import json
import os
from copy import deepcopy
from functools import partial
from itertools import starmap, repeat
from operator import itemgetter
from typing import List

import fpdf
import pdf2image
import pytest
from funcy import juxt, one, first

from image_prediction.formatter.formatters.enum import ReverseEnumFormatter
from image_prediction.image_extractor.extractor import ImageMetadataPair
from image_prediction.info import Info
from image_prediction.stitching.grouping import group_by_coordinate
from image_prediction.stitching.merging import (
    merge_metadata_horizontally,
    merge_metadata_vertically,
    merge_pair_horizontally,
    merge_pair_vertically,
    concat_images_horizontally,
    concat_images_vertically,
    merge_group_horizontally,
    merge_group_vertically,
)
from image_prediction.stitching.stitching import stitch_pairs
from image_prediction.stitching.utils import (
    make_coord_getter,
    make_length_getter,
)
from test.utils.comparison import images_equal
from test.utils.generation.image import random_single_color_image_from_metadata, gray_image_from_metadata
from test.utils.generation.pdf import add_image
from test.utils.stitching import BoxSplitter

x1_getter, y1_getter, x2_getter, y2_getter = map(make_coord_getter, ("x1", "y1", "x2", "y2"))
width_getter, height_getter = map(make_length_getter, ("width", "height"))


def test_group_by_coordinate_exact():
    pairs = [(0, 1), (0, 3), (1, 4), (1, 4), (1, 2), (3, 3)]
    pairs_grouped = list(group_by_coordinate(pairs, itemgetter(0), tolerance=0))
    assert pairs_grouped == [[(0, 1), (0, 3)], [(1, 4), (1, 4), (1, 2)], [(3, 3)]]


def test_group_by_coordinate_fuzzy():
    pairs = [(0, 1), (1, 3), (1, 4), (2, 4), (2, 2), (3, 3)]
    pairs_grouped = list(group_by_coordinate(pairs, itemgetter(0), tolerance=1))
    assert pairs_grouped == [[(0, 1), (1, 3), (1, 4)], [(2, 4), (2, 2), (3, 3)]]


def test_image_stitcher(patch_image_metadata_pairs, base_patch_metadata, base_patch_image):
    pairs_stitched = stitch_pairs(patch_image_metadata_pairs)
    pair_stitched = first(pairs_stitched)

    assert len(pairs_stitched) == 1
    assert pair_stitched.metadata == base_patch_metadata
    assert images_equal(pair_stitched.image.resize((10, 10)), base_patch_image.resize((10, 10)), atol=0.4)


def test_image_stitcher_with_gaps_must_succeed():
    from image_prediction.locations import TEST_DATA_DIR

    with open(os.path.join(TEST_DATA_DIR, "stitching_with_tolerance.json")) as f:
        patches_metadata, base_patch_metadata = itemgetter("input", "target")(ReverseEnumFormatter(Info)(json.load(f)))

    images = map(gray_image_from_metadata, patches_metadata)
    patch_image_metadata_pairs = list(starmap(ImageMetadataPair, zip(images, patches_metadata)))

    pairs_stitched = stitch_pairs(patch_image_metadata_pairs, tolerance=7)

    assert len(pairs_stitched) == 1
    pair_stitched = first(pairs_stitched)
    assert pair_stitched.metadata == base_patch_metadata


@pytest.mark.parametrize("noise", [(0, 2)])
@pytest.mark.parametrize("split_count", [5])
@pytest.mark.parametrize("width", [100])
@pytest.mark.parametrize("height", [100])
@pytest.mark.parametrize("page_width", [100])
@pytest.mark.parametrize("page_height", [100])
@pytest.mark.parametrize("execution_number", range(100))
@pytest.mark.xfail(reason="Does not always succeed due to locally maximizing merging logic.")
def test_image_stitcher_with_gaps_can_fail(patch_image_metadata_pairs, base_patch_metadata, execution_number):
    pairs_stitched = stitch_pairs(patch_image_metadata_pairs, tolerance=4)
    assert len(pairs_stitched) == 1 and first(pairs_stitched).metadata == base_patch_metadata


def test_merge_group_horizontally(horizontal_merge_test_pairs):
    pr1, pr2, pr_merged_expected = horizontal_merge_test_pairs

    prs_merged = merge_group_horizontally([pr1, pr2])
    assert len(prs_merged) == 1
    assert pair_equal(prs_merged[0], pr_merged_expected)

    mdat3 = deepcopy(pr2.metadata)
    mdat3[Info.HEIGHT] += 30
    mdat3[Info.Y2] += 30
    im3 = gray_image_from_metadata(mdat3)
    pr3 = ImageMetadataPair(im3, mdat3)

    prs_merged = merge_group_horizontally([pr1, pr2, pr3])
    assert len(prs_merged) == 2
    assert one(partial(pair_equal, pr_merged_expected), prs_merged)


def test_merge_group_vertically(vertical_merge_test_pairs):
    pr1, pr2, pr_merged_expected = vertical_merge_test_pairs

    prs_merged = merge_group_vertically([pr1, pr2])
    assert len(prs_merged) == 1
    assert pair_equal(prs_merged[0], pr_merged_expected)

    mdat3 = deepcopy(pr2.metadata)
    mdat3[Info.WIDTH] += 30
    mdat3[Info.X2] += 30
    im3 = gray_image_from_metadata(mdat3)
    pr3 = ImageMetadataPair(im3, mdat3)

    prs_merged = merge_group_vertically([pr1, pr2, pr3])
    assert len(prs_merged) == 2
    assert one(partial(pair_equal, pr_merged_expected), prs_merged)


def pair_equal(pr1, pr2):
    return pr1.metadata == pr2.metadata and images_equal(pr1.image, pr2.image)


def test_merge_pairs_horizontally(horizontal_merge_test_pairs):
    pr1, pr2, pr_merged_expected = horizontal_merge_test_pairs
    pr_merged = merge_pair_horizontally(pr1, pr2)
    assert pair_equal(pr_merged, pr_merged_expected)


def test_merge_pairs_vertically(vertical_merge_test_pairs):
    pr1, pr2, pr_merged_expected = vertical_merge_test_pairs
    pr_merged = merge_pair_vertically(pr1, pr2)
    assert pair_equal(pr_merged, pr_merged_expected)


@pytest.fixture
def horizontal_merge_test_pairs(horizontal_merge_test_metadata):
    images = map(gray_image_from_metadata, horizontal_merge_test_metadata)
    return list(starmap(ImageMetadataPair, zip(images, horizontal_merge_test_metadata)))


@pytest.fixture
def vertical_merge_test_pairs(vertical_merge_test_metadata):
    images = map(gray_image_from_metadata, vertical_merge_test_metadata)
    return list(starmap(ImageMetadataPair, zip(images, vertical_merge_test_metadata)))


def test_merge_metadata_horizontally(horizontal_merge_test_metadata):
    mdat1, mdat2, mdat_merged = horizontal_merge_test_metadata
    assert merge_metadata_horizontally(mdat1, mdat2) == mdat_merged


def test_merge_metadata_vertically(vertical_merge_test_metadata):
    mdat1, mdat2, mdat_merged = vertical_merge_test_metadata
    assert merge_metadata_vertically(mdat1, mdat2) == mdat_merged


@pytest.fixture
def horizontal_merge_test_metadata(merge_test_metadata):
    mdat1, mdat2, mdat_merged = merge_test_metadata

    mdat2[Info.X1] = mdat1[Info.X2]
    mdat2[Info.X2] = mdat2[Info.X1] + mdat2[Info.WIDTH]

    mdat_merged.update({Info.WIDTH: mdat1[Info.WIDTH] + mdat2[Info.WIDTH], Info.X2: mdat2[Info.X2]})

    return mdat1, mdat2, mdat_merged


@pytest.fixture
def vertical_merge_test_metadata(merge_test_metadata):
    mdat1, mdat2, mdat_merged = merge_test_metadata

    mdat2[Info.Y1] = mdat1[Info.Y2]
    mdat2[Info.Y2] = mdat2[Info.Y1] + mdat2[Info.HEIGHT]

    mdat_merged.update({Info.HEIGHT: mdat1[Info.HEIGHT] + mdat2[Info.HEIGHT], Info.Y2: mdat2[Info.Y2]})

    return mdat1, mdat2, mdat_merged


@pytest.fixture
def merge_test_metadata(base_patch_metadata):
    return juxt(*repeat(deepcopy, 3))(base_patch_metadata)


@pytest.fixture
def base_patch_image(stitch_test_pdf):
    return pdf2image.convert_from_bytes(stitch_test_pdf)[0]


def test_concat_images_horizontally(horizontal_merge_test_metadata):
    mdat1, mdat2, mdat_merged = horizontal_merge_test_metadata
    im1, im2, im_merged_expected = map(gray_image_from_metadata, [mdat1, mdat2, mdat_merged])
    im_merged = concat_images_horizontally(im1, im2, mdat_merged)
    assert im_merged.size == im_merged_expected.size
    assert images_equal(im_merged, im_merged_expected)


def test_concat_images_vertically(vertical_merge_test_metadata):
    mdat1, mdat2, mdat_merged = vertical_merge_test_metadata
    im1, im2, im_merged_expected = map(gray_image_from_metadata, [mdat1, mdat2, mdat_merged])
    im_merged = concat_images_vertically(im1, im2, mdat_merged)
    assert im_merged.size == im_merged_expected.size
    assert images_equal(im_merged, im_merged_expected)


@pytest.fixture
def stitch_test_pdf(patch_image_metadata_pairs, width, height):

    pdf = fpdf.FPDF(unit="pt", format=(width, height))

    for pair in patch_image_metadata_pairs:
        add_image(pdf, pair)

    return pdf.output(dest="S").encode("latin1")


@pytest.fixture
def patch_image_metadata_pairs(patches_metadata) -> List[ImageMetadataPair]:
    images = map(random_single_color_image_from_metadata, patches_metadata)
    return list(starmap(ImageMetadataPair, zip(images, patches_metadata)))


@pytest.fixture
def patches_metadata(base_patch_metadata, noise, split_count):
    patches_metadata = list(BoxSplitter(noise).split_box(base_patch_metadata, split_count))
    return patches_metadata


@pytest.fixture(params=[(0, 0)])
def noise(request):
    return request.param


@pytest.fixture(params=[5])
def split_count(request):
    return request.param