#!/usr/bin/env python
"""
Transient Laplace equation (heat/diffusion equation) with constant initial conditions
given by a function

In the SfePy top-level directory the following command executes the script

python time_poisson_explicity_1d.py 
"""

from __future__ import absolute_import
import sys
from six.moves import range
sys.path.append('.')
from argparse import ArgumentParser, RawDescriptionHelpFormatter

import numpy as nm
import matplotlib.pyplot as plt


def main():

    from sfepy.base.base import output
    from sfepy.base.conf import ProblemConf, get_standard_keywords
    from sfepy.discrete import (FieldVariable, Material, Integral, Function,
                            Equation, Equations, Problem, Domain, State)
    # from sfepy.base.plotutils import plt
    from sfepy.solvers.ts_solvers import SimpleTimeSteppingSolver
    from sfepy.solvers.ls import ScipyDirect
    from sfepy.solvers.nls import Newton

    # required, other = get_standard_keywords()
    ### Use this file as the input file.
    conf = ProblemConf.from_file('time_poisson_explicit_1d.py')

    #### Create problem instance, but do not set equations.
    problemInstance = Problem.from_conf(conf)
    problemInstance.setup_default_output()

    # initializing simple time step solver from configurationf ile
    tss = SimpleTimeSteppingSolver(problemInstance.ts_conf, problem=problemInstance)
    tss.init_time()

    print ("initial problem/solver configured....")

    print ("")

    print ("problemInstance.ts_conf: " + str(problemInstance.ts_conf))
    print ("problemInstance.ts.t0: " + str(problemInstance.ts.t0))
    print ("problemInstance.ts.t1: " + str(problemInstance.ts.t1))
    print ("problemInstance.ts.dt: " + str(problemInstance.ts.dt))
    print ("")
    print ("tss.ts.t0: " + str(tss.ts.t0))
    print ("tss.ts.t1: " + str(tss.ts.t1))
    print ("tss.ts.dt: " + str(tss.ts.dt))
    print ("")

    # Solve the problem using the time stepping solver.
    suffix = tss.ts.suffix

    genpath = "output/"


    ##### TYPICAL MAIN LOOP STATEMENT ####
    # for step, time, state in tss():
            # print("step: " + str(step))


    #### initialize state for problem from sfepy.solvers.ts_solvers
    #### def get_initial_state(problem) calls...
    state0 = problemInstance.create_state()
    problemInstance.setup_ics()
    state0.apply_ic()
    # Initialize variables with history.
    state0.init_history()
    print (state0.vec)
    staten1 = state0.copy(deep=True)


    ##### MAIN LOOP #####
    totalsteps = 3
    plotstep = 1
    for i in range(totalsteps):

        ### print current step
        print("step: " + str(i))


        #### manual plotting of every plotstep
        if (i%plotstep == 0):

            ###get materials of current problem instance
            matl = problemInstance.get_materials()

            #####  command to change flux (natural boundary condition)
            # matl['LoadRHS'].datas['special']['val'] = 1.0

            #####  command to change conccentration (essential boundary condition)
            # parts = state.get_parts()
            # parts['c'][45] = 0.15

            if (i == 0):
                conc = state0.get_parts()['c']
                print (conc)
            else: 
                conc = state.get_parts()['c']
                print (conc)


        #### solving commands
        state = tss.solve_step(tss.ts, staten1)
        staten1 = state.copy(deep=True)
        problemInstance.advance(tss.ts)

        #### other solving commands suggested on main tutorial page
        # problemInstance.time_update()
        # state = problemInstance.solve()
        # print (state.vec)



if __name__ == '__main__':
    main()