import assert from "node:assert/strict";
import test from "node:test";
import { createCompletedTaskAutoClear, TODO_AUTO_CLEAR_DELAY_MS } from "../src/auto-clear.ts";
import { TaskState } from "../src/state.ts";

function clearState(state: TaskState, onClear: () => void): boolean {
  state.set("replace", [], false);
  onClear();
  return true;
}

test("clears the task tree ten seconds after every task remains done", (context) => {
  context.mock.timers.enable({ apis: ["setTimeout"] });
  const state = new TaskState();
  state.add([{ name: "Done", status: "done" }]);
  let clearCount = 0;
  const autoClear = createCompletedTaskAutoClear(state, () => clearState(state, () => {
    clearCount += 1;
  }));

  autoClear.sync();
  context.mock.timers.tick(TODO_AUTO_CLEAR_DELAY_MS - 1);
  assert.equal(state.stats().total, 1);

  context.mock.timers.tick(1);
  assert.deepEqual(state.snapshot(), { tasks: [], nextId: 1 });
  assert.equal(clearCount, 1);
});

test("cancels a pending clear when unfinished work appears", (context) => {
  context.mock.timers.enable({ apis: ["setTimeout"] });
  const state = new TaskState();
  state.add([{ name: "Done", status: "done" }]);
  let clearCount = 0;
  const autoClear = createCompletedTaskAutoClear(state, () => clearState(state, () => {
    clearCount += 1;
  }));

  autoClear.sync();
  state.add([{ name: "New work" }]);
  autoClear.sync();
  context.mock.timers.tick(TODO_AUTO_CLEAR_DELAY_MS);

  assert.equal(state.stats().total, 2);
  assert.equal(clearCount, 0);
});

test("preserves the deadline for unrelated refreshes", (context) => {
  context.mock.timers.enable({ apis: ["setTimeout"] });
  const state = new TaskState();
  state.add([{ name: "Done", status: "done" }]);
  const autoClear = createCompletedTaskAutoClear(state, () => clearState(state, () => {}));

  autoClear.sync();
  context.mock.timers.tick(9_000);
  state.update([{ id: 1, name: "Renamed" }]);
  autoClear.sync();
  context.mock.timers.tick(1_000);

  assert.equal(state.stats().total, 0);
});

test("restarts the delay for changed or restored completed trees", (context) => {
  context.mock.timers.enable({ apis: ["setTimeout"] });
  const state = new TaskState();
  state.add([{ name: "Done", status: "done" }]);
  const autoClear = createCompletedTaskAutoClear(state, () => clearState(state, () => {}));

  autoClear.sync();
  context.mock.timers.tick(9_000);
  state.add([{ name: "Also done", status: "done" }]);
  autoClear.sync();
  context.mock.timers.tick(1_000);
  assert.equal(state.stats().total, 2);

  context.mock.timers.tick(8_000);
  autoClear.sync(true);
  context.mock.timers.tick(2_000);
  assert.equal(state.stats().total, 2);

  context.mock.timers.tick(8_000);
  assert.equal(state.stats().total, 0);
});

test("retries after a clear transaction fails and supports shutdown cancellation", (context) => {
  context.mock.timers.enable({ apis: ["setTimeout"] });
  const state = new TaskState();
  state.add([{ name: "Done", status: "done" }]);
  let attempts = 0;
  const autoClear = createCompletedTaskAutoClear(state, () => {
    attempts += 1;
    if (attempts === 1) return false;
    return clearState(state, () => {});
  });

  autoClear.sync();
  context.mock.timers.tick(TODO_AUTO_CLEAR_DELAY_MS);
  assert.equal(state.stats().total, 1);
  context.mock.timers.tick(TODO_AUTO_CLEAR_DELAY_MS);
  assert.equal(state.stats().total, 0);

  state.add([{ name: "Done again", status: "done" }]);
  autoClear.sync();
  autoClear.cancel();
  context.mock.timers.tick(TODO_AUTO_CLEAR_DELAY_MS);
  assert.equal(state.stats().total, 1);
});