#!/usr/bin/env python

"""

MODULE:       r.colors.out_sld
AUTHOR(S):    Hamish Bowman
              Stefan Blumentrath, NINA: Port to GRASS GIS 7 / Python, 
              lable and opacity support
PURPOSE:      Export GRASS raster color table to OGC SLD template v1.0.0
COPYRIGHT:    (C) 2011 by Hamish Bowman, and the GRASS Development Team

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

Based on hints from
http://docs.geoserver.org/stable/en/user/styling/sld/reference/rastersymbolizer.html

"""

"""
To Dos:
- add category support
- add transparency support
- support for intervalls ColorMap?
"""

#%Module
#% description: Exports the color table associated with a raster map layer in SLD format.
#% keyword: raster
#% keyword: export
#% keyword: color table
#%End

#%Option G_OPT_R_MAP
#% required: yes
#%End

#%Option
#% key: style_name
#% required: no
#% label: Name for style
#% description: A name for the style which might be displayed on the server
#% answer: GRASS color table
#%End

#%Option G_OPT_F_OUTPUT
#% required: no
#% label: Name for output SLD rules file
#% description: "-" to write to stdout
#% answer: -
#%End

import os
import sys
import grass.script as grass

def set_output_encoding(encoding='utf-8'):
    import codecs
    current = sys.stdout.encoding
    if current is None :
        sys.stdout = codecs.getwriter(encoding)(sys.stdout)
    current = sys.stderr.encoding
    if current is None :
        sys.stderr = codecs.getwriter(encoding)(sys.stderr)

def main():

    # Set output encoding to UTF-8
    set_output_encoding()
    # Parse input
    output = options['output'] # done
    style_name = options['style_name'] # done
    map = options['map'] # done

    # Get map metadata
    mapinfo = grass.parse_command('r.info', flags='e', map=map)

    if mapinfo['title']:
        name = '{} : {}'.format(mapinfo['map'], mapinfo['title'])
    else:
        name = mapinfo['map']

    # Get color rules
    color_rules = grass.read_command('r.colors.out', map=map).split('\n')

    # Get maptype (CELL, FCELL, DCELL)
    maptype = grass.parse_command('r.info', flags='g', map=map)['datatype']

    # Check if map has categories if type is CELL
    if maptype == 'CELL':
        grass.verbose('Reading category lables, may take a while...')
        categories = grass.parse_command('r.category', map=map, separator='=')
        if list(set(categories.values()))[0] or len(list(set(categories.values()))) > 1:
            use_categories = True
        else:
            use_categories = False
    else:
        use_categories = False

    # Initialize SLD with header
    sld = """<?xml version="1.0" encoding="UTF-8"?>
<StyledLayerDescriptor version="1.0.0" 
    xsi:schemaLocation="http://www.opengis.net/sld StyledLayerDescriptor.xsd" 
    xmlns="http://www.opengis.net/sld" 
    xmlns:ogc="http://www.opengis.net/ogc" 
    xmlns:xlink="http://www.w3.org/1999/xlink" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <NamedLayer>
    <Name>{}</Name>""".format(style_name)
    sld+="""    <UserStyle>
      <Title>{}</Title>\n
      <FeatureTypeStyle>
        <Rule>
          <RasterSymbolizer>\n""".format(name)

    # Define type of ColorMap depending on data type of input map
    if use_categories:
        sld+='            <ColorMap type={}>\n'.format('"values"')
        ColorMapEntry = '              <ColorMapEntry color="#{0:02x}{1:02x}{2:02x}" quantity="{3}" label="{4}" opacity="{5}" />\n'
    else:
        sld+='            <ColorMap>\n'
        # sld+='            <ColorMap type={}>\n'.format('"ramp"')
        ColorMapEntry = '              <ColorMapEntry color="#{0:02x}{1:02x}{2:02x}" quantity="{3}" opacity="{4}" />\n'

    # 
    for c in color_rules:
        if len(c.split(' ')) == 2 and not c.split(' ')[0] == 'default':
            q = c.split(' ')[0]
            if q == 'nv':
                q = 'NaN'
                r = 255
                g = 255
                b = 255
                o = 0
            else:
                r = int(c.split(' ')[1].split(':')[0])
                g = int(c.split(' ')[1].split(':')[1])
                b = int(c.split(' ')[1].split(':')[2])
                o = 1
            if use_categories:
                if str(q) in list(categories.keys()):
                    l = categories[str(q)]
                elif q == 'NaN':
                    l = 'NoData'
                else:
                    continue
                sld+=ColorMapEntry.format(r,g,b,q,l,o)
            else:
                sld+=ColorMapEntry.format(r,g,b,q,o)

    # write file footer
    sld+="""            </ColorMap>
          </RasterSymbolizer>
        </Rule>
      </FeatureTypeStyle>
    </UserStyle>
  </NamedLayer>
</StyledLayerDescriptor>\n"""

    if output == '-':
        # Write SLD to stdout if no output is requested
        print(sld)
    else:
        # Write SLD to file if requested
        with open(output, 'w+') as o:
            o.write(sld.encode('utf8'))

if __name__ == "__main__":
    options, flags = grass.parser()
    sys.exit(main())