import numpy as np
import pySDC.core.deprecated.PFASST_stepwise as mp
from examples.advection_1d_implicit.TransferClass import mesh_to_mesh_1d_periodic

from pySDC.core import CollocationClasses as collclass
from pySDC.core import Log
from pySDC.implementations.sweeper_classes.generic_LU import generic_LU
from pySDC.playgrounds.deprecated.advection_1d_implicit.ProblemClass import advection

if __name__ == "__main__":

    # set global logger (remove this if you do not want the output at all)
    logger = Log.setup_custom_logger('root')

    num_procs = 1

    # This comes as read-in for the level class (this is optional!)
    lparams = {}
    lparams['restol'] = 1E-10

    # This comes as read-in for the step class (this is optional!)
    sparams = {}
    sparams['maxiter'] = 10
    sparams['fine_comm'] = True

    # This comes as read-in for the problem class
    pparams = {}
    pparams['c'] = 1
    pparams['nvars'] = [8,4]
    pparams['order'] = [2]

    # This comes as read-in for the transfer operations (this is optional!)
    tparams = {}
    tparams['finter'] = True
    tparams['iorder'] = 2
    tparams['rorder'] = 1

    # Fill description dictionary for easy hierarchy creation
    description = {}
    description['problem_class'] = advection
    description['problem_params'] = pparams
    description['collocation_class'] = collclass.CollGaussLegendre
    description['num_nodes'] = 5
    description['sweeper_class'] = generic_LU
    description['level_params'] = lparams
    description['transfer_class'] = mesh_to_mesh_1d_periodic
    description['transfer_params'] = tparams

    # quickly generate block of steps
    MS = mp.generate_steps(num_procs,sparams,description)

    # setup parameters "in time"
    t0 = 0.0
    dt = 0.1
    Tend = dt

    # get initial values on finest level
    P = MS[0].levels[0].prob
    uinit = P.u_exact(t0)

    # call main function to get things done...
    uend,stats = mp.run_pfasst(MS,u0=uinit,t0=t0,dt=dt,Tend=Tend)

    # compute exact solution and compare
    uex = P.u_exact(Tend)

    print('error at time %s: %s' %(Tend,np.linalg.norm(uex.values-uend.values,np.inf)/np.linalg.norm(
        uex.values,np.inf)))

    # extract_stats = grep_stats(stats,iter=-1,type='residual')
    # sortedlist_stats = sort_stats(extract_stats,sortby='step')
    # print(extract_stats,sortedlist_stats)