local queue = require "util.queue";

describe("util.queue", function()

	describe("#new()", function()

		it("should work", function()

			do

				local q = queue.new(10);

				assert.are.equal(q.size, 10);

				assert.are.equal(q:count(), 0);

				assert.is_true(q:push("one"));

				assert.is_true(q:push("two"));

				assert.is_true(q:push("three"));

				for i = 4, 10 do

					assert.is_true(q:push("hello"));

					assert.are.equal(q:count(), i, "count is not "..i.."("..q:count()..")");

				end

				assert.are.equal(q:push("hello"), nil, "queue overfull!");

				assert.are.equal(q:push("hello"), nil, "queue overfull!");

				assert.are.equal(q:pop(), "one", "queue item incorrect");

				assert.are.equal(q:pop(), "two", "queue item incorrect");

				assert.is_true(q:push("hello"));

				assert.is_true(q:push("hello"));

				assert.are.equal(q:pop(), "three", "queue item incorrect");

				assert.is_true(q:push("hello"));

				assert.are.equal(q:push("hello"), nil, "queue overfull!");

				assert.are.equal(q:push("hello"), nil, "queue overfull!");

				assert.are.equal(q:count(), 10, "queue count incorrect");

				for _ = 1, 10 do

					assert.are.equal(q:pop(), "hello", "queue item incorrect");

				end

				assert.are.equal(q:count(), 0, "queue count incorrect");

				assert.are.equal(q:pop(), nil, "empty queue pops non-nil result");

				assert.are.equal(q:count(), 0, "popping empty queue affects count");

				assert.are.equal(q:peek(), nil, "empty queue peeks non-nil result");

				assert.are.equal(q:count(), 0, "peeking empty queue affects count");

				assert.is_true(q:push(1));

				for i = 1, 1001 do

					assert.are.equal(q:pop(), i);

					assert.are.equal(q:count(), 0);

					assert.is_true(q:push(i+1));

					assert.are.equal(q:count(), 1);

				end

				assert.are.equal(q:pop(), 1002);

				assert.is_true(q:push(1));

				for i = 1, 1000 do

					assert.are.equal(q:pop(), i);

					assert.is_true(q:push(i+1));

				end

				assert.are.equal(q:pop(), 1001);

				assert.are.equal(q:count(), 0);

			end

			do

				-- Test queues that purge old items when pushing to a full queue

				local q = queue.new(10, true);

				for i = 1, 10 do

					q:push(i);

				end

				assert.are.equal(q:count(), 10);

				assert.is_true(q:push(11));

				assert.are.equal(q:count(), 10);

				assert.are.equal(q:pop(), 2); -- First item should have been purged

				assert.are.equal(q:peek(), 3);

				for i = 12, 32 do

					assert.is_true(q:push(i));

				end

				assert.are.equal(q:count(), 10);

				assert.are.equal(q:pop(), 23);

			end

			do

				-- Test iterator

				local q = queue.new(10, true);

				for i = 1, 10 do

					q:push(i);

				end

				local i = 0;

				for item in q:items() do

					i = i + 1;

					assert.are.equal(item, i, "unexpected item returned by iterator")

				end

			end

		end);

	end);

	describe("consume()", function ()

		it("should work", function ()

			local q = queue.new(10);

			for i = 1, 5 do

				q:push(i);

			end

			local c = 0;

			for i in q:consume() do

				assert(i == c + 1);

				assert(q:count() == (5-i));

				c = i;

			end

		end);

		it("should work even if items are pushed in the loop", function ()

			local q = queue.new(10);

			for i = 1, 5 do

				q:push(i);

			end

			local c = 0;

			for i in q:consume() do

				assert(i == c + 1);

				if c < 3 then

					assert(q:count() == (5-i));

				else

					assert(q:count() == (6-i));

				end

				c = i;

				if c == 3 then

					q:push(6);

				end

			end

			assert.equal(c, 6);

		end);

	end);

end);