###############################################################################
# Copyright (c), Forschungszentrum Jülich GmbH, IAS-1/PGI-1, Germany.         #
#                All rights reserved.                                         #
# This file is part of the AiiDA-FLEUR package.                               #
#                                                                             #
# The code is hosted on GitHub at https://github.com/JuDFTteam/aiida-fleur    #
# For further information on the license, see the LICENSE.txt file            #
# For further information please visit http://www.flapw.de or                 #
# http://aiida-fleur.readthedocs.io/en/develop/                               #
###############################################################################
"""
    In this module you find the workflow 'FleurSSDispWorkChain' for the calculation of
    spin spiral dispersion using scalar-relatevistic Hamiltonian.
"""

import copy
from typing import Type

from lxml import etree
from ase.dft.kpoints import monkhorst_pack

from aiida.engine import WorkChain, ToContext, if_
from aiida.engine import calcfunction as cf
from aiida.orm import Code, load_node
from aiida.orm import RemoteData, Dict, KpointsData
from aiida.common import AttributeDict
from aiida.common.exceptions import NotExistent

from masci_tools.util.constants import HTR_TO_EV

from aiida_fleur.tools.common_fleur_wf import test_and_get_codenode
from aiida_fleur.tools.common_fleur_wf import get_inputs_fleur
from aiida_fleur.workflows.scf import FleurScfWorkChain
from aiida_fleur.data.fleurinpmodifier import FleurinpModifier, inpxml_changes
from aiida_fleur.workflows.base_fleur import FleurBaseWorkChain
from aiida_fleur.data.fleurinp import FleurinpData, get_fleurinp_from_remote_data


class FleurSSDispWorkChain(WorkChain):
    """
    This workflow calculates spin spiral dispersion of a structure.
    """

    _workflowversion = '0.3.0'

    _default_options = {
        'resources': {
            'num_machines': 1,
            'num_mpiprocs_per_machine': 1
        },
        'max_wallclock_seconds': 2 * 60 * 60,
        'queue_name': '',
        'custom_scheduler_commands': '',
        'import_sys_environment': False,
        'environment_variables': {}
    }

    _default_wf_para = {
        'beta': {
            'all': 1.57079
        },
        'prop_dir': [1.0, 0.0, 0.0],
        'q_vectors': [[0.0, 0.0, 0.0], [0.125, 0.0, 0.0], [0.250, 0.0, 0.0], [0.375, 0.0, 0.0]],
        'ref_qss': [0.0, 0.0, 0.0],
        'add_comp_para': {
            'only_even_MPI': False,
            'max_queue_nodes': 20,
            'max_queue_wallclock_sec': 86400
        },
        'kmesh_force_theorem': None,
        'inpxml_changes': []
    }

    @classmethod
    def define(cls, spec):
        super().define(spec)
        spec.expose_inputs(FleurScfWorkChain,
                           namespace_options={
                               'required': False,
                               'populate_defaults': False
                           },
                           namespace='scf')
        spec.input('wf_parameters', valid_type=Dict, required=False)
        spec.input('fleur', valid_type=Code, required=True)
        spec.input('remote', valid_type=RemoteData, required=False)
        spec.input('fleurinp', valid_type=FleurinpData, required=False)
        spec.input('options', valid_type=Dict, required=False)

        spec.outline(cls.start,
                     if_(cls.scf_needed)(
                         cls.converge_scf,
                         cls.force_after_scf,
                     ).else_(
                         cls.force_wo_scf,
                     ), cls.get_results, cls.return_results)

        spec.output('output_ssdisp_wc_para', valid_type=Dict)

        # exit codes
        spec.exit_code(230, 'ERROR_INVALID_INPUT_PARAM', message='Invalid workchain parameters.')
        spec.exit_code(231, 'ERROR_INVALID_INPUT_CONFIG', message='Invalid input configuration.')
        spec.exit_code(233,
                       'ERROR_INVALID_CODE_PROVIDED',
                       message='Invalid code node specified, check inpgen and fleur code nodes.')
        spec.exit_code(235, 'ERROR_CHANGING_FLEURINPUT_FAILED', message='Input file modification failed.')
        spec.exit_code(236, 'ERROR_INVALID_INPUT_FILE', message="Input file was corrupted after user's modifications.")
        spec.exit_code(334, 'ERROR_REFERENCE_CALCULATION_FAILED', message='Reference calculation failed.')
        spec.exit_code(335,
                       'ERROR_REFERENCE_CALCULATION_NOREMOTE',
                       message='Found no reference calculation remote repository.')
        spec.exit_code(336, 'ERROR_FORCE_THEOREM_FAILED', message='Force theorem calculation failed.')

    def start(self):
        """
        Retrieve and initialize paramters of the WorkChain
        """
        self.report(f'INFO: started Spin Stiffness calculation workflow version {self._workflowversion}\n')
        self.ctx.info = []
        self.ctx.warnings = []
        self.ctx.errors = []
        self.ctx.energy_dict = []

        # initialize the dictionary using defaults if no wf paramters are given
        wf_default = copy.deepcopy(self._default_wf_para)
        if 'wf_parameters' in self.inputs:
            wf_dict = self.inputs.wf_parameters.get_dict()
        else:
            wf_dict = wf_default

        extra_keys = []
        for key in wf_dict.keys():
            if key not in wf_default.keys():
                extra_keys.append(key)
        if extra_keys:
            error = f'ERROR: input wf_parameters for SSDisp contains extra keys: {extra_keys}'
            self.report(error)
            return self.exit_codes.ERROR_INVALID_INPUT_PARAM

        # extend wf parameters given by user using defaults
        for key, val in wf_default.items():
            wf_dict[key] = wf_dict.get(key, val)
        self.ctx.wf_dict = wf_dict

        if wf_dict['ref_qss'] != wf_dict['q_vectors'][0]:
            error = ('The first q_vector of the forceTheorem step has to be equal to'
                     'the q vector of the reference calculation.')
            self.control_end_wc(error)
            return self.exit_codes.ERROR_INVALID_INPUT_PARAM

        # initialize the dictionary using defaults if no options are given
        defaultoptions = self._default_options
        if 'options' in self.inputs:
            options = self.inputs.options.get_dict()
        else:
            options = defaultoptions

        # extend options given by user using defaults
        for key, val in defaultoptions.items():
            options[key] = options.get(key, val)
        self.ctx.options = options

        # Check if user gave valid fleur executable
        inputs = self.inputs
        if 'fleur' in inputs:
            try:
                test_and_get_codenode(inputs.fleur, 'fleur.fleur')
            except ValueError:
                error = 'The code you provided for FLEUR does not use the plugin fleur.fleur'
                self.control_end_wc(error)
                return self.exit_codes.ERROR_INVALID_CODE_PROVIDED

        # Check if user gave an input setup making any sense
        if 'scf' in inputs:
            self.ctx.scf_needed = True
            if 'remote' in inputs:
                error = 'ERROR: you gave SCF input + remote for the FT'
                self.control_end_wc(error)
                return self.exit_codes.ERROR_INVALID_INPUT_CONFIG
            if 'fleurinp' in inputs:
                error = 'ERROR: you gave SCF input + fleurinp for the FT'
                self.control_end_wc(error)
                return self.exit_codes.ERROR_INVALID_INPUT_CONFIG
        elif 'remote' not in inputs:
            error = 'ERROR: you gave neither SCF input nor remote for the FT'
            self.control_end_wc(error)
            return self.exit_codes.ERROR_INVALID_INPUT_CONFIG
        else:
            self.ctx.scf_needed = False

    def scf_needed(self):
        """
        Returns True if SCF WC is needed.
        """
        return self.ctx.scf_needed

    def converge_scf(self):
        """
        Converge charge density for collinear case which is a reference for futher
        spin spiral calculations.
        """
        inputs = self.get_inputs_scf()
        res = self.submit(FleurScfWorkChain, **inputs)
        return ToContext(reference=res)

    def get_inputs_scf(self):
        """
        Initialize inputs for the scf cycle
        """
        input_scf = AttributeDict(self.exposed_inputs(FleurScfWorkChain, namespace='scf'))
        input_scf.metadata.label = 'reference_scf_SSDisp'
        input_scf.metadata.description = ('The SCF workchain converging reference charge'
                                          ' density for Spin Spiral Dispersion')

        if 'wf_parameters' not in input_scf:
            scf_wf_dict = {}
        else:
            scf_wf_dict = input_scf.wf_parameters.get_dict()

        with inpxml_changes(scf_wf_dict) as fm:

            if [x for x in self.ctx.wf_dict['ref_qss'] if x != 0]:
                fm.set_inpchanges({'qss': self.ctx.wf_dict['ref_qss'], 'l_noco': True, 'ctail': False, 'l_ss': True})
            else:
                fm.set_inpchanges({'qss': ' 0.0 0.0 0.0 ', 'l_noco': False, 'ctail': True, 'l_ss': False})

            # change beta parameter
            for key, val in self.ctx.wf_dict['beta'].items():
                fm.set_atomgroup_label(key, {'nocoParams': {'beta': val}})

        input_scf.wf_parameters = Dict(scf_wf_dict)

        if 'structure' in input_scf:  # add info about spin spiral propagation
            if 'calc_parameters' in input_scf:
                calc_parameters = input_scf.calc_parameters.get_dict()
            else:
                calc_parameters = {}
            calc_parameters['qss'] = {
                'x': self.ctx.wf_dict['prop_dir'][0],
                'y': self.ctx.wf_dict['prop_dir'][1],
                'z': self.ctx.wf_dict['prop_dir'][2]
            }
            input_scf.calc_parameters = Dict(calc_parameters)

        return input_scf

    def change_fleurinp(self):
        """
        This routine sets somethings in the fleurinp file before running a fleur
        calculation.
        """
        self.report('INFO: run change_fleurinp')

        if self.ctx.scf_needed:  # use fleurinp from scf wc
            try:
                fleurin = self.ctx.reference.outputs.fleurinp
            except NotExistent:
                error = 'Fleurinp generated in the reference calculation is not found.'
                self.control_end_wc(error)
                return self.exit_codes.ERROR_REFERENCE_CALCULATION_FAILED
        else:
            if 'fleurinp' in self.inputs:  # use the given fleurinp
                fleurin = self.inputs.fleurinp
            else:  # or generate a new one from inp.xml located in the remote folder
                fleurin = get_fleurinp_from_remote_data(self.inputs.remote)

        # copy inpchanges from wf parameters
        with inpxml_changes(self.ctx.wf_dict) as fm:
            fm.set_complex_tag('spinSpiralDispersion', {'q': self.ctx.wf_dict['q_vectors']}, create=True)
            fm.set_inpchanges({'itmax': 1, 'l_noco': True, 'ctail': False, 'l_ss': True})

            if self.ctx.wf_dict['kmesh_force_theorem'] is not None:
                kmesh = KpointsData()
                kmesh.set_kpoints(monkhorst_pack(self.ctx.wf_dict['kmesh_force_theorem']))
                kmesh.store()
                fm.set_kpointsdata(kmesh.uuis, switch=True, kpoint_type='mesh')

            # change beta parameter
            for label, beta in self.ctx.wf_dict['beta'].items():
                fm.set_atomgroup_label(label, {'nocoParams': {'beta': beta}})

        fleurmode = FleurinpModifier(fleurin)
        try:
            fleurmode.add_task_list(self.ctx.wf_dict['inpxml_changes'])
        except (ValueError, TypeError) as exc:
            error = ('ERROR: Changing the inp.xml file failed. Tried to apply inpxml_changes'
                     f', which failed with {exc}. I abort, good luck next time!')
            self.control_end_wc(error)
            return self.exit_codes.ERROR_CHANGING_FLEURINPUT_FAILED

        # validate?
        try:
            fleurmode.show(display=False, validate=True)
        except etree.DocumentInvalid:
            error = ('ERROR: input, user wanted inp.xml changes did not validate')
            self.report(error)
            return self.exit_codes.ERROR_INVALID_INPUT_FILE
        except (ValueError, TypeError) as exc:
            error = ('ERROR: input, user wanted inp.xml changes could not be applied.'
                     f'The following error was raised {exc}')
            self.control_end_wc(error)
            return self.exit_codes.ERROR_CHANGING_FLEURINPUT_FAILED

        # apply
        out = fleurmode.freeze()
        self.ctx.fleurinp = out

    def force_after_scf(self):
        '''
        This routine uses the force theorem to calculate energies dispersion of
        spin spirals. The force theorem calculations implemented into the FLEUR
        code. Hence a single iteration FLEUR input file having <forceTheorem> tag
        has to be created and submitted.
        '''
        calc = self.ctx.reference

        if not calc.is_finished_ok:
            message = ('The reference SCF calculation was not successful.')
            self.control_end_wc(message)
            return self.exit_codes.ERROR_REFERENCE_CALCULATION_FAILED

        try:
            outpara_node = calc.outputs.output_scf_wc_para
        except NotExistent:
            message = ('The reference SCF calculation failed, no scf output node.')
            self.control_end_wc(message)
            return self.exit_codes.ERROR_REFERENCE_CALCULATION_FAILED

        outpara = outpara_node.get_dict()

        if 'total_energy' not in outpara:
            message = ('Did not manage to extract float total energy from the reference SCF calculation.')
            self.control_end_wc(message)
            return self.exit_codes.ERROR_REFERENCE_CALCULATION_FAILED

        self.report('INFO: run Force theorem calculations')

        status = self.change_fleurinp()
        if status:
            return status

        fleurin = self.ctx.fleurinp

        # Do not copy mixing_history* files from the parent
        settings = {'remove_from_remotecopy_list': ['mixing_history*']}

        # Retrieve remote folder of the reference calculation
        pk_last = 0
        scf_ref_node = load_node(calc.pk)
        for i in scf_ref_node.called:
            if i.node_type == 'process.workflow.workchain.WorkChainNode.':
                if i.process_class is FleurBaseWorkChain:
                    if pk_last < i.pk:
                        pk_last = i.pk
        try:
            remote = load_node(pk_last).outputs.remote_folder
        except AttributeError:
            message = ('Found no remote folder of the reference scf calculation.')
            self.control_end_wc(message)
            return self.exit_codes.ERROR_REFERENCE_CALCULATION_NOREMOTE

        label = 'Force_theorem_calculation'
        description = 'This is a force theorem calculation for all SQA'

        code = self.inputs.fleur
        options = self.ctx.options.copy()

        inputs_builder = get_inputs_fleur(code,
                                          remote,
                                          fleurin,
                                          options,
                                          label,
                                          description,
                                          settings,
                                          add_comp_para=self.ctx.wf_dict['add_comp_para'])
        future = self.submit(FleurBaseWorkChain, **inputs_builder)
        return ToContext(f_t=future)

    def force_wo_scf(self):
        """
        Submit FLEUR force theorem calculation using input remote
        """
        self.report('INFO: run Force theorem calculations')

        status = self.change_fleurinp()
        if status:
            return status

        fleurin = self.ctx.fleurinp

        # Do not copy mixing_history* files from the parent
        settings = {'remove_from_remotecopy_list': ['mixing_history*']}

        # Retrieve remote folder from the inputs
        remote = self.inputs.remote

        label = 'SSDisp_force_theorem'
        description = 'This is the force theorem calculation for Spin Spiral Dispersion.'

        code = self.inputs.fleur
        options = self.ctx.options.copy()

        inputs_builder = get_inputs_fleur(code,
                                          remote,
                                          fleurin,
                                          options,
                                          label,
                                          description,
                                          settings,
                                          add_comp_para=self.ctx.wf_dict['add_comp_para'])
        future = self.submit(FleurBaseWorkChain, **inputs_builder)
        return ToContext(f_t=future)

    def get_results(self):
        """
        Generates results of the workchain.
        """
        t_energydict = []
        try:
            calculation = self.ctx.f_t
            if not calculation.is_finished_ok:
                message = f'ERROR: Force theorem Fleur calculation failed somehow it has exit status {calculation.exit_status}'
                self.control_end_wc(message)
                return self.exit_codes.ERROR_FORCE_THEOREM_FAILED
        except AttributeError:
            message = 'ERROR: Something went wrong I do not have a force theorem Fleur calculation'
            self.control_end_wc(message)
            return self.exit_codes.ERROR_FORCE_THEOREM_FAILED

        try:
            out_dict = calculation.outputs.output_parameters.dict
            t_energydict = out_dict.spst_force_evsum
            e_u = out_dict.spst_force_units

            # Find a minimal value of SpSp and count it as 0
            minenergy = min(t_energydict)

            if e_u in ['Htr', 'htr']:
                t_energydict = [HTR_TO_EV * (x - minenergy) for x in t_energydict]
            else:
                t_energydict = [(x - minenergy) for x in t_energydict]

            self.ctx.energy_dict = t_energydict

        except AttributeError:
            message = ('Did not manage to read evSum or energy units after FT calculation.')
            self.control_end_wc(message)
            return self.exit_codes.ERROR_FORCE_THEOREM_FAILED

    def return_results(self):
        """
        This function outputs results of the wc
        """
        out = {
            'workflow_name': self.__class__.__name__,
            'workflow_version': self._workflowversion,
            # 'initial_structure': self.inputs.structure.uuid, # parse from fleurinp or remove
            'is_it_force_theorem': True,
            'energies': self.ctx.energy_dict,
            'q_vectors': self.ctx.wf_dict['q_vectors'],
            'energy_units': 'eV',
            'info': self.ctx.info,
            'warnings': self.ctx.warnings,
            'errors': self.ctx.errors
        }

        out = save_output_node(Dict(dict=out))
        self.out('output_ssdisp_wc_para', out)

    def control_end_wc(self, errormsg):
        """
        Controlled way to shutdown the workchain. It will initialize the output nodes
        The shutdown of the workchain will has to be done afterwards
        """
        self.report(errormsg)  # because return_results still fails sometimes
        self.ctx.errors.append(errormsg)
        self.return_results()


@cf
def save_output_node(out):
    """
    This calcfunction saves the out dict in the db
    """
    out_wc = out.clone()
    return out_wc
