import os
import galsim
import ctypes
import numpy as np
from astropy.io import fits
from datetime import datetime

from observation_sim.instruments.chip import effects
from observation_sim.config.header import generatePrimaryHeader, generateExtensionHeader

try:
    import importlib.resources as pkg_resources
except ImportError:
    # Try backported to PY<37 'importlib_resources'
    import importlib_resources as pkg_resources


def log_info(msg, logger=None):
    if logger:
        logger.info(msg)
    else:
        print(msg, flush=True)


def getChipSLSGratingID(chipID):
    gratingID = ['', '']
    if chipID == 1:
        gratingID = ['GI2', 'GI1']
    if chipID == 2:
        gratingID = ['GV4', 'GV3']
    if chipID == 3:
        gratingID = ['GU2', 'GU1']
    if chipID == 4:
        gratingID = ['GU4', 'GU3']
    if chipID == 5:
        gratingID = ['GV2', 'GV1']
    if chipID == 10:
        gratingID = ['GI4', 'GI3']
    if chipID == 21:
        gratingID = ['GI6', 'GI5']
    if chipID == 26:
        gratingID = ['GV8', 'GV7']
    if chipID == 27:
        gratingID = ['GU6', 'GU5']
    if chipID == 28:
        gratingID = ['GU8', 'GU7']
    if chipID == 29:
        gratingID = ['GV6', 'GV5']
    if chipID == 30:
        gratingID = ['GI8', 'GI7']
    return gratingID


def getChipSLSConf(chipID):
    confFile = ''
    if chipID == 1:
        confFile = ['CSST_GI2.conf', 'CSST_GI1.conf']
    if chipID == 2:
        confFile = ['CSST_GV4.conf', 'CSST_GV3.conf']
    if chipID == 3:
        confFile = ['CSST_GU2.conf', 'CSST_GU1.conf']
    if chipID == 4:
        confFile = ['CSST_GU4.conf', 'CSST_GU3.conf']
    if chipID == 5:
        confFile = ['CSST_GV2.conf', 'CSST_GV1.conf']
    if chipID == 10:
        confFile = ['CSST_GI4.conf', 'CSST_GI3.conf']
    if chipID == 21:
        confFile = ['CSST_GI6.conf', 'CSST_GI5.conf']
    if chipID == 26:
        confFile = ['CSST_GV8.conf', 'CSST_GV7.conf']
    if chipID == 27:
        confFile = ['CSST_GU6.conf', 'CSST_GU5.conf']
    if chipID == 28:
        confFile = ['CSST_GU8.conf', 'CSST_GU7.conf']
    if chipID == 29:
        confFile = ['CSST_GV6.conf', 'CSST_GV5.conf']
    if chipID == 30:
        confFile = ['CSST_GI8.conf', 'CSST_GI7.conf']
    return confFile


def generateHeader(chip, pointing, img_type=None, img_type_code=None, project_cycle='9', run_counter='1'):
    if (img_type is None) or (img_type_code is None):
        img_type = pointing.pointing_type
        img_type_code = pointing.pointing_type_code

    h_prim = generatePrimaryHeader(
        xlen=chip.npix_x,
        ylen=chip.npix_y,
        pointing_id=pointing.obs_id,
        pointing_type_code=img_type_code,
        ra=pointing.ra,
        dec=pointing.dec,
        pixel_scale=chip.pix_scale,
        time_pt=pointing.timestamp,
        exptime=pointing.exp_time,
        im_type=img_type,
        sat_pos=[pointing.sat_x, pointing.sat_y, pointing.sat_z],
        sat_vel=[pointing.sat_vx, pointing.sat_vy, pointing.sat_vz],
        project_cycle=project_cycle,
        run_counter=run_counter,
        chip_name=str(chip.chipID).rjust(2, '0'))
    h_ext = generateExtensionHeader(
        chip=chip,
        xlen=chip.npix_x,
        ylen=chip.npix_y,
        ra=pointing.ra,
        dec=pointing.dec,
        pa=pointing.img_pa.deg,
        gain=chip.gain,
        readout=chip.read_noise,
        dark=chip.dark_noise,
        saturation=90000,
        pixel_scale=chip.pix_scale,
        pixel_size=chip.pix_size,
        xcen=chip.x_cen,
        ycen=chip.y_cen,
        extName=img_type,
        timestamp=pointing.timestamp,
        exptime=pointing.exp_time,
        readoutTime=chip.readout_time,
        t_shutter_open=pointing.t_shutter_open,
        t_shutter_close=pointing.t_shutter_close)
    return h_prim, h_ext


def output_fits_image(chip, pointing, img, output_dir, img_type=None, img_type_code=None, project_cycle='9', run_counter='1'):
    h_prim, h_ext = generateHeader(
        chip=chip,
        pointing=pointing,
        img_type=img_type,
        img_type_code=img_type_code,
        project_cycle=project_cycle,
        run_counter=run_counter)
    hdu1 = fits.PrimaryHDU(header=h_prim)
    hdu1.add_checksum()
    hdu1.header.comments['CHECKSUM'] = 'HDU checksum'
    hdu1.header.comments['DATASUM'] = 'data unit checksum'
    hdu2 = fits.ImageHDU(img.array, header=h_ext)
    hdu2.add_checksum()
    hdu2.header.comments['XTENSION'] = 'extension type'
    hdu2.header.comments['CHECKSUM'] = 'HDU checksum'
    hdu2.header.comments['DATASUM'] = 'data unit checksum'
    hdu1 = fits.HDUList([hdu1, hdu2])
    fname = os.path.join(output_dir, h_prim['FILENAME']+'.fits')
    hdu1.writeto(fname, output_verify='ignore', overwrite=True)


def add_sky_background(img, filt, exptime, sky_map=None, tel=None):
    # Add sky background
    if sky_map is None:
        sky_map = filt.getSkyNoise(exptime=exptime)
        sky_map = sky_map * np.ones_like(img.array)
        sky_map = galsim.Image(array=sky_map)
        # Apply Poisson noise to the sky map
        # # (NOTE): only for photometric chips if it utilizes the photon shooting to draw stamps
        # if self.survey_type == "photometric":
        #     sky_map.addNoise(poisson_noise)
    elif img.array.shape != sky_map.shape:
        raise ValueError("The shape img and sky_map must be equal.")
    elif tel is not None:  # If sky_map is given in flux
        sky_map = sky_map * tel.pupil_area * exptime
    img += sky_map
    return img, sky_map


def get_flat(img, seed):
    flat_img = effects.MakeFlatSmooth(
        GSBounds=img.bounds,
        seed=seed)
    flat_normal = flat_img / np.mean(flat_img.array)
    return flat_img, flat_normal


def add_cosmic_rays(img, chip, exptime=150, seed=0):
    cr_map, cr_event_num = effects.produceCR_Map(
        xLen=chip.npix_x, yLen=chip.npix_y,
        exTime=exptime+0.5*chip.readout_time,
        cr_pixelRatio=0.003*(exptime+0.5*chip.readout_time)/600.,
        gain=chip.gain,
        attachedSizes=chip.attachedSizes,
        seed=seed)   # seed: obj-imaging:+0; bias:+1; dark:+2; flat:+3;
    img += cr_map
    cr_map[cr_map > 65535] = 65535
    cr_map[cr_map < 0] = 0
    crmap_gsimg = galsim.Image(cr_map, dtype=np.uint16)
    del cr_map
    return img, crmap_gsimg, cr_event_num


def add_PRNU(img, chip, seed=0):
    prnu_img = effects.PRNU_Img(
        xsize=chip.npix_x,
        ysize=chip.npix_y,
        sigma=0.01,
        seed=seed)
    img *= prnu_img
    return img, prnu_img


def get_poisson(seed=0, sky_level=0.):
    rng_poisson = galsim.BaseDeviate(seed)
    poisson_noise = galsim.PoissonNoise(rng_poisson, sky_level=sky_level)
    return rng_poisson, poisson_noise


def get_base_img(img, chip, read_noise, readout_time, dark_noise, exptime=150., InputDark=None):
    if InputDark == None:
        # base_level = read_noise**2 + dark_noise*(exptime+0.5*readout_time)
        # base_level = dark_noise*(exptime+0.5*readout_time)
        base_level = dark_noise*(exptime)
        base_img1 = base_level * np.ones_like(img.array)
    else:
        base_img1 = np.zeros_like(img.array)

    ny = int(chip.npix_y/2)
    nx = chip.npix_x
    arr = np.arange(ny).reshape(ny, 1)
    arr = np.broadcast_to(arr, (ny, nx))
    base_img2 = np.zeros_like(img.array)
    base_img2[:ny, :] = arr
    base_img2[ny:, :] = arr[::-1, :]
    base_img2[:, :] = base_img2[:, :]*(readout_time/ny)*dark_noise
    return base_img1+base_img2


def add_poisson(img, chip, exptime=150., seed=0, sky_level=0., poisson_noise=None, dark_noise=None, InputDark=None):
    if poisson_noise is None:
        _, poisson_noise = get_poisson(seed=seed, sky_level=sky_level)
    read_noise = chip.read_noise
    if dark_noise is None:
        dark_noise = chip.dark_noise
    base_img = get_base_img(img=img, chip=chip, read_noise=read_noise, readout_time=chip.readout_time,
                            dark_noise=dark_noise, exptime=exptime, InputDark=InputDark)
    img += base_img
    img.addNoise(poisson_noise)
    # img -= read_noise**2

    if InputDark != None:
        # "Instrument/data/dark/dark_1000s_example_0.fits"
        hdu = fits.open(InputDark)
        img += hdu[0].data/hdu[0].header['exptime']*exptime
        hdu.close()
    return img, base_img


def add_brighter_fatter(img):
    # Inital dynamic lib
    try:
        with pkg_resources.files('observation_sim.instruments.chip.libBF').joinpath("libmoduleBF.so") as lib_path:
            lib_bf = ctypes.CDLL(lib_path)
    except AttributeError:
        with pkg_resources.path('observation_sim.instruments.chip.libBF', "libmoduleBF.so") as lib_path:
            lib_bf = ctypes.CDLL(lib_path)
    lib_bf.addEffects.argtypes = [ctypes.c_int, ctypes.c_int, ctypes.POINTER(
        ctypes.c_float), ctypes.POINTER(ctypes.c_float), ctypes.c_int]

    # Set bit flag
    bit_flag = 1
    bit_flag = bit_flag | (1 << 2)

    nx, ny = img.array.shape
    nn = nx * ny
    arr_ima = (ctypes.c_float*nn)()
    arr_imc = (ctypes.c_float*nn)()

    arr_ima[:] = img.array.reshape(nn)
    arr_imc[:] = np.zeros(nn)

    lib_bf.addEffects(nx, ny, arr_ima, arr_imc, bit_flag)
    img.array[:, :] = np.reshape(arr_imc, [nx, ny])
    del arr_ima, arr_imc
    return img


"""
def add_inputdark(img, chip, exptime):
    fname = "/share/home/weichengliang/CSST_git/test_new_sim/csst-simulation/ObservationSim/Instrument/data/dark/dark_1000s_example_0.fits"
    hdu = fits.open(fname)
    #ny, nx = img.array.shape
    #inputdark = np.zeros([ny, nx])
    img.array[:, :] += hdu[0].data/hdu[0].header['exptime']*exptime
    hdu.close()
    del inputdark
    return img
"""


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
            # chunk1-[1,2,3,4], chunk2-[5,6,7,8], chunk3-[9,10,11,12], chunk4-[13,14,15,16]
            chunkidx = int(tx+ty*nsecx)

            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, :]

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

    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


def AddPreScanFO(GSImage, pre1=27, pre2=4, over1=71, over2=80, nsecy=1, nsecx=16):
    img = GSImage.array
    ny, nx = img.shape
    dx = int(nx/nsecx)
    dy = int(ny/nsecy)

    newimg = galsim.Image(int(nx+(pre1+over1)*nsecx),
                          int(ny+(pre2+over2)*nsecy), init_value=0)
    for ix in range(nsecx):
        newimg.array[pre2:pre2+dy, pre1+ix *
                     (dx+pre1+over1):pre1+dx+ix*(dx+pre1+over1)] = img[0:dy, 0+ix*dx:dx+ix*dx]

    newimg.wcs = GSImage.wcs
    return newimg


def formatOutput(GSImage, nsecy=2, nsecx=8):
    img = GSImage.array
    ny, nx = img.shape
    dx = int(nx/nsecx)
    dy = int(ny/nsecy)

    imgt = np.zeros([int(nsecx*nsecy), dy, dx])
    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)
            if int(chunkidx/4) == 0:
                imgt[chunkidx, :, :] = img[iy*dy:(iy+1)*dy, ix*dx:(ix+1)*dx]
            if int(chunkidx/4) == 1:
                imgt[chunkidx, :, :] = img[iy*dy:(iy+1)*dy, ix*dx:(ix+1)*dx]
            if int(chunkidx/4) == 2:
                imgt[chunkidx, :, :] = img[iy*dy:(iy+1)*dy, ix*dx:(ix+1)*dx]
            if int(chunkidx/4) == 3:
                imgt[chunkidx, :, :] = img[iy*dy:(iy+1)*dy, ix*dx:(ix+1)*dx]

    imgttx0 = np.hstack(imgt[0:4:, :, :])
    imgttx1 = np.hstack(imgt[4:8:, :, ::-1])
    imgttx2 = np.hstack(imgt[8:12:, ::-1, ::-1])
    imgttx3 = np.hstack(imgt[12:16:, ::-1, :])

    newimg = galsim.Image(int(dx*nsecx*nsecy), dy, init_value=0)
    newimg.array[:, :] = np.hstack([imgttx0, imgttx1, imgttx2, imgttx3])
    return newimg


def formatRevert(GSImage, nsecy=1, nsecx=16):
    img = GSImage.array
    ny, nx = img.shape
    dx = int(nx/nsecx)
    dy = int(ny/nsecy)

    newimg = galsim.Image(int(dx*8), int(dy*2), init_value=0)

    for ix in range(0, 4):
        tx = ix
        newimg.array[0:dy, 0+tx*dx:dx+tx*dx] = img[:, 0+ix*dx:dx+ix*dx]
    for ix in range(4, 8):
        tx = ix
        newimg.array[0:dy, 0+tx*dx:dx+tx *
                     dx] = img[:, 0+ix*dx:dx+ix*dx][:, ::-1]
    for ix in range(8, 12):
        tx = 7-(ix-8)
        newimg.array[0+dy:dy+dy, 0+tx*dx:dx+tx *
                     dx] = img[:, 0+ix*dx:dx+ix*dx][::-1, ::-1]
    for ix in range(12, 16):
        tx = 7-(ix-8)
        newimg.array[0+dy:dy+dy, 0+tx*dx:dx+tx *
                     dx] = img[:, 0+ix*dx:dx+ix*dx][::-1, :]

    return newimg