import numpy
import time
import subprocess
import os
from ComputeHessian import ComputeHessian
from ComputeMetric import ComputeMetric

def YamsCall(md,field,hmin,hmax,gradation,epsilon):
	"""
	YAMSCALL - call yams

	   build a metric using the Hessian of the given field
	   call Yams and the output mesh is plugged onto the model
	   -hmin = minimum edge length (m)
	   -hmax = maximum edge length (m)
	   -gradation = maximum edge length gradation between 2 elements
	   -epsilon = average error on each element (m/yr)

	   Usage:
	      md=YamsCall(md,field,hmin,hmax,gradation,epsilon);

	   Example:
	      md=YamsCall(md,md.inversion.vel_obs,1500,10^8,1.3,0.9);
	"""

	#2d geometric parameter (do not change)
	scale=2./9.

	#Compute Hessian
	t1=time.time()
	print "%s" % '      computing Hessian...'
	hessian=ComputeHessian(md.mesh.elements,md.mesh.x,md.mesh.y,field,'node')
	t2=time.time()
	print "%s%d%s\n" % (' done (',t2-t1,' seconds)')

	#Compute metric
	t1=time.time()
	print "%s" % '      computing metric...'
	metric=ComputeMetric(hessian,scale,epsilon,hmin,hmax,numpy.empty(0,int))
	t2=time.time()
	print "%s%d%s\n" % (' done (',t2-t1,' seconds)')

	#write files
	t1=time.time()
	print "%s" % '      writing initial mesh files...'
	numpy.savetxt('carre0.met',metric)

	f=open('carre0.mesh','w')

	#initialiation
	f.write("\n%s\n%i\n" % ('MeshVersionFormatted',1))

	#dimension
	f.write("\n%s\n%i\n" % ('Dimension',2))

	#Vertices
	f.write("\n%s\n%i\n\n" % ('Vertices',md.mesh.numberofvertices))
	for i in xrange(0,md.mesh.numberofvertices):
		f.write("%8g %8g %i\n" % (md.mesh.x[i],md.mesh.y[i],0))

	#Triangles
	f.write("\n\n%s\n%i\n\n" % ('Triangles',md.mesh.numberofelements))
	for i in xrange(0,md.mesh.numberofelements):
		f.write("%i %i %i %i\n" % (md.mesh.elements[i,0],md.mesh.elements[i,1],md.mesh.elements[i,2],0))
	numberofelements1=md.mesh.numberofelements

	#Deal with rifts
	if numpy.any(not numpy.isnan(md.rifts.riftstruct)):

		#we have the list of triangles that make up the rift. keep those triangles around during refinement.
		triangles=numpy.empty(0,int)
		for riftstruct in md.rifts.riftstruct:
			triangles=numpy.concatenate((triangles,riftstruct.segments[:,2]))

		f.write("\n\n%s\n%i\n\n" % ('RequiredTriangles',numpy.size(triangles)))
		for triangle in triangles:
			f.write("%i\n" % triangle)

	#close
	f.close()
	t2=time.time()
	print "%s%d%s\n" % (' done (',t2-t1,' seconds)')

	#call yams
	print "%s\n" % '      call Yams...'
	if   m.ispc():
		#windows
		subprocess.call('yams2-win -O 1 -v -0 -ecp -hgrad %g carre0 carre1' % gradation,shell=True)
	elif ismac():
		#Macosx
		subprocess.call('yams2-osx -O 1 -v -0 -ecp -hgrad %g carre0 carre1' % gradation,shell=True)
	else:
		#Linux
		subprocess.call('yams2-linux -O 1 -v -0 -ecp -hgrad %g carre0 carre1' % gradation,shell=True)

	#plug new mesh
	t1=time.time()
	print "\n%s" % '      reading final mesh files...'
	Tria=numpy.loadtxt('carre1.tria',int)
	Coor=numpy.loadtxt('carre1.coor',float)
	md.mesh.x=Coor[:,0]
	md.mesh.y=Coor[:,1]
	md.mesh.z=numpy.zeros((numpy.size(Coor,axis=0),1))
	md.mesh.elements=Tria
	md.mesh.numberofvertices=numpy.size(Coor,axis=0)
	md.mesh.numberofelements=numpy.size(Tria,axis=0)
	numberofelements2=md.mesh.numberofelements
	t2=time.time()
	print "%s%d%s\n\n" % (' done (',t2-t1,' seconds)')

	#display number of elements
	print "\n%s %i" % ('      inital number of elements:',numberofelements1)
	print "\n%s %i\n\n" % ('      new    number of elements:',numberofelements2)

	#clean up:
	os.remove('carre0.mesh')
	os.remove('carre0.met')
	os.remove('carre1.tria')
	os.remove('carre1.coor')
	os.remove('carre1.meshb')

	return md

