import os
import numpy as np
from ContourToMesh import ContourToMesh
import MatlabFuncs as m

def SetIceShelfBC(md,icefrontfile=''):
	"""
	SETICESHELFBC - Create the boundary conditions for stressbalance and thermal models for a  Ice Shelf with Ice Front

	   Neumann BC are used on the ice front (an ARGUS contour around the ice front
	   must be given in input)
	   Dirichlet BC are used elsewhere for stressbalance

	   Usage:
	      md=SetIceShelfBC(md,varargin)

	   Example:
	      md=SetIceShelfBC(md);
	      md=SetIceShelfBC(md,'Front.exp');

	   See also: SETICESHEETBC, SETMARINEICESHEETBC
	"""

	#node on Dirichlet (boundary and ~icefront)
	if icefrontfile:
		if not os.path.exists(icefrontfile):
			raise IOError("SetIceShelfBC error message: ice front file '%s' not found." % icefrontfile)
		nodeinsideicefront=ContourToMesh(md.mesh.elements,md.mesh.x,md.mesh.y,icefrontfile,'node',2)
		nodeonicefront=np.logical_and(md.mesh.vertexonboundary,nodeinsideicefront.reshape(-1))
	else:
		nodeonicefront=np.zeros((md.mesh.numberofvertices),bool)

#	pos=find(md.mesh.vertexonboundary & ~nodeonicefront);
	pos=np.nonzero(np.logical_and(md.mesh.vertexonboundary,np.logical_not(nodeonicefront)))[0]
	md.stressbalance.spcvx=float('nan')*np.ones(md.mesh.numberofvertices)
	md.stressbalance.spcvy=float('nan')*np.ones(md.mesh.numberofvertices)
	md.stressbalance.spcvz=float('nan')*np.ones(md.mesh.numberofvertices)
	md.stressbalance.referential=float('nan')*np.ones((md.mesh.numberofvertices,6))
	md.stressbalance.loadingforce=0*np.ones((md.mesh.numberofvertices,3))

	#Icefront position
	pos=np.nonzero(nodeonicefront)[0]
	md.mask.ice_levelset[pos]=0

	#First find segments that are not completely on the front
	if m.strcmp(md.mesh.elementtype(),'Penta'):
		numbernodesfront=4;
	elif m.strcmp(md.mesh.elementtype(),'Tria'):
		numbernodesfront=2;
	else:
		raise	error('mesh type not supported yet')
	if any(md.mask.ice_levelset<=0):
		values=md.mask.ice_levelset[md.mesh.segments[:,0:-1]-1]
		segmentsfront=1-values
		np.sum(segmentsfront,axis=1)!=numbernodesfront
		segments=np.nonzero(np.sum(segmentsfront,axis=1)!=numbernodesfront)[0]
		#Find all nodes for these segments and spc them
		pos=md.mesh.segments[segments,0:-1]-1
	else:
		pos=np.nonzero(md.mesh.vertexonboundary)[0]
	md.stressbalance.spcvx[pos]=0
	md.stressbalance.spcvy[pos]=0
	md.stressbalance.spcvz[pos]=0
																													   
	#Dirichlet Values
	if isinstance(md.inversion.vx_obs,np.ndarray) and np.size(md.inversion.vx_obs,axis=0)==md.mesh.numberofvertices and isinstance(md.inversion.vy_obs,np.ndarray) and np.size(md.inversion.vy_obs,axis=0)==md.mesh.numberofvertices:
		#reshape to rank-2 if necessary to match spc arrays
		if np.ndim(md.inversion.vx_obs)==1:
			md.inversion.vx_obs=md.inversion.vx_obs.reshape(-1,)
		if np.ndim(md.inversion.vy_obs)==1:
			md.inversion.vy_obs=md.inversion.vy_obs.reshape(-1,)
		print "      boundary conditions for stressbalance model: spc set as observed velocities"
		md.stressbalance.spcvx[pos]=md.inversion.vx_obs[pos]
		md.stressbalance.spcvy[pos]=md.inversion.vy_obs[pos]
	else:
		print "      boundary conditions for stressbalance model: spc set as zero"

	#Create zeros basalforcings and smb
	md.smb.initialize(md)
	md.basalforcings.initialize(md)

	#Deal with other boundary conditions
	if np.all(np.isnan(md.balancethickness.thickening_rate)):
		md.balancethickness.thickening_rate=np.zeros((md.mesh.numberofvertices))
		print "      no balancethickness.thickening_rate specified: values set as zero"
	md.masstransport.spcthickness=float('nan')*np.ones((md.mesh.numberofvertices))
	md.balancethickness.spcthickness=float('nan')*np.ones((md.mesh.numberofvertices))
	md.damage.spcdamage=float('nan')*np.ones((md.mesh.numberofvertices))

	if isinstance(md.initialization.temperature,np.ndarray) and np.size(md.initialization.temperature,axis=0)==md.mesh.numberofvertices:
		md.thermal.spctemperature=float('nan')*np.ones((md.mesh.numberofvertices))
		if hasattr(md.mesh,'vertexonsurface'):
			pos=np.nonzero(md.mesh.vertexonsurface)[0]
			md.thermal.spctemperature[pos]=md.initialization.temperature[pos]    #impose observed temperature on surface
		if not isinstance(md.basalforcings.geothermalflux,np.ndarray) or not np.size(md.basalforcings.geothermalflux,axis=0)==md.mesh.numberofvertices:
			md.basalforcings.geothermalflux=np.zeros((md.mesh.numberofvertices))
	else:
		print "      no thermal boundary conditions created: no observed temperature found"

	return md

