"use strict";

const Promise = require("bluebird");
const execAll = require("execall");
const execBinary = require("../exec-binary");
const createJSONParser = require("../text-parser-json");

const controllerFieldMapping = require("./controller-field-mapping");

function createNamespaceParser() {
	return {
		supportsStreams: false,
		parse: function (input) {
			return {
				namespaces: execAll(/^\[\s*[0-9]+\]:(?:(0)|0x([0-9A-F]+))$/gm, input)
					.map((match) => {
						let [ idLiteral, idHex ] = match.subMatches;

						if (idLiteral != null) {
							/* NOTE: This is a special case for when the value is exactly 0 - and maybe there are others too, hence still doing a parseInt, so we can easily change the regex later if needed:
								https://stackoverflow.com/questions/11922876/what-does-a-hash-sign-do-in-printf#comment15879638_11922887
								https://github.com/linux-nvme/nvme-cli/blob/f9ebefe27b0596006d76d58f3219a9fc12e88664/nvme.c#L979
							*/
							return parseInt(idLiteral);
						} else {
							return parseInt(idHex, 16);
						}
					})
			};
		}
	};
}

module.exports = {
	listNamespaces: function ({ devicePath }) {
		return Promise.try(() => {
			return execBinary("nvme", [ "list-ns", devicePath ])
				.asRoot()
				.expectOnStdout(createNamespaceParser())
				.execute();
		}).then((output) => {
			return output.result.namespaces;
		});
	},
	identifyController: function ({ devicePath }) {
		return Promise.try(() => {
			return execBinary([ "nvme", "id-ctrl" ], [ devicePath ])
				.asRoot()
				.withFlags({ "output-format": "json" })
				.requireOnStdout(createJSONParser())
				.execute();
		}).then(({ result }) => {
			let transformed = {};

			for (let key of Object.keys(result)) {
				let mapping = controllerFieldMapping[key];

				if (mapping != null) {
					let { name, transform } = (typeof mapping === "string")
						? { name: mapping, transform: (value) => value }
						: { name: mapping.name, transform: mapping.transform };

					transformed[name] = transform(result[key]);
				}
			}

			// TODO: Warn on unrecognized keys
			return transformed;
		// }).catch((error) => {
		// 	console.dir(error);
		});
	}
};