function randstr(length, charset='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789') {
	var res = '', i;
	if((window.crypto) && (window.crypto.getRandomValues)) {
		var values = new Uint32Array(length);
		window.crypto.getRandomValues(values);
		for(var i = 0; i < length; ++i) res += charset[values[i] % charset.length];
	} else for(var i = 0; i < length; ++i) res += charset[Math.floor(Math.random()*charset.length)];
	return res;
}

function str_to_ab(str) {
	var buf = new ArrayBuffer(str.length);
	var bufview = new Uint8Array(buf);
	for(var i = str.length - 1; i >= 0; --i) bufview[i] = str.charCodeAt(i);
	return buf;
}

function uint8array_to_b64(arr) {
	return btoa(String.fromCharCode.apply(null, arr)).replace(/\+/g, '-').replace(/\//g, '_').replace(/=/g, '');
}

function b64_to_uint8array(b64) {
	return Uint8Array.from(atob(b64.replace(/\-/g, '+').replace(/_/g, '/')), c => c.charCodeAt(null));
}

async function digest(algorithm, value) {
	var buffer = str_to_ab(value);
	return await window.crypto.subtle.digest(algorithm, str_to_ab(value));
}

export function randpassword() {
	return randstr(64) + ':' + randstr(16);
}

function TplFSError(...args) {
	this.message = args;
}
TplFSError.prototype = Object.create(Error.prototype);

function TplFSErrorNotFound(...args) {
	this.message = args;
}
TplFSErrorNotFound.prototype = Object.create(TplFSError.prototype);

function TplFSErrorPerm(...args) {
	this.message = args;
}
TplFSErrorPerm.prototype = Object.create(TplFSError.prototype);

function TplFSErrorInvalid(...args) {
	this.message = args;
}
TplFSErrorInvalid.prototype = Object.create(TplFSError.prototype);

export function TplFS(client, parent, desc) {
	this.parent = parent;
	this.desc = desc;
	this.path = parent ? parent.path + '/' + desc.name : '';

	async function lock(tries=5, delay=1000) {
		var res = null;
		for(var i = 1; i <= tries; ++i) {
			if((res = await client.TIU_TEMPLATE_LOCK(desc.IEN)) == '1') break;
			await new Promise(resolve => setTimeout(resolve, Math.pow(delay, i)));
		}
		return res;
	}

	async function enumerate(ien) {
		var res = [ien];
		var items = await client.TIU_TEMPLATE_GETITEMS(ien);
		for(var i = items.length - 1; i >= 0; --i) Array.prototype.push.apply(res, await enumerate(items[i].IEN));
		return res;
	}

	this.chroot = () => new TplFS(client, null, desc);

	this.list = async (filter=null) => {
		var items = await client.TIU_TEMPLATE_GETITEMS(desc.IEN);
		if(filter) items = items.filter(filter);
		return items.map(x => new TplFS(client, this, x));
	};

	this.open = async (path) => {
		if((typeof path === 'string') || (path instanceof String)) path = path.split('/');
		if(((desc.type == 'C') || (desc.type == 'P')) && (path.length > 0)) {
			var items = await client.TIU_TEMPLATE_GETITEMS(desc.IEN), name = path[0];
			var item = items.find(x => x.name == name);
			if(item) {
				if(path.length > 1) return (new TplFS(client, this, item)).open(path.slice(1));
				else return new TplFS(client, this, item);
			} else throw new TplFSErrorNotFound('open', (this.path != '' ? this.path + '/' : '') + name, 'Directory not found');
		} else throw new TplFSErrorInvalid('open', (this.path != '' ? this.path + '/' : '') + path.join('/'), 'Invalid path');
	};

	this.mkdir = async (path, tries=5, delay=1000) => {
		if((typeof path === 'string') || (path instanceof String)) path = path.split('/');
		var node = this;
		for(var i = 0; i < path.length; ++i) node = await node.raw_mkdir(path[i], tries, delay);
		return node;
	};

	this.create = async (path, data, mkdir=false, tries=5, delay=1000) => {
		if((typeof path === 'string') || (path instanceof String)) path = path.split('/');
		if(path.length > 1) return await (mkdir ? await this.mkdir(path.slice(0, -1), tries, delay) : await this.open(path.slice(0, -1))).create(path.slice(-1), data, tries, delay);
		else if(path.length == 1) return await this.raw_create(path[0], data, tries, delay);
		else throw new TplFSErrorInvalid('create', (this.path != '' ? this.path + '/' : '') + path.join('/'), 'Invalid path');
	};

	this.remove = async (path, tries=5, delay=1000) => {
		if((typeof path === 'string') || (path instanceof String)) path = path.split('/');
		if(path.length > 1) return await (await this.open(path.slice(0, -1))).remove(path.slice(-1), tries, delay);
		else if(path.length == 1) return await this.raw_remove(path[0], tries, delay);
		else throw new TplFSErrorInvalid('remove', (this.path != '' ? this.path + '/' : '') + path.join('/'), 'Invalid path');
	};

	this.update = async (path, data) => {
		if((typeof path === 'string') || (path instanceof String)) path = path.split('/');
		if(path.length > 0) return await (await this.open(path)).update([], data);
		else return await this.raw_update(data);
	};

	this.cat = async (path=[]) => {
		if((typeof path === 'string') || (path instanceof String)) path = path.split('/');
		if(path.length > 0) return await (await this.open(path)).raw_cat();
		else return await this.raw_cat();
	};

	this.raw_mkdir = async (name, tries=5, delay=1000) => {
		if((desc.type == 'C') || (desc.type == 'P')) {
			if(name == '.') return this;
			else if(name == '..') return this.parent ? this.parent : this;
			if(await lock(tries, delay) == '1') try {
				var items = await client.TIU_TEMPLATE_GETITEMS(desc.IEN);
				var item = items.find(x => x.name == name);
				if(item) return new TplFS(client, this, item);
				var nodeid = await client.TIU_TEMPLATE_CREATE_MODIFY(0, { '.01': name, '.02': '@', '.03': 'C', '.04': 'I', '.05': '0', '.08': '0', '.09': '0', '.1': '0', '.11': '0', '.12': '0', '.13': '0', '.14': '0', '.15': '@', '.16': '0', '.17': '@', '.18': '@', '.19': '@', '.06': desc.personal_owner, '2,1': '@', '5,1': '@' });
				var nodes = (await client.TIU_TEMPLATE_GETITEMS(desc.IEN)).map(x => x.IEN);
				nodes.push(nodeid);
				await client.TIU_TEMPLATE_SET_ITEMS(desc.IEN, nodes);
				nodeid = (await client.TIU_TEMPLATE_GETITEMS(desc.IEN)).find(x => (x.type == 'C') && (x.name == name));
				if(nodeid) return new TplFS(client, this, nodeid);
				else throw new TplFSErrorPerm('mkdir', (this.path != '' ? this.path + '/' : '') + name, 'Failed to create directory');
			} finally {
				await client.TIU_TEMPLATE_UNLOCK(desc.IEN);
			} else throw new TplFSErrorPerm('mkdir', this.path, 'Failed to obtain lock');
		} else throw new TplFSErrorInvalid('mkdir', this.path, 'Not a directory');
	};

	this.raw_create = async (name, data, tries=5, delay=1000) => {
		if((desc.type == 'C') || (desc.type == 'P')) {
			if((name == '.') || (name == '..')) throw new TplFSErrorInvalid('create', (this.path != '' ? this.path + '/' : '') + name, 'Invalid path');
			if(await lock(tries, delay) == '1') try {
				var items = await client.TIU_TEMPLATE_GETITEMS(desc.IEN);
				var item = items.find(x => x.name == name);
				if((item) && (item.type != 'T')) throw new TplFSErrorInvalid('create', (this.path != '' ? this.path + '/' : '') + name, 'Not a file');
				var nodeid = await client.TIU_TEMPLATE_CREATE_MODIFY(item && item.IEN ? item.IEN : 0, { '.01': name, '.02': '@', '.03': 'T', '.04': 'I', '.05': '0', '.08': '0', '.09': '0', '.1': '0', '.11': '0', '.12': '0', '.13': '0', '.14': '0', '.15': '@', '.16': '0', '.17': '@', '.18': '@', '.19': '@', '.06': desc.personal_owner, '2,1,0': data, '5,1,0': 'TplFS' });
				if((item) && (item.IEN == nodeid)) return new TplFS(client, this, item);
				var nodes = items.map(x => x.IEN);
				nodes.push(nodeid);
				await client.TIU_TEMPLATE_SET_ITEMS(desc.IEN, nodes);
				item = (await client.TIU_TEMPLATE_GETITEMS(desc.IEN)).find(x => (x.type == 'T') && (x.name == name));
				if(item) return new TplFS(client, this, item);
				else throw new TplFSErrorPerm('create', (this.path != '' ? this.path + '/' : '') + name, 'Failed to create file');
			} finally {
				await client.TIU_TEMPLATE_UNLOCK(desc.IEN);
			} else throw new TplFSErrorPerm('create', this.path, 'Failed to obtain lock');
		} else throw new TplFSErrorInvalid('create', this.path, 'Not a directory');
	};

	this.raw_remove = async (name, tries=5, delay=1000) => {
		if((desc.type == 'C') || (desc.type == 'P')) {
			if((name == '.') || (name == '..')) throw new TplFSErrorInvalid('remove', (this.path != '' ? this.path + '/' : '') + name, 'Invalid path');
			var garbage = null;
			if(await lock(tries, delay) == '1') try {
				var items = await client.TIU_TEMPLATE_GETITEMS(desc.IEN);
				var item = items.find(x => x.name == name);
				if(item) {
					garbage = await enumerate(item.IEN);
					items.splice(items.indexOf(item), 1);
					await client.TIU_TEMPLATE_SET_ITEMS(desc.IEN, items.map(x => x.IEN));
				}
			} finally {
				await client.TIU_TEMPLATE_UNLOCK(desc.IEN);
				if(garbage) return await client.TIU_TEMPLATE_DELETE(garbage);
			} else throw new TplFSErrorPerm('remove', this.path, 'Failed to obtain lock');
		} else throw new TplFSErrorInvalid('remove', this.path, 'Not a directory');
	};

	this.raw_update = async (data) => {
		if(desc.type == 'T') {
			await client.TIU_TEMPLATE_CREATE_MODIFY(desc.IEN, { '.01': desc.name, '.02': '@', '.03': 'T', '.04': 'I', '.05': '0', '.08': '0', '.09': '0', '.1': '0', '.11': '0', '.12': '0', '.13': '0', '.14': '0', '.15': '@', '.16': '0', '.17': '@', '.18': '@', '.19': '@', '.06': desc.personal_owner, '2,1,0': data, '5,1,0': 'TplFS' });
			return this;
		} else throw new TplFSErrorInvalid('update', this.path, 'Not a file');
	};

	this.raw_cat = async () => {
		if(desc.type == 'T') return await client.TIU_TEMPLATE_GETBOIL(desc.IEN);
		else throw new TplFSErrorInvalid('retrieve', this.path, 'Not a file');
	};

	this.raw_list = () => client.TIU_TEMPLATE_GETITEMS(desc.IEN);

	this.raw_open = (child) => new TplFS(client, this, child);

	return this;
}

TplFS.fromUser = async function(client, user_ien=null) {
	if(!user_ien) user_ien = (await client.userinfo()).result[0];
	return new TplFS(client, null, (await client.TIU_TEMPLATE_GETPROOT(user_ien))[0]);
};

export function EncFS(fs, data_encrypt, data_decrypt, path_encrypt, path_decrypt) {
	this.fs = fs;
	if(fs.path) path_decrypt(fs.path).then(value => this.path = value);

	this.list = async (filter=null) => (await fs.list(filter)).map(x => new EncFS(x, data_encrypt, data_decrypt, path_encrypt, path_decrypt));
	this.open = async (path) => new EncFS(await fs.open(await path_encrypt(path)), data_encrypt, data_decrypt, path_encrypt, path_decrypt);
	this.mkdir = async (path, tries=5, delay=1000) => new EncFS(await fs.mkdir(await path_encrypt(path), tries=5, delay=1000), data_encrypt, data_decrypt, path_encrypt, path_decrypt);
	this.create = async (path, data, mkdir=false, tries=5, delay=1000) => new EncFS(await fs.create(await path_encrypt(path), await data_encrypt(data), mkdir=false, tries=5, delay=1000), data_encrypt, data_decrypt, path_encrypt, path_decrypt);
	this.remove = async (path, tries=5, delay=1000) => await fs.remove(await path_encrypt(path), tries=5, delay=1000);
	this.update = async (path, data) => new EncFS(await fs.update(await path_encrypt(path), await data_encrypt(data)), data_encrypt, data_decrypt, path_encrypt, path_decrypt);
	this.cat = async (path) => await data_decrypt(await fs.cat(await path_encrypt(path)));
}
EncFS.fromPassword = async function(fs, password) {
	var password_salt = password.split(':');
	var key_pbkdf2 = await window.crypto.subtle.importKey('raw', str_to_ab(password_salt[0]), 'PBKDF2', false, ['deriveKey']);
	var salt = new Uint8Array(str_to_ab(password_salt[1]));
	var key_aes_gcm = await window.crypto.subtle.deriveKey(
		{
			name: 'PBKDF2',
			salt: salt,
			iterations: 250000,
			hash: 'SHA-256',
		},
		key_pbkdf2,
		{ name: 'AES-GCM', length: 256 },
		false,
		['encrypt', 'decrypt']
	);
	async function data_encrypt(data) {
		var iv = window.crypto.getRandomValues(new Uint8Array(12));
		var ciphertextbuf = await window.crypto.subtle.encrypt({ name: 'AES-GCM', iv: iv }, key_aes_gcm, str_to_ab(data));
		var res = new Uint8Array(iv.byteLength + ciphertextbuf.byteLength);
		res.set(iv, 0);
		res.set(new Uint8Array(ciphertextbuf), iv.byteLength);
		return uint8array_to_b64(res);
	}
	async function data_decrypt(data) {
		var ciphertextarr = b64_to_uint8array(data);
		var res = await window.crypto.subtle.decrypt({ name: 'AES-GCM', iv: ciphertextarr.slice(0, 12) }, key_aes_gcm, ciphertextarr.slice(12));
		return String.fromCharCode.apply(null, new Uint8Array(res));
	}
	var key_aes_ctr = await window.crypto.subtle.deriveKey(
		{
			name: 'PBKDF2',
			salt: salt,
			iterations: 250000,
			hash: 'SHA-256',
		},
		key_pbkdf2,
		{ name: 'AES-CTR', length: 256 },
		false,
		['encrypt', 'decrypt']
	);
	var key_hmac = await window.crypto.subtle.importKey('raw', str_to_ab(password_salt[0]), { name: 'HMAC', hash: 'SHA-256' }, false, ['sign', 'verify']);
	async function path_component_encrypt(data) {
		var counter = (await window.crypto.subtle.sign({ name: 'HMAC' }, key_hmac, str_to_ab(data))).slice(0, 16);
		var ciphertextbuf = await window.crypto.subtle.encrypt({ name: 'AES-CTR', counter: counter, length: 128 }, key_aes_ctr, str_to_ab(data));
		var res = new Uint8Array(counter.byteLength + ciphertextbuf.byteLength);
		res.set(new Uint8Array(counter), 0);
		res.set(new Uint8Array(ciphertextbuf), counter.byteLength);
		return uint8array_to_b64(res);
	}
	async function path_component_decrypt(data) {
		var ciphertextarr = b64_to_uint8array(data);
		var res = await window.crypto.subtle.decrypt({ name: 'AES-CTR', counter: ciphertextarr.slice(0, 16), length: 128 }, key_aes_ctr, ciphertextarr.slice(16));
		return String.fromCharCode.apply(null, new Uint8Array(res));
	}
	async function path_encrypt(data) {
		return (await Promise.all(data.split('/').map(x => path_component_encrypt(x)))).join('/');
	}
	async function path_decrypt(data) {
		if(data.startsWith('/')) return '/' + await path_decrypt(data.replace(/^\/+/g, ''));
		return (await Promise.all(data.split('/').map(x => path_component_decrypt(x)))).join('/');
	}
	return new EncFS((await fs.mkdir('ZZZE ' + uint8array_to_b64(new Uint8Array(await digest('SHA-1', password))))).chroot(), data_encrypt, data_decrypt, path_encrypt, path_decrypt);
};

export default window.tplfs = { TplFS, EncFS, randpassword };