import unittest

import sys
import os
import math
from itertools import islice
import numpy as np
import galsim
import yaml

from observation_sim.instruments import Chip, Filter, FilterParam, FocalPlane


# test FUNCTION --- START #
def AddPreScan(GSImage, pre1=27, pre2=4, over1=71, over2=80, nsecy=2, nsecx=8):
    img = GSImage.array
    ny, nx = img.shape
    dx = int(nx/nsecx)
    dy = int(ny/nsecy)

    imgt = np.zeros([int(nsecy*nsecx), int(ny/nsecy+pre2+over2), int(nx/nsecx+pre1+over1)])
    for iy in range(nsecy):
        for ix in range(nsecx):
            if iy % 2 == 0:
                tx = ix
            else:
                tx = (nsecx-1)-ix
            ty = iy
            chunkidx = int(tx+ty*nsecx)  # chunk1-[1,2,3,4], chunk2-[5,6,7,8], chunk3-[9,10,11,12], chunk4-[13,14,15,16]

            imgtemp = np.zeros([int(ny/nsecy+pre2+over2), int(nx/nsecx+pre1+over1)])
            if int(chunkidx/4) == 0:
                imgtemp[pre2:pre2+dy, pre1:pre1+dx] = img[iy*dy:(iy+1)*dy, ix*dx:(ix+1)*dx]
                imgt[chunkidx, :, :] = imgtemp
            if int(chunkidx/4) == 1:
                imgtemp[pre2:pre2+dy, over1:over1+dx] = img[iy*dy:(iy+1)*dy, ix*dx:(ix+1)*dx]
                imgt[chunkidx, :, :] = imgtemp  # [:, ::-1]
            if int(chunkidx/4) == 2:
                imgtemp[over2:over2+dy, over1:over1+dx] = img[iy*dy:(iy+1)*dy, ix*dx:(ix+1)*dx]
                imgt[chunkidx, :, :] = imgtemp  # [::-1, ::-1]
            if int(chunkidx/4) == 3:
                imgtemp[over2:over2+dy, pre1:pre1+dx] = img[iy*dy:(iy+1)*dy, ix*dx:(ix+1)*dx]
                imgt[chunkidx, :, :] = imgtemp  # [::-1, :]

    imgtx1 = np.hstack(imgt[:nsecx:, :, :])  # hstack chunk(1,2)-[1,2,3,4,5,6,7,8]
    imgtx2 = np.hstack(imgt[:(nsecx-1):-1, :, :])  # hstack chunk(4,3)-[16,15,14,13,12,11,,10,9]

    newimg = galsim.Image(int(nx+(pre1+over1)*nsecx), int(ny+(pre2+over2)*nsecy), init_value=0)
    newimg.array[:, :] = np.concatenate([imgtx1, imgtx2])  # vstack chunk(1,2) & chunk(4,3)

    newimg.wcs = GSImage.wcs
    return newimg

# test FUNCTION --- END #


def defineCCD(iccd, config_file):
    with open(config_file, "r") as stream:
        try:
            config = yaml.safe_load(stream)
            # for key, value in config.items():
            #     print (key + " : " + str(value))
        except yaml.YAMLError as exc:
            print(exc)
    chip = Chip(chipID=iccd, config=config)
    chip.img = galsim.ImageF(chip.npix_x, chip.npix_y)
    focal_plane = FocalPlane(chip_list=[iccd])
    chip.img.wcs = focal_plane.getTanWCS(192.8595, 27.1283, -113.4333*galsim.degrees, chip.pix_scale)
    return chip


def defineFilt(chip):
    filter_param = FilterParam()
    filter_id, filter_type = chip.getChipFilter()
    filt = Filter(
        filter_id=filter_id,
        filter_type=filter_type,
        filter_param=filter_param,
        ccd_bandpass=chip.effCurve)
    bandpass_list = filt.bandpass_sub_list
    return bandpass_list


class detModule_coverage(unittest.TestCase):
    def __init__(self, methodName='runTest'):
        super(detModule_coverage, self).__init__(methodName)
        self.dataPath = os.path.join(os.getenv('UNIT_TEST_DATA_ROOT'), 'csst_msc_sim/csst_fz_msc')
        self.iccd = 1

    def test_add_prescan_overscan(self):
        config_file = os.path.join(self.dataPath, 'config_test.yaml')
        chip = defineCCD(self.iccd, config_file)
        bandpass = defineFilt(chip)
        print(chip.chipID)
        print(chip.cen_pix_x, chip.cen_pix_y)

        chip.img = AddPreScan(GSImage=chip.img,
                              pre1=chip.prescan_x,
                              pre2=chip.prescan_y,
                              over1=chip.overscan_x,
                              over2=chip.overscan_y)

        self.assertTrue((chip.prescan_x+chip.overscan_x)*8+chip.npix_x == np.shape(chip.img.array)[1])
        self.assertTrue((chip.prescan_y+chip.overscan_y)*2+chip.npix_y == np.shape(chip.img.array)[0])


if __name__ == '__main__':
    unittest.main()