text: # Copyright (c) 2015,2016,2017,2019 MetPy Developers.
  # Distributed under the terms of the BSD 3-Clause License.
  # SPDX-License-Identifier: BSD-3-Clause
  """Tools to process GINI-formatted products."""
  
  import contextlib
  from datetime import datetime
  from enum import Enum
  from io import BytesIO
  from itertools import repeat  # noqa: I202
  import logging
  import re
  
  import numpy as np
  from xarray import Variable
  from xarray.backends.common import AbstractDataStore
  from xarray.core.utils import FrozenDict
  
  from ._tools import Bits, IOBuffer, NamedStruct, open_as_needed, zlib_decompress_all_frames
  from ..package_tools import Exporter
  
  exporter = Exporter(globals())
  log = logging.getLogger(__name__)
  
  
  def _make_datetime(s):
      r"""Convert 7 bytes from a GINI file to a `datetime` instance."""
      year, month, day, hour, minute, second, cs = s
      if year < 70:
          year += 100
      return datetime(1900 + year, month, day, hour, minute, second, 10000 * cs)
  
  
  def _scaled_int(s):
      r"""Convert a 3 byte string to a signed integer value."""
      # Get leftmost bit (sign) as 1 (if 0) or -1 (if 1)
      sign = 1 - ((s[0] & 0x80) >> 6)
  
      # Combine remaining bits
      int_val = (((s[0] & 0x7f) << 16) | (s[1] << 8) | s[2])
      log.debug('Source: %s Int: %x Sign: %d', ' '.join(hex(c) for c in s), int_val, sign)
  
      # Return scaled and with proper sign
      return (sign * int_val) / 10000.
  
  
  def _name_lookup(names):
      r"""Create an io helper to convert an integer to a named value."""
      mapper = dict(zip(range(len(names)), names))
  
      def lookup(val):
          return mapper.get(val, 'UnknownValue')
      return lookup
  
  
  class GiniProjection(Enum):
      r"""Represents projection values in GINI files."""
  
      mercator = 1
      lambert_conformal = 3
      polar_stereographic = 5
  
  
  @exporter.export
  class GiniFile(AbstractDataStore):
      """A class that handles reading the GINI format satellite images from the NWS.
  
      This class attempts to decode every byte that is in a given GINI file.
  
      Notes
      -----
      The internal data structures that things are decoded into are subject to change.
  
      """
  
      missing = 255
      wmo_finder = re.compile('(T\\w{3}\\d{2})[\\s\\w\\d]+\\w*(\\w{3})\r\r\n')
  
      crafts = ['Unknown', 'Unknown', 'Miscellaneous', 'JERS', 'ERS/QuikSCAT', 'POES/NPOESS',
                'Composite', 'DMSP', 'GMS', 'METEOSAT', 'GOES-7', 'GOES-8', 'GOES-9',
                'GOES-10', 'GOES-11', 'GOES-12', 'GOES-13', 'GOES-14', 'GOES-15', 'GOES-16']
  
      sectors = ['NH Composite', 'East CONUS', 'West CONUS', 'Alaska Regional',
                 'Alaska National', 'Hawaii Regional', 'Hawaii National', 'Puerto Rico Regional',
                 'Puerto Rico National', 'Supernational', 'NH Composite', 'Central CONUS',
                 'East Floater', 'West Floater', 'Central Floater', 'Polar Floater']
  
      channels = ['Unknown', 'Visible', 'IR (3.9 micron)', 'WV (6.5/6.7 micron)',
                  'IR (11 micron)', 'IR (12 micron)', 'IR (13 micron)', 'IR (1.3 micron)',
                  'Reserved', 'Reserved', 'Reserved', 'Reserved', 'Reserved', 'LI (Imager)',
                  'PW (Imager)', 'Surface Skin Temp (Imager)', 'LI (Sounder)', 'PW (Sounder)',
                  'Surface Skin Temp (Sounder)', 'CAPE', 'Land-sea Temp', 'WINDEX',
                  'Dry Microburst Potential Index', 'Microburst Day Potential Index',
                  'Convective Inhibition', 'Volcano Imagery', 'Scatterometer', 'Cloud Top',
                  'Cloud Amount', 'Rainfall Rate', 'Surface Wind Speed', 'Surface Wetness',
                  'Ice Concentration', 'Ice Type', 'Ice Edge', 'Cloud Water Content',
                  'Surface Type', 'Snow Indicator', 'Snow/Water Content', 'Volcano Imagery',
                  'Reserved', 'Sounder (14.71 micron)', 'Sounder (14.37 micron)',
                  'Sounder (14.06 micron)', 'Sounder (13.64 micron)', 'Sounder (13.37 micron)',
                  'Sounder (12.66 micron)', 'Sounder (12.02 micron)', 'Sounder (11.03 micron)',
                  'Sounder (9.71 micron)', 'Sounder (7.43 micron)', 'Sounder (7.02 micron)',
                  'Sounder (6.51 micron)', 'Sounder (4.57 micron)', 'Sounder (4.52 micron)',
                  'Sounder (4.45 micron)', 'Sounder (4.13 micron)', 'Sounder (3.98 micron)',
                  # Percent Normal TPW found empirically from Service Change Notice 20-03
                  'Sounder (3.74 micron)', 'Sounder (Visible)', 'Percent Normal TPW']
  
      prod_desc_fmt = NamedStruct([('source', 'b'),
                                   ('creating_entity', 'b', _name_lookup(crafts)),
                                   ('sector_id', 'b', _name_lookup(sectors)),
                                   ('channel', 'b', _name_lookup(channels)),
                                   ('num_records', 'H'), ('record_len', 'H'),
                                   ('datetime', '7s', _make_datetime),
                                   ('projection', 'b', GiniProjection), ('nx', 'H'), ('ny', 'H'),
                                   ('la1', '3s', _scaled_int), ('lo1', '3s', _scaled_int)
                                   ], '>', 'ProdDescStart')
  
      lc_ps_fmt = NamedStruct([('reserved', 'b'), ('lov', '3s', _scaled_int),
                               ('dx', '3s', _scaled_int), ('dy', '3s', _scaled_int),
                               ('proj_center', 'b')], '>', 'LambertOrPolarProjection')
  
      mercator_fmt = NamedStruct([('resolution', 'b'), ('la2', '3s', _scaled_int),
                                  ('lo2', '3s', _scaled_int), ('di', 'H'), ('dj', 'H')
                                  ], '>', 'MercatorProjection')
  
      prod_desc2_fmt = NamedStruct([('scanning_mode', 'b', Bits(3)),
                                    ('lat_in', '3s', _scaled_int), ('resolution', 'b'),
                                    ('compression', 'b'), ('version', 'b'), ('pdb_size', 'H'),
                                    ('nav_cal', 'b')], '>', 'ProdDescEnd')
  
      nav_fmt = NamedStruct([('sat_lat', '3s', _scaled_int), ('sat_lon', '3s', _scaled_int),
                             ('sat_height', 'H'), ('ur_lat', '3s', _scaled_int),
                             ('ur_lon', '3s', _scaled_int)], '>', 'Navigation')
  
      def __init__(self, filename):
          r"""Create an instance of `GiniFile`.
  
          Parameters
          ----------
          filename : str or file-like object
              If str, the name of the file to be opened. Gzip-ed files are
              recognized with the extension ``'.gz'``, as are bzip2-ed files with
              the extension ``'.bz2'`` If `filename` is a file-like object,
              this will be read from directly.
  
          """
          fobj = open_as_needed(filename)
  
          # Just read in the entire set of data at once
          with contextlib.closing(fobj):
              self._buffer = IOBuffer.fromfile(fobj)
  
          # Pop off the WMO header if we find it
          self.wmo_code = ''
          self._process_wmo_header()
          log.debug('First wmo code: %s', self.wmo_code)
  
          # Decompress the data if necessary, and if so, pop off new header
          log.debug('Length before decompression: %s', len(self._buffer))
          self._buffer = IOBuffer(self._buffer.read_func(zlib_decompress_all_frames))
          log.debug('Length after decompression: %s', len(self._buffer))
  
          # Process WMO header inside compressed data if necessary
          self._process_wmo_header()
          log.debug('2nd wmo code: %s', self.wmo_code)
  
          # Read product description start
          start = self._buffer.set_mark()
  
          #: :desc: Decoded first section of product description block
          #: :type: namedtuple
          self.prod_desc = self._buffer.read_struct(self.prod_desc_fmt)
          log.debug(self.prod_desc)
  
          #: :desc: Decoded geographic projection information
          #: :type: namedtuple
          self.proj_info = None
  
          # Handle projection-dependent parts
          if self.prod_desc.projection in (GiniProjection.lambert_conformal,
                                           GiniProjection.polar_stereographic):
              self.proj_info = self._buffer.read_struct(self.lc_ps_fmt)
          elif self.prod_desc.projection == GiniProjection.mercator:
              self.proj_info = self._buffer.read_struct(self.mercator_fmt)
          else:
              log.warning('Unknown projection: %d', self.prod_desc.projection)
          log.debug(self.proj_info)
  
          # Read the rest of the guaranteed product description block (PDB)
          #: :desc: Decoded second section of product description block
          #: :type: namedtuple
          self.prod_desc2 = self._buffer.read_struct(self.prod_desc2_fmt)
          log.debug(self.prod_desc2)
  
          if self.prod_desc2.nav_cal not in (0, -128):  # TODO: See how GEMPAK/MCIDAS parses
              # Only warn if there actually seems to be useful navigation data
              if self._buffer.get_next(self.nav_fmt.size) != b'\x00' * self.nav_fmt.size:
                  log.warning('Navigation/Calibration unhandled: %d', self.prod_desc2.nav_cal)
              if self.prod_desc2.nav_cal in (1, 2):
                  self.navigation = self._buffer.read_struct(self.nav_fmt)
                  log.debug(self.navigation)
  
          # Catch bad PDB with size set to 0
          if self.prod_desc2.pdb_size == 0:
              log.warning('Adjusting bad PDB size from 0 to 512.')
              self.prod_desc2 = self.prod_desc2._replace(pdb_size=512)
  
          # Jump past the remaining empty bytes in the product description block
          self._buffer.jump_to(start, self.prod_desc2.pdb_size)
  
          # Read the actual raster--unless it's PNG compressed, in which case that happens later
          blob = self._buffer.read(self.prod_desc.num_records * self.prod_desc.record_len)
  
          # Check for end marker
          end = self._buffer.read(self.prod_desc.record_len)
          if end != b''.join(repeat(b'\xff\x00', self.prod_desc.record_len // 2)):
              log.warning('End marker not as expected: %s', end)
  
          # Check to ensure that we processed all of the data
          if not self._buffer.at_end():
              if not blob:
                  log.debug('No data read yet, trying to decompress remaining data as an image.')
                  from matplotlib.image import imread
                  blob = (imread(BytesIO(self._buffer.read())) * 255).astype('uint8')
              else:
                  log.warning('Leftover unprocessed data beyond EOF marker: %s',
                              self._buffer.get_next(10))
  
          self.data = np.array(blob).reshape((self.prod_desc.ny,
                                              self.prod_desc.nx))
  
      def _process_wmo_header(self):
          """Read off the WMO header from the file, if necessary."""
          data = self._buffer.get_next(64).decode('utf-8', 'ignore')
          match = self.wmo_finder.search(data)
          if match:
              self.wmo_code = match.groups()[0]
              self.siteID = match.groups()[-1]
              self._buffer.skip(match.end())
  
      def __str__(self):
          """Return a string representation of the product."""
          parts = [self.__class__.__name__ + ': {0.creating_entity} {0.sector_id} {0.channel}',
                   'Time: {0.datetime}', 'Size: {0.ny}x{0.nx}',
                   'Projection: {0.projection.name}',
                   'Lower Left Corner (Lon, Lat): ({0.lo1}, {0.la1})',
                   'Resolution: {1.resolution}km']
          return '\n\t'.join(parts).format(self.prod_desc, self.prod_desc2)
  
      def _make_proj_var(self):
          proj_info = self.proj_info
          prod_desc2 = self.prod_desc2
          attrs = {'earth_radius': 6371200.0}
          if self.prod_desc.projection == GiniProjection.lambert_conformal:
              attrs['grid_mapping_name'] = 'lambert_conformal_conic'
              attrs['standard_parallel'] = prod_desc2.lat_in
              attrs['longitude_of_central_meridian'] = proj_info.lov
              attrs['latitude_of_projection_origin'] = prod_desc2.lat_in
          elif self.prod_desc.projection == GiniProjection.polar_stereographic:
              attrs['grid_mapping_name'] = 'polar_stereographic'
              attrs['straight_vertical_longitude_from_pole'] = proj_info.lov
              attrs['latitude_of_projection_origin'] = -90 if proj_info.proj_center else 90
              attrs['standard_parallel'] = 60.0  # See Note 2 for Table 4.4A in ICD
          elif self.prod_desc.projection == GiniProjection.mercator:
              attrs['grid_mapping_name'] = 'mercator'
              attrs['longitude_of_projection_origin'] = self.prod_desc.lo1
              attrs['latitude_of_projection_origin'] = self.prod_desc.la1
              attrs['standard_parallel'] = prod_desc2.lat_in
          else:
              raise NotImplementedError(
                  f'Unhandled GINI Projection: {self.prod_desc.projection}')
  
          return 'projection', Variable((), 0, attrs)
  
      def _make_time_var(self):
          base_time = self.prod_desc.datetime.replace(hour=0, minute=0, second=0, microsecond=0)
          offset = self.prod_desc.datetime - base_time
          time_var = Variable((), data=offset.seconds + offset.microseconds / 1e6,
                              attrs={'units': 'seconds since ' + base_time.isoformat()})
  
          return 'time', time_var
  
      def _get_proj_and_res(self):
          import pyproj
  
          proj_info = self.proj_info
          prod_desc2 = self.prod_desc2
  
          kwargs = {'a': 6371200.0, 'b': 6371200.0}
          if self.prod_desc.projection == GiniProjection.lambert_conformal:
              kwargs['proj'] = 'lcc'
              kwargs['lat_0'] = prod_desc2.lat_in
              kwargs['lon_0'] = proj_info.lov
              kwargs['lat_1'] = prod_desc2.lat_in
              kwargs['lat_2'] = prod_desc2.lat_in
              dx, dy = proj_info.dx, proj_info.dy
          elif self.prod_desc.projection == GiniProjection.polar_stereographic:
              kwargs['proj'] = 'stere'
              kwargs['lon_0'] = proj_info.lov
              kwargs['lat_0'] = -90 if proj_info.proj_center else 90
              kwargs['lat_ts'] = 60.0  # See Note 2 for Table 4.4A in ICD
              kwargs['x_0'] = False  # Easting
              kwargs['y_0'] = False  # Northing
              dx, dy = proj_info.dx, proj_info.dy
          elif self.prod_desc.projection == GiniProjection.mercator:
              kwargs['proj'] = 'merc'
              kwargs['lat_0'] = self.prod_desc.la1
              kwargs['lon_0'] = self.prod_desc.lo1
              kwargs['lat_ts'] = prod_desc2.lat_in
              kwargs['x_0'] = False  # Easting
              kwargs['y_0'] = False  # Northing
              dx, dy = prod_desc2.resolution, prod_desc2.resolution
  
          return pyproj.Proj(**kwargs), dx, dy
  
      def _make_coord_vars(self):
          proj, dx, dy = self._get_proj_and_res()
  
          # Get projected location of lower left point
          x0, y0 = proj(self.prod_desc.lo1, self.prod_desc.la1)
  
          # Coordinate variable for x
          xlocs = x0 + np.arange(self.prod_desc.nx) * (1000. * dx)
          attrs = {'units': 'm', 'long_name': 'x coordinate of projection',
                   'standard_name': 'projection_x_coordinate'}
          x_var = Variable(('x',), xlocs, attrs)
  
          # Now y--Need to flip y because we calculated from the lower left corner,
          # but the raster data is stored with top row first.
          ylocs = (y0 + np.arange(self.prod_desc.ny) * (1000. * dy))[::-1]
          attrs = {'units': 'm', 'long_name': 'y coordinate of projection',
                   'standard_name': 'projection_y_coordinate'}
          y_var = Variable(('y',), ylocs, attrs)
  
          # Get the two-D lon,lat grid as well
          x, y = np.meshgrid(xlocs, ylocs)
          lon, lat = proj(x, y, inverse=True)
  
          lon_var = Variable(('y', 'x'), data=lon,
                             attrs={'long_name': 'longitude', 'units': 'degrees_east'})
          lat_var = Variable(('y', 'x'), data=lat,
                             attrs={'long_name': 'latitude', 'units': 'degrees_north'})
  
          return [('x', x_var), ('y', y_var), ('lon', lon_var), ('lat', lat_var)]
  
      def get_variables(self):
          """Get all variables in the file.
  
          This is used by `xarray.open_dataset`.
  
          """
          proj_var_name, proj_var = self._make_proj_var()
          variables = [self._make_time_var(), (proj_var_name, proj_var)]
          variables.extend(self._make_coord_vars())
  
          # Now the data
          name = self.prod_desc.channel
          if '(' in name:
              name = name.split('(')[0].rstrip()
  
          missing_val = self.missing
          attrs = {'long_name': self.prod_desc.channel, 'missing_value': missing_val,
                   'coordinates': 'y x time', 'grid_mapping': proj_var_name}
          data_var = Variable(('y', 'x'),
                              data=np.ma.array(self.data,
                                               mask=self.data == missing_val),
                              attrs=attrs)
          variables.append((name, data_var))
  
          return FrozenDict(variables)
  
      def get_attrs(self):
          """Get the global attributes.
  
          This is used by `xarray.open_dataset`.
  
          """
          return FrozenDict(satellite=self.prod_desc.creating_entity,
                            sector=self.prod_desc.sector_id)
  