# For examples in paper -- do not modify

import os
from pyclaw import data 


#------------------------------
def setrun(claw_pkg='Classic'):
#------------------------------
    
    """ 
    Define the parameters used for running Clawpack.

    INPUT:
        claw_pkg expected to be "Classic4" for this setrun.

    OUTPUT:
        rundata - object of class ClawRunData 
    
    """ 
    
    assert claw_pkg.lower() == 'classic',  "Expected claw_pkg = 'classic'"

    rundata = data.ClawRunData(pkg=claw_pkg, ndim=1)

    #------------------------------------------------------------------
    # Problem-specific parameters to be written to setprob.data:
    #------------------------------------------------------------------

    probdata = rundata.new_UserData(name='probdata',fname='setprob.data')
    probdata.add_param('u',     1.0,  'advection velocity')
    probdata.add_param('mthsrc',     4,  'see rp1.f')

    
    #------------------------------------------------------------------
    # Standard Clawpack parameters to be written to claw.data:
    #------------------------------------------------------------------

    clawdata = rundata.clawdata  # initialized when rundata instantiated

    # ---------------
    # Spatial domain:
    # ---------------

    # Number of space dimensions:
    clawdata.ndim = 1
    
    # Lower and upper edge of computational domain:
    clawdata.xlower = 0.0
    clawdata.xupper = 10.0

    # Number of grid cells:
    clawdata.mx = 100
    
    

    # ---------------
    # Size of system:
    # ---------------

    # Number of equations in the system:
    clawdata.meqn = 1

    # Number of auxiliary variables in the aux array (initialized in setaux)
    clawdata.maux = 1
    
    # Index of aux array corresponding to capacity function, if there is one:
    clawdata.mcapa = 0
    
    
    
    # -------------
    # Initial time:
    # -------------

    clawdata.t0 = 0.0
    
    
    # -------------
    # Output times:
    #--------------

    # Specify at what times the results should be written to fort.q files.
    # Note that the time integration stops after the final output time.
    # The solution at initial time t0 is always written in addition.

    clawdata.outstyle = 2

    if clawdata.outstyle==1:
        # Output nout frames at equally spaced times up to tfinal:
        clawdata.nout = 50
        clawdata.tfinal = 25.0

    elif clawdata.outstyle == 2:
        # Specify a list of output times.  
        clawdata.tout =  [10., 12., 15., 20.]   # used if outstyle == 2
        clawdata.nout = len(clawdata.tout)

    elif clawdata.outstyle == 3:
        # Output every iout timesteps with a total of ntot time steps:
        iout = 1
        ntot = 5
        clawdata.iout = [iout, ntot]
    


    # ---------------------------------------------------
    # Verbosity of messages to screen during integration:  
    # ---------------------------------------------------

    # The current t, dt, and cfl will be printed every time step
    # at AMR levels <= verbosity.  Set verbosity = 0 for no printing.
    #   (E.g. verbosity == 2 means print only on levels 1 and 2.)
    clawdata.verbosity = 0
    
    

    # --------------
    # Time stepping:
    # --------------

    # if dt_variable==1: variable time steps used based on cfl_desired,
    # if dt_variable==0: fixed time steps dt = dt_initial will always be used.
    clawdata.dt_variable = 1
    
    # Initial time step for variable dt.  
    # If dt_variable==0 then dt=dt_initial for all steps:
    clawdata.dt_initial = 0.1
    
    # Max time step to be allowed if variable dt used:
    clawdata.dt_max = 1e+99
    
    # Desired Courant number if variable dt used, and max to allow without 
    # retaking step with a smaller dt:
    clawdata.cfl_desired = 0.9
    clawdata.cfl_max = 1.0
    
    # Maximum number of time steps to allow between output times:
    clawdata.max_steps = 500

    
    

    # ------------------
    # Method to be used:
    # ------------------

    # Order of accuracy:  1 => Godunov,  2 => Lax-Wendroff plus limiters
    clawdata.order = 2
    
    # Transverse order for 2d or 3d (not used in 1d):
    clawdata.order_trans = 0
    
    # Number of waves in the Riemann solution:
    clawdata.mwaves = 1
    
    # List of limiters to use for each wave family:  
    # Required:  len(mthlim) == mwaves
    clawdata.mthlim = [2]
    
    # Source terms splitting:
    #   src_split == 0  => no source term (src routine never called)
    #   src_split == 1  => Godunov (1st order) splitting used, 
    #   src_split == 2  => Strang (2nd order) splitting used,  not recommended.
    clawdata.src_split = 1
    
    
    # --------------------
    # Boundary conditions:
    # --------------------

    # Number of ghost cells (usually 2)
    clawdata.mbc = 2
    
    # Choice of BCs at xlower and xupper:
    #   0 => user specified (must modify bcN.f to use this option)
    #   1 => extrapolation (non-reflecting outflow)
    #   2 => periodic (must specify this at both boundaries)
    #   3 => solid wall for systems where q(2) is normal velocity
    
    clawdata.mthbc_xlower = 0
    clawdata.mthbc_xupper = 1
    
    return rundata
    # end of function setrun
    # ----------------------