from bopytex.planner import Task
from bopytex.scheduler import Scheduler
import pytest


def test_schedule_append():
    actions = {"DO": lambda deps, args: "done"}
    scheduler = Scheduler(actions)
    tasks = [Task(action="DO", args={}, deps=[])]
    scheduler.append(tasks)
    assert scheduler.tasks == tasks


def test_schedule_dispatch():
    actions = {"DO": lambda deps, args: "done"}
    scheduler = Scheduler(actions)
    task = Task(action="DO", args={}, deps=[])
    result = scheduler.dispatch(task)
    assert result == "done"


def test_schedule_one_task():
    actions = {"DO": lambda deps, args: "done"}
    scheduler = Scheduler(actions)
    scheduler.append([Task(action="DO", args={}, deps=[])])
    result = scheduler.next()
    assert result == "done"
    assert scheduler.tasks == []
    assert scheduler.done == ["done"]


def test_schedule_one_task_with_args():
    actions = {"DO": lambda deps, args: f"{args['task']} done"}
    scheduler = Scheduler(actions)
    scheduler.append([Task(action="DO", args={"task": "one"}, deps=[])])
    result = scheduler.next()
    assert result == "one done"
    assert scheduler.tasks == []
    assert scheduler.done == ["one done"]


def test_schedule_multiple_tasks():
    actions = {"DO": lambda deps, args: f"{args['task']} done"}
    scheduler = Scheduler(actions)
    t1 = Task(action="DO", args={"task": "one"}, deps=[])
    t2 = Task(action="DO", args={"task": "two"}, deps=[])
    t3 = Task(action="DO", args={"task": "three"}, deps=[])
    scheduler.append([t1, t2, t3])
    result = scheduler.next()
    assert result == "one done"
    assert scheduler.tasks == [t2, t3]
    assert scheduler.done == ["one done"]

    result = scheduler.next()
    assert result == "two done"
    assert scheduler.tasks == [t3]
    assert scheduler.done == ["one done", "two done"]

    result = scheduler.next()
    assert result == "three done"
    assert scheduler.tasks == []
    assert scheduler.done == ["one done", "two done", "three done"]


def test_schedule_multiple_tasks_with_dependencies():
    actions = {"DO": lambda deps, args: f"{args['task']} done"}
    scheduler = Scheduler(actions)
    t1 = Task(action="DO", args={"task": "one"}, deps=["three done"])
    t2 = Task(action="DO", args={"task": "two"}, deps=["one done"])
    t3 = Task(action="DO", args={"task": "three"}, deps=[])
    scheduler.append([t1, t2, t3])

    result = scheduler.next()
    assert result == "three done"
    assert scheduler.tasks == [t1, t2]
    assert scheduler.done == ["three done"]

    result = scheduler.next()
    assert result == "one done"
    assert scheduler.tasks == [t2]
    assert scheduler.done == ["three done", "one done"]

    result = scheduler.next()
    assert result == "two done"
    assert scheduler.tasks == []
    assert scheduler.done == ["three done", "one done", "two done"]


def test_schedule_empty_task():
    actions = {"DO": lambda deps, args: f"{args['task']} done"}
    scheduler = Scheduler(actions)
    scheduler.append([])
    with pytest.raises(StopIteration):
        scheduler.next()


def test_schedule_multiple_tasks_with_undoable_dependencies():
    actions = {"DO": lambda deps, args: f"{args['task']} done"}
    scheduler = Scheduler(actions)
    t1 = Task(action="DO", args={"task": "one"}, deps=["three done"])
    t2 = Task(action="DO", args={"task": "two"}, deps=[])
    scheduler.append([t1, t2])
    scheduler.run()
    assert scheduler.tasks == [t1]
    assert scheduler.done == ["two done"]