local async = require "util.async";

describe("util.async", function()

	local debug = false;

	local print = print;

	if debug then

		require "util.logger".add_simple_sink(print);

	else

		print = function () end

	end

	local function new(func, name)

		local log = {};

		return async.runner(func, setmetatable({}, {

			__index = function (_, event)

				return function (runner, err)

					print(name, "event", event, err)

					print "--"

					table.insert(log, { event = event, err = err });

				end;

			end;

		})), log;

	end

	describe("#runner", function()

		it("should work", function()			

			local r, l = new(function (item) assert(type(item) == "number") end);

			r:run(1);

			r:run(2);

		end);

		it("should be ready after creation", function ()

			local r = async.runner(function (item) end);

			assert.equal(r.state, "ready");

		end);

		it("should do nothing if the queue is empty", function ()

			local did_run;

			local r = async.runner(function (item) did_run = true end);

			r:run();

			assert.equal(r.state, "ready");

			assert.is_nil(did_run);

			r:run("hello");

			assert.is_true(did_run);

		end);

		it("should support queuing work items without running", function ()

			local did_run;

			local r = async.runner(function (item) did_run = true end);

			r:enqueue("hello");

			assert.equal(r.state, "ready");

			assert.is_nil(did_run);

			r:run();

			assert.is_true(did_run);

		end);

		it("should support queuing multiple work items", function ()

			local last_item;

			local s = spy(function (item) last_item = item; end);

			local r = async.runner(s);

			r:enqueue("hello");

			r:enqueue("there");

			r:enqueue("world");

			assert.equal(r.state, "ready");

			r:run();

			assert.equal(r.state, "ready");

			assert.spy(s).was.called(3);

			assert.equal(last_item, "world");

		end);

		it("should support all simple data types", function ()

			local last_item;

			local s = spy(function (item) last_item = item; end);

			local r = async.runner(s);

			local values = { {}, 123, "hello", true, false };

			for i = 1, #values do

				r:enqueue(values[i]);

			end

			assert.equal(r.state, "ready");

			r:run();

			assert.equal(r.state, "ready");

			assert.spy(s).was.called(#values);

			for i = 1, #values do

				assert.spy(s).was.called_with(values[i]);

			end

			assert.equal(last_item, values[#values]);

		end);

		describe("#errors", function ()

			local last_processed_item, last_error;

			local r;

			local wait, done;

			r = async.runner(function (item)

				if item == "error" then

					error({ e = "test error" });

				elseif item == "wait" then

					wait, done = async.waiter();

					wait();

					error({ e = "post wait error" });

				end

				last_processed_item = item;

			end, {

				error = function (runner, err)

					assert.equal(r, runner);

					last_error = err;

				end;

			});

			randomize(false);

			it("should notify", function ()

				local last_processed_item, last_error;

				local r;

				r = async.runner(function (item)

					if item == "error" then

						error({ e = "test error" });

					end

					last_processed_item = item;

				end, {

					error = function (runner, err)

						assert.equal(r, runner);

						last_error = err;

					end;

				});

				r:run("hello");

				assert.equal(r.state, "ready");

				assert.equal(last_processed_item, "hello");

				assert.equal(last_error, nil);

				r:run("error");

				assert.is_table(last_error);

				assert.equal(last_error.e, "test error");

				last_error = nil;

				assert.equal(r.state, "ready");

				assert.equal(last_processed_item, "hello");

			end);

			it("should not be fatal to the runner", function ()

				r:run("world");

				assert.equal(r.state, "ready");

				assert.equal(last_processed_item, "world");

			end);

			it("should work despite a #waiter", function ()

				-- This test covers an important case where a runner

				-- throws an error while being executed outside of the

				-- main loop. This happens when it was blocked ('waiting'),

				-- and then released (via a call to done()).

				last_error = nil;

				r:run("wait");

				assert.equal(r.state, "waiting");

				done();

				-- At this point an error happens (state goes error->ready)

				assert.equal(r.state, "ready");

				assert.is_table(last_error);

				assert.equal(last_error.e, "post wait error");

				last_error = nil;

				r:run("hello again");

				assert.equal(r.state, "ready");

				assert.equal(last_processed_item, "hello again");

			end);

		end);

	end);

	describe("#waiter", function()

		it("should error outside of async context", function ()

			assert.has_error(function ()

				async.waiter();

			end);

		end);

		it("should work", function ()

			local wait, done;

			local r, l = new(function (item)

				assert(type(item) == "number")

				if item == 3 then

					wait, done = async.waiter();

					wait();

				end

			end);

			r:run(1);

			assert(r.state == "ready");

			r:run(2);

			assert(r.state == "ready");

			r:run(3);

			assert(r.state == "waiting");

			done();

			assert(r.state == "ready");

			--for k, v in ipairs(l) do print(k,v) end

		end);

		it("should work", function ()

			--------------------

			local wait, done;

			local last_item = 0;

			local r, l = new(function (item)

				assert(type(item) == "number")

				assert(item == last_item + 1);

				last_item = item;

				if item == 3 then

					wait, done = async.waiter();

					wait();

				end

			end);

			r:run(1);

			assert(r.state == "ready");

			r:run(2);

			assert(r.state == "ready");

			r:run(3);

			assert(r.state == "waiting");

			r:run(4);

			assert(r.state == "waiting");

			done();

			assert(r.state == "ready");

			--for k, v in ipairs(l) do print(k,v) end

		end);

		it("should work", function ()

			--------------------

			local wait, done;

			local last_item = 0;

			local r, l = new(function (item)

				assert(type(item) == "number")

				assert((item == last_item + 1) or item == 3);

				last_item = item;

				if item == 3 then

					wait, done = async.waiter();

					wait();

				end

			end);

			r:run(1);

			assert(r.state == "ready");

			r:run(2);

			assert(r.state == "ready");

			local dones = {};

			r:run(3);

			assert(r.state == "waiting");

			r:run(3);

			assert(r.state == "waiting");

			r:run(3);

			assert(r.state == "waiting");

			r:run(4);

			assert(r.state == "waiting");

			for i = 1, 3 do

				done();

				if i < 3 then

					assert(r.state == "waiting");

				end

			end

			assert(r.state == "ready");

			--for k, v in ipairs(l) do print(k,v) end

		end);

		it("should work", function ()

			--------------------

			local wait, done;

			local last_item = 0;

			local r, l = new(function (item)

				assert(type(item) == "number")

				assert((item == last_item + 1) or item == 3);

				last_item = item;

				if item == 3 then

					wait, done = async.waiter();

					wait();

				end

			end);

			r:run(1);

			assert(r.state == "ready");

			r:run(2);

			assert(r.state == "ready");

			local dones = {};

			r:run(3);

			assert(r.state == "waiting");

			r:run(3);

			assert(r.state == "waiting");

			for i = 1, 2 do

				done();

				if i < 2 then

					assert(r.state == "waiting");

				end

			end

			assert(r.state == "ready");

			r:run(4);

			assert(r.state == "ready");

			assert(r.state == "ready");

			--for k, v in ipairs(l) do print(k,v) end

		end);

		it("should work with multiple runners in parallel", function ()

			-- Now with multiple runners

			--------------------

			local wait1, done1;

			local last_item1 = 0;

			local r1, l1 = new(function (item)

				assert(type(item) == "number")

				assert((item == last_item1 + 1) or item == 3);

				last_item1 = item;

				if item == 3 then

					wait1, done1 = async.waiter();

					wait1();

				end

			end, "r1");

			local wait2, done2;

			local last_item2 = 0;

			local r2, l2 = new(function (item)

				assert(type(item) == "number")

				assert((item == last_item2 + 1) or item == 3);

				last_item2 = item;

				if item == 3 then

					wait2, done2 = async.waiter();

					wait2();

				end

			end, "r2");

			r1:run(1);

			assert(r1.state == "ready");

			r1:run(2);

			assert(r1.state == "ready");

			local dones = {};

			r1:run(3);

			assert(r1.state == "waiting");

			r1:run(3);

			assert(r1.state == "waiting");

			r2:run(1);

			assert(r1.state == "waiting");

			assert(r2.state == "ready");

			r2:run(2);

			assert(r1.state == "waiting");

			assert(r2.state == "ready");

			r2:run(3);

			assert(r1.state == "waiting");

			assert(r2.state == "waiting");

			done2();

			r2:run(3);

			assert(r1.state == "waiting");

			assert(r2.state == "waiting");

			done2();

			r2:run(4);

			assert(r1.state == "waiting");

			assert(r2.state == "ready");

			for i = 1, 2 do

				done1();

				if i < 2 then

					assert(r1.state == "waiting");