source: TI05-delivery/ows_framework/trunk/ows_server/ows_server/controllers/csml_wcs.py @ 2693

# Copyright (C) 2007 STFC & NERC (Science and Technology Facilities Council).
# This software may be distributed under the terms of the
# Q Public License, version 1.0 or later.
# http://ndg.nerc.ac.uk/public_docs/QPublic_license.txt
"""
WCS controller driven by CSML.

@author: DominicLowe, Stephen Pascoe
"""

#NOTE, much of this is straight from WMS and needs to be overhauled.
import os, time, string, StringIO

from ows_server.lib.base import *
from ows_server.lib.decorators import *
import ows_server.lib.validators as V

from elementtree import ElementTree as ET
from ows_common import exceptions as OWS_E
from ows_common.wcs import *
from ows_common.common import BoundingBox
from ows_common.domain import ValuesUnit, PossibleValues

from ows_server.lib.csml_util import get_csml_doc, extractToNetCDF
from ows_server.lib.csml_cache import csmlCache, extractCache

from email.mime.multipart import MIMEMultipart
from email.mime.base import MIMEBase
from email.mime.text import MIMEText
from email import encoders

class CsmlWcsController(OwsController):
    _ows_parameters = {
        'Format': make_domain(['text/xml']),
        'ExceptionFormat': make_domain(['text/xml']),
        }



    def _createMultipartMime(self, xml, netcdf):
        #returns a multipart mime file containing the coverage xml + a netcdf file
        
        # Create the container (outer) email message.
        msg = MIMEMultipart()        
        
        xmlfile =StringIO.StringIO(xml)
        xmlfile.readline(), xmlfile.readline() #don't read in first 2 lines (the content type) as MIMEBase also provides it.
            
        
        #add the XML part
        submsg=MIMEText(xmlfile.read(), _subtype='xml')
        submsg.add_header('Content-ID', '<coverage.xml>')
        submsg.add_header('Content-Disposition', 'attachment; filename="coverage.xml"')
        #submsg.set_type('text/xml; name="coverage.xml"')
        msg.attach(submsg)

        
        #add the NetCDF part
        submsg= MIMEBase('application', 'CF-netcdf') #check in ogc docs
        submsg.set_payload(netcdf.read())
        submsg.set_type('application/CF-netcdf')
        submsg.add_header('Content-Disposition', 'attachment; filename="coverage.nc"')
        submsg.add_header('Content-ID', '<coverage.nc>')
        netcdf.close()
        # Encode the payload using Base64
        encoders.encode_base64(submsg)
        msg.attach(submsg)
        
        #return the message
        return msg
        

    def _loadFeatureDimensions(self, feature):
        dims = {}
        #!WARNING
        # This bit is a hack until the CSML API implements a mechanism
        # to determine which elements of a domain are longitude and latitude.
        lon=feature.getLongitudeAxis()
        lat=feature.getLongitudeAxis()
        domain=feature.getDomain()
        for axis_name, axis in domain.iteritems():
            if axis_name in [lon,lat]:
                continue            
            dims[axis_name] =            Domain(possibleValues=PossibleValues.fromAllowedValues(axis),
                                 #!TODO: this is a fudge until we can deduce UOM.
                                 valuesUnit=ValuesUnit(uoms=[''],
                                                       referenceSystems=['']))
        return dims

    def _loadFeatureSummary(self, feature):
        dims = self._loadFeatureDimensions(feature)
        #TODO - need to ensure proper values for Name. ID and Description are populated.
        cvgTitle=[feature.description.CONTENT]
        cvgDescription=feature.description.CONTENT
        cvgAbstract=[feature.description.CONTENT]
        bbox=c.dataset.getBoundingBox()  #TODO, use the bounding box of the feature not the dataset.
        return WcsDatasetSummary(identifier=feature.id,
                                 titles=cvgTitle,
                                 boundingBoxes=[BoundingBox([bbox[0],bbox[1]], [bbox[2],bbox[3]],
                                 crs='CRS:84')], dimensions=dims,  description=cvgDescription,abstracts=cvgAbstract
                                 )

    def _loadCapabilities(self):
        """
        Overriding subclass to add layer capabilities

        """
        # Get default capabilities from superclass
        sm = super(CsmlWcsController, self)._loadCapabilities()
        ds = WcsDatasetSummary(titles=['Root Dataset'], datasetSummaries=[], CRSs=['CRS:84'])
        # Add a DatasetSummary for each feature        
        for f_n in c.dataset.getFeatureList():        
            feature_ds = self._loadFeatureSummary(c.dataset.getFeature(f_n))
            ds.datasetSummaries.append(feature_ds)
        sm.contents = Contents(datasetSummaries=[ds])
        return sm

    
    @operation
    @parameter('Format', possibleValues=['text/xml'])
    @parameter('Service', possibleValues=['WCS'], required=True)
    @parameter('Version', possibleValues=['1.1.0'])
    def GetCapabilities(self, fileoruri, service=None, version=None):
        """
        @note: format and updatesequence parameters are not supported
            by this WMS.

        """
        # Populate the context object with information required by the template
        
        #get doc from cache or disk:
        c.dataset = csmlCache[fileoruri]
        if type(c.dataset) is str:
            #If not a csml datset is some message from exist such as 'access denied'           
            return Response(c.dataset)
        return self._renderCapabilities('ows/wcs_capabilities')

    
    @operation
    @parameter('Version', possibleValues=['1.1.0'], required=True)
    @parameter('Identifier', required=True)
    @parameter('BoundingBox', required=True, validator=V.bbox_2or3d)
    @parameter('TimeSequence',required=True, validator=V.iso8601_time)
    @parameter('Format', possibleValues=['application/netcdf'], required=True)
    @parameter('Store', validator = V.boolean('Store'))
    @parameter('Status', validator = V.boolean('Status'))
    #TODO some more parameters to add here
    # Dimension parameters Time, Elevation, etc. are handled separately
    def GetCoverage(self, fileoruri, version, format, identifier, boundingbox, timesequence, store=False, status=False):
        try:
                    # Retrieve dataset and selected feature            
            dataset = csmlCache[fileoruri]
            feature = dataset.getFeature(identifier)
            if feature is None:
                raise OWS_E.InvalidParameterValue('Coverage not found', 'identifier')
            
                        
            #set bounding box TODO
            sel = dict(latitude=(boundingbox[1], boundingbox[3]), longitude=(boundingbox[0], boundingbox[2]))           
            sel['time']=timesequence
            
            lon=feature.getLongitudeAxis()
            lat=feature.getLatitudeAxis()
            t=feature.getTimeAxis()
            
            if None in [lon, lat, time]:
                #TODO need to return a suitable wcs error.
                pass
            
            #create selection dictionary:
            sel={}
            sel[lat]=(boundingbox[1], boundingbox[3])
            sel[lon]=(boundingbox[0], boundingbox[2])
            sel[t]=timesequence
            
            #z is the 4th axis (eg height or pressure).
            #NOTE, need to decide whether bounding box is of form: x1,y1,z1,x2,y2,z2 or x1,y1,x2,y2,z1,z2
            #currently the latter is implemented. 
           
            if len(boundingbox)  == 6:
                for ax in feature.getAxisLabels():
                    if ax not in [lat, lon, t]:
                        #must be Z  
                        z=str(ax)
                        sel[z]=(boundingbox[4], boundingbox[5])
            
           
            axisNames=feature.getAxisLabels()
       
                        
            # Extract via CSML.subsetToGridSeries()
            if store:
                #need to farm off to WPS
                #but for now...
                filename = extractToNetCDF(feature, sel, publish = True) 
            else:
                filename = extractToNetCDF(feature, sel)

                
            #use the randomly allocated filename as a basis for an identifier           
            f=os.path.basename(filename)
            c.fileID=os.path.splitext(f)[0]
            
            #Depending on if the 'store' parameter is set, either return the netcdf file + coverage xml as a multipart mime or return a coverage document containing a link.
                      
            if store:
                if status:
                    #STORE = true, STATUS = true:
                    #hand off file "id" to StatusController to determine correct ExectuteResponse type response.
                    status=StatusController()
                    jobID=os.path.splitext(os.path.basename(filename)[9:])[0] #remove the 'csml_wxs_' prefix and file extension to create a jobID
                    return status.getStatus(jobID)                   
                else:
                    #STORE=true, STATUS = false: Return Coverage XML document with link to file.
                    #use the temp file name (minus extension) as an ID
                    c.hyperlink = 'http://'+request.environ['HTTP_HOST']+'/'+os.path.basename(request.environ['paste.config']['app_conf']['publish_dir'])+'/'+os.path.basename(filename)
                    r=render_response('wcs_getCoverageResponse', format='xml')
                    r.headers['content-type'] = 'text/xml'
                    return r                                 
            else:                
                #STORE = FALSE, STATUS therefore irrelevant, return Multipart Mime.
                netcdfFile=open(filename, 'r')
                c.hyperlink="cid:coverage.nc"
                xmlfile=render_response('wcs_getCoverageResponse', format='xml')
                xmlfile.headers['content-type'] = 'text/xml'
                multipart=self._createMultipartMime(xmlfile, netcdfFile)        
                msg=multipart
                #msg=open(multipart, 'r').readlines()
                return Response(content=msg, mimetype='multipart') 
                  
        except Exception, e:
            if isinstance(e, OWS_E.OwsError):
                raise e
            else:
                raise OWS_E.NoApplicableCode(e)