# Copyright The PyTorch Lightning team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import os
import pickle
import sys
from collections import defaultdict
from typing import Union
from unittest import mock
from unittest.mock import ANY, call, PropertyMock

import pytest
import torch
from torch.utils.data.dataloader import DataLoader

from pytorch_lightning import Trainer
from pytorch_lightning.callbacks import ModelCheckpoint, ProgressBarBase, TQDMProgressBar
from pytorch_lightning.callbacks.progress.tqdm_progress import Tqdm
from pytorch_lightning.core.lightning import LightningModule
from pytorch_lightning.utilities.exceptions import MisconfigurationException
from tests.helpers.boring_model import BoringModel, RandomDataset
from tests.helpers.runif import RunIf


@pytest.mark.parametrize(
    "kwargs",
    [
        # won't print but is still set
        {"callbacks": TQDMProgressBar(refresh_rate=0)},
        {"callbacks": TQDMProgressBar()},
        {"progress_bar_refresh_rate": 1},
    ],
)
def test_tqdm_progress_bar_on(tmpdir, kwargs):
    """Test different ways the progress bar can be turned on."""
    if "progress_bar_refresh_rate" in kwargs:
        with pytest.deprecated_call(match=r"progress_bar_refresh_rate=.*` is deprecated"):
            trainer = Trainer(default_root_dir=tmpdir, **kwargs)
    else:
        trainer = Trainer(default_root_dir=tmpdir, **kwargs)

    progress_bars = [c for c in trainer.callbacks if isinstance(c, ProgressBarBase)]
    assert len(progress_bars) == 1
    assert progress_bars[0] is trainer.progress_bar_callback


@pytest.mark.parametrize("kwargs", [{"enable_progress_bar": False}, {"progress_bar_refresh_rate": 0}])
def test_tqdm_progress_bar_off(tmpdir, kwargs):
    """Test different ways the progress bar can be turned off."""
    if "progress_bar_refresh_rate" in kwargs:
        pytest.deprecated_call(match=r"progress_bar_refresh_rate=.*` is deprecated").__enter__()
    trainer = Trainer(default_root_dir=tmpdir, **kwargs)
    progress_bars = [c for c in trainer.callbacks if isinstance(c, ProgressBarBase)]
    assert not len(progress_bars)


def test_tqdm_progress_bar_misconfiguration():
    """Test that Trainer doesn't accept multiple progress bars."""
    # Trainer supports only a single progress bar callback at the moment
    callbacks = [TQDMProgressBar(), TQDMProgressBar(), ModelCheckpoint(dirpath="../trainer")]
    with pytest.raises(MisconfigurationException, match=r"^You added multiple progress bar callbacks"):
        Trainer(callbacks=callbacks)

    with pytest.raises(MisconfigurationException, match=r"enable_progress_bar=False` but found `TQDMProgressBar"):
        Trainer(callbacks=TQDMProgressBar(), enable_progress_bar=False)


def test_tqdm_progress_bar_totals(tmpdir):
    """Test that the progress finishes with the correct total steps processed."""

    model = BoringModel()

    trainer = Trainer(default_root_dir=tmpdir, max_epochs=1)
    bar = trainer.progress_bar_callback

    trainer.fit(model)

    # check main progress bar total
    n = bar.total_train_batches
    m = bar.total_val_batches
    assert len(trainer.train_dataloader) == n
    assert bar.main_progress_bar.total == n + m
    assert bar.main_progress_bar.leave

    # check val progress bar total
    assert sum(len(loader) for loader in trainer.val_dataloaders) == m
    assert bar.val_progress_bar.total == m
    assert not bar.val_progress_bar.leave

    # main progress bar should have reached the end (train batches + val batches)
    assert bar.main_progress_bar.n == n + m
    assert bar.train_batch_idx == n

    # val progress bar should have reached the end
    assert bar.val_progress_bar.n == m
    assert bar.val_batch_idx == m

    # check that the test progress bar is off
    assert 0 == bar.total_test_batches
    with pytest.raises(TypeError, match="test_progress_bar` .* not been set"):
        assert bar.test_progress_bar is None

    trainer.validate(model)

    assert bar.val_progress_bar.total == m
    assert bar.val_progress_bar.n == m
    assert bar.val_batch_idx == m
    assert bar.val_progress_bar.leave

    trainer.test(model)

    # check test progress bar total
    k = bar.total_test_batches
    assert sum(len(loader) for loader in trainer.test_dataloaders) == k
    assert bar.test_progress_bar.total == k
    assert bar.test_progress_bar.leave

    # test progress bar should have reached the end
    assert bar.test_progress_bar.n == k
    assert bar.test_batch_idx == k


def test_tqdm_progress_bar_fast_dev_run(tmpdir):
    model = BoringModel()

    trainer = Trainer(default_root_dir=tmpdir, fast_dev_run=True)

    trainer.fit(model)

    progress_bar = trainer.progress_bar_callback
    assert 1 == progress_bar.total_train_batches
    # total val batches are known only after val dataloaders have reloaded

    assert 1 == progress_bar.total_val_batches
    assert 1 == progress_bar.train_batch_idx
    assert 1 == progress_bar.val_batch_idx
    assert 0 == progress_bar.test_batch_idx

    # the main progress bar should display 2 batches (1 train, 1 val)
    assert 2 == progress_bar.main_progress_bar.total
    assert 2 == progress_bar.main_progress_bar.n

    trainer.validate(model)

    # the validation progress bar should display 1 batch
    assert 1 == progress_bar.val_batch_idx
    assert 1 == progress_bar.val_progress_bar.total
    assert 1 == progress_bar.val_progress_bar.n

    trainer.test(model)

    # the test progress bar should display 1 batch
    assert 1 == progress_bar.test_batch_idx
    assert 1 == progress_bar.test_progress_bar.total
    assert 1 == progress_bar.test_progress_bar.n


@pytest.mark.parametrize("refresh_rate", [0, 1, 50])
def test_tqdm_progress_bar_progress_refresh(tmpdir, refresh_rate: int):
    """Test that the three progress bars get correctly updated when using different refresh rates."""

    model = BoringModel()

    class CurrentProgressBar(TQDMProgressBar):

        train_batches_seen = 0
        val_batches_seen = 0
        test_batches_seen = 0

        def on_train_batch_end(self, trainer, pl_module, outputs, batch, batch_idx):
            super().on_train_batch_end(trainer, pl_module, outputs, batch, batch_idx)
            self.train_batches_seen += 1

        def on_validation_batch_end(self, trainer, pl_module, outputs, batch, batch_idx, dataloader_idx):
            super().on_validation_batch_end(trainer, pl_module, outputs, batch, batch_idx, dataloader_idx)
            self.val_batches_seen += 1

        def on_test_batch_end(self, trainer, pl_module, outputs, batch, batch_idx, dataloader_idx):
            super().on_test_batch_end(trainer, pl_module, outputs, batch, batch_idx, dataloader_idx)
            self.test_batches_seen += 1

    progress_bar = CurrentProgressBar(refresh_rate=refresh_rate)
    with pytest.deprecated_call(match=r"progress_bar_refresh_rate=101\)` is deprecated"):
        trainer = Trainer(
            default_root_dir=tmpdir,
            callbacks=[progress_bar],
            progress_bar_refresh_rate=101,  # should not matter if custom callback provided
            limit_train_batches=1.0,
            num_sanity_val_steps=2,
            max_epochs=3,
        )
    assert trainer.progress_bar_callback.refresh_rate == refresh_rate

    trainer.fit(model)
    assert progress_bar.train_batches_seen == 3 * progress_bar.total_train_batches
    assert progress_bar.val_batches_seen == 3 * progress_bar.total_val_batches + trainer.num_sanity_val_steps
    assert progress_bar.test_batches_seen == 0

    trainer.validate(model)
    assert progress_bar.train_batches_seen == 3 * progress_bar.total_train_batches
    assert progress_bar.val_batches_seen == 4 * progress_bar.total_val_batches + trainer.num_sanity_val_steps
    assert progress_bar.test_batches_seen == 0

    trainer.test(model)
    assert progress_bar.train_batches_seen == 3 * progress_bar.total_train_batches
    assert progress_bar.val_batches_seen == 4 * progress_bar.total_val_batches + trainer.num_sanity_val_steps
    assert progress_bar.test_batches_seen == progress_bar.total_test_batches


@pytest.mark.parametrize("limit_val_batches", (0, 5))
def test_num_sanity_val_steps_progress_bar(tmpdir, limit_val_batches: int):
    """Test val_progress_bar total with 'num_sanity_val_steps' Trainer argument."""

    class CurrentProgressBar(TQDMProgressBar):
        val_pbar_total = 0
        sanity_pbar_total = 0

        def on_sanity_check_end(self, *args):
            self.sanity_pbar_total = self.val_progress_bar.total
            super().on_sanity_check_end(*args)

        def on_validation_epoch_end(self, *args):
            self.val_pbar_total = self.val_progress_bar.total
            super().on_validation_epoch_end(*args)

    model = BoringModel()
    progress_bar = CurrentProgressBar()
    num_sanity_val_steps = 2

    trainer = Trainer(
        default_root_dir=tmpdir,
        max_epochs=1,
        num_sanity_val_steps=num_sanity_val_steps,
        limit_train_batches=1,
        limit_val_batches=limit_val_batches,
        callbacks=[progress_bar],
        logger=False,
        enable_checkpointing=False,
    )
    trainer.fit(model)

    assert progress_bar.sanity_pbar_total == min(num_sanity_val_steps, limit_val_batches)
    assert progress_bar.val_pbar_total == limit_val_batches


def test_tqdm_progress_bar_default_value(tmpdir):
    """Test that a value of None defaults to refresh rate 1."""
    trainer = Trainer(default_root_dir=tmpdir)
    assert trainer.progress_bar_callback.refresh_rate == 1


@mock.patch.dict(os.environ, {"COLAB_GPU": "1"})
def test_tqdm_progress_bar_value_on_colab(tmpdir):
    """Test that Trainer will override the default in Google COLAB."""
    trainer = Trainer(default_root_dir=tmpdir)
    assert trainer.progress_bar_callback.refresh_rate == 20

    trainer = Trainer(default_root_dir=tmpdir, callbacks=TQDMProgressBar())
    assert trainer.progress_bar_callback.refresh_rate == 20

    trainer = Trainer(default_root_dir=tmpdir, callbacks=TQDMProgressBar(refresh_rate=19))
    assert trainer.progress_bar_callback.refresh_rate == 19

    with pytest.deprecated_call(match=r"progress_bar_refresh_rate=19\)` is deprecated"):
        trainer = Trainer(default_root_dir=tmpdir, progress_bar_refresh_rate=19)
    assert trainer.progress_bar_callback.refresh_rate == 19


class MockTqdm(Tqdm):
    def __init__(self, *args, **kwargs):
        self.n_values = []
        super().__init__(*args, **kwargs)
        self.__n = 0
        # again to reset additions from `super().__init__`
        self.n_values = []

    @property
    def n(self):
        return self.__n

    @n.setter
    def n(self, value):
        self.__n = value
        # track the changes in the `n` value
        if not len(self.n_values) or value != self.n_values[-1]:
            self.n_values.append(value)


@pytest.mark.parametrize(
    "train_batches,val_batches,refresh_rate,train_updates,val_updates",
    [
        [2, 3, 1, [1, 2, 3, 4, 5], [1, 2, 3]],
        [0, 0, 3, None, None],
        [1, 0, 3, [1], None],
        [1, 1, 3, [2], [1]],
        [5, 0, 3, [3, 5], None],
        [5, 2, 3, [3, 7], [2]],
        [5, 2, 6, [7], [2]],
    ],
)
def test_main_progress_bar_update_amount(
    tmpdir, train_batches: int, val_batches: int, refresh_rate: int, train_updates, val_updates
):
    """Test that the main progress updates with the correct amount together with the val progress.

    At the end of the epoch, the progress must not overshoot if the number of steps is not divisible by the refresh
    rate.
    """
    model = BoringModel()
    progress_bar = TQDMProgressBar(refresh_rate=refresh_rate)
    trainer = Trainer(
        default_root_dir=tmpdir,
        max_epochs=1,
        limit_train_batches=train_batches,
        limit_val_batches=val_batches,
        callbacks=[progress_bar],
        logger=False,
        enable_checkpointing=False,
    )
    with mock.patch("pytorch_lightning.callbacks.progress.tqdm_progress.Tqdm", MockTqdm):
        trainer.fit(model)
    if train_batches > 0:
        assert progress_bar.main_progress_bar.n_values == train_updates
    if val_batches > 0:
        assert progress_bar.val_progress_bar.n_values == val_updates


@pytest.mark.parametrize("test_batches,refresh_rate,updates", [[1, 3, [1]], [3, 1, [1, 2, 3]], [5, 3, [3, 5]]])
def test_test_progress_bar_update_amount(tmpdir, test_batches: int, refresh_rate: int, updates: list):
    """Test that test progress updates with the correct amount."""
    model = BoringModel()
    progress_bar = TQDMProgressBar(refresh_rate=refresh_rate)
    trainer = Trainer(
        default_root_dir=tmpdir,
        max_epochs=1,
        limit_test_batches=test_batches,
        callbacks=[progress_bar],
        logger=False,
        enable_checkpointing=False,
    )
    with mock.patch("pytorch_lightning.callbacks.progress.tqdm_progress.Tqdm", MockTqdm):
        trainer.test(model)
    assert progress_bar.test_progress_bar.n_values == updates


def test_tensor_to_float_conversion(tmpdir):
    """Check tensor gets converted to float."""

    class TestModel(BoringModel):
        def training_step(self, batch, batch_idx):
            self.log("a", torch.tensor(0.123), prog_bar=True, on_epoch=False)
            self.log("b", {"b1": torch.tensor([1])}, prog_bar=True, on_epoch=False)
            self.log("c", {"c1": 2}, prog_bar=True, on_epoch=False)
            return super().training_step(batch, batch_idx)

    trainer = Trainer(
        default_root_dir=tmpdir, max_epochs=1, limit_train_batches=2, logger=False, enable_checkpointing=False
    )
    trainer.fit(TestModel())

    torch.testing.assert_allclose(trainer.progress_bar_metrics["a"], 0.123)
    assert trainer.progress_bar_metrics["b"] == {"b1": 1.0}
    assert trainer.progress_bar_metrics["c"] == {"c1": 2.0}
    pbar = trainer.progress_bar_callback.main_progress_bar
    actual = str(pbar.postfix)
    assert actual.endswith("a=0.123, b={'b1': 1.0}, c={'c1': 2.0}"), actual


@pytest.mark.parametrize(
    "input_num, expected",
    [
        [1, "1"],
        [1.0, "1.000"],
        [0.1, "0.100"],
        [1e-3, "0.001"],
        [1e-5, "1e-5"],
        ["1.0", "1.000"],
        ["10000", "10000"],
        ["abc", "abc"],
    ],
)
def test_tqdm_format_num(input_num: Union[str, int, float], expected: str):
    """Check that the specialized tqdm.format_num appends 0 to floats and strings."""
    assert Tqdm.format_num(input_num) == expected


class PrintModel(BoringModel):
    def training_step(self, *args, **kwargs):
        self.print("training_step", end="")
        return super().training_step(*args, **kwargs)

    def validation_step(self, *args, **kwargs):
        self.print("validation_step", file=sys.stderr)
        return super().validation_step(*args, **kwargs)

    def test_step(self, *args, **kwargs):
        self.print("test_step")
        return super().test_step(*args, **kwargs)

    def predict_step(self, *args, **kwargs):
        self.print("predict_step")
        return super().predict_step(*args, **kwargs)


@mock.patch("tqdm.tqdm.write")
def test_tqdm_progress_bar_print(tqdm_write, tmpdir):
    """Test that printing in the LightningModule redirects arguments to the progress bar."""
    model = PrintModel()
    bar = TQDMProgressBar()
    trainer = Trainer(
        default_root_dir=tmpdir,
        num_sanity_val_steps=0,
        limit_train_batches=1,
        limit_val_batches=1,
        limit_test_batches=1,
        limit_predict_batches=1,
        max_steps=1,
        callbacks=[bar],
    )
    trainer.fit(model)
    trainer.test(model)
    trainer.predict(model)
    assert tqdm_write.call_args_list == [
        call("training_step", end=""),
        call("validation_step", file=sys.stderr),
        call("test_step"),
        call("predict_step"),
    ]


@mock.patch("tqdm.tqdm.write")
def test_tqdm_progress_bar_print_no_train(tqdm_write, tmpdir):
    """Test that printing in the LightningModule redirects arguments to the progress bar without training."""
    model = PrintModel()
    bar = TQDMProgressBar()
    trainer = Trainer(
        default_root_dir=tmpdir,
        num_sanity_val_steps=0,
        limit_val_batches=1,
        limit_test_batches=1,
        limit_predict_batches=1,
        max_steps=1,
        callbacks=[bar],
    )

    trainer.validate(model)
    trainer.test(model)
    trainer.predict(model)
    assert tqdm_write.call_args_list == [
        call("validation_step", file=sys.stderr),
        call("test_step"),
        call("predict_step"),
    ]


@mock.patch("builtins.print")
@mock.patch("pytorch_lightning.callbacks.progress.tqdm_progress.Tqdm.write")
def test_tqdm_progress_bar_print_disabled(tqdm_write, mock_print, tmpdir):
    """Test that printing in LightningModule goes through built-in print function when progress bar is disabled."""
    model = PrintModel()
    bar = TQDMProgressBar()
    trainer = Trainer(
        default_root_dir=tmpdir,
        num_sanity_val_steps=0,
        limit_train_batches=1,
        limit_val_batches=1,
        limit_test_batches=1,
        limit_predict_batches=1,
        max_steps=1,
        callbacks=[bar],
    )
    bar.disable()
    trainer.fit(model)
    trainer.test(model, verbose=False)
    trainer.predict(model)

    mock_print.assert_has_calls(
        [call("training_step", end=""), call("validation_step", file=ANY), call("test_step"), call("predict_step")]
    )
    tqdm_write.assert_not_called()


def test_tqdm_progress_bar_can_be_pickled():
    bar = TQDMProgressBar()
    trainer = Trainer(fast_dev_run=True, callbacks=[bar], max_steps=1)
    model = BoringModel()

    pickle.dumps(bar)
    trainer.fit(model)
    pickle.dumps(bar)
    trainer.test(model)
    pickle.dumps(bar)
    trainer.predict(model)
    pickle.dumps(bar)


@RunIf(min_gpus=2, standalone=True)
@pytest.mark.parametrize(
    ["total_train_samples", "train_batch_size", "total_val_samples", "val_batch_size", "val_check_interval"],
    [(8, 4, 2, 1, 0.2), (8, 4, 2, 1, 0.5)],
)
def test_progress_bar_max_val_check_interval(
    tmpdir, total_train_samples, train_batch_size, total_val_samples, val_batch_size, val_check_interval
):
    world_size = 2
    train_data = DataLoader(RandomDataset(32, total_train_samples), batch_size=train_batch_size)
    val_data = DataLoader(RandomDataset(32, total_val_samples), batch_size=val_batch_size)

    model = BoringModel()
    trainer = Trainer(
        default_root_dir=tmpdir,
        num_sanity_val_steps=0,
        max_epochs=1,
        enable_model_summary=False,
        val_check_interval=val_check_interval,
        gpus=world_size,
        strategy="ddp",
    )
    trainer.fit(model, train_dataloaders=train_data, val_dataloaders=val_data)

    total_train_batches = total_train_samples // (train_batch_size * world_size)
    val_check_batch = max(1, int(total_train_batches * val_check_interval))
    assert trainer.val_check_batch == val_check_batch
    val_checks_per_epoch = total_train_batches / val_check_batch
    total_val_batches = total_val_samples // (val_batch_size * world_size)
    assert trainer.progress_bar_callback.total_train_batches == total_train_batches
    assert trainer.progress_bar_callback.total_val_batches == total_val_batches
    total_val_batches = total_val_batches * val_checks_per_epoch
    if trainer.is_global_zero:
        assert trainer.progress_bar_callback.main_progress_bar.total == total_train_batches + total_val_batches


def test_get_progress_bar_metrics(tmpdir: str):
    class TestProgressBar(TQDMProgressBar):
        def get_metrics(self, trainer: Trainer, model: LightningModule):
            items = super().get_metrics(trainer, model)
            items.pop("v_num", None)
            return items

    progress_bar = TestProgressBar()
    trainer = Trainer(
        default_root_dir=tmpdir,
        callbacks=[progress_bar],
        fast_dev_run=True,
    )
    model = BoringModel()
    trainer.fit(model)
    model.truncated_bptt_steps = 2
    standard_metrics = progress_bar.get_metrics(trainer, model)
    assert "loss" in standard_metrics.keys()
    assert "split_idx" in standard_metrics.keys()
    assert "v_num" not in standard_metrics.keys()


def test_tqdm_progress_bar_correct_value_epoch_end(tmpdir):
    """TQDM counterpart to test_rich_progress_bar::test_rich_progress_bar_correct_value_epoch_end."""

    class MockedProgressBar(TQDMProgressBar):
        calls = defaultdict(list)

        def get_metrics(self, trainer, pl_module):
            items = super().get_metrics(trainer, model)
            del items["v_num"]
            del items["loss"]
            # this is equivalent to mocking `set_postfix` as this method gets called every time
            self.calls[trainer.state.fn].append(
                (trainer.state.stage, trainer.current_epoch, trainer.global_step, items)
            )
            return items

    class MyModel(BoringModel):
        def training_step(self, batch, batch_idx):
            self.log("a", self.global_step, prog_bar=True, on_step=False, on_epoch=True, reduce_fx=max)
            return super().training_step(batch, batch_idx)

        def validation_step(self, batch, batch_idx):
            self.log("b", self.global_step, prog_bar=True, on_step=False, on_epoch=True, reduce_fx=max)
            return super().validation_step(batch, batch_idx)

        def test_step(self, batch, batch_idx):
            self.log("c", self.global_step, prog_bar=True, on_step=False, on_epoch=True, reduce_fx=max)
            return super().test_step(batch, batch_idx)

    model = MyModel()
    pbar = MockedProgressBar()
    trainer = Trainer(
        default_root_dir=tmpdir,
        limit_train_batches=2,
        limit_val_batches=2,
        limit_test_batches=2,
        max_epochs=2,
        enable_model_summary=False,
        enable_checkpointing=False,
        log_every_n_steps=1,
        callbacks=pbar,
    )

    trainer.fit(model)
    assert pbar.calls["fit"] == [
        ("sanity_check", 0, 0, {"b": 0}),
        ("train", 0, 0, {}),
        ("train", 0, 1, {}),
        ("validate", 0, 1, {"b": 1}),  # validation end
        # epoch end over, `on_epoch=True` metrics are computed
        ("train", 0, 2, {"a": 1, "b": 1}),  # training epoch end
        ("train", 1, 2, {"a": 1, "b": 1}),
        ("train", 1, 3, {"a": 1, "b": 1}),
        ("validate", 1, 3, {"a": 1, "b": 3}),  # validation end
        ("train", 1, 4, {"a": 3, "b": 3}),  # training epoch end
    ]

    trainer.validate(model, verbose=False)
    assert pbar.calls["validate"] == []

    trainer.test(model, verbose=False)
    assert pbar.calls["test"] == []


@mock.patch("pytorch_lightning.trainer.trainer.Trainer.is_global_zero", new_callable=PropertyMock, return_value=False)
def test_tqdm_progress_bar_disabled_when_not_rank_zero(is_global_zero):
    """Test that the progress bar is disabled when not in global rank zero."""
    progress_bar = TQDMProgressBar()
    model = BoringModel()
    trainer = Trainer(
        callbacks=[progress_bar],
        fast_dev_run=True,
    )

    progress_bar.enable()
    trainer.fit(model)
    assert progress_bar.is_disabled

    progress_bar.enable()
    trainer.predict(model)
    assert progress_bar.is_disabled

    progress_bar.enable()
    trainer.validate(model)
    assert progress_bar.is_disabled

    progress_bar.enable()
    trainer.test(model)
    assert progress_bar.is_disabled