"""Simple water flow example using ANUGA

Will Powers example of a simple sinusoidal wave which showed diffusive effects of
thefirst order and standard second order method. Problem resolved if "rk2" timestepping
and higher beta = 2 limiter used. Also new edge limiter with rk2 resolves problem 
"""

#------------------------------------------------------------------------------
# Import necessary modules
#------------------------------------------------------------------------------

import sys
from anuga.abstract_2d_finite_volumes.mesh_factory import rectangular_cross
from anuga.shallow_water import Domain
from anuga.shallow_water import Reflective_boundary
from anuga.shallow_water import Dirichlet_boundary
from anuga.shallow_water import Time_boundary
from anuga.shallow_water import Transmissive_boundary
from anuga.shallow_water import Transmissive_Momentum_Set_Stage_boundary
from anuga.shallow_water.data_manager import start_screen_catcher, copy_code_files

from math import cos
from Numeric import zeros, Float
from time import localtime, strftime, gmtime
from os import sep



#-------------------------------------------------------------------------------
# Copy scripts to time stamped output directory and capture screen
# output to file
#-------------------------------------------------------------------------------
time = strftime('%Y%m%d_%H%M%S',localtime())

output_dir = 'wave_'+time
output_file = 'wave'

copy_code_files(output_dir,__file__)
#start_screen_catcher(output_dir+sep)

interactive_visualisation = False

#------------------------------------------------------------------------------
# Setup domain
#------------------------------------------------------------------------------
dx = 1000.
dy = dx
L = 100000.
W = 10*dx

# structured mesh
points, vertices, boundary = rectangular_cross(int(L/dx), int(W/dy), L, W, (0.0, -W/2))

domain = Domain(points, vertices, boundary) 

domain.set_name(output_file)                
domain.set_datadir(output_dir)  

#------------------------------------------------------------------------------
# Setup Algorithm
#------------------------------------------------------------------------------
domain.set_timestepping_method('rk2')
domain.set_default_order(2)

print domain.get_timestepping_method()

domain.use_edge_limiter = True
domain.tight_slope_limiters = False
domain.use_centroid_velocities = False

domain.CFL = 1.0

domain.beta_w      = 1.0
domain.beta_w_dry  = 0.0
domain.beta_uh     = 1.0
domain.beta_uh_dry = 0.0
domain.beta_vh     = 1.0
domain.beta_vh_dry = 0.0


#------------------------------------------------------------------------------
# Setup initial conditions
#------------------------------------------------------------------------------
domain.set_quantity('elevation',-100.0)
domain.set_quantity('friction', 0.00)
domain.set_quantity('stage', 0.0)            

#-----------------------------------------------------------------------------
# Setup boundary conditions
#------------------------------------------------------------------------------
from math import sin, pi, exp
Br = Reflective_boundary(domain)      # Solid reflective wall
Bt = Transmissive_boundary(domain)    # Continue all values on boundary 
Bd = Dirichlet_boundary([1,0.,0.]) # Constant boundary values
amplitude = 1
Bw = Time_boundary(domain=domain,     # Time dependent boundary  
## Sine wave
                  f=lambda t: [(-amplitude*sin((1./300.)*t*2*pi)), 0.0, 0.0])
## Sawtooth?
#                   f=lambda t: [(-8.0*(sin((1./180.)*t*2*pi))+(1./2.)*sin((2./180.)*t*2*pi)+(1./3.)*sin((3./180.)*t*2*pi)), 0.0, 0.0])
## Sharp rise, linear fall
#                   f=lambda t: [(5.0*(-((t-0.)/300.)*(t<300.)-cos((t-300.)*2.*pi*(1./240.))*(t>=300. and t<420.)+(1.-(t-420.)/300.)*(t>=420. and t <720.))), 0.0, 0.0])
#                   f=lambda t: [amplitude*(1.-2.*(pi*(1./720.)*(t-720.))**2)/exp((pi*(1./720.)*(t-720.))**2) , 0.0, 0.0])
#                   f=lambda t: [(-8.0*sin((1./720.)*t*2*pi))*((t<720.)-0.5*(t<360.)), 0.0, 0.0])

# Associate boundary tags with boundary objects
domain.set_boundary({'left': Bw, 'right': Bt, 'top': Br, 'bottom': Br})


#===============================================================================
if interactive_visualisation:
    from anuga.visualiser import RealtimeVisualiser
    vis = RealtimeVisualiser(domain)
    vis.render_quantity_height("stage", zScale =10000, dynamic=True)
    vis.colour_height_quantity('stage', (1.0, 0.5, 0.5))
    vis.start()
#===============================================================================


#------------------------------------------------------------------------------
# Evolve system through time
#------------------------------------------------------------------------------

for t in domain.evolve(yieldstep = 50.0, finaltime = 60*60.):
    domain.write_time()
    if interactive_visualisation:
        vis.update()

if interactive_visualisation:
    vis.evolveFinished()