'use strict';

const apidoc = require('gulp-apidoc'),
	documentation = require('gulp-documentation'),
	eslint = require('gulp-eslint'),
	gulp = require('gulp'),
	istanbul = require('gulp-istanbul'),
	jscs = require('gulp-jscs'),
	mocha = require('gulp-mocha'),
	pipe = require('gulp-pipe'),
	nsp = require('gulp-nsp');

/*
 * Path(s) to all source files
 */
const SRC_FILES = [
	'app/base/**/*.js',
	'app/config/**/*.js',
	'app/controllers/**/*.js',
	'app/helpers/**/*.js',
	'app/models/**/*.js',
	'app/*.js',
];

/*
 * Path to unit test files
 */
const UNIT_TEST_FILES = ['test/unit/**/*_test.js'];

/*
 * Path to integration test files
 */
const INTEGRATION_TEST_FILES = ['test/integration/**/*_test.js'];

/*
 * Path(s) to all test files
 */
const TEST_FILES = ['test/**/*_test.js'];

/*
 * Configuration values for eslint
 */
const ESLINT_SETTINGS = {
	env: {
		node: true,
		es6: true,
	},

	// Each rule has an error level (0-2), and some have extra parameters
	// 0 turns a rule off
	// 1 makes a rule give a warning
	// 2 makes a rule fail linting
	rules: {
		'linebreak-style': [2, 'unix'], // Only unix line endings
		'arrow-parens': [2, 'always'], // No parens on arrow functions with one param
		'no-console': [1], // Avoid using console methods
		'no-constant-condition': [1],
		'no-extra-semi': [1], // Enliminate extra semicolons
		'no-func-assign': [1],
		'no-obj-calls': [2],
		'no-unexpected-multiline': [2], // Catch syntax errors due to automatic semicolon insertion
		'no-unneeded-ternary': [2], // Avoid redundant ternary expressions
		radix: [2], // Require radix parameter on parseInt
		'no-with': [2], // No use of with construct
		'no-eval': [2], // No use of eval
		'no-unreachable': [1], // Avoid code that is not reachable
		'no-irregular-whitespace': [1], // Highlight whitespace that isn't a tab or space
		'no-new-wrappers': [2], // Avoid using primitive constructors
		'no-new-func': [2], // Avoid Function constructor eval
		curly: [2, 'multi-line'], // Require braces for if,for,while,do contructs that are not on the same line
		'no-implied-eval': [2], // Avoid camoflauged eval
		'no-invalid-this': [2],
		'constructor-super': [2],
		'no-dupe-args': [2], // Disallow functions to have more than one parameter with the same name
		'no-dupe-keys': [2], // Disaalow objects to have more than one property with the same name
		'no-dupe-class-members': [2], // Disallow classes to have more than one method/memeber with the same name
		'no-this-before-super': [2],
		'prefer-arrow-callback': [1], // Prefer arrow functions for callbacks
		'no-var': [2], // Use let or const instead of var
		'valid-jsdoc': [1],
		semi: [2, 'always'], // Require use of semicolons
		strict: [2, 'global'], // have a global 'use strict' in every code file
		'callback-return': [1], // return when invoking a callback
		'object-shorthand': [1, 'methods'], // Prefer shorthand for functions in object literals/classes, but avoid property shorthand
		'prefer-template': [1], // Prefer template strings eg. `Hello ${name}`, to string concatenation
		'no-case-declarations': [2], // Don't define variables in switch labels
		'no-const-assign': [2], // Highlight instances where assigning to const declaration
		'no-new-symbol': [2], // Symbol is not a constructor, don't use the new keyword
		'no-unused-labels': [2], // Error on labels in code that aren't used
	},
};

/*
 * Configuration values for mocha
 */
const MOCHA_SETTINGS = {
	ui: 'tdd',
	bail: true,
	slow: 1000,
	timeout: 5000,
};

/*
 * Check syntax and style of test/miscellaneous files
 */
gulp.task('lint-tests', () => {
	const LINT_TESTS_FILES = TEST_FILES.concat([
		'gulpfile.js',
		'server.js',
	]);

	// eslint
	pipe(gulp.src(LINT_TESTS_FILES), [
		eslint(ESLINT_SETTINGS),
		eslint.format(),
		eslint.failAfterError(),
	]);

	// JSCS rules are defined in /.jscsrc
	pipe(gulp.src(['test/**/*.js', 'gulpfile.js']), [
		jscs(),
		jscs.reporter(),
	]);
});

/*
 * Check syntax and style of source files
 */
gulp.task('lint-src', () => {
	// eslint
	pipe(gulp.src(SRC_FILES), [
		eslint(ESLINT_SETTINGS),
		eslint.format(),
		eslint.failAfterError(),
	]);

	// JSCS
	// JSCS rules are defined in /.jscsrc
	pipe(gulp.src(SRC_FILES), [
		jscs(),
		jscs.reporter(),
	]);
});

/*
 * Run all lint tasks
 */
gulp.task('lint', ['lint-src', 'lint-tests']);

/*
 * Create internal method documentation of source files
 */
gulp.task('src-docs', () => {
	pipe(gulp.src(SRC_FILES), [
		documentation({
			format: 'html',
		}),
		gulp.dest('public/docs'),
	]);
});

/*
 * Create api documentation from source files
 */
gulp.task('api-docs', (done) => {
	apidoc({
		src: 'app/',
		dest: 'public/api-docs/',
	}, done);
});

/*
 * Run all documentation generation tasks
 */
gulp.task('docs', ['src-docs', 'api-docs']);

/*
 * Run integration tests
 */
gulp.task('integration-test', ['lint'], () => {
	return gulp.src(INTEGRATION_TEST_FILES)
		.pipe(mocha(MOCHA_SETTINGS));
});

/*
 * Run unit tests
 */
gulp.task('unit-test', ['lint'], () => {
	return gulp.src(UNIT_TEST_FILES)
		.pipe(mocha(MOCHA_SETTINGS));
});

/*
 * Run all tests
 */
gulp.task('test', ['lint'], () => {
	return gulp.src(TEST_FILES)
		.pipe(mocha(MOCHA_SETTINGS));
});

/*
 * Run hooks for istanbul coverage generation
 */
gulp.task('pre-coverage', () => {
	return pipe(gulp.src(SRC_FILES), [
		istanbul(),
		istanbul.hookRequire(),
	]);
});

/*
 * Run unit tests and generate code coverage
 *
 * Does not run integration tests
 */
gulp.task('coverage', ['lint', 'pre-coverage'], () => {
	return pipe(gulp.src(UNIT_TEST_FILES), [
		mocha(MOCHA_SETTINGS),
		istanbul.writeReports({
			dir: 'public/coverage',
			reporters:['lcov', 'lcovonly', 'html', 'text'],
		}),
	]);
});

/*
 * Check dependencies for known security vulnerabilites
 */
gulp.task('audit', (cb) => {
	nsp({
		package: `${__dirname}/package.json`,
	}, cb);
});

/*
 * Run all tasks
 */
gulp.task('default', [
	'audit',
	'lint',
	'docs',
	'coverage',
]);

// End of gulpfile.js