const assert = require('assert').strict;
const fs = require('fs-extra');
const path = require('path');

const mock = require('../mock');
const link = require('lib/link');
const plugin = require('lib/plugin');
const errors = require('lib/errors');


describe("lib/plugin", function() {
	describe("class BaseInstancePlugin", function() {
		let instancePlugin;
		it("should be constructible", async function() {
			instancePlugin = new plugin.BaseInstancePlugin();
			await instancePlugin.init();
		})
		it("should define defaults for hooks", async function() {
			await instancePlugin.onMetrics();
			await instancePlugin.onStart();
			await instancePlugin.onStop();
			instancePlugin.onExit();
			await instancePlugin.onOutput({});
		})
	});

	describe("class BaseMasterPlugin", function() {
		let masterPlugin;
		it("should be constructible", async function() {
			masterPlugin = new plugin.BaseMasterPlugin();
			await masterPlugin.init();
		})
		it("should define defaults for hooks", async function() {
			await masterPlugin.onMetrics();
			await masterPlugin.onShutdown();
		})
	});

	describe("loadPluginInfos()", function() {
		let baseDir = path.join("temp", "test", "plugin");
		let emptyDir = path.join(baseDir, 'emptyDir');
		let emptyPlugin = path.join(baseDir, 'emptyPlugin');
		let testPlugin = path.join(baseDir, 'testPlugin');
		let brokenPlugin = path.join(baseDir, 'brokenPlugin');
		let invalidPlugin = path.join(baseDir, 'invalidPlugin');
		before(async function() {
			await fs.ensureDir(emptyDir);
			await fs.ensureDir(path.join(emptyPlugin, 'empty'));

			async function writePlugin(pluginPath, name, infoName = name) {
				await fs.outputFile(
					path.join(pluginPath, name, 'info.js'),
					`module.exports = { name: "${infoName}" };`
				);
			}

			await writePlugin(testPlugin, 'test');
			await writePlugin(brokenPlugin, 'broken');
			await fs.outputFile(path.join(brokenPlugin, 'broken', 'info.js'), "Syntax Error");
			await writePlugin(invalidPlugin, 'invalid', 'wrong');
		});

		it("should return an empty array for an empty directory", async function() {
			assert.deepEqual(await plugin.loadPluginInfos(emptyDir), []);
		});
		it("should ignore plugin dirs without info module", async function() {
			assert.deepEqual(await plugin.loadPluginInfos(emptyPlugin), []);
		});
		it("should discover test plugin", async function() {
			assert.deepEqual(
				await plugin.loadPluginInfos(testPlugin),
				[{ name: 'test' }]
			);
		});
		it("should reject on broken plugin", async function() {
			await assert.rejects(
				plugin.loadPluginInfos(brokenPlugin),
				{ message: "PluginError: Unexpected identifier" }
			);
		});
		it("should reject on invalid plugin", async function() {
			await assert.rejects(
				plugin.loadPluginInfos(invalidPlugin),
				{ message: `Plugin dir ${invalidPlugin}/invalid does not match the name of the plugin (wrong)` }
			);
		});

		after(async function() {
			await fs.unlink(path.join(brokenPlugin, 'broken', 'info.js'));
		});
	});

	describe("attachPluginMessages()", function() {
		let mockLink = new link.Link('source', 'target', new mock.MockConnector());
		let mockEvent = new link.Event({ type: 'test', links: ['target-source'] });
		it("should accept pluginInfo without messages", function() {
			plugin.attachPluginMessages(mockLink, {}, null);
		});
		it("should attach handler for the given message", function() {
			let mockEventEventHandler = function() {};
			plugin.attachPluginMessages(mockLink, { messages: { mockEvent }}, { mockEventEventHandler });
			assert(mockLink._handlers.get('test_event'), "handler was not registered");
		});
		it("should throw if missing handler for the given message", function() {
			assert.throws(
				() => plugin.attachPluginMessages(mockLink, { messages: { mockEvent }}, {}),
				new Error("Missing handler for test_event on source-target link")
			);
		});
	});
});