import os
import galsim
import random
import numpy as np
import h5py as h5
import healpy as hp
import astropy.constants as cons
from astropy.coordinates import spherical_to_cartesian
from astropy.table import Table
from scipy import interpolate
from datetime import datetime

from ObservationSim.MockObject import CatalogBase, Star, Galaxy, Quasar
from ObservationSim.MockObject._util import tag_sed, getObservedSED, getABMAG, integrate_sed_bandpass, comoving_dist
from ObservationSim.Astrometry.Astrometry_util import on_orbit_obs_position

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

NSIDE = 128

class C6_Catalog(CatalogBase):
    def __init__(self, config, chip, pointing, chip_output, filt, **kwargs):
        super().__init__()
        self.cat_dir = os.path.join(config["data_dir"], config["input_path"]["cat_dir"])
        self.seed_Av = config["random_seeds"]["seed_Av"]

        self.chip_output = chip_output
        self.filt = filt
        self.logger = chip_output.logger

        with pkg_resources.path('Catalog.data', 'SLOAN_SDSS.g.fits') as filter_path:
            self.normF_star = Table.read(str(filter_path))
        # with pkg_resources.path('Catalog.data', 'lsst_throuput_g.fits') as filter_path:
        #     self.normF_galaxy = Table.read(str(filter_path))
        
        self.config = config
        self.chip = chip
        self.pointing = pointing

        # (DEBUG)
        self.max_size = 0.

        if "star_cat" in config["input_path"] and config["input_path"]["star_cat"] and not config["run_option"]["galaxy_only"]:
            star_file = config["input_path"]["star_cat"]
            star_SED_file = config["SED_templates_path"]["star_SED"]
            self.star_path = os.path.join(self.cat_dir, star_file)
            self.star_SED_path = os.path.join(config["data_dir"], star_SED_file)
            self._load_SED_lib_star()
        if "galaxy_cat" in config["input_path"] and config["input_path"]["galaxy_cat"] and not config["run_option"]["star_only"]:
            galaxy_dir = config["input_path"]["galaxy_cat"]
            self.galaxy_path = os.path.join(self.cat_dir, galaxy_dir)
            self.galaxy_SED_path = os.path.join(config["data_dir"], config["SED_templates_path"]["galaxy_SED"])
            self._load_SED_lib_gals()
        
        if "rotateEll" in config["shear_setting"]:
            self.rotation = float(int(config["shear_setting"]["rotateEll"]/45.))
        else:
            self.rotation = 0.

        # Update output .cat header with catalog specific output columns
        self._add_output_columns_header()

        self._get_healpix_list()
        self._load()
    
    def _add_output_columns_header(self):
        self.add_hdr = " model_tag teff logg feh"
        self.add_hdr += " bulgemass diskmass detA e1 e2 kappa g1 g2 size galType veldisp "

        self.add_fmt = " %10s %8.4f %8.4f %8.4f"
        self.add_fmt += " %8.4f %8.4f %8.4f %8.4f %8.4f %8.4f %8.4f %8.4f %8.4f %4d %8.4f "
        self.chip_output.update_ouptut_header(additional_column_names=self.add_hdr)

    def _get_healpix_list(self):
        self.sky_coverage = self.chip.getSkyCoverageEnlarged(self.chip.img.wcs, margin=0.2)
        ra_min, ra_max, dec_min, dec_max = self.sky_coverage.xmin, self.sky_coverage.xmax, self.sky_coverage.ymin, self.sky_coverage.ymax
        ra = np.deg2rad(np.array([ra_min, ra_max, ra_max, ra_min]))
        dec = np.deg2rad(np.array([dec_max, dec_max, dec_min, dec_min]))
        vertices = spherical_to_cartesian(1., dec, ra)
        self.pix_list = hp.query_polygon(NSIDE, np.array(vertices).T, inclusive=True)
        if self.logger is not None:
            msg = str(("HEALPix List: ", self.pix_list))
            self.logger.info(msg)
        else:
            print("HEALPix List: ", self.pix_list)

    def load_norm_filt(self, obj):
        if obj.type == "star":
            return self.normF_star
        elif obj.type == "galaxy" or obj.type == "quasar":
            # return self.normF_galaxy
            return None
        else:
            return None

    def _load_SED_lib_star(self):
        self.tempSED_star = h5.File(self.star_SED_path,'r')

    def _load_SED_lib_gals(self):
        pcs = h5.File(os.path.join(self.galaxy_SED_path, "pcs.h5"), "r")
        lamb = h5.File(os.path.join(self.galaxy_SED_path, "lamb.h5"), "r")
        self.lamb_gal = lamb['lamb'][()]
        self.pcs = pcs['pcs'][()]


    def _load_gals(self, gals, pix_id=None, cat_id=0):
        ngals = len(gals['ra'])

        # Apply astrometric modeling
        # in C3 case only aberration
        ra_arr = gals['ra'][:]
        dec_arr = gals['dec'][:]
        if self.config["obs_setting"]["enable_astrometric_model"]:
            ra_list = ra_arr.tolist()
            dec_list = dec_arr.tolist()
            pmra_list = np.zeros(ngals).tolist()
            pmdec_list = np.zeros(ngals).tolist()
            rv_list = np.zeros(ngals).tolist()
            parallax_list = [1e-9] * ngals
            dt = datetime.utcfromtimestamp(self.pointing.timestamp)
            date_str = dt.date().isoformat()
            time_str = dt.time().isoformat()
            ra_arr, dec_arr = on_orbit_obs_position(
                input_ra_list=ra_list,
                input_dec_list=dec_list,
                input_pmra_list=pmra_list,
                input_pmdec_list=pmdec_list,
                input_rv_list=rv_list,
                input_parallax_list=parallax_list,
                input_nstars=ngals,
                input_x=self.pointing.sat_x,
                input_y=self.pointing.sat_y,
                input_z=self.pointing.sat_z,
                input_vx=self.pointing.sat_vx,
                input_vy=self.pointing.sat_vy,
                input_vz=self.pointing.sat_vz,
                input_epoch="J2000",
                input_date_str=date_str,
                input_time_str=time_str
            )

        for igals in range(ngals):
            # (TEST)
            # if igals > 100:
            #     break
            
            param = self.initialize_param()
            param['ra'] = ra_arr[igals]
            param['dec'] = dec_arr[igals]
            param['ra_orig'] = gals['ra'][igals]
            param['dec_orig'] = gals['dec'][igals]
            # param['mag_use_normal'] = gals['mag_true_g_lsst'][igals]
            # if param['mag_use_normal'] >= 26.5:
            #     continue
            param['z'] = gals['redshift'][igals]
            param['model_tag'] = 'None'
            param['g1'] = gals['shear'][igals][0]
            param['g2'] = gals['shear'][igals][1]
            param['kappa'] = gals['kappa'][igals]
            param['e1'] = gals['ellipticity_true'][igals][0]
            param['e2'] = gals['ellipticity_true'][igals][1]
            
            # For shape calculation
            param['e1_disk'] = param['e1']
            param['e2_disk'] = param['e2']
            param['e1_bulge'] = param['e1']
            param['e2_bulge'] = param['e2']

            param['delta_ra'] = 0
            param['delta_dec'] = 0

            # Masses
            param['bulgemass'] = gals['bulgemass'][igals]
            param['diskmass'] = gals['diskmass'][igals]

            param['size'] = gals['size'][igals]
            if param['size'] > self.max_size:
                self.max_size = param['size']

            # Sizes
            param['bfrac'] = param['bulgemass']/(param['bulgemass'] + param['diskmass'])
            if param['bfrac'] >= 0.6:
                param['hlr_bulge'] = param['size']
                param['hlr_disk'] = param['size'] * (1. - param['bfrac'])
            else:
                param['hlr_disk'] = param['size']
                param['hlr_bulge'] = param['size'] * param['bfrac']

            # SED coefficients
            param['coeff'] = gals['coeff'][igals]
            param['detA'] = gals['detA'][igals]

            # Others
            param['galType'] = gals['type'][igals]
            param['veldisp'] = gals['veldisp'][igals]
            
            # TEST no redening and no extinction
            param['av'] = 0.0
            param['redden'] = 0

            param['star'] = 0   # Galaxy

            # NOTE: this cut cannot be put before the SED type has been assigned
            if not self.chip.isContainObj(ra_obj=param['ra'], dec_obj=param['dec'], margin=200):
                continue

            # TEMP
            self.ids += 1
            # param['id'] = self.ids
            param['id'] = str(pix_id) + '%02d'%(cat_id) + '%08d'%(igals)
            
            if param['star'] == 0:
                obj = Galaxy(param, self.rotation, logger=self.logger)
            if param['star'] == 2:
                obj = Quasar(param, logger=self.logger)
            
            # Need to deal with additional output columns
            obj.additional_output_str = self.add_fmt%("n", 0., 0., 0.,
                                                    param['bulgemass'], param['diskmass'], param['detA'],
                                                    param['e1'], param['e2'], param['kappa'], param['g1'], param['g2'], param['size'],
                                                    param['galType'], param['veldisp'])
            
            self.objs.append(obj)

    def _load_stars(self, stars, pix_id=None):
        nstars = len(stars['sourceID'])
        # Apply astrometric modeling
        ra_arr = stars["RA"][:]
        dec_arr = stars["Dec"][:]
        pmra_arr = stars['pmra'][:]
        pmdec_arr = stars['pmdec'][:]
        rv_arr = stars['RV'][:]
        parallax_arr = stars['parallax'][:]
        if self.config["obs_setting"]["enable_astrometric_model"]:
            ra_list = ra_arr.tolist()
            dec_list = dec_arr.tolist()
            pmra_list = pmra_arr.tolist()
            pmdec_list = pmdec_arr.tolist()
            rv_list = rv_arr.tolist()
            parallax_list = parallax_arr.tolist()
            dt = datetime.utcfromtimestamp(self.pointing.timestamp)
            date_str = dt.date().isoformat()
            time_str = dt.time().isoformat()
            ra_arr, dec_arr = on_orbit_obs_position(
                input_ra_list=ra_list,
                input_dec_list=dec_list,
                input_pmra_list=pmra_list,
                input_pmdec_list=pmdec_list,
                input_rv_list=rv_list,
                input_parallax_list=parallax_list,
                input_nstars=nstars,
                input_x=self.pointing.sat_x,
                input_y=self.pointing.sat_y,
                input_z=self.pointing.sat_z,
                input_vx=self.pointing.sat_vx,
                input_vy=self.pointing.sat_vy,
                input_vz=self.pointing.sat_vz,
                input_epoch="J2000",
                input_date_str=date_str,
                input_time_str=time_str
            )
        for istars in range(nstars):
            # (TEST)
            # if istars > 10:
            #     break

            param = self.initialize_param()
            param['ra'] = ra_arr[istars]
            param['dec'] = dec_arr[istars]
            param['ra_orig'] = stars["RA"][istars]
            param['dec_orig'] = stars["Dec"][istars]
            param['pmra'] = pmra_arr[istars]
            param['pmdec'] = pmdec_arr[istars]
            param['rv'] = rv_arr[istars]
            param['parallax'] = parallax_arr[istars]
            if not self.chip.isContainObj(ra_obj=param['ra'], dec_obj=param['dec'], margin=200):
                continue
            param['mag_use_normal'] = stars['app_sdss_g'][istars]
            # if param['mag_use_normal'] >= 26.5:
            #     continue
            self.ids += 1
            # param['id'] = self.ids
            param['id'] = stars['sourceID'][istars]
            param['sed_type'] = stars['sourceID'][istars]
            param['model_tag'] = stars['model_tag'][istars]
            param['teff'] = stars['teff'][istars]
            param['logg'] = stars['grav'][istars]
            param['feh'] = stars['feh'][istars]
            param['z'] = 0.0
            param['star'] = 1   # Star
            obj = Star(param, logger=self.logger)

            # Append additional output columns to the .cat file
            obj.additional_output_str = self.add_fmt%(param["model_tag"], param['teff'], param['logg'], param['feh'],
                                                    0., 0., 0., 0., 0., 0., 0., 0., 0., -1, 0.)

            self.objs.append(obj)

    def _load(self, **kwargs):
        self.objs = []
        self.ids = 0
        
        if "star_cat" in self.config["input_path"] and self.config["input_path"]["star_cat"] and not self.config["run_option"]["galaxy_only"]:
            star_cat = h5.File(self.star_path, 'r')['catalog']
            for pix in self.pix_list:
                try:
                    stars = star_cat[str(pix)]
                    self._load_stars(stars, pix_id=pix)
                    del stars
                except Exception as e:
                    self.logger.error(str(e))
                    print(e)
        
        if "galaxy_cat" in self.config["input_path"] and self.config["input_path"]["galaxy_cat"] and not self.config["run_option"]["star_only"]:
            for i in range(76):
                file_path = os.path.join(self.galaxy_path, "galaxies%04d_C6.h5"%(i))
                gals_cat = h5.File(file_path, 'r')['galaxies']
                for pix in self.pix_list:
                    try:
                        gals = gals_cat[str(pix)]
                        self._load_gals(gals, pix_id=pix, cat_id=i)
                        del gals
                    except Exception as e:
                        self.logger.error(str(e))
                        print(e)
        if self.logger is not None:
            self.logger.info("maximum galaxy size: %.4f"%(self.max_size))
            self.logger.info("number of objects in catalog: %d"%(len(self.objs)))
        else:
            print("number of objects in catalog: ", len(self.objs))


    def load_sed(self, obj, **kwargs):
        if obj.type == 'star':
            _, wave, flux = tag_sed(
                h5file=self.tempSED_star,
                model_tag=obj.param['model_tag'],
                teff=obj.param['teff'],
                logg=obj.param['logg'],
                feh=obj.param['feh']
            )
        elif obj.type == 'galaxy' or obj.type == 'quasar':
            dist_L_pc = (1 + obj.z) * comoving_dist(z=obj.z)[0]
            factor = (10 / dist_L_pc)**2
            flux = np.matmul(self.pcs, obj.coeff) * factor
            if np.any(flux < 0):
                raise ValueError("Glaxy %s: negative SED fluxes"%obj.id)
            sedcat = np.vstack((self.lamb_gal, flux)).T
            sed_data = getObservedSED(
                sedCat=sedcat,
                redshift=obj.z,
                av=obj.param["av"],
                redden=obj.param["redden"]
            )
            wave, flux = sed_data[0], sed_data[1]
            # print("sed (erg/s/cm2/A) = ", sed_data)
            # np.savetxt(os.path.join(self.config["work_dir"], "%s_sed.txt"%(obj.id)), sedcat)
        else:
            raise ValueError("Object type not known")
        speci = interpolate.interp1d(wave, flux)
        lamb = np.arange(2000, 11001+0.5, 0.5)
        y = speci(lamb)
        # erg/s/cm2/A --> photon/s/m2/A
        all_sed = y * lamb / (cons.h.value * cons.c.value) * 1e-13
        sed = Table(np.array([lamb, all_sed]).T, names=('WAVELENGTH', 'FLUX'))
        
        if obj.type == 'galaxy' or obj.type == 'quasar':
            # integrate to get the magnitudes
            sed_photon = np.array([sed['WAVELENGTH'], sed['FLUX']]).T
            # print("sed_photon = ", sed_photon)
            sed_photon = galsim.LookupTable(x=np.array(sed_photon[:, 0]), f=np.array(sed_photon[:, 1]), interpolant='nearest')
            sed_photon = galsim.SED(sed_photon, wave_type='A', flux_type='1', fast=False)
            interFlux = integrate_sed_bandpass(sed=sed_photon, bandpass=self.filt.bandpass_full)
            obj.param['mag_use_normal'] = getABMAG(interFlux, self.filt.bandpass_full)
            # print("mag_use_normal = %.3f"%obj.param['mag_use_normal'])
        
        del wave
        del flux
        return sed