package raid

import (
	"encoding/json"
	"log"
	"net/http"
	"path/filepath"
	"strconv"
	"strings"

	"imuslab.com/arozos/mod/utils"
)

/*
	Handler.go

	This module handle api call to the raid module
*/

// List all the raid device in this system
func (m *Manager) HandleListRaidDevices(w http.ResponseWriter, r *http.Request) {
	rdev, err := m.GetRAIDDevicesFromProcMDStat()
	if err != nil {
		utils.SendErrorResponse(w, err.Error())
		return
	}

	js, _ := json.Marshal(rdev)
	utils.SendJSONResponse(w, string(js))
}

// Create a RAID storage pool
func (m *Manager) HandleCreateRAIDDevice(w http.ResponseWriter, r *http.Request) {
	devName, err := utils.GetPara(r, "devName")
	if err != nil {
		utils.SendErrorResponse(w, "invalid device name given")
		return
	}
	raidName, err := utils.GetPara(r, "raidName")
	if err != nil {
		utils.SendErrorResponse(w, "invalid raid storage name given")
		return
	}
	raidLevelStr, err := utils.GetPara(r, "level")
	if err != nil {
		utils.SendErrorResponse(w, "invalid raid level given")
		return
	}

	raidDevicesJSON, err := utils.GetPara(r, "raidDev")
	if err != nil {
		utils.SendErrorResponse(w, "invalid raid device array given")
		return
	}

	spareDevicesJSON, err := utils.GetPara(r, "spareDev")
	if err != nil {
		utils.SendErrorResponse(w, "invalid spare device array given")
		return
	}

	//Convert raidDevices and spareDevices ID into string slice
	raidDevices := []string{}
	spareDevices := []string{}

	err = json.Unmarshal([]byte(raidDevicesJSON), &raidDevices)
	if err != nil {
		utils.SendErrorResponse(w, "unable to parse raid device into array")
		return
	}

	err = json.Unmarshal([]byte(spareDevicesJSON), &spareDevices)
	if err != nil {
		utils.SendErrorResponse(w, "unable to parse spare devices into array")
		return
	}

	//Make sure RAID Name do not contain spaces or werid charcters
	if strings.Contains(raidName, " ") {
		utils.SendErrorResponse(w, "raid name cannot contain space")
		return
	}

	//Convert raidLevel to int
	raidLevel, err := strconv.Atoi(raidLevelStr)
	if err != nil {
		utils.SendErrorResponse(w, "invalid raid level given")
		return
	}

	//Create the RAID device
	err = m.CreateRAIDDevice(devName, raidName, raidLevel, raidDevices, spareDevices)
	if err != nil {
		utils.SendErrorResponse(w, err.Error())
		return
	}

	//Update the mdadm config
	err = m.UpdateMDADMConfig()
	if err != nil {
		utils.SendErrorResponse(w, err.Error())
		return
	}

	utils.SendOK(w)
}

// Request to reload the RAID manager and scan new / fix missing raid pools
func (m *Manager) HandleRaidDevicesAssemble(w http.ResponseWriter, r *http.Request) {
	err := m.RestartRAIDService()
	if err != nil {
		utils.SendErrorResponse(w, err.Error())
		return
	}

	utils.SendOK(w)
}

// Remove a given raid device with its name, USE WITH CAUTION
func (m *Manager) HandleRemoveRaideDevice(w http.ResponseWriter, r *http.Request) {
	//TODO: Add protection and switch to POST
	targetDevice, err := utils.GetPara(r, "dev")
	if err != nil {
		utils.SendErrorResponse(w, "target device not given")
		return
	}

	//Check if the raid device exists
	if !m.RAIDDeviceExists(targetDevice) {
		utils.SendErrorResponse(w, "target device not exists")
		return
	}

	//Get the RAID device memeber disks
	targetRAIDDevice, err := m.GetRAIDDeviceByDevicePath(targetDevice)
	if err != nil {
		utils.SendErrorResponse(w, "error occured when trying to load target RAID device info")
		return
	}

	//Check if it is mounted. If yes, unmount it
	if !strings.HasPrefix("/dev/", targetDevice) {
		targetDevice = filepath.Join("/dev/", targetDevice)
	}

	mounted, err := DeviceIsMounted(targetDevice)
	if err != nil {
		log.Println("[RAID] Unmount failed: " + err.Error())
		utils.SendErrorResponse(w, err.Error())
		return
	}

	if mounted {
		err = UnmountDevice(targetDevice)
		if err != nil {
			log.Println("[RAID] Unmount failed: " + err.Error())
			utils.SendErrorResponse(w, err.Error())
			return
		}
	}

	//Stop & Remove RAID service on the target device
	err = m.StopRAIDDevice(targetDevice)
	if err != nil {
		log.Println("[RAID] Stop RAID partition failed: " + err.Error())
		utils.SendErrorResponse(w, err.Error())
		return
	}

	//Zeroblock the RAID device member disks
	for _, memberDisk := range targetRAIDDevice.Members {
		//Member disk name do not contain full path
		name := memberDisk.Name
		if !strings.HasPrefix(name, "/dev/") {
			name = filepath.Join("/dev/", name)
		}

		err = m.ClearSuperblock(name)
		if err != nil {
			log.Println("[RAID] Unable to clear superblock on device " + name)
			continue
		}
	}

	//Update the mdadm config
	//TODO: Validate this actually works
	err = m.UpdateMDADMConfig()
	if err != nil {
		utils.SendErrorResponse(w, err.Error())
		return
	}

	//Done
	utils.SendOK(w)
}