"""
    Copyright (C) 2020 SunSpec Alliance

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
    IN THE SOFTWARE.
"""

import csv
import json
import copy
from sunspec2 import mdef

ADDRESS_OFFSET = 'Address Offset'
GROUP_OFFSET = 'Group Offset'
NAME = 'Name'
VALUE = 'Value'
COUNT = 'Count'
TYPE = 'Type'
SIZE = 'Size'
SCALE_FACTOR = 'Scale Factor'
UNITS = 'Units'
ACCESS = 'RW Access (RW)'
MANDATORY = 'Mandatory (M)'
STATIC = 'Static (S)'
LABEL = 'Label'
DESCRIPTION = 'Description'
NOTES = 'Notes'
DETAIL = 'Detailed Description'
STANDARDS = 'Standards'


columns = [ADDRESS_OFFSET, GROUP_OFFSET, NAME, VALUE, COUNT, TYPE, SIZE, SCALE_FACTOR,
           UNITS, ACCESS, MANDATORY, STATIC, LABEL, DESCRIPTION, DETAIL, STANDARDS, NOTES]

empty_row = [''] * len(columns)

ADDRESS_OFFSET_IDX = columns.index(ADDRESS_OFFSET)
GROUP_OFFSET_IDX = columns.index(GROUP_OFFSET)
NAME_IDX = columns.index(NAME)
VALUE_IDX = columns.index(VALUE)
COUNT_IDX = columns.index(COUNT)
TYPE_IDX = columns.index(TYPE)
SIZE_IDX = columns.index(SIZE)
SCALE_FACTOR_IDX = columns.index(SCALE_FACTOR)
UNITS_IDX = columns.index(UNITS)
ACCESS_IDX = columns.index(ACCESS)
MANDATORY_IDX = columns.index(MANDATORY)
STATIC_IDX = columns.index(STATIC)
LABEL_IDX = columns.index(LABEL)
DESCRIPTION_IDX = columns.index(DESCRIPTION)
NOTES_IDX = columns.index(NOTES)
DETAIL_IDX = columns.index(DETAIL)
STANDARDS_IDX = columns.index(STANDARDS)


class PySunSpecException(Exception):
    pass


def idx(row, attr, mandatory=False):
    try:
        return row.index(attr)
    except:
        if mandatory:
            raise ValueError('Missing required attribute column: %s' % attr)


def row_is_empty(row, idx):
    for e in row[idx:]:
        if e is not None and e != '':
            return False
    return True


def find_name(entities, name):
    for e in entities:
        if e[mdef.NAME] == name:
            return e


def from_spreadsheet(spreadsheet):
    model_def = {}
    row = spreadsheet[0]

    name_idx = idx(row, NAME, mandatory=True)
    value_idx = mdef.to_number_type(idx(row, VALUE, mandatory=True))
    count_idx = mdef.to_number_type(idx(row, COUNT, mandatory=True))
    type_idx = idx(row, TYPE, mandatory=True)
    size_idx = mdef.to_number_type(idx(row, SIZE, mandatory=True))
    scale_factor_idx = mdef.to_number_type(idx(row, SCALE_FACTOR, mandatory=True))
    units_idx = idx(row, UNITS, mandatory=True)
    access_idx = idx(row, ACCESS, mandatory=True)
    mandatory_idx = idx(row, MANDATORY, mandatory=True)
    static_idx = idx(row, STATIC, mandatory=True)
    label_idx = idx(row, LABEL)
    description_idx = idx(row, DESCRIPTION)
    detail_idx = idx(row, DETAIL)
    standards_idx = idx(row, STANDARDS)

    has_notes = False
    notes_idx = idx(row, NOTES)  # if notes col not present, notes_idx will be None
    if notes_idx and row[notes_idx] == 'Notes':
        has_notes = True
    row_num = 1

    group = None
    point = None
    detail = None
    standards = []
    comments = []  # Speadsheet comments - single gray lines
    parent = ''

    for row in spreadsheet[1:]:
        row_num += 1
        name = row[name_idx]
        value = mdef.to_number_type(row[value_idx])
        etype = row[type_idx]

        label = description = notes = ''
        if len(row) > label_idx:
            label = row[label_idx]
        if len(row) > description_idx:
            description = row[description_idx]
        if len(row) > detail_idx:
            detail = row[detail_idx]
        if len(row) > standards_idx:
            standards = row[standards_idx]
        if has_notes:
            notes = row[notes_idx]
            if notes is None:
                notes = ''

        # point
        if etype in mdef.point_type_info:
            # point
            if group:
                if not group.get(mdef.POINTS):
                    group[mdef.POINTS] = []
                if find_name(group[mdef.POINTS], name) is not None:
                    raise PySunSpecException('Duplicate point definition in group %s: %s' % (group[mdef.NAME], name))
            else:
                raise PySunSpecException('Point %s defined outside of group' % name)
            if etype == mdef.TYPE_STRING:
                size = mdef.to_number_type(row[size_idx])
            else:
                size = mdef.point_type_info[etype]['len']
            sf = mdef.to_number_type(row[scale_factor_idx])
            units = row[units_idx]
            access = row[access_idx]
            mandatory = row[mandatory_idx]
            static = row[static_idx]
            point = {mdef.NAME: name}
            if etype:
                point[mdef.TYPE] = etype
            if size is not None and size != '':
                point[mdef.SIZE] = size
            if sf:
                point[mdef.SF] = sf
            if units:
                point[mdef.UNITS] = units
            if access:
                point[mdef.ACCESS] = access
            if mandatory:
                point[mdef.MANDATORY] = mandatory
            if static:
                point[mdef.STATIC] = static
            if label:
                point[mdef.LABEL] = label
            if description:
                point[mdef.DESCRIPTION] = description
            if has_notes:
                point[mdef.NOTES] = notes
            if value is not None and value != '':
                point[mdef.VALUE] = value
            if detail:
                point[mdef.DETAIL] = detail
            if standards:
                if isinstance(standards, str):
                    stds_list = standards.split(',')
                    for std in stds_list:
                        stds_list[stds_list.index(std)] = std.strip()
                    point[mdef.STANDARDS] = stds_list
            else:
                point[mdef.STANDARDS] = []

            group[mdef.POINTS].append(point)

            # set the model id
            if not parent and name == mdef.MODEL_ID_POINT_NAME:
                model_def[mdef.ID] = value
            if comments:
                if len(comments) > 1:
                    point[mdef.COMMENTS] = [comments[-1]]
                else:
                    point[mdef.COMMENTS] = comments
            comments = []  # reset comments

        # group
        elif etype in mdef.group_types:
            path = name.split('.')
            group = model_def.get(mdef.GROUP)
            parent = ''
            if len(path) > 1:
                parent = group[mdef.NAME]
                for g in path[1:-1]:
                    group = find_name(group[mdef.GROUPS], g)
                    if group is None:
                        raise PySunSpecException('Unknown parent group id %s in group id %s' % (g, group))
                    parent += '.%s' % group[mdef.NAME]
            else:
                if group is not None:
                    raise PySunSpecException('Redefintion of top-level group %s with %s' % (group[mdef.ID], name))

            new_group = {mdef.NAME: path[-1], mdef.TYPE: etype}
            if label:
                new_group[mdef.LABEL] = label
            if description:
                new_group[mdef.DESCRIPTION] = description
            if has_notes:
                new_group[mdef.NOTES] = notes
            if detail:
                new_group[mdef.DETAIL] = detail
            if comments:
                new_group[mdef.COMMENTS] = comments
            comments = []  # reset comments

            count = mdef.to_number_type(row[count_idx])
            if count is not None and count != '':
                new_group[mdef.COUNT] = count
            if group is None:
                model_def[mdef.GROUP] = new_group
            else:
                if not group.get(mdef.GROUPS):
                    group[mdef.GROUPS] = []
                group[mdef.GROUPS].append(new_group)
            group = new_group

        # symbol - has name and value with no type
        elif name and value is not None and value != '':
            if point is None:
                raise PySunSpecException('Unknown point for symbol %s' % name)
            if not point.get(mdef.SYMBOLS):
                point[mdef.SYMBOLS] = []
            if find_name(point[mdef.SYMBOLS], name) is not None:
                raise PySunSpecException('Duplicate symbol definition in point %s: %s' % (point[mdef.ID], name))
            symbol = {mdef.NAME: name, mdef.VALUE: value}
            point[mdef.SYMBOLS].append(symbol)
            if label:
                symbol[mdef.LABEL] = label
            if description:
                symbol[mdef.DESCRIPTION] = description
            if has_notes:
                symbol[mdef.NOTES] = notes
            if detail:
                symbol[mdef.DETAIL] = detail
            comments = []

        elif not row_is_empty(row, 1):
            raise ValueError('Invalid spreadsheet entry row %s: %s' % (row_num, row))
        # comment - no name, value, or type
        elif row[0]:
            comments.append(row[0])
        # blank line - comment with nothing in column 1
    return model_def


def to_spreadsheet(model_def):
    """
    Entry point to generate a spreadsheet from a model definition

    :param model_def: Model definition
    :return: Spreadsheet
    """

    # check if model_def has notes attr by searching string
    mdef_str = json.dumps(model_def)
    has_notes = '\"notes\"' in mdef_str
    c_columns = copy.deepcopy(columns)
    if has_notes:
        spreadsheet = [columns]
    else:
        c_columns.remove('Notes')
        spreadsheet = [c_columns]
    to_spreadsheet_group(spreadsheet, model_def[mdef.GROUP], has_notes, addr_offset=0)
    return spreadsheet


def to_spreadsheet_group(ss, group, has_notes, parent='', addr_offset=None):
    """
    Add a group to the spreadsheet

    :param ss: Spreadsheet
    :param group: SunSpec group
    :param has_notes: whether the spreadsheet has notes
    :param parent: group parent
    :param addr_offset: register offset
    :return: None
    """
    # process comments
    for c in group.get(mdef.COMMENTS, []):
        to_spreadsheet_comment(ss, c, has_notes=has_notes)

    # add group info
    if has_notes:
        row = [''] * len(columns)
    else:
        row = [''] * (len(columns) - 1)

    name = group.get(mdef.NAME, '')
    if name:
        if parent:
            name = '%s.%s' % (parent, name)
        row[NAME_IDX] = name
    else:
        raise PySunSpecException('Group missing name attribute')

    row[TYPE_IDX] = group.get(mdef.TYPE, '')
    row[COUNT_IDX] = group.get(mdef.COUNT, '')
    row[LABEL_IDX] = group.get(mdef.LABEL, '')
    row[DESCRIPTION_IDX] = group.get(mdef.DESCRIPTION, '')
    row[DETAIL_IDX] = group.get(mdef.DETAIL, '')

    row[STANDARDS_IDX] = group.get(mdef.STANDARDS, [])
    if len(row[STANDARDS_IDX]) > 0:
        row[STANDARDS_IDX] = ', '.join(row[STANDARDS_IDX])
    else:
        row[STANDARDS_IDX] = ''

    if has_notes:
        row[NOTES_IDX] = group.get(mdef.NOTES, '')
    ss.append(row)

    # process points
    group_offset = 0
    for p in group.get(mdef.POINTS, []):
        plen = to_spreadsheet_point(ss, p, has_notes=has_notes, addr_offset=addr_offset, group_offset=group_offset)
        if addr_offset is not None:
            addr_offset += plen
        if group_offset is not None:
            group_offset += plen

    # process groups
    addr_offset = None
    for g in group.get(mdef.GROUPS, []):
        to_spreadsheet_group(ss, g, has_notes=has_notes, parent=name,  addr_offset=addr_offset)


def to_spreadsheet_point(ss, point, has_notes, addr_offset=None, group_offset=None):
    """
    Add a point to the spreadsheet

    :param ss: Spreadsheet
    :param point: SunSpec point
    :param has_notes: whether the spreadsheet has notes
    :param addr_offset: register offset
    :param group_offset: group offset
    :return: plen, integer point length in bytes
    """

    # process comments
    for c in point.get(mdef.COMMENTS, []):
        to_spreadsheet_comment(ss, c, has_notes=has_notes)

    # add point info
    if has_notes:
        row = [''] * len(columns)
    else:
        row = [''] * (len(columns) - 1)

    name = point.get(mdef.NAME, '')
    if name:
        row[NAME_IDX] = name
    else:
        raise PySunSpecException('Point missing name attribute')

    ptype = point.get(mdef.TYPE, '')
    if ptype == '':
        raise PySunSpecException('Point %s missing type attribute' % name)

    if mdef.point_type_info.get(ptype) is None:
        raise PySunSpecException('Unknown point type %s for point %s' % (ptype, name))

    row[TYPE_IDX] = ptype

    if addr_offset is not None:
        row[ADDRESS_OFFSET_IDX] = addr_offset
    elif group_offset is not None:
        row[GROUP_OFFSET_IDX] = group_offset

    access = point.get(mdef.ACCESS, '')
    if access != mdef.ACCESS_RW:
        access = ''
    row[ACCESS_IDX] = access

    mandatory = point.get(mdef.MANDATORY, '')
    if mandatory != mdef.MANDATORY_TRUE:
        mandatory = ''
    row[MANDATORY_IDX] = mandatory

    static = point.get(mdef.STATIC, '')
    if static != mdef.STATIC_TRUE:
        static = ''
    row[STATIC_IDX] = static

    row[UNITS_IDX] = point.get(mdef.UNITS, '')
    row[SCALE_FACTOR_IDX] = mdef.to_number_type(point.get(mdef.SF, ''))

    if ptype == mdef.TYPE_STRING:
        row[SIZE_IDX] = mdef.to_number_type(point.get(mdef.SIZE, ''))
    else:
        row[SIZE_IDX] = mdef.point_type_info[ptype]['len']

    row[VALUE_IDX] = mdef.to_number_type(point.get(mdef.VALUE, ''))
    row[LABEL_IDX] = point.get(mdef.LABEL, '')
    row[DESCRIPTION_IDX] = point.get(mdef.DESCRIPTION, '')
    row[DETAIL_IDX] = point.get(mdef.DETAIL, '')

    row[STANDARDS_IDX] = point.get(mdef.STANDARDS, [])
    if len(row[STANDARDS_IDX]) > 0:
        row[STANDARDS_IDX] = ', '.join(row[STANDARDS_IDX])
    else:
        row[STANDARDS_IDX] = ''

    if has_notes:
        row[NOTES_IDX] = point.get(mdef.NOTES, '')
    ss.append(row)

    # process symbols
    symbols = point.get(mdef.SYMBOLS, [])
    if symbols:
        symbols = sorted(symbols, key=lambda sy: sy['value'])
        for s in symbols:
            to_spreadsheet_symbol(ss, s, has_notes=has_notes)

    # return point length
    try:
        plen = mdef.point_type_info[ptype]['len']
    except KeyError:
        raise PySunSpecException('Unknown point type %s for point %s' % (ptype, name))

    if not plen:
        try:
            plen = int(row[SIZE_IDX])
        except ValueError:
            raise PySunSpecException('Point size is for point %s not an integer value: %s' % (name, row[SIZE_IDX]))

    return plen


def to_spreadsheet_symbol(ss, symbol, has_notes):
    """
    Add a symbol to the spreadsheet

    :param ss: Spreadsheet
    :param symbol: symbol value
    :param has_notes: whether the spreadsheet has notes
    :return: None
    """
    # process comments
    for c in symbol.get(mdef.COMMENTS, []):
        to_spreadsheet_comment(ss, c, has_notes=has_notes)

    # add symbol info
    row = None
    if has_notes:
        row = [''] * len(columns)
    else:
        row = [''] * (len(columns) - 1)

    name = symbol.get(mdef.NAME, '')
    if name:
        row[NAME_IDX] = name
    else:
        raise PySunSpecException('Symbol missing name attribute')

    value = symbol.get(mdef.VALUE, '')
    if value != '':
        row[VALUE_IDX] = value
    else:
        raise PySunSpecException('Symbol %s missing value' % name)

    row[LABEL_IDX] = symbol.get(mdef.LABEL, '')
    row[DESCRIPTION_IDX] = symbol.get(mdef.DESCRIPTION, '')
    row[DETAIL_IDX] = symbol.get(mdef.DETAIL, '')

    if has_notes:
        row[NOTES_IDX] = symbol.get(mdef.NOTES, '')

    ss.append(row)


def to_spreadsheet_comment(ss, comment, has_notes):
    """
    Add a group comment to the spreadsheet - single gray line with information on the group/point

    :param ss: spreadsheet
    :param comment: comment to add
    :param has_notes: whether the spreadsheet has notes
    :return: None
    """
    row = None
    if has_notes:
        row = [''] * len(columns)
    else:
        row = [''] * (len(columns) - 1)
    row[0] = comment
    ss.append(row)


def spreadsheet_equal(ss1, ss2):
    count = len(ss1)
    if count != len(ss2):
        raise PySunSpecException('Different length: %s %s' % (count, len(ss2)))
    for i in range(count):
        if ss1[i] != ss2[i]:
            raise PySunSpecException('Line %s different: %s %s' % (i + 1, ss1[i], ss2[i]))
    return True


def from_csv(filename=None, csv_str=None):
    return from_spreadsheet(spreadsheet_from_csv(filename=filename, csv_str=csv_str))


def to_csv(model_def, filename=None, csv_str=None):
    spreadsheet_to_csv(to_spreadsheet(model_def), filename=filename, csv_str=csv_str)


def spreadsheet_from_csv(filename=None, csv_str=None):
    spreadsheet = []
    file = ''

    if filename:
        file = open(filename)
    if file:
        for row in csv.reader(file):
            if len(row) > 0:
                # filter out informative offset information from the normative model definition
                if row[TYPE_IDX] and row[TYPE_IDX] != TYPE:
                    row[ADDRESS_OFFSET_IDX] = ''
                    row[GROUP_OFFSET_IDX] = ''
                if row[VALUE_IDX]:
                    row[VALUE_IDX] = mdef.to_number_type(row[VALUE_IDX])
                if row[COUNT_IDX]:
                    row[COUNT_IDX] = mdef.to_number_type(row[COUNT_IDX])
                if row[SIZE_IDX]:
                    row[SIZE_IDX] = mdef.to_number_type(row[SIZE_IDX])
                if row[SCALE_FACTOR_IDX]:
                    row[SCALE_FACTOR_IDX] = mdef.to_number_type(row[SCALE_FACTOR_IDX])
                spreadsheet.append(row)

    return spreadsheet


def spreadsheet_to_csv(spreadsheet, filename=None, csv_str=None):
    file = None
    if filename:
        file = open(filename, 'w')
    writer = csv.writer(file, lineterminator='\n')
    for row in spreadsheet:
        writer.writerow(row)
    file.close()