# Source code for drizzlepac.pixtosky

    """ pixtosky - A module to perform coordinate transformation from pixel to sky coordinates.

        :Authors: Warren Hack

        :License: `<http://www.stsci.edu/resources/software_hardware/pyraf/LICENSE>`_

        PARAMETERS
        ----------
        input : str
            full filename with path of input image, an extension name ['sci',1] should be
            provided if input is a multi-extension FITS file

        Optional Parameters
        -------------------
        x : float or list or array, optional
            X position from input image for a single or multiple sources
        y : float or list or array, optional
            Y position from input image for a single or multiple sources
        coords : str, deprecated
            [DEPRECATED] full filename with path of file with x,y coordinates
            Filename given here will be *ignored* if a file has been specified
            in `coordfile` parameter.
        coordfile : str, optional
            full filename with path of file with x,y coordinates
        colnames : str, optional
            comma separated list of column names or list of column name strings
            from 'coordfile' files containing x,y coordinates, respectively.
            This parameter will default to first two columns if None are specified.
            Column names for ASCII files will use 'c1','c2',... convention.
            Valid syntax: ['c1','c3'] or 'c1,c3'
        separator : str, optional
            non-blank separator used as the column delimiter in the coordfile file
        hms : bool, optional
            Produce output in HH:MM:SS.S format instead of decimal degrees? (default: False)
        precision : int, optional
            Number of floating-point digits in output values
        output : str, optional
            Name of output file with results, if desired
        verbose : bool
            Print out full list of transformation results (default: False)

        RETURNS
        -------
        ra : float or array
            Right Ascension of pixel. If more than 1 input value, then it will be a
            numpy array.
        dec : float or array
            Declination of pixel. If more than 1 input value, then it will be a
            numpy array.

        NOTES
        -----
        This task performs a full distortion-correction coordinate transformation
        based on all WCS keywords and any recognized distortion keywords from the
        input image header. The transformation recognizes the conventions for
        describing distortion implemented as part of the SIP and Paper IV conventions
        used with `AstroDrizzle`.  Input images can be updated to use these conventions
        through the use of the `updatewcs` module the STWCS package.

        See Also
        --------
        `stwcs`

        EXAMPLES
        --------
        1. The following command will transform the position 256,256 into a
           position on the sky for the image 'input_flt.fits[sci,1]' using::

           >>> from drizzlepac import pixtosky
           >>> r,d = pixtosky.xy2rd("input_file_flt.fits[sci,1]", 256,256)

        2. The set of X,Y positions from 'input_flt.fits[sci,1]' stored as
           the 3rd and 4th columns from the ASCII file 'xy_sci1.dat'
           will be transformed and written out to 'radec_sci1.dat' using::

           >>> from drizzlepac import pixtosky
           >>> r,d = pixtosky.xy2rd("input_flt.fits[sci,1]", coordfile='xy_sci1.dat',
           ...                      colnames=['c3','c4'], output="radec_sci1.dat")

    """
    from __future__ import absolute_import, division, print_function # confidence medium

    import os,copy
    import warnings
    import numpy as np

    from stsci.tools import fileutil, teal
    from . import util
    from . import wcs_functions
    import stwcs
    from stwcs import distortion, wcsutil

    # This is specifically NOT intended to match the package-wide version information.
    __version__ = '0.1'
    __vdate__ = '20-Jan-2011'

    __taskname__ = 'pixtosky'

    blank_list = [None, '', ' ']

    def xy2rd(input,x=None,y=None,coords=None, coordfile=None,colnames=None,separator=None,
                hms=True, precision=6,output=None,verbose=True):
        """ Primary interface to perform coordinate transformations from
            pixel to sky coordinates using STWCS and full distortion models
            read from the input image header.
        """
        single_coord = False
        # Only use value provided in `coords` if nothing has been specified for coordfile
        if coords is not None and coordfile is None:
            coordfile = coords
            warnings.simplefilter('always',DeprecationWarning)
            warnings.warn("Please update calling code to pass in `coordfile` instead of `coords`.",
                category=DeprecationWarning)
            warnings.simplefilter('default',DeprecationWarning)

        if coordfile is not None:
            if colnames in blank_list:
                colnames = ['c1','c2']
            # Determine columns which contain pixel positions
            cols = util.parse_colnames(colnames,coordfile)
            # read in columns from input coordinates file
            xyvals = np.loadtxt(coordfile,usecols=cols,delimiter=separator)
            if xyvals.ndim == 1:  # only 1 entry in coordfile
                xlist = [xyvals[0].copy()]
                ylist = [xyvals[1].copy()]
            else:
                xlist = xyvals[:,0].copy()
                ylist = xyvals[:,1].copy()
            del xyvals
        else:
            if isinstance(x, np.ndarray):
                xlist = x.tolist()
                ylist = y.tolist()
            elif not isinstance(x,list):
                xlist = [x]
                ylist = [y]
                single_coord = True
            else:
                xlist = x
                ylist = y

        # start by reading in WCS+distortion info for input image
        inwcs = wcsutil.HSTWCS(input)
        if inwcs.wcs.is_unity():
            print("####\nNo valid WCS found in {}.\n  Results may be invalid.\n####\n".format(input))

        # Now, convert pixel coordinates into sky coordinates
        dra,ddec = inwcs.all_pix2world(xlist,ylist,1)

        # convert to HH:MM:SS.S format, if specified
        if hms:
            ra,dec = wcs_functions.ddtohms(dra,ddec,precision=precision)
            rastr = ra
            decstr = dec
        else:
            # add formatting based on precision here...
            rastr = []
            decstr = []
            fmt = "%."+repr(precision)+"f"
            for r,d in zip(dra,ddec):
                rastr.append(fmt%r)
                decstr.append(fmt%d)

            ra = dra
            dec = ddec

        if verbose or (not verbose and util.is_blank(output)):
            print('# Coordinate transformations for ',input)
            print('# X      Y         RA             Dec\n')
            for x,y,r,d in zip(xlist,ylist,rastr,decstr):
                print("%.4f  %.4f    %s  %s"%(x,y,r,d))

        # Create output file, if specified
        if output:
            f = open(output,mode='w')
            f.write("# Coordinates converted from %s\n"%input)
            for r,d in zip(rastr,decstr):
                f.write('%s    %s\n'%(r,d))
            f.close()
            print('Wrote out results to: ',output)

        if single_coord:
            ra = ra[0]
            dec = dec[0]

        return ra,dec

    #--------------------------
    # TEAL Interface functions
    #--------------------------
    def run(configObj):

        if 'coords' in configObj:
            coords = util.check_blank(configObj['coords'])
        else:
            coords = None
        coordfile = util.check_blank(configObj['coordfile'])
        colnames = util.check_blank(configObj['colnames'])
        sep = util.check_blank(configObj['separator'])
        outfile = util.check_blank(configObj['output'])

        xy2rd(configObj['input'],
                x = configObj['x'], y = configObj['y'], coords=coords,
                coordfile = coordfile, colnames = colnames,
                separator= sep, hms = configObj['hms'], precision= configObj['precision'],
                output= outfile, verbose = configObj['verbose'])

    def help(file=None):
        """
        Print out syntax help for running astrodrizzle

        Parameters
        ----------
        file : str (Default = None)
            If given, write out help to the filename specified by this parameter
            Any previously existing file with this name will be deleted before
            writing out the help.

        """
        helpstr = getHelpAsString(docstring=True, show_ver = True)
        if file is None:
            print(helpstr)
        else:
            if os.path.exists(file): os.remove(file)
            f = open(file, mode = 'w')
            f.write(helpstr)
            f.close()

    def getHelpAsString(docstring = False, show_ver = True):
        """
        return useful help from a file in the script directory called
        __taskname__.help

        """
        install_dir = os.path.dirname(__file__)
        taskname = util.base_taskname(__taskname__, '')
        htmlfile = os.path.join(install_dir, 'htmlhelp', taskname + '.html')
        helpfile = os.path.join(install_dir, taskname + '.help')

        if docstring or (not docstring and not os.path.exists(htmlfile)):
            if show_ver:
                helpString = os.linesep + \
                    ' '.join([__taskname__, 'Version', __version__,
                    ' updated on ', __vdate__]) + 2*os.linesep
            else:
                helpString = ''
            if os.path.exists(helpfile):
                helpString += teal.getHelpFileAsString(taskname, __file__)
            else:
                if __doc__ is not None:
                    helpString += __doc__ + os.linesep
        else:
            helpString = 'file://' + htmlfile

        return helpString

    __doc__ = getHelpAsString(docstring = True, show_ver = False)