# Copyright (c) 2020 Ultimaker B.V.
# Cura is released under the terms of the LGPLv3 or higher.
import json
import threading
from datetime import datetime
from typing import Any, Dict, Optional

from PyQt5.QtNetwork import QNetworkReply, QNetworkRequest

from UM.Job import Job
from UM.Logger import Logger
from UM.Message import Message
from UM.TaskManagement.HttpRequestManager import HttpRequestManager
from UM.TaskManagement.HttpRequestScope import JsonDecoratorScope
from UM.i18n import i18nCatalog
from cura.CuraApplication import CuraApplication
from cura.UltimakerCloud.UltimakerCloudScope import UltimakerCloudScope

catalog = i18nCatalog("cura")


class CreateBackupJob(Job):
    """Creates backup zip, requests upload url and uploads the backup file to cloud storage."""

    MESSAGE_TITLE = catalog.i18nc("@info:title", "Backups")
    DEFAULT_UPLOAD_ERROR_MESSAGE = catalog.i18nc("@info:backup_status", "There was an error while uploading your backup.")

    def __init__(self, api_backup_url: str) -> None:
        """ Create a new backup Job. start the job by calling start()

        :param api_backup_url: The url of the 'backups' endpoint of the Cura Drive Api
        """

        super().__init__()

        self._api_backup_url = api_backup_url
        self._json_cloud_scope = JsonDecoratorScope(UltimakerCloudScope(CuraApplication.getInstance()))

        self._backup_zip = None  # type: Optional[bytes]
        self._job_done = threading.Event()
        """Set when the job completes. Does not indicate success."""
        self.backup_upload_error_message = ""
        """After the job completes, an empty string indicates success. Othrerwise, the value is a translated message."""

    def run(self) -> None:
        upload_message = Message(catalog.i18nc("@info:backup_status", "Creating your backup..."), title = self.MESSAGE_TITLE, progress = -1)
        upload_message.show()
        CuraApplication.getInstance().processEvents()
        cura_api = CuraApplication.getInstance().getCuraAPI()
        self._backup_zip, backup_meta_data = cura_api.backups.createBackup()

        if not self._backup_zip or not backup_meta_data:
            self.backup_upload_error_message = catalog.i18nc("@info:backup_status", "There was an error while creating your backup.")
            upload_message.hide()
            return

        upload_message.setText(catalog.i18nc("@info:backup_status", "Uploading your backup..."))
        CuraApplication.getInstance().processEvents()

        # Create an upload entry for the backup.
        timestamp = datetime.now().isoformat()
        backup_meta_data["description"] = "{}.backup.{}.cura.zip".format(timestamp, backup_meta_data["cura_release"])
        self._requestUploadSlot(backup_meta_data, len(self._backup_zip))

        self._job_done.wait()
        if self.backup_upload_error_message == "":
            upload_message.setText(catalog.i18nc("@info:backup_status", "Your backup has finished uploading."))
            upload_message.setProgress(None)  # Hide progress bar
        else:
            # some error occurred. This error is presented to the user by DrivePluginExtension
            upload_message.hide()

    def _requestUploadSlot(self, backup_metadata: Dict[str, Any], backup_size: int) -> None:
        """Request a backup upload slot from the API.

        :param backup_metadata: A dict containing some meta data about the backup.
        :param backup_size: The size of the backup file in bytes.
        """

        payload = json.dumps({"data": {"backup_size": backup_size,
                                       "metadata": backup_metadata
                                       }
                              }).encode()

        HttpRequestManager.getInstance().put(
            self._api_backup_url,
            data = payload,
            callback = self._onUploadSlotCompleted,
            error_callback = self._onUploadSlotCompleted,
            scope = self._json_cloud_scope)

    def _onUploadSlotCompleted(self, reply: QNetworkReply, error: Optional["QNetworkReply.NetworkError"] = None) -> None:
        if error is not None:
            Logger.warning(str(error))
            self.backup_upload_error_message = self.DEFAULT_UPLOAD_ERROR_MESSAGE
            self._job_done.set()
            return
        if reply.attribute(QNetworkRequest.HttpStatusCodeAttribute) >= 300:
            Logger.warning("Could not request backup upload: %s", HttpRequestManager.readText(reply))
            self.backup_upload_error_message = self.DEFAULT_UPLOAD_ERROR_MESSAGE
            self._job_done.set()
            return

        backup_upload_url = HttpRequestManager.readJSON(reply)["data"]["upload_url"]

        # Upload the backup to storage.
        HttpRequestManager.getInstance().put(
            backup_upload_url,
            data=self._backup_zip,
            callback=self._uploadFinishedCallback,
            error_callback=self._uploadFinishedCallback
        )

    def _uploadFinishedCallback(self, reply: QNetworkReply, error: QNetworkReply.NetworkError = None):
        if not HttpRequestManager.replyIndicatesSuccess(reply, error):
            Logger.log("w", "Could not upload backup file: %s", HttpRequestManager.readText(reply))
            self.backup_upload_error_message = self.DEFAULT_UPLOAD_ERROR_MESSAGE

        self._job_done.set()