"use strict";

const Promise = require("bluebird");
const fs = Promise.promisifyAll(require("fs"));
const matchValue = require("match-value");
const asyncpipe = require("../../packages/asyncpipe");

const dlayerSource = require("../../packages/dlayer-source");
const All = require("../../packages/graphql-interface/symbols/all"); // FIXME: Move to dlayer-source?
const treecutter = require("../../packages/treecutter");
const types = require("./");

module.exports = function BlockDevice({ name, path }) {
	return dlayerSource.withSources({
		// TODO: Eventually make this produce a (filtered) tree instead?
		mounts: function ({ type }, { $getProperty, $getPropertyPath, sources }) {
			return Promise.try(() => {
				return sources.findmnt.load(All);
			}).then((mountTree) => {
				return asyncpipe(mountTree, [
					(_) => treecutter.flatten(_),
					(_) => _.map((mount) => types.Mount({ mountpoint: mount.mountpoint })),
					(_) => Promise.filter(_, async (mount) => {
						let sourcePath = await $getPropertyPath(mount, "sourceDevice.path");
						let sourceName = await $getPropertyPath(mount, "sourceDevice.name");

						return (
							(sourcePath != null && sourcePath === path)
							|| (sourceName != null && sourceName === name)
						);
					})
				]);
			}).then((relevantMounts) => {
				if (type == null) {
					return relevantMounts;
				} else {
					return Promise.filter(relevantMounts, async (mount) => {
						return (await $getProperty(mount, "type") === type);
					});
				}
			});
		},
		$sources: {
			lsblk: {
				[dlayerSource.ID]: { name, path },
				name: "name",
				path: (device) => fs.realpathAsync(device.path),
				type: (device) => matchValue(device.type, {
					partition: "PARTITION",
					disk: "DISK",
					loopDevice: "LOOP_DEVICE"
				}),
				size: "size",
				mountpoint: "mountpoint", // FIXME: Isn't this obsoleted by `mounts`?
				deviceNumber: "deviceNumber",
				removable: "removable",
				readOnly: "readOnly",
				children: (device) => device.children.map((child) => {
					return BlockDevice({ name: child.name });
				})
			}
		}
	});
};