background.js

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/
 *
 * © 2022 Roy Orbison
 * */

const commandGtrash = 'gtrash';
const folderTypeTrash = 'trash';
const tabTypeMessage = 'messageDisplay';
const tabTypeMail = 'mail';

messenger.commands.onCommand.addListener(async function(command) {
	if (command === commandGtrash) {
		moveSelectedToTrash();
	}
});

messenger.messageDisplayAction.onClicked.addListener(async function(tab, info) {
	moveSelectedToTrash(tab);
});

async function moveSelectedToTrash(tab) {
	try {
		let messageList,
			synthesiseMessageList = false,
			ownTab = false,
			moves = {};

		if (tab) {
			synthesiseMessageList = true;
		}
		else {
			try {
				messageList = await messenger.mailTabs.getSelectedMessages();
			}
			catch (error) {
				let tabs = await messenger.tabs.query({
						active: true,
						currentWindow: true
					}),
					displayed;
				if (
					tabs?.length
					&& (tab = tabs[0])
				) {
					ownTab = synthesiseMessageList = true;
				}
				else {
					throw error;
				}
			}
		}
		if (synthesiseMessageList) {
			let allowedTabTypes = [
				tabTypeMessage
			];
			if (!ownTab) {
				allowedTabTypes.push(tabTypeMail);
			}
			if (
				tab.id !== messenger.tabs.TAB_ID_NONE
				&& allowedTabTypes.includes(tab.type)
				&& (displayed = await messenger.messageDisplay.getDisplayedMessage(tab.id))
			) {
				messageList = {
					messages: [
						displayed
					]
				};
			}
			else {
				throw error;
			}
		}

		do {
			if (messageList?.messages?.length) {
				for (let messageHeader of messageList.messages) {
					// queue up moves, ignoring messages already in trash
					if (messageHeader.folder && messageHeader.folder.type !== folderTypeTrash) {
						if (!moves[messageHeader.folder.accountId]) {
							moves[messageHeader.folder.accountId] = {
								ids: []
							};
						}
						moves[messageHeader.folder.accountId].ids.push(messageHeader.id);
					}
				}
				for (let accountId in moves) {
					if (moves[accountId].trash === undefined) {
						moves[accountId].trash = null;
						let account = await messenger.accounts.get(accountId);
						if (!account?.folders?.length) {
							continue;
						}
						findTrash: for (let folder of account.folders) {
							// in case user set special as IMAP dir
							if (folder.type === folderTypeTrash) {
								moves[accountId].trash = folder;
								break findTrash;
							}
							// otherwise look in special, folders named like "[Gmail]" and "[Googlemail]"
							if (/^\[[^\/]+\]$/.test(folder.name)) {
								for (let subFolder of folder.subFolders) {
									if (subFolder.type === folderTypeTrash) {
										moves[accountId].trash = subFolder;
										break findTrash;
									}
								}
							}
						}
					}
					if (moves[accountId].trash || moves[accountId].ids.length) {
						await messenger.messages.move(moves[accountId].ids, moves[accountId].trash);
						moves[accountId].ids = [];
						if (ownTab) {
							messenger.tabs.remove(tab.id);
						}
					}
				}
			}
		} while (
			messageList.id
			&& (messageList = await messenger.messages.continueList(messageList.id))
		);
	}
	catch (error) {
	}
}