package main

import (
	"encoding/json"
	"net/http"
	"path/filepath"

	"imuslab.com/arozos/mod/disk/hybridBackup"

	prout "imuslab.com/arozos/mod/prouter"
)

func backup_init() {
	//Register HybridBackup storage restore endpoints
	router := prout.NewModuleRouter(prout.RouterOption{
		AdminOnly:   false,
		UserHandler: userHandler,
		DeniedHandler: func(w http.ResponseWriter, r *http.Request) {
			sendErrorResponse(w, "Permission Denied")
		},
	})

	//Register API endpoints
	router.HandleFunc("/system/backup/listRestorable", backup_listRestorable)
	router.HandleFunc("/system/backup/restoreFile", backup_restoreSelected)
}

//Restore a given file
func backup_restoreSelected(w http.ResponseWriter, r *http.Request) {
	//Get user accessiable storage pools
	userinfo, err := userHandler.GetUserInfoFromRequest(w, r)
	if err != nil {
		sendErrorResponse(w, "User not logged in")
		return
	}

	//Get Backup disk ID from request
	bdid, err := mv(r, "bdid", true)
	if err != nil {
		sendErrorResponse(w, "Invalid backup disk ID given")
		return
	}

	//Get fsh from the id
	fsh, err := GetFsHandlerByUUID(bdid)
	if err != nil {
		sendErrorResponse(w, err.Error())
		return
	}

	//Get the relative path for the restorable file
	relpath, err := mv(r, "relpath", true)
	if err != nil {
		sendErrorResponse(w, "Invalid relative path given")
		return
	}

	//Handle restore of the file
	err = userinfo.HomeDirectories.HyperBackupManager.HandleRestore(fsh.UUID, relpath)
	if err != nil {
		sendErrorResponse(w, err.Error())
		return
	}

	type RestoreResult struct {
		RestoreDiskID       string
		TargetDiskID        string
		RestoredVirtualPath string
	}

	result := RestoreResult{
		RestoreDiskID: fsh.UUID,
	}

	//Get access path for this file
	parentDiskId, err := userinfo.HomeDirectories.HyperBackupManager.GetParentDiskIDByRestoreDiskID(fsh.UUID)
	if err != nil {
		//Unable to get parent disk ID???

	} else {
		//Get the path of the parent disk
		parentDiskHandler, err := GetFsHandlerByUUID(parentDiskId)
		if err == nil {
			//Join the result to create a virtual path
			assumedRestoreRealPath := filepath.ToSlash(filepath.Join(parentDiskHandler.Path, relpath))
			restoreVpath, err := userinfo.RealPathToVirtualPath(assumedRestoreRealPath)
			if err == nil {
				result.RestoredVirtualPath = restoreVpath
			}
			result.TargetDiskID = parentDiskId
		}

	}

	js, _ := json.Marshal(result)
	sendJSONResponse(w, string(js))
}

//Generate and return a restorable report
func backup_listRestorable(w http.ResponseWriter, r *http.Request) {
	//Get user accessiable storage pools
	userinfo, err := userHandler.GetUserInfoFromRequest(w, r)
	if err != nil {
		sendErrorResponse(w, "User not logged in")
		return
	}

	//Get Vroot ID from request
	vroot, err := mv(r, "vroot", true)
	if err != nil {
		sendErrorResponse(w, "Invalid vroot given")
		return
	}

	//Get fsh from the id
	fsh, err := GetFsHandlerByUUID(vroot)
	if err != nil {
		sendErrorResponse(w, err.Error())
		return
	}

	userBackupManager := userinfo.HomeDirectories.HyperBackupManager

	//Get the user's storage pool and list restorable by the user's storage pool access
	restorableReport, err := userBackupManager.ListRestorable(fsh.UUID)
	if err != nil {
		sendErrorResponse(w, err.Error())
		return
	}

	//Get and check if the parent disk has a user Hierarcy
	paretnfsh, err := GetFsHandlerByUUID(restorableReport.ParentUID)
	if err != nil {
		sendErrorResponse(w, err.Error())
		return
	}

	result := hybridBackup.RestorableReport{
		ParentUID:       restorableReport.ParentUID,
		RestorableFiles: []*hybridBackup.RestorableFile{},
	}

	if paretnfsh.Hierarchy == "user" {
		//The file system is user based. Filter out those file that is not belong to this user
		for _, restorableFile := range restorableReport.RestorableFiles {
			if restorableFile.IsSnapshot {
				//Is snapshot. Always allow access
				result.RestorableFiles = append(result.RestorableFiles, restorableFile)
			} else {
				//Is file
				fileAbsPath := filepath.Join(fsh.Path, restorableFile.RelpathOnDisk)
				_, err := userinfo.RealPathToVirtualPath(fileAbsPath)
				if err != nil {
					//Cannot translate this file. That means the file is not owned by this user
				} else {
					//Can translate the path.
					result.RestorableFiles = append(result.RestorableFiles, restorableFile)
				}
			}

		}
	} else {
		result = restorableReport
	}

	js, _ := json.Marshal(result)
	sendJSONResponse(w, string(js))
}