fields {
		if strings.HasPrefix(field, "UUID=") {
			uuid := strings.TrimPrefix(field, "UUID=\"")
			uuid = strings.TrimSuffix(uuid, "\"")
			return uuid, nil
		}
	}

	return "", fmt.Errorf("UUID not found for device %s", devicePath)
}

// CreateRAIDDevice creates a RAID device using the mdadm command.
func (m *Manager) CreateRAIDDevice(devName string, raidLevel int, raidDeviceIds []string, spareDeviceIds []string) error {
	//Calculate the size of the raid devices
	raidDev := len(raidDeviceIds)
	spareDevice := len(spareDeviceIds)

	//Validate the number of disk is enough for the raid
	if raidLevel == 0 && raidDev < 2 {
		return fmt.Errorf("not enough disks for raid0")
	} else if raidLevel == 1 && raidDev < 2 {
		return fmt.Errorf("not enough disks for raid1")
	} else if raidLevel == 5 && raidDev < 3 {
		return fmt.Errorf("not enough disk for raid5")
	} else if raidLevel == 6 && raidDev < 4 {
		return fmt.Errorf("not enough disk for raid6")
	}

	// Concatenate RAID and spare device arrays
	allDeviceIds := append(raidDeviceIds, spareDeviceIds...)

	// Build the mdadm command
	cmdArgs := []string{"mdadm", "--create", devName, fmt.Sprintf("--level=%d", raidLevel),
		fmt.Sprintf("--raid-devices=%d", raidDev), fmt.Sprintf("--spare-devices=%d", spareDevice)}
	cmdArgs = append(cmdArgs, allDeviceIds...)

	cmd := exec.Command("sudo", cmdArgs...)

	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	fmt.Println(cmdArgs)
	err := cmd.Run()
	if err != nil {
		return fmt.Errorf("error running mdadm command: %v", err)
	}

	return nil
}

// DANGER: Wipe the whole disk given the disk path
func (m *Manager) WipeDisk(diskPath string) error {
	// Unmount the disk
	isMounted, _ := DeviceIsMounted(diskPath)
	if isMounted {
		umountCmd := exec.Command("sudo", "umount", diskPath)
		if err := umountCmd.Run(); err != nil {
			return fmt.Errorf("error unmounting disk %s: %v", diskPath, err)
		}
	}

	// Wipe all filesystem signatures on each of the partitions
	wipeCmd1 := exec.Command("sudo", "wipefs", "--all", "--force", diskPath+"?")
	if err := wipeCmd1.Run(); err != nil {
		return fmt.Errorf("error wiping filesystem signatures on %s?: %v", diskPath, err)
	}

	// Wipe all filesystem signatures on the entire disk
	wipeCmd2 := exec.Command("sudo", "wipefs", "--all", "--force", diskPath)
	if err := wipeCmd2.Run(); err != nil {
		return fmt.Errorf("error wiping filesystem signatures on %s: %v", diskPath, err)
	}

	return nil
}