import uuid, { createSecureRandom } from '@joplin/lib/uuid';
import { ActionableClient, FuzzContext, HttpMethod, Json, RandomFolderOptions, RandomNoteOptions, ShareOptions } from '../types';
import { assertIsNote, assertIsNoteData, FolderData, ItemId, NoteData, ResourceData } from '../model/types';
import { join } from 'path';
import { copy, exists, mkdir, remove } from 'fs-extra';
import getStringProperty from '../utils/getStringProperty';
import { strict as assert } from 'assert';
import ClipperServer from '@joplin/lib/ClipperServer';
import ActionTracker from '../model/ActionTracker';
import Logger from '@joplin/utils/Logger';
import { cliDirectory } from '../constants';
import { commandToString } from '@joplin/utils';
import { quotePath } from '@joplin/utils/path';
import getNumberProperty from '../utils/getNumberProperty';
import retryWithCount from '../utils/retryWithCount';
import resolvePathWithinDir from '@joplin/lib/utils/resolvePathWithinDir';
import { formatMsToDateTimeLocal, msleep, Second } from '@joplin/utils/time';
import { spawn } from 'child_process';
import AsyncActionQueue from '@joplin/lib/AsyncActionQueue';
import { createInterface } from 'readline/promises';
import Stream = require('stream');
import ProgressBar from '../utils/ProgressBar';
import getDiffDebugMessage from '../utils/getBinaryDiffDebugMessage';
import { NoteEntity } from '@joplin/lib/services/database/types';
import diffSortedStringArrays from '../utils/diffSortedStringArrays';
import extractResourceIds from '../utils/extractResourceIds';
import { substrWithEllipsis } from '@joplin/lib/string-utils';
import hangingIndent from '../utils/hangingIndent';
import { readFile, writeFile } from 'fs/promises';
import { hasOwnProperty } from '@joplin/utils/object';
import removeInvalidUtf8 from '../utils/removeInvalidUtf8';

const logger = Logger.create('Client');

type AccountData = Readonly<{
	email: string;
	password: string;
	userId: string;
	e2eePassword: string|null;
	associatedClientCount: number;
	onClientConnected: ()=> void;
	onClientDisconnected: ()=> Promise<void>;
}>;

// Don't generate passwords starting with '-'. Such passwords can
// be interpreted as command arguments if sent to the CLI app via
// the command line.
const createPassword = () => createSecureRandom().replace(/^-/, '_');

const emailPrefix = 'fuzzer-user-';

const loadAccountAndResetPassword = async (
	userId: string,
	e2eePassword: string|null,
	context: FuzzContext,
): Promise<AccountData> => {
	const userRoute = `api/users/${encodeURIComponent(userId)}`;
	const response = await context.execApi('GET', userRoute, undefined);

	if (typeof response !== 'object' || !hasOwnProperty(response, 'email')) {
		throw new Error(`Failed to look up the email for user ${userId}`);
	}
	// The fuzzer can do things like delete accounts.
	// Do an extra check to make sure that we're working with an account created by the fuzzer:
	if (typeof response.email !== 'string' || !response.email.startsWith(emailPrefix)) {
		throw new Error(`Invalid email: ${JSON.stringify(response.email)} (should start with "${emailPrefix}")`);
	}

	const email = response.email;

	// The password needs to be set *after* creating the user.
	const password = createPassword();
	await context.execApi('PATCH', userRoute, {
		email,
		password,
		email_confirmed: 1,
	});

	const closeAccount = async () => {
		await context.execApi('DELETE', userRoute, {});
	};

	let referenceCounter = 0;
	return {
		email,
		password,
		e2eePassword,
		userId: userId,
		get associatedClientCount() {
			return referenceCounter;
		},
		onClientConnected: () => {
			referenceCounter++;
		},
		onClientDisconnected: async () => {
			referenceCounter --;
			assert.ok(referenceCounter >= 0, 'reference counter should be non-negative');
			if (referenceCounter === 0 && !context.keepAccounts) {
				await closeAccount();
			}
		},
	};
};

const createNewAccount = async (email: string, context: FuzzContext): Promise<AccountData> => {
	const apiOutput = await context.execApi('POST', 'api/users', {
		email,
		full_name: `Fuzzer user from ${formatMsToDateTimeLocal(Date.now())}`,
	});
	const userId = getStringProperty(apiOutput, 'id');

	const e2eePassword = context.enableE2ee ? createPassword() : null;
	return loadAccountAndResetPassword(userId, e2eePassword, context);
};

type ApiData = Readonly<{
	port: number;
	token: string;
}>;

type OnCloseListener = ()=> void;

type ChildProcessWrapper = {
	stdout: Stream.Readable;
	stderr: Stream.Readable;
	writeStdin: (data: Buffer|string)=> void;
	close: ()=> void;
	onClosed: (eventHandler: OnCloseListener)=> void;
};

// Should match the prompt used by the CLI "batch" command.
const cliProcessPromptString = 'command> ';

interface CreateOrUpdateOptions {
	quiet?: boolean;
	message?: string;
}

interface CreateRandomItemOptions extends CreateOrUpdateOptions {
	parentId: ItemId;
	id?: ItemId;
	quiet?: boolean;
}

interface CreateRandomFolderOptions extends CreateRandomItemOptions {
	title?: string;
}

interface CreateOrUpdateManyOptions {
	createProbability: number;
	updateProbability: number;
	deleteProbability: number;
}

class ApiResponseError extends Error {
	public constructor(public readonly code: number, message: string) {
		super(message);
	}
}

class Client implements ActionableClient {
	public readonly email: string;

	public static async create(actionTracker: ActionTracker, context: FuzzContext) {
		const account = await createNewAccount(`${emailPrefix}${uuid.createNano()}@localhost`, context);

		try {
			const client = await this.fromAccount(account, actionTracker, context);
			return client;
		} catch (error) {
			logger.error('Error creating client:', error);
			await account.onClientDisconnected();
			throw error;
		}
	}

	private static async buildClipperConfig_() {
		const apiData: ApiData = {
			token: createSecureRandom().replace(/[-]/g, '_'),
			port: await ClipperServer.instance().findAvailablePort(),
		};
		return apiData;
	}

	private static async fromAccount(account: AccountData, actionTracker: ActionTracker, context: FuzzContext) {
		const id = context.randomId();
		const profileDirectory = join(context.baseDir, id);
		await mkdir(profileDirectory);

		const apiData = await this.buildClipperConfig_();

		const client = new Client(
			context,
			actionTracker,
			actionTracker.track({ email: account.email }),
			account,
			profileDirectory,
			apiData,
			`${account.email}${account.associatedClientCount ? ` (${account.associatedClientCount})` : ''}`,
		);

		account.onClientConnected();

		await client.setInitialSettings_();

		if (account.e2eePassword) {
			await client.execCliCommand_('e2ee', 'enable', '--password', account.e2eePassword);
		}
		logger.info('Created and configured client');

		await client.startClipperServer_();
		return client;
	}

	public static async fromSnapshotDirectory(
		path: string,
		actionTracker: ActionTracker,
		context: FuzzContext,

		// A map from client IDs to client accounts. Use this to ensure that
		// only one AccountData reference exists for each account:
		userIdToAccount: Map<string, Promise<AccountData>>,
	) {
		logger.info('Reading client from snapshot', path, '...');

		const { userId, e2eePassword } = JSON.parse(await readFile(join(path, 'info.json'), 'utf-8'));

		const getAccount = () => {
			// Reuse the existing account promise if possible this:
			// 1. Avoids resetting the password multiple times for the same account.
			// 2. Avoids closing the account multiple times when exiting the fuzzer.
			// 3. Caching promises, rather than the final account object, helps avoid race conditions.
			let accountPromise = userIdToAccount.get(userId);
			// Reset the account password to simplify re-authentication.
			accountPromise ??= loadAccountAndResetPassword(userId, e2eePassword, context);
			userIdToAccount.set(userId, accountPromise);

			return accountPromise;
		};

		const account = await getAccount();

		const profileDirectory = join(context.baseDir, uuid.createNano());
		await copy(path, profileDirectory);

		const apiData = await this.buildClipperConfig_();

		const client = new Client(
			context,
			actionTracker,
			actionTracker.track({ email: account.email }),
			account,
			profileDirectory,
			apiData,
			`${account.email}${account.associatedClientCount ? ` (${account.associatedClientCount})` : ''}`,
		);

		account.onClientConnected();

		await client.setInitialSettings_();

		logger.info('Created and configured client in', profileDirectory);

		await client.startClipperServer_();
		return client;
	}

	private onCloseListeners_: OnCloseListener[] = [];

	private childProcess_: ChildProcessWrapper;
	private childProcessQueue_ = new AsyncActionQueue();
	private bufferedChildProcessStdout_: string[] = [];
	private bufferedChildProcessStderr_: string[] = [];
	private onChildProcessOutput_: ()=> void = ()=>{};

	private transcript_: string[] = [];
	private static isFirstClient_ = true;

	private constructor(
		private readonly context_: FuzzContext,
		private readonly globalActionTracker_: ActionTracker,
		private readonly tracker_: ActionableClient,
		private readonly account_: AccountData,
		private readonly profileDirectory: string,
		private readonly apiData_: ApiData,
		private readonly clientLabel_: string,
	) {
		this.email = account_.email;

		// Don't skip child process-related tasks.
		this.childProcessQueue_.setCanSkipTaskHandler(() => false);

		// For faster startup, don't rebuild the CLI app for every new client:
		const rebuildCliApp = Client.isFirstClient_;
		Client.isFirstClient_ = false;

		const initializeChildProcess = () => {
			const rawChildProcess = spawn('yarn', [
				...this.cliCommandArguments(rebuildCliApp),
				'batch',
				'--continue-on-failure',
				'-',
			], {
				cwd: cliDirectory,
			});
			rawChildProcess.stdout.on('data', (chunk: Buffer) => {
				const chunkString = chunk.toString('utf-8');
				this.transcript_.push(chunkString);

				this.bufferedChildProcessStdout_.push(chunkString);
				this.onChildProcessOutput_();
			});
			rawChildProcess.stderr.on('data', (chunk: Buffer) => {
				const chunkString = chunk.toString('utf-8');
				logger.warn('Child process', this.label, 'stderr:', chunkString);

				this.transcript_.push(chunkString);
				this.bufferedChildProcessStderr_.push(chunkString);
				this.onChildProcessOutput_();
			});

			this.childProcess_ = {
				writeStdin: (data: Buffer|string) => {
					this.transcript_.push(data.toString());
					rawChildProcess.stdin.write(data);
				},
				stderr: rawChildProcess.stderr,
				stdout: rawChildProcess.stdout,
				onClosed: (eventHandler) => {
					rawChildProcess.once('close', eventHandler);
				},
				close: () => {
					rawChildProcess.stdin.destroy();
					rawChildProcess.kill();
				},
			};
		};
		initializeChildProcess();
	}

	public async saveSnapshot(outputDirectory: string) {
		assert.ok(await exists(outputDirectory));
		await copy(this.profileDirectory, outputDirectory);

		await writeFile(
			join(outputDirectory, 'info.json'),
			JSON.stringify({
				userId: this.account_.userId,
				email: this.account_.email,
				e2eePassword: this.account_.e2eePassword,
			}),
			'utf-8',
		);
	}

	private async setInitialSettings_() {
		// Joplin Server sync
		const targetId = this.context_.isJoplinCloud ? '10' : '9';
		await this.execCliCommand_('config', 'sync.target', targetId);
		await this.execCliCommand_('config', `sync.${targetId}.path`, this.context_.serverUrl);
		await this.execCliCommand_('config', `sync.${targetId}.username`, this.account_.email);
		await this.execCliCommand_('config', `sync.${targetId}.password`, this.account_.password);
		// userContentPath only applies to Joplin Cloud:
		await this.execCliCommand_('config', 'sync.10.userContentPath', this.context_.serverUrl);

		await this.execCliCommand_('config', 'api.token', this.apiData_.token);
		await this.execCliCommand_('config', 'api.port', String(this.apiData_.port));
	}

	private async startClipperServer_() {
		await this.execCliCommand_('server', '--quiet', '--exit-early', 'start');

		// Wait for the server to start
		await retryWithCount(async () => {
			await this.execApiCommand_('GET', '/ping');
		}, {
			count: 3,
			onFail: async () => {
				await msleep(1000);
			},
		});
	}

	private closed_ = false;
	public async close() {
		if (this.closed_) {
			// This can happen if:
			// - Multiple cleanup callbacks are registered for the client.
			// - The client was manually closed, but also has a cleanup callback registered.
			logger.info('Client', this.clientLabel_, 'already closed. Skipping.');
			return;
		}

		assert.ok(!this.closed_, 'should not be closed');

		await this.account_.onClientDisconnected();

		for (const listener of this.onCloseListeners_) {
			listener();
		}

		// Before removing the profile directory, verify that the profile directory is in the
		// expected location:
		const profileDirectory = resolvePathWithinDir(this.context_.baseDir, this.profileDirectory);
		assert.ok(profileDirectory, 'profile directory for client should be contained within the main temporary profiles directory (should be safe to delete)');
		this.childProcess_.onClosed(async () => {
			try {
				await remove(profileDirectory);
				logger.info('Removed profile directory', profileDirectory);
			} catch (error) {
				logger.error('Failed to remove profile directory', profileDirectory);
			}
		});

		this.childProcess_.close();

		this.closed_ = true;
		logger.info('Closed client ', this.email);
	}

	public onClose(listener: OnCloseListener) {
		this.onCloseListeners_.push(listener);
	}

	public async createClientOnSameAccount() {
		return await Client.fromAccount(this.account_, this.globalActionTracker_, this.context_);
	}

	public hasSameAccount(other: Client) {
		return other.account_ === this.account_;
	}

	public get label() {
		return this.clientLabel_;
	}

	private cliCommandArguments(build: boolean) {
		return [
			build ? 'start' : 'start-no-build',
			'--profile', this.profileDirectory,
			'--env', 'dev',
		];
	}

	public getHelpText() {
		return [
			`Client ${this.label}:`,
			`\tCommand: cd ${quotePath(cliDirectory)} && ${commandToString('yarn', this.cliCommandArguments(true))}`,
		].join('\n');
	}

	public getTranscript() {
		const lines = this.transcript_.join('').split('\n');
		return (
			lines
				// indent, for readability
				.map(line => `  ${line}`)
				// Since the server could still be running if the user posts the log, don't including
				// web clipper tokens in the output:
				.map(line => line.replace(/token=[a-z0-9A-Z_]+/g, 'token=*****'))
				// Don't include the sync password in the output
				.map(line => line.replace(/(config "(sync.9.password|api.token)") ".*"/, '$1 "****"'))
				.join('\n')
		);
	}

	// Connects the child process to the main terminal interface.
	// Useful for debugging.
	public async startCliDebugSession() {
		this.childProcessQueue_.push(async () => {
			this.onChildProcessOutput_ = () => {
				process.stdout.write(this.bufferedChildProcessStdout_.join('\n'));
				process.stderr.write(this.bufferedChildProcessStderr_.join('\n'));
				this.bufferedChildProcessStdout_ = [];
				this.bufferedChildProcessStderr_ = [];
			};
			this.bufferedChildProcessStdout_ = [];
			this.bufferedChildProcessStderr_ = [];
			process.stdout.write('CLI debug session. Enter a blank line or "exit" to exit.\n');
			process.stdout.write('To review a transcript of all interactions with this client,\n');
			process.stdout.write('enter "[transcript]". To log information about a particular item\n');
			process.stdout.write('enter "[item:...id here...]".\n\n');
			process.stdout.write(cliProcessPromptString);

			const isExitRequest = (input: string) => {
				return input === 'exit' || input === '';
			};

			// Per https://github.com/nodejs/node/issues/32291, we can't pipe process.stdin
			// to childProcess_.stdin without causing issues. Forward using readline instead:
			const readline = createInterface({ input: process.stdin, output: process.stdout });
			let lastInput = '';
			do {
				lastInput = await readline.question('');
				if (lastInput === '[transcript]') {
					process.stdout.write(`\n\n# Transcript\n\n${this.getTranscript()}\n\n# End transcript\n\n`);
				} else if (lastInput.startsWith('[item:') && lastInput.endsWith(']')) {
					let id = lastInput.substring('[item:'.length);
					id = id.substring(0, id.length - 1);
					this.globalActionTracker_.printActionLog(id);
				} else if (!isExitRequest(lastInput)) {
					this.childProcess_.writeStdin(`${lastInput}\n`);
				}
			} while (!isExitRequest(lastInput));

			this.onChildProcessOutput_ = () => {};
			readline.close();
		});
		await this.childProcessQueue_.processAllNow();
	}

	private async execCliCommand_(commandName: string, ...args: string[]) {
		assert.match(commandName, /^[a-z]/, 'Command name must start with a lowercase letter.');
		let commandStdout = '';
		let commandStderr = '';
		this.childProcessQueue_.push(() => {
			return new Promise<void>(resolve => {
				this.onChildProcessOutput_ = () => {
					const lines = this.bufferedChildProcessStdout_.join('\n').split('\n');
					const promptIndex = lines.lastIndexOf(cliProcessPromptString);

					if (promptIndex >= 0) {
						commandStdout = lines.slice(0, promptIndex).join('\n');
						commandStderr = this.bufferedChildProcessStderr_.join('\n');

						resolve();
					} else {
						logger.debug('waiting...');
					}
				};
				this.bufferedChildProcessStdout_ = [];
				this.bufferedChildProcessStderr_ = [];
				const command = `${[commandName, ...args.map(arg => JSON.stringify(arg))].join(' ')}\n`;
				logger.debug('exec', command);
				this.childProcess_.writeStdin(command);
			});
		});
		await this.childProcessQueue_.processAllNow();
		return {
			stdout: commandStdout,
			stderr: commandStderr,
		};
	}

	// eslint-disable-next-line no-dupe-class-members -- This is not a duplicate class member
	private async execApiCommand_(method: 'GET', route: string): Promise<string>;
	// eslint-disable-next-line no-dupe-class-members -- This is not a duplicate class member
	private async execApiCommand_(method: 'POST'|'PUT', route: string, data: Json|FormData): Promise<string>;
	// eslint-disable-next-line no-dupe-class-members -- This is not a duplicate class member
	private async execApiCommand_(method: HttpMethod, route: string, data: Json|FormData|null = null): Promise<string> {
		route = route.replace(/^[/]/, '');
		const url = new URL(`http://localhost:${this.apiData_.port}/${route}`);
		url.searchParams.append('token', this.apiData_.token);

		this.transcript_.push(`\n[[${method} ${url}; body: ${JSON.stringify(data)}]]\n`);

		const response = await fetch(url.toString(), {
			method,
			...(data ? {
				body: data instanceof FormData ? data : JSON.stringify(data),
			} : undefined),
		});

		if (!response.ok) {
			throw new ApiResponseError(response.status, `Request to ${route} failed with error: ${await response.text()}`);
		}

		return await response.text();
	}

	private async execPagedApiCommand_<Result>(
		method: 'GET',
		route: string,
		params: Record<string, string>,
		deserializeItem: (data: Json)=> Result,
	): Promise<Result[]> {
		const searchParams = new URLSearchParams(params);

		const results: Result[] = [];
		let hasMore = true;
		for (let page = 1; hasMore; page++) {
			searchParams.set('page', String(page));
			searchParams.set('limit', '10');
			const response = JSON.parse(await this.execApiCommand_(
				method, `${route}?${searchParams}`,
			));
			if (
				typeof response !== 'object'
				|| !('has_more' in response)
				|| !('items' in response)
				|| !Array.isArray(response.items)
			) {
				throw new Error(`Invalid response: ${JSON.stringify(response)}`);
			}
			hasMore = !!response.has_more;

			for (const item of response.items) {
				results.push(deserializeItem(item));
			}
		}

		return results;
	}

	private async decrypt_() {
		if (!this.context_.enableE2ee) return;

		const result = await this.execCliCommand_('e2ee', 'decrypt', '--force');
		if (!result.stdout.includes('Completed decryption.')) {
			throw new Error(`Decryption did not complete: ${result.stdout}`);
		}
	}

	public async sync() {
		logger.info('Sync', this.label);
		await this.tracker_.sync();

		await retryWithCount(async () => {
			const result = await this.execCliCommand_('sync');
			if (result.stdout.match(/Last error:/i)) {
				throw new Error(`Sync failed: ${result.stdout}`);
			}

			await this.decrypt_();
		}, {
			count: 4,
			// Certain sync failures self-resolve after a background task is allowed to
			// run. Delay:
			delayOnFailure: retry => retry * Second * 2,
			onFail: async ({ error, willRetry }) => {
				logger.debug('Sync error: ', error);
				if (willRetry) {
					logger.info('Sync failed. Retrying...');
				}
			},
		});

		await this.handleResourceIdChanges_();
	}

	// Joplin occasionally changes the ID of a resource. Handle this here.
	// Assumes that the client is up-to-date with the server.
	private async handleResourceIdChanges_() {
		type UntrackedAttachment = {
			id: ItemId;
			linkedNotes: Set<ItemId>;
		};
		const collectUntrackedAttachments = async () => {
			// Maps from untracked item IDs to the notes that contain that item.
			const untrackedItemsById = new Map<ItemId, UntrackedAttachment>();
			const noteActualStates = new Map<ItemId, NoteData>();
			for (const note of await this.listNotes()) {
				// Skip notes that are not yet in the expected state. It's possible
				// that these notes still need to be synced by another client. If so,
				// attachments in these notes will be processed later:
				if (!this.tracker_.itemExists(note.id)) continue;

				for (const itemId of extractResourceIds(note.body)) {
					if (this.tracker_.itemExists(itemId)) continue;

					const noteIds = untrackedItemsById.get(itemId);
					if (noteIds) {
						noteIds.linkedNotes.add(note.id);
					} else {
						untrackedItemsById.set(itemId, {
							id: itemId,
							linkedNotes: new Set([note.id]),
						});
					}
					noteActualStates.set(note.id, note);
				}
			}

			return { untrackedItemsById, noteActualStates };
		};

		const fetchResourceData = async (resourceId: ItemId) => {
			try {
				const resourceJson = JSON.parse(
					await this.execApiCommand_('GET', `/resources/${resourceId}?fields=id,title,mime`),
				);
				const resourceData: ResourceData = {
					id: getStringProperty(resourceJson, 'id'),
					mimeType: getStringProperty(resourceJson, 'mime'),
					title: getStringProperty(resourceJson, 'title'),
				};
				return resourceData;
			} catch (error) {
				if (error instanceof ApiResponseError && error.code === 404) {
					return null;
				} else {
					throw error;
				}
			}
		};

		const removeResourceIds = (text: string) => {
			for (const id of extractResourceIds(text)) {
				text = text.split(id).join('');
			}
			return text;
		};

		const textsMatchIgnoringResources = (actual: string, expected: string) => {
			return removeResourceIds(expected) === removeResourceIds(actual);
		};

		const { untrackedItemsById, noteActualStates } = await collectUntrackedAttachments();

		for (const { id: resourceId, linkedNotes } of untrackedItemsById.values()) {
			const resourceData = await fetchResourceData(resourceId);
			if (!resourceData) {
				logger.warn('Resource not found:', resourceId);
				continue;
			}

			await this.createResource(resourceData);
			for (const id of linkedNotes) {
				const expected = this.tracker_.itemById(id);
				assertIsNote(expected);
				const actual = noteActualStates.get(id);
				assertIsNoteData(actual);

				if (textsMatchIgnoringResources(actual.body, expected.body)) {
					const firstMatchIndex = actual.body.indexOf(resourceId);
					// This relies on the fact that **all** resource IDs are length-32 strings:
					const originalId = expected.body.substring(firstMatchIndex, firstMatchIndex + 32);

					logger.info('Resource rewrite: Updating note', id, ': Replacing', originalId, 'with', resourceId);

					await this.tracker_.updateNote({
						...expected,
						body: expected.body.split(originalId).join(resourceId),
					});
				}
			}
		}
	}

	public async createOrUpdateMany(actionCount: number, options: CreateOrUpdateManyOptions) {
		logger.info(`Creating/updating ${actionCount} items...`);
		const bar = new ProgressBar('Creating/updating');

		const actions = {
			create: async () => {
				let parentId = (await this.randomFolder({ includeReadOnly: false }))?.id;
				const createSubfolder = this.context_.randInt(0, 100) < 10;
				if (!parentId || createSubfolder) {
					const folder = await this.createRandomFolder({ parentId, quiet: true });
					parentId = folder.id;
				}

				await this.createRandomNote({ parentId, quiet: true });
			},
			update: async (targetNote: NoteData, step: number) => {
				const keep = targetNote.body.substring(
					0, this.context_.randInt(0, targetNote.body.length),
				);
				const append = this.context_.randomString(this.context_.randInt(0, 5000));

				let body = keep + append;
				// Only keep unicode that can be represented as UTF-8 to prevent false-positive fuzzer failures
				body = removeInvalidUtf8(body);

				await this.updateNote({
					...targetNote,
					body,
				}, {
					quiet: true,
					message: `sub-step: ${step}: keep: ${keep.length}, append: ${append.length}`,
				});
			},
			delete: async (targetNote: NoteData) => {
				await this.deleteNote(targetNote.id, { quiet: true });
			},
		};
		const actionKeys: (keyof typeof actions)[] = ['create', 'update', 'delete'];

		for (let i = 0; i < actionCount; i++) {
			bar.update(i, actionCount);

			const targetNote = await this.randomNote({ includeReadOnly: false });
			const actionWeights = [
				options.createProbability,
				targetNote ? options.updateProbability : 0,
				targetNote ? options.deleteProbability : 0,
			];

			const actionId = this.context_.randomFrom(actionKeys, actionWeights);
			if (actionId) {
				await actions[actionId](targetNote, i);
			}
		}
		bar.complete();
	}

	public async createRandomFolder({ quiet, parentId, id, title }: CreateRandomFolderOptions) {
		const titleLength = this.context_.randInt(1, 128);
		const folder = {
			parentId: parentId,
			id: id ?? this.context_.randomId(),
			title: title ?? this.context_.randomString(titleLength).replace(/\n/g, ' '),
		};

		await this.createFolder(folder, { quiet });

		return folder;
	}

	public async createFolder(folder: FolderData, { quiet = false }: CreateOrUpdateOptions = {}) {
		if (!quiet) {
			logger.info('Create folder', folder.id, 'in', `${folder.parentId ?? 'root'}/${this.label}`);
		}
		await this.tracker_.createFolder(folder);

		await this.execApiCommand_('POST', '/folders', {
			id: folder.id,
			title: folder.title,
			parent_id: folder.parentId ?? '',
		});
	}

	private async assertNoteMatchesState_(expected: NoteData) {
		const normalizeForCompare = (text: string) => {
			// Handle invalid unicode (replace with placeholder characters)
			return Buffer.from(new TextEncoder().encode(text))
				.toString()
				// Rule out differences caused by control characters:
				.replace(/\p{C}/ug, '')
				.trimEnd();
		};

		let lastActualNote: NoteEntity|null = null;
		try {
			await retryWithCount(async () => {
				const noteResult = JSON.parse(
					await this.execApiCommand_('GET', `/notes/${encodeURIComponent(expected.id)}?fields=title,body`),
				);
				lastActualNote = noteResult;

				assert.equal(
					normalizeForCompare(noteResult.title),
					normalizeForCompare(expected.title),
					'note title should match',
				);
				assert.equal(
					normalizeForCompare(noteResult.body),
					normalizeForCompare(expected.body),
					'note body should match',
				);
			}, {
				count: 3,
				onFail: async () => {
					// Send an event to the server and wait for it to be processed -- it's possible that the server
					// hasn't finished processing the API event for creating the note:
					await this.execApiCommand_('GET', '/ping');
				},
			});
		} catch (error) {
			// Log additional information to help debug binary differences
			if (lastActualNote) {
				logger.warn(getDiffDebugMessage(lastActualNote.title, expected.title));
				logger.warn(getDiffDebugMessage(lastActualNote.body, expected.body));
			}
			// Log all transactions associated with the item
			this.globalActionTracker_.printActionLog(expected.id);

			throw error;
		}
	}

	public async createRandomNote({ parentId, id, quiet = false }: CreateRandomItemOptions) {
		const titleLength = this.context_.randInt(0, 256);
		const bodyLength = this.context_.randInt(0, 10_000);
		await this.createNote({
			published: false,
			parentId,
			title: this.context_.randomString(titleLength),
			body: this.context_.randomString(bodyLength),
			id: id ?? this.context_.randomId(),
		}, { quiet });
	}

	public async createNote(note: NoteData, { quiet = false }: CreateOrUpdateOptions = { }) {
		if (!quiet) {
			logger.info('Create note', note.id, 'in', `${note.parentId}/${this.label}`);
		}
		await this.tracker_.createNote(note);

		await this.execApiCommand_('POST', '/notes', {
			id: note.id,
			title: note.title,
			body: note.body,
			parent_id: note.parentId ?? '',
		});
		await this.assertNoteMatchesState_(note);
	}

	public async updateNote(note: NoteData, { message, quiet = false }: CreateOrUpdateOptions = { }) {
		if (!quiet) {
			logger.info('Update note', note.id, 'in', `${note.parentId}/${this.label}`);
		}

		await this.tracker_.updateNote(note, { message });
		await this.execApiCommand_('PUT', `/notes/${encodeURIComponent(note.id)}`, {
			title: note.title,
			body: note.body,
			parent_id: note.parentId ?? '',
		});
		await this.assertNoteMatchesState_(note);
	}

	public async deleteNote(id: ItemId, { quiet }: CreateOrUpdateOptions = {}) {
		if (!quiet) {
			logger.info('Delete note', id, 'in', this.label);
		}

		await this.tracker_.deleteNote(id);

		await this.execCliCommand_('rmnote', '--permanent', '--force', id);
	}

	public async attachResource(note: NoteData, resource: ResourceData): Promise<NoteData> {
		logger.info('Attach resource', resource.id, 'to note', note.id);
		const updatedNote = await this.tracker_.attachResource(note, resource);

		await this.execApiCommand_('PUT', `/notes/${encodeURIComponent(note.id)}`, {
			title: updatedNote.title,
			body: updatedNote.body,
			parent_id: updatedNote.parentId ?? '',
		});

		// Create the resource on the client *after* attaching it to the note so that the
		// resource is always referenced by at least one note:
		await this.createResource(resource);

		await this.assertNoteMatchesState_(updatedNote);
		return updatedNote;
	}

	public async createResource(resource: ResourceData): Promise<void> {
		await this.tracker_.createResource(resource);

		const checkExists = async () => {
			try {
				await this.execApiCommand_('GET', `/resources/${resource.id}`);
				return true;
			} catch (error) {
				if (error instanceof ApiResponseError && error.code === 404) {
					return false;
				}
				throw error;
			}
		};

		if (!await checkExists()) {
			const resourceForm = new FormData();
			resourceForm.append('data', new Blob(['test'], { type: resource.mimeType }));
			resourceForm.append('props', JSON.stringify({
				title: resource.title,
				id: resource.id,
				mime: resource.mimeType,
			}));

			await this.execApiCommand_('POST', '/resources', resourceForm);
		}
	}

	public async deleteFolder(id: string) {
		logger.info('Delete folder', id, 'in', this.label);
		await this.tracker_.deleteFolder(id);

		await this.execCliCommand_('rmbook', '--permanent', '--force', id);
	}

	public async shareFolder(id: string, shareWith: Client, options: ShareOptions) {
		await this.tracker_.shareFolder(id, shareWith, options);

		const getPendingInvitations = async (target: Client) => {
			const shareWithIncoming = JSON.parse((await target.execCliCommand_('share', 'list', '--json')).stdout);
			return shareWithIncoming.invitations.filter((invitation: unknown) => {
				if (typeof invitation !== 'object' || !('accepted' in invitation)) {
					throw new Error('Invalid invitation format');
				}
				return !invitation.accepted;
			});
		};

		await retryWithCount(async () => {
			logger.info('Share', id, 'with', shareWith.label, options.readOnly ? '(read-only)' : '');
			const readOnlyArgs = options.readOnly ? ['--read-only'] : [];
			await this.execCliCommand_(
				'share', 'add', ...readOnlyArgs, id, shareWith.email,
			);

			await this.sync();
			await shareWith.sync();

			const pendingInvitations = await getPendingInvitations(shareWith);
			assert.deepEqual(pendingInvitations, [
				{
					accepted: false,
					waiting: true,
					rejected: false,
					canWrite: !options.readOnly,
					folderId: id,
					fromUser: {
						email: this.email,
					},
				},
			], 'there should be a single incoming share from the expected user');
		}, {
			count: 2,
			delayOnFailure: count => count * Second,
			onFail: ({ error, willRetry })=>{
				logger.warn('Share failed:', error, willRetry ? 'Retrying...' : '');
			},
		});

		await shareWith.execCliCommand_('share', 'accept', id);
		await shareWith.sync();
	}

	public async removeFromShare(id: string, other: Client) {
		await this.tracker_.removeFromShare(id, other);

		logger.info('Remove', other.label, 'from share', id);
		await this.execCliCommand_('share', 'remove', id, other.email);
		await other.sync();
	}

	public async deleteAssociatedShare(id: string) {
		await this.tracker_.deleteAssociatedShare(id);
		logger.info('Unshare', id, '(from', this.label, ')');
		await this.execCliCommand_('share', 'delete', '-f', id);
	}

	public async publishNote(id: ItemId) {
		await this.tracker_.publishNote(id);

		await this.sync();

		logger.info('Publish note', id, 'in', this.label);
		const publishOutput = await this.execCliCommand_('publish', '-f', id);
		const publishUrl = publishOutput.stdout.match(/http[s]?:\/\/\S+/);

		assert.notEqual(publishUrl, null, 'should log the publication URL');

		logger.info('Testing publication URL: ', publishUrl[0]);
		const fetchResult = await fetch(publishUrl[0]);

		if (!fetchResult.ok) {
			logger.warn('Fetch failed', fetchResult.statusText);
		}
		assert.equal(fetchResult.status, 200, `should be able to fetch the published note (status: ${fetchResult.statusText}).`);
	}

	public async unpublishNote(id: ItemId) {
		await this.tracker_.unpublishNote(id);

		logger.info('Unpublish note', id, 'in', this.label);
		await this.execCliCommand_('unpublish', id);
	}

	public async moveItem(itemId: ItemId, newParentId: ItemId) {
		logger.info('Move', itemId, 'to', newParentId);
		await this.tracker_.moveItem(itemId, newParentId);
		const movingToRoot = !newParentId;
		await this.execCliCommand_('mv', itemId, movingToRoot ? 'root' : newParentId);
	}

	public async listResources() {
		const params = {
			fields: 'id,title,mime',
			include_deleted: '1',
			include_conflicts: '1',
		};
		return await this.execPagedApiCommand_(
			'GET',
			'/resources',
			params,
			(item): ResourceData => ({
				id: getStringProperty(item, 'id'),
				title: getStringProperty(item, 'title'),
				mimeType: getStringProperty(item, 'mime'),
			}),
		);
	}

	public async listNotes() {
		const params = {
			fields: 'id,parent_id,body,title,is_conflict,conflict_original_id,share_id,is_shared',
			include_deleted: '1',
			include_conflicts: '1',
		};
		return await this.execPagedApiCommand_(
			'GET',
			'/notes',
			params,
			item => ({
				id: getStringProperty(item, 'id'),
				parentId: getNumberProperty(item, 'is_conflict') === 1 ? (
					`[conflicts for ${getStringProperty(item, 'conflict_original_id')} in ${this.label}]`
				) : getStringProperty(item, 'parent_id'),
				title: getStringProperty(item, 'title'),
				body: getStringProperty(item, 'body'),
				isShared: getStringProperty(item, 'share_id') !== '',
				published: getNumberProperty(item, 'is_shared') === 1,
			}),
		);
	}

	public async listFolders() {
		const params = {
			fields: 'id,parent_id,title,share_id',
			include_deleted: '1',
		};
		return await this.execPagedApiCommand_(
			'GET',
			'/folders',
			params,
			item => ({
				id: getStringProperty(item, 'id'),
				parentId: getStringProperty(item, 'parent_id'),
				title: getStringProperty(item, 'title'),
				isShared: getStringProperty(item, 'share_id') !== '',
			}),
		);
	}

	public async randomFolder(options: RandomFolderOptions) {
		return this.tracker_.randomFolder(options);
	}

	public async allFolderDescendants(parentId: ItemId) {
		return this.tracker_.allFolderDescendants(parentId);
	}

	public async randomNote(options: RandomNoteOptions) {
		return this.tracker_.randomNote(options);
	}

	public itemById(itemId: ItemId) {
		return this.tracker_.itemById(itemId);
	}

	public itemExists(itemId: ItemId) {
		return this.tracker_.itemExists(itemId);
	}

	public async checkState() {
		logger.info('Check state', this.label);

		type ItemSlice = { id: string; title: string };
		const compare = (a: ItemSlice, b: ItemSlice) => {
			if (a.id === b.id) return 0;
			return a.id < b.id ? -1 : 1;
		};

		const assertNoAdjacentEqualIds = (sortedById: ItemSlice[], assertionLabel: string) => {
			for (let i = 1; i < sortedById.length; i++) {
				const current = sortedById[i];
				const previous = sortedById[i - 1];
				assert.notEqual(
					current.id,
					previous.id,
					`[${assertionLabel}] item ${i} should have a different ID from item ${i - 1}`,
				);
			}
		};

		const idLogs = (ids: ItemId[], items: ItemSlice[]) => {
			const itemTitle = (id: ItemId) => {
				const itemTitle = items.find(item => item.id === id)?.title;
				return itemTitle ? JSON.stringify(substrWithEllipsis(itemTitle, 0, 28)) : 'Unknown';
			};

			const output = [];
			for (const id of ids) {
				const log = this.globalActionTracker_.getActionLog(id);

				output.push(`id: ${id} (${itemTitle(id)})`);
				if (log.length > 0) {
					output.push(`\t${hangingIndent(log, '\t')}`);
				} else {
					output.push('\tNo history found');
				}
			}
			return output.join('\n');
		};

		const assertSameIds = async (actualSorted: ItemSlice[], expectedSorted: ItemSlice[], assertionLabel: string) => {
			const actualIds = actualSorted.map(i => i.id);
			const expectedIds = expectedSorted.map(i => i.id);
			const { missing, unexpected } = diffSortedStringArrays(actualIds, expectedIds);

			if (missing.length || unexpected.length) {
				const message = [
					`${assertionLabel}: IDs were different:`,
					missing.length && `Expected ${JSON.stringify(missing)} to be present, but were missing.`,
					unexpected.length && `Present but should not have been: ${JSON.stringify(unexpected)}`,
					'Logs:',
					idLogs(missing, expectedSorted),
					idLogs(unexpected, actualSorted),
				].filter(line => !!line).join('\n');

				throw new Error(message);
			}
		};

		const assertStringPropertyMatches = <Key extends string, Entity extends Record<Key|'id', string>> (
			key: Key, actualSorted: Entity[], expectedSorted: Entity[], assertionLabel: string,
		) => {
			if (actualSorted.length !== expectedSorted.length) {
				throw new Error(`Input arrays have different lengths (in: ${assertionLabel})`);
			}

			const differentItems = [];
			for (let i = 0; i < actualSorted.length; i++) {
				const actualBody = actualSorted[i][key];
				const expectedBody = expectedSorted[i][key];

				if (actualBody !== expectedBody) {
					differentItems.push([actualSorted[i], expectedSorted[i]]);
				}
			}

			if (differentItems.length) {
				const message = [`Some items have different bodies (in: ${assertionLabel})`];
				for (const [actual, expected] of differentItems) {
					message.push(`- item: ${actual.id}${actual.id !== expected.id ? ` (compare ${expected.id}) ` : ''}:`);
					message.push(` ${hangingIndent(getDiffDebugMessage(actual[key], expected[key]))}`);

					// Only display the full value for easy-to-inspect content:
					const simpleContentExp = /^[a-z0-9;.,!?[\]() \t\n"']{0,200}$/i;
					if (actual[key].match(simpleContentExp) && expected[key].match(simpleContentExp)) {
						message.push(`  actual:  ${JSON.stringify(actual)}`);
						message.push(`  expected:${JSON.stringify(expected)}`);
					}
				}
				throw new Error(message.join('\n'));
			}
		};

		const checkNoteState = async () => {
			const notes = [...await this.listNotes()];
			const expectedNotes = [...await this.tracker_.listNotes()];

			notes.sort(compare);
			expectedNotes.sort(compare);

			assertNoAdjacentEqualIds(notes, 'notes');
			assertNoAdjacentEqualIds(expectedNotes, 'expectedNotes');
			await assertSameIds(notes, expectedNotes, 'Note IDs should match');
			assertStringPropertyMatches('body', notes, expectedNotes, 'should have the same note bodies');
			assert.deepEqual(notes, expectedNotes, 'should have the same notes as the expected state');
		};

		const checkFolderState = async () => {
			const folders = [...await this.listFolders()];
			const expectedFolders = [...await this.tracker_.listFolders()];

			folders.sort(compare);
			expectedFolders.sort(compare);

			assertNoAdjacentEqualIds(folders, 'folders');
			assertNoAdjacentEqualIds(expectedFolders, 'expectedFolders');
			await assertSameIds(folders, expectedFolders, 'Folder IDs should match');
			assertStringPropertyMatches('title', folders, expectedFolders, 'should have the same folder titles');
			assert.deepEqual(folders, expectedFolders, 'should have the same folders as the expected state');
		};

		const checkResourceState = async () => {
			const actualResources = [...await this.listResources()];
			const actualResourceIds = new Set(actualResources.map(r => r.id));
			const expectedResources = [...await this.tracker_.listResources()];

			const missingResources = [];
			for (const resource of expectedResources) {
				if (!actualResourceIds.has(resource.id)) {
					missingResources.push(resource.id);
				}
			}

			if (missingResources.length > 0) {
				const log = idLogs(missingResources, expectedResources);

				throw new Error(`Missing resource(s): All expected resources should exist on the client. Resource(s) with ID(s) ${JSON.stringify(missingResources)} were not found (total resource count: ${actualResourceIds.size}).\nResource action history:\n${log}`);
			}
		};

		const errors: Error[] = [];
		const runCheck = async (check: ()=> Promise<void>) => {
			try {
				await check();
			} catch (error) {
				errors.push(error);
			}
		};

		await runCheck(checkResourceState);
		await runCheck(checkNoteState);
		await runCheck(checkFolderState);

		if (errors.length) {
			const errorList = errors
				.map((error, index) => `Error ${index + 1} of ${errors.length}: ${error}`)
				.map(message => hangingIndent(message))
				.join('\n');
			throw new Error(`Incorrect state in client: ${this.clientLabel_}:\n${errorList}`);
		}
	}
}

export default Client;