from fielddisplay import fielddisplay
from project3d import project3d
from checkfield import checkfield
from WriteData import WriteData

class frictionshakti(object):
	"""
	FRICTIONSHAKTI class definition

	Usage:
	friction=frictionshakti()
	"""

	def __init__(self,md): # {{{
		self.coefficient = md.friction.coefficient
		#set defaults
		self.setdefaultparameters()
	#}}}

	def __repr__(self): # {{{
		string="Basal shear stress parameters: Sigma_b = coefficient^2 * Neff * u_b\n(effective stress Neff=rho_ice*g*thickness+rho_water*g*(head-b))"
		string="%s\n%s"%(string,fielddisplay(self,"coefficient","friction coefficient [SI]"))
		return string
	#}}}

	def extrude(self,md): # {{{
		self.coefficient=project3d(md,'vector',self.coefficient,'type','node','layer',1)
		return self
	#}}}

	def setdefaultparameters(self): # {{{
		return self
	#}}}

	def checkconsistency(self,md,solution,analyses):    # {{{
		#Early return
		if 'StressbalanceAnalysis' not in analyses and 'ThermalAnalysis' not in analyses:
			return md

		md = checkfield(md,'fieldname','friction.coefficient','timeseries',1,'NaN',1,'Inf',1)
		return md
	# }}}

	def marshall(self,prefix,md,fid):    # {{{
		yts=md.constants.yts
		WriteData(fid,prefix,'name','md.friction.law','data',8,'format','Integer')
		WriteData(fid,prefix,'object',self,'fieldname','coefficient','format','DoubleMat','mattype',1,'timeserieslength',md.mesh.numberofvertices+1,'yts',md.constants.yts)
    # }}}