import time

import numpy as np
import pytest

import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui, QtTest
from tests.image_testing import TransposedImageItem, assertImageApproved

try:
    import cupy
except ImportError:
    cupy = None
app = pg.mkQApp()


@pytest.mark.skipif(cupy is None, reason="CuPy unavailable to test")
def test_useCupy_can_be_set_after_init():
    prev_setting = pg.getConfigOption("useCupy")
    try:
        pg.setConfigOption("useCupy", False)
        w = pg.GraphicsLayoutWidget()
        w.show()
        view = pg.ViewBox()
        w.setCentralWidget(view)
        w.resize(200, 200)
        img = cupy.random.randint(0, 255, size=(32, 32)).astype(cupy.uint8)
        ii = pg.ImageItem()
        view.addItem(ii)
        pg.setConfigOption("useCupy", True)
        ii.setImage(img)
        w.hide()
    finally:
        pg.setConfigOption("useCupy", prev_setting)


@pytest.mark.skipif(cupy is None, reason="CuPy unavailable to test")
def test_ensuring_substrate():
    prev_setting = pg.getConfigOption("useCupy")
    try:
        pg.setConfigOption("useCupy", True)
        ii = pg.ImageItem()

        data = cupy.random.randint(0, 255, size=(32, 32)).astype(cupy.uint8)
        assert data is ii._ensure_proper_substrate(data, cupy)
        assert isinstance(ii._ensure_proper_substrate(data, cupy), cupy.ndarray)
        assert data is not ii._ensure_proper_substrate(data, np)
        assert isinstance(ii._ensure_proper_substrate(data, np), np.ndarray)

        data = np.random.randint(0, 255, size=(32, 32)).astype(np.uint8)
        assert data is ii._ensure_proper_substrate(data, np)
        assert isinstance(ii._ensure_proper_substrate(data, np), np.ndarray)
        assert data is not ii._ensure_proper_substrate(data, cupy)
        assert isinstance(ii._ensure_proper_substrate(data, cupy), cupy.ndarray)

        data = range(0, 255)
        assert data is not ii._ensure_proper_substrate(data, np)
        assert isinstance(ii._ensure_proper_substrate(data, np), np.ndarray)
        assert data is not ii._ensure_proper_substrate(data, cupy)
        assert isinstance(ii._ensure_proper_substrate(data, cupy), cupy.ndarray)
    finally:
        pg.setConfigOption("useCupy", prev_setting)


def test_ImageItem(transpose=False):
    w = pg.GraphicsLayoutWidget()
    w.show()
    view = pg.ViewBox()
    w.setCentralWidget(view)
    w.resize(200, 200)
    img = TransposedImageItem(border=0.5, transpose=transpose)

    view.addItem(img)
    
    # test mono float
    np.random.seed(0)
    data = np.random.normal(size=(20, 20))
    dmax = data.max()
    data[:10, 1] = dmax + 10
    data[1, :10] = dmax + 12
    data[3, :10] = dmax + 13
    img.setImage(data)
    
    QtTest.QTest.qWaitForWindowExposed(w)
    time.sleep(0.1)
    app.processEvents()
    assertImageApproved(w, 'imageitem/init', 'Init image item. View is auto-scaled, image axis 0 marked by 1 line, axis 1 is marked by 2 lines. Origin in bottom-left.')
    
    # ... with colormap
    cmap = pg.ColorMap([0, 0.25, 0.75, 1], [[0, 0, 0, 255], [255, 0, 0, 255], [255, 255, 0, 255], [255, 255, 255, 255]])
    img.setLookupTable(cmap.getLookupTable())
    assertImageApproved(w, 'imageitem/lut', 'Set image LUT.')
    
    # ... and different levels
    img.setLevels([dmax+9, dmax+13])
    assertImageApproved(w, 'imageitem/levels1', 'Levels show only axis lines.')

    img.setLookupTable(None)

    # test mono int
    data = np.fromfunction(lambda x,y: x+y*10, (129, 128)).astype(np.int16)
    img.setImage(data)
    assertImageApproved(w, 'imageitem/gradient_mono_int', 'Mono int gradient.')
    
    img.setLevels([640, 641])
    assertImageApproved(w, 'imageitem/gradient_mono_int_levels', 'Mono int gradient w/ levels to isolate diagonal.')

    # test mono byte
    data = np.fromfunction(lambda x,y: x+y, (129, 128)).astype(np.ubyte)
    img.setImage(data)
    assertImageApproved(w, 'imageitem/gradient_mono_byte', 'Mono byte gradient.')
    
    img.setLevels([127, 128])
    assertImageApproved(w, 'imageitem/gradient_mono_byte_levels', 'Mono byte gradient w/ levels to isolate diagonal.')

    # test monochrome image
    data = np.zeros((10, 10), dtype='uint8')
    data[:5,:5] = 1
    data[5:,5:] = 1
    img.setImage(data)
    assertImageApproved(w, 'imageitem/monochrome', 'Ubyte image with only 0,1 values.')
    
    # test bool
    data = data.astype(bool)
    img.setImage(data)
    assertImageApproved(w, 'imageitem/bool', 'Boolean mask.')

    # test RGBA byte
    data = np.zeros((100, 100, 4), dtype='ubyte')
    data[..., 0] = np.linspace(0, 255, 100).reshape(100, 1)
    data[..., 1] = np.linspace(0, 255, 100).reshape(1, 100)
    data[..., 3] = 255
    img.setImage(data)
    assertImageApproved(w, 'imageitem/gradient_rgba_byte', 'RGBA byte gradient.')
    
    img.setLevels([[128, 129], [128, 255], [0, 1], [0, 255]])
    assertImageApproved(w, 'imageitem/gradient_rgba_byte_levels', 'RGBA byte gradient. Levels set to show x=128 and y>128.')
    
    # test RGBA float
    data = data.astype(float)
    img.setImage(data / 1e9)
    assertImageApproved(w, 'imageitem/gradient_rgba_float', 'RGBA float gradient.')

    # checkerboard to test alpha
    img2 = TransposedImageItem(transpose=transpose)
    img2.setImage(np.fromfunction(lambda x,y: (x+y)%2, (10, 10)), levels=[-1,2])
    view.addItem(img2)
    img2.setScale(10)
    img2.setZValue(-10)
    
    data[..., 0] *= 1e-9
    data[..., 1] *= 1e9
    data[..., 3] = np.fromfunction(lambda x,y: np.sin(0.1 * (x+y)), (100, 100))
    img.setImage(data, levels=[[0, 128e-9],[0, 128e9],[0, 1],[-1, 1]])
    assertImageApproved(w, 'imageitem/gradient_rgba_float_alpha', 'RGBA float gradient with alpha.')    

    # test composition mode
    img.setCompositionMode(QtGui.QPainter.CompositionMode.CompositionMode_Plus)
    assertImageApproved(w, 'imageitem/gradient_rgba_float_additive', 'RGBA float gradient with alpha and additive composition mode.')    
    
    img2.hide()
    img.setCompositionMode(QtGui.QPainter.CompositionMode.CompositionMode_SourceOver)
    
    # test downsampling
    data = np.fromfunction(lambda x,y: np.cos(0.002 * x**2), (800, 100))
    img.setImage(data, levels=[-1, 1])
    assertImageApproved(w, 'imageitem/resolution_without_downsampling', 'Resolution test without downsampling.')
    
    img.setAutoDownsample(True)
    assertImageApproved(w, 'imageitem/resolution_with_downsampling_x', 'Resolution test with downsampling across x axis.')
    assert img._lastDownsample == (4, 1)
    
    img.setImage(data.T, levels=[-1, 1])
    assertImageApproved(w, 'imageitem/resolution_with_downsampling_y', 'Resolution test with downsampling across y axis.')
    assert img._lastDownsample == (1, 4)
    
    w.hide()


def test_ImageItem_axisorder():
    # All image tests pass again using the opposite axis order
    origMode = pg.getConfigOption('imageAxisOrder')
    altMode = 'row-major' if origMode == 'col-major' else 'col-major'
    pg.setConfigOptions(imageAxisOrder=altMode)
    try:
        test_ImageItem(transpose=True)
    finally:
        pg.setConfigOptions(imageAxisOrder=origMode)
        
def test_setRect():    
    def assert_equal_transforms(tr1, tr2):
        dic = { # there seems to be no easy way to get the matrix in one call:
            'tr11': ( tr1.m11(), tr2.m11() ),
            'tr12': ( tr1.m12(), tr2.m12() ),
            'tr13': ( tr1.m13(), tr2.m13() ),
            'tr21': ( tr1.m21(), tr2.m21() ),
            'tr22': ( tr1.m22(), tr2.m22() ),
            'tr23': ( tr1.m23(), tr2.m23() ),
            'tr31': ( tr1.m31(), tr2.m31() ),
            'tr32': ( tr1.m32(), tr2.m32() ),
            'tr33': ( tr1.m33(), tr2.m33() )
        }
        log_string = 'Matrix element mismatch\n'
        good = True
        for key, values in dic.items():
            val1, val2 = values
            if val1 != val2:
                good = False
                log_string += f'{key}: {val1} != {val2}\n'
        assert good, log_string
    
    tr = QtGui.QTransform() # construct a reference transform
    tr.scale(2, 4)          # scale 2x2 image to 4x8
    tr.translate(-1, -1)    # after shifting by -1, -1 
    # the transformed 2x2 image would cover (-2,-4) to (2,4).
    # Now have setRect construct the same transform:
    imgitem = pg.ImageItem(np.eye(2), rect=(-2,-4, 4,8) ) # test tuple of floats
    assert_equal_transforms(tr, imgitem.transform())

    imgitem = pg.ImageItem(np.eye(2), rect=QtCore.QRectF(-2,-4, 4,8) ) # test QRectF
    assert_equal_transforms(tr, imgitem.transform())
    
    imgitem = pg.ImageItem(np.eye(2))
    imgitem.setRect(-2,-4, 4,8) # test individual parameters
    assert_equal_transforms(tr, imgitem.transform())

    imgitem = pg.ImageItem(np.eye(2))
    imgitem.setRect(QtCore.QRect(-2,-4, 4,8)) # test QRect argument
    assert_equal_transforms(tr, imgitem.transform())


def test_dividebyzero():
    # test that the calculation of downsample factors
    # does not result in a division by zero
    plt = pg.PlotWidget()
    plt.show()
    plt.setAspectLocked(True)
    imgitem = pg.ImageItem(np.random.normal(size=(100,100)))
    imgitem.setAutoDownsample(True)
    plt.addItem(imgitem)

    plt.setRange(xRange=[-5e+25, 5e+25],yRange=[-5e+25, 5e+25])
    QtTest.QTest.qWaitForWindowExposed(plt)
    QtTest.QTest.qWait(100)
    # must manually call imgitem.render here or the exception
    # will only exist on the Qt event loop
    imgitem.render()
