"""Validation of the AnuGA implementation of the shallow water wave equation.

This script sets up LWRU2 benchmark with initial condition stated

See also

http://www.cee.cornell.edu/longwave/index.cfm?page=benchmark&problem=2

Depth at western boundary is d = 13.5 cm
"""


use_variable_mesh = True #Use large variable mesh generated by create_mesh.py
#use_variable_mesh = False #Use small structured mesh for speed


import sys
from os import sep
sys.path.append('..'+sep+'..'+sep) #FIXME: Shouldn't be necessary

def prepare_timeboundary(filename):
    """Converting benchmark 2 time series to NetCDF tms file.
    This is a 'throw-away' code taylor made for files like
    'Benchmark_2_input.txt' from the LWRU2 benchmark
    """

    print 'Preparing time boundary from %s' %filename
    from Numeric import array

    fid = open(filename)

    #Skip first line
    line = fid.readline()

    #Read remaining lines
    lines = fid.readlines()
    fid.close()


    N = len(lines)
    T = zeros(N, Float)  #Time
    Q = zeros(N, Float)  #Values

    for i, line in enumerate(lines):
        fields = line.split()

        T[i] = float(fields[0])
        Q[i] = float(fields[1])


    #Create tms file
    from Scientific.IO.NetCDF import NetCDFFile

    outfile = filename[:-4] + '.tms'
    print 'Writing to', outfile
    fid = NetCDFFile(outfile, 'w')

    fid.institution = 'Geoscience Australia'
    fid.description = 'Input wave for Benchmark 2'
    fid.starttime = 0.0
    fid.createDimension('number_of_timesteps', len(T))
    fid.createVariable('time', Float, ('number_of_timesteps',))
    fid.variables['time'][:] = T

    fid.createVariable('stage', Float, ('number_of_timesteps',))
    fid.variables['stage'][:] = Q[:]

    fid.createVariable('xmomentum', Float, ('number_of_timesteps',))
    fid.variables['xmomentum'][:] = 0.0

    fid.createVariable('ymomentum', Float, ('number_of_timesteps',))
    fid.variables['ymomentum'][:] = 0.0

    fid.close()


# Module imports
from pyvolution.shallow_water import Domain, Reflective_boundary,\
     File_boundary, Transmissive_Momentum_Set_Stage_boundary
from pyvolution.mesh_factory import rectangular_cross
from pyvolution.pmesh2domain import pmesh_to_domain_instance
from Numeric import array, zeros, Float, allclose
import project
from caching import cache

#Preparing time boundary
prepare_timeboundary(project.boundary_filename)

#Preparing points (Only when using original Benchmark_2_Bathymetry.txt file)
#from pyvolution.data_manager import xya2pts
#xya2pts(project.bathymetry_filename, verbose = True,
#        z_func = lambda z: -z)



#######################
# Create Domain
if use_variable_mesh is True:
    print 'Creating domain from', project.mesh_filename

    domain = Domain(project.mesh_filename, use_cache=True, verbose=True)

else:
    print 'Creating regular mesh'
    N = 150
    points, vertices, boundary = rectangular_cross(N, N/5*3,
                                                   len1=5.448, len2=3.402)
    print 'Creating domain'

    #domain = Domain(points, vertices, boundary)
    domain = cache(Domain, (points, vertices, boundary))




import sys, os
base = os.path.basename(sys.argv[0])
domain.filename, _ = os.path.splitext(base)
domain.default_order = 2
domain.store = True    #Store for visualisation purposes

#domain.check_integrity()
print 'Number of triangles = ', len(domain)
print 'The extent is ', domain.get_extent()
print domain.statistics()



#######################
# Initial Conditions
print 'Initial values'

domain.set_quantity('elevation',
                    filename = project.bathymetry_filename[:-4] + '.pts',
                    alpha = 0.001,
                    verbose = True,
                    use_cache = True)

domain.set_quantity('friction', 0.0)
domain.set_quantity('stage', 0.0)



######################
# Boundary Conditions
#
print 'Boundaries'
Br = Reflective_boundary(domain)

from pyvolution.util import file_function
function = file_function(project.boundary_filename[:-4] + '.tms',
                         domain,
                         verbose = True)
Bts = Transmissive_Momentum_Set_Stage_boundary(domain, function)

#Set boundary conditions
if use_variable_mesh is True:
    domain.set_boundary({'wave': Bts, 'wall': Br})
else:
    domain.set_boundary({'left': Bts, 'right': Br, 'bottom': Br, 'top': Br})



#######################
# Evolve
import time
t0 = time.time()

for t in domain.evolve(yieldstep = 0.05, finaltime = 22.5):
    domain.write_time()

print 'That took %.2f seconds' %(time.time()-t0)