import os
import shutil

import pytest
from fasthtml.components import Div

from components.undo_redo.components.UndoRedo import UndoRedo
from components.undo_redo.constants import UndoRedoAttrs
from core.dbengine import DbEngine
from core.settings_management import SettingsManager, MemoryDbEngine
from helpers import matches, div_icon, Contains, DoesNotContain
from my_mocks import tabs_manager

DB_ENGINE_ROOT = "undo_redo_test_db"
TEST_DB_ENTRY = "TestDbEntry"
TEST_DB_KEY = "TestDbKey"


class TestCommand:
  def __init__(self, value):
    self.value = value
  
  def __eq__(self, other):
    if not isinstance(other, TestCommand):
      return False
    
    return self.value == other.value
  
  def __hash__(self):
    return hash(self.value)


@pytest.fixture()
def engine(session):
  if os.path.exists(DB_ENGINE_ROOT):
    shutil.rmtree(DB_ENGINE_ROOT)
  
  engine = DbEngine(DB_ENGINE_ROOT)
  engine.init(session["user_id"])
  
  yield engine
  
  shutil.rmtree(DB_ENGINE_ROOT)


@pytest.fixture()
def settings_manager(engine):
  return SettingsManager(engine=engine)


@pytest.fixture
def undo_redo(session, tabs_manager, settings_manager):
  return UndoRedo(session,
                  UndoRedo.create_component_id(session),
                  settings_manager=settings_manager,
                  tabs_manager=tabs_manager)


def init_command(session, settings_manager, undo_redo, value, on_undo=None):
  settings_manager.save(session, TEST_DB_ENTRY, {TEST_DB_KEY: TestCommand(value)})
  undo_redo.snapshot(UndoRedoAttrs(f"Set value to {value}", on_undo=on_undo), TEST_DB_ENTRY, TEST_DB_KEY)


def test_i_can_render(undo_redo):
  actual = undo_redo.__ft__()
  expected = Div(
    Div(div_icon("undo", cls=Contains("mmt-btn-disabled")), data_tooltip="Nothing to undo."),
    Div(div_icon("redo", cls=Contains("mmt-btn-disabled")), data_tooltip="Nothing to redo."),
    id=undo_redo.get_id(),
  )
  
  assert matches(actual, expected)


def test_i_can_render_when_undoing_and_redoing(session, settings_manager, undo_redo):
  init_command(session, settings_manager, undo_redo, "1")
  init_command(session, settings_manager, undo_redo, "2")
  
  actual = undo_redo.__ft__()
  expected = Div(
    Div(div_icon("undo", cls=DoesNotContain("mmt-btn-disabled")), data_tooltip="Undo 'Set value to 2'."),
    Div(div_icon("redo", cls=Contains("mmt-btn-disabled")), data_tooltip="Nothing to redo."),
    id=undo_redo.get_id(),
  )
  assert matches(actual, expected)
  
  undo_redo.undo()  # The command is now undone. We can redo it and undo the first command.
  actual = undo_redo.__ft__()
  expected = Div(
    Div(div_icon("undo", cls=DoesNotContain("mmt-btn-disabled")), data_tooltip="Undo 'Set value to 1'."),
    Div(div_icon("redo", cls=DoesNotContain("mmt-btn-disabled")), data_tooltip="Redo 'Set value to 2'."),
    id=undo_redo.get_id(),
  )
  assert matches(actual, expected)
  
  undo_redo.undo()  # Undo again, I cannot undo anymore.
  actual = undo_redo.__ft__()
  expected = Div(
    Div(div_icon("undo", cls=Contains("mmt-btn-disabled"))),
    Div(div_icon("redo", cls=DoesNotContain("mmt-btn-disabled"))),
    id=undo_redo.get_id(),
  )
  assert matches(actual, expected)
  
  undo_redo.redo()  # Redo once.
  actual = undo_redo.__ft__()
  expected = Div(
    Div(div_icon("undo", cls=DoesNotContain("mmt-btn-disabled"))),
    Div(div_icon("redo", cls=DoesNotContain("mmt-btn-disabled"))),
    id=undo_redo.get_id(),
  )
  assert matches(actual, expected)
  
  undo_redo.redo()  # Redo a second time.
  actual = undo_redo.__ft__()
  expected = Div(
    Div(div_icon("undo", cls=DoesNotContain("mmt-btn-disabled"))),
    Div(div_icon("redo", cls=Contains("mmt-btn-disabled"))),
    id=undo_redo.get_id(),
  )
  assert matches(actual, expected)


def test_values_are_correctly_reset(session, settings_manager, undo_redo):
  # checks that the values are correctly returned
  # Only checks that hx_swap_oob="true" is automatically put when id is present in the return
  
  def on_undo():
    current = settings_manager.get(session, TEST_DB_ENTRY, TEST_DB_KEY)
    return Div(current.value, id='an_id')
  
  init_command(session, settings_manager, undo_redo, "1", on_undo=on_undo)
  init_command(session, settings_manager, undo_redo, "2", on_undo=on_undo)
  
  self, res = undo_redo.undo()
  expected = Div("1", id='an_id', hx_swap_oob="true")
  assert matches(res, expected)
  
  self, res = undo_redo.redo()
  expected = Div("2", id='an_id', hx_swap_oob="true")
  assert matches(res, expected)


def test_i_can_manage_when_the_entry_was_not_present(session, settings_manager, undo_redo):
  def on_undo():
    snapshot = settings_manager.load(session, TEST_DB_ENTRY)
    if TEST_DB_KEY in snapshot:
      return Div(snapshot[TEST_DB_KEY].value, id='an_id')
    else:
      return Div("**Not Found**", id='an_id')
  
  init_command(session, settings_manager, undo_redo, "1", on_undo=on_undo)
  
  self, res = undo_redo.undo()
  expected = Div("**Not Found**", id='an_id', hx_swap_oob="true")
  assert matches(res, expected)


def test_history_is_rewritten_when_pushing_a_command_after_undo(session, settings_manager, undo_redo):
  init_command(session, settings_manager, undo_redo, "1")
  init_command(session, settings_manager, undo_redo, "2")
  init_command(session, settings_manager, undo_redo, "3")
  
  undo_redo.undo()
  undo_redo.undo()
  init_command(session, settings_manager, undo_redo, "5")
  
  assert len(undo_redo.history) == 3  # do not forget that history always has a default command with digest = None