from collections import namedtuple

from .helpers import excel_value_as_number

KIND_OBLIGO = "obligo"
KIND_EXPENSES = "expenses"

VALID_MATERIAL_IDS = {
    "0216 - Sachmittel",
    "0227 - Verbrauchsmaterial",
    "0843 - Verbrauch/Stoffe",
    "2 - Sachmittel",
}

OverviewBudgetEntry = namedtuple(
    "OverviewBudgetEntry", ["description", "kind", "amount"]
)


class ProjectOverview:
    def __init__(self, budget_data):
        """ initializes the class """
        self.budget_data = budget_data
        self.entries = []
        self.found = False

    @property
    def project(self):
        """ returns the project number """
        return self.budget_data.project

    @property
    def row(self):
        """ returns the excel row number """
        return self.budget_data.row

    @property
    def expenses(self):
        """ returns the accumulated expenses """
        numbers = (excel_value_as_number(e.amount) for e in self.entries)
        values = (abs(entry) for entry in numbers)
        return sum(values)

    @property
    def available(self):
        """ returns the still available budget """
        return self.budget_data.budget - self.expenses

    def add(self, description, kind, amount):
        """ adds an entry that modifies the available budget """
        entry = OverviewBudgetEntry(description, kind, amount)
        self.entries.append(entry)


def _create_overview_map(budget_list):
    """ returns a dictonary with project as key and overview as value """
    map = {}
    for budget_data in budget_list:
        overview = ProjectOverview(budget_data)
        map[str(overview.project)] = overview
    return map


def _filter_superx_material_expenses(superx_export):
    """ filters superx data to only contain material entries """
    return (i for i in superx_export.data if i.kind in VALID_MATERIAL_IDS)


def _create_entries_from_superx(overview_map, superx_export_data):
    """ adds overview entries from superx data """
    for line in superx_export_data:
        if line.project in overview_map:
            overview = overview_map[line.project]
            overview.add(line.kind, KIND_OBLIGO, line.obligo)
            overview.add(line.kind, KIND_EXPENSES, line.expenses)
    return overview_map


def _set_found_state(overview_map, superx_export):
    superx_projects = {line.project for line in superx_export.data}
    found_projects = superx_projects.intersection(set(overview_map.keys()))
    for project in found_projects:
        overview_map[project].found = True
    return overview_map


def create_overview(budget_list, superx_export):
    """ create a overview map with budget entries from the parsed raw data """
    tmp_map = _create_overview_map(budget_list)
    overview_map = _set_found_state(tmp_map, superx_export)
    material_expenses = _filter_superx_material_expenses(superx_export)
    return _create_entries_from_superx(overview_map, material_expenses)