import concurrent.futures
import random
import shutil
import time
from pathlib import Path

import numpy as np
import pytest

from tests.conftest import apply_constants_patch


def _patch_augmentation_paths(monkeypatch, base: Path):
    apply_constants_patch(monkeypatch, base)


def _augment_annotation_with_total(monkeypatch):
    import augmentation as aug

    orig = aug.Augmentator.augment_annotation

    def wrapped(self, image_file):
        self.total_to_process = self.total_images_to_process
        return orig(self, image_file)

    monkeypatch.setattr(aug.Augmentator, "augment_annotation", wrapped)


def _seed():
    random.seed(42)
    np.random.seed(42)


@pytest.mark.performance
def test_pt_aug_01_throughput_ten_images_sixty_seconds(
    tmp_path, monkeypatch, sample_images_labels
):
    # Arrange
    _patch_augmentation_paths(monkeypatch, tmp_path)
    _augment_annotation_with_total(monkeypatch)
    _seed()
    import constants as c
    from augmentation import Augmentator

    img_dir = Path(c.config.data_images_dir)
    lbl_dir = Path(c.config.data_labels_dir)
    img_dir.mkdir(parents=True, exist_ok=True)
    lbl_dir.mkdir(parents=True, exist_ok=True)
    src_img, src_lbl = sample_images_labels(10)
    for p in src_img.glob("*.jpg"):
        shutil.copy2(p, img_dir / p.name)
    for p in src_lbl.glob("*.txt"):
        shutil.copy2(p, lbl_dir / p.name)
    # Act
    t0 = time.perf_counter()
    Augmentator().augment_annotations()
    elapsed = time.perf_counter() - t0
    # Assert
    assert elapsed <= 60.0


@pytest.mark.performance
def test_pt_aug_02_parallel_at_least_one_point_five_x_faster(
    tmp_path, monkeypatch, sample_images_labels
):
    # Arrange
    _patch_augmentation_paths(monkeypatch, tmp_path)
    _augment_annotation_with_total(monkeypatch)
    _seed()
    import constants as c
    from augmentation import Augmentator

    img_dir = Path(c.config.data_images_dir)
    lbl_dir = Path(c.config.data_labels_dir)
    proc_dir = Path(c.config.processed_dir)
    img_dir.mkdir(parents=True, exist_ok=True)
    lbl_dir.mkdir(parents=True, exist_ok=True)
    src_img, src_lbl = sample_images_labels(10)
    for p in src_img.glob("*.jpg"):
        shutil.copy2(p, img_dir / p.name)
    for p in src_lbl.glob("*.txt"):
        shutil.copy2(p, lbl_dir / p.name)
    Path(c.config.processed_images_dir).mkdir(parents=True, exist_ok=True)
    Path(c.config.processed_labels_dir).mkdir(parents=True, exist_ok=True)
    names = sorted(p.name for p in img_dir.glob("*.jpg"))

    class _E:
        __slots__ = ("name",)

        def __init__(self, name):
            self.name = name

    entries = [_E(n) for n in names]

    # Act
    aug_seq = Augmentator()
    aug_seq.total_images_to_process = len(entries)
    t0 = time.perf_counter()
    for e in entries:
        aug_seq.augment_annotation(e)
    seq_elapsed = time.perf_counter() - t0

    shutil.rmtree(proc_dir)
    Path(c.config.processed_images_dir).mkdir(parents=True, exist_ok=True)
    Path(c.config.processed_labels_dir).mkdir(parents=True, exist_ok=True)

    aug_par = Augmentator()
    aug_par.total_images_to_process = len(entries)
    t0 = time.perf_counter()
    with concurrent.futures.ThreadPoolExecutor() as ex:
        list(ex.map(aug_par.augment_annotation, entries))
    par_elapsed = time.perf_counter() - t0

    # Assert
    assert seq_elapsed >= par_elapsed * 1.5