# Part of Odoo. See LICENSE file for full copyright and licensing details.

from datetime import datetime, time
from collections import defaultdict
from dateutil.relativedelta import relativedelta
import pytz

from odoo import _, api, fields, models


class HrEmployee(models.Model):
    _inherit = 'hr.employee'

    current_leave_id = fields.Many2one('hr.leave.type', compute='_compute_current_leave', string="Current Time Off Type",
                                       groups="hr.group_hr_user")

    def _compute_current_leave(self):
        self.current_leave_id = False

        holidays = self.env['hr.leave'].sudo().search([
            ('employee_id', 'in', self.ids),
            ('date_from', '<=', fields.Datetime.now()),
            ('date_to', '>=', fields.Datetime.now()),
            ('state', '=', 'validate'),
        ])
        for holiday in holidays:
            employee = self.filtered(lambda e: e.id == holiday.employee_id.id)
            employee.current_leave_id = holiday.holiday_status_id.id

    def _get_user_m2o_to_empty_on_archived_employees(self):
        return super()._get_user_m2o_to_empty_on_archived_employees() + ['leave_manager_id']

    def action_time_off_dashboard(self):
        return {
            'name': _('Time Off Dashboard'),
            'type': 'ir.actions.act_window',
            'res_model': 'hr.leave',
            'views': [[self.env.ref('hr_holidays.hr_leave_employee_view_dashboard').id, 'calendar']],
            'domain': [('employee_id', 'in', self.ids)],
            'context': {
                'employee_id': self.ids,
            },
        }

    def _is_leave_user(self):
        return self == self.env.user.employee_id and self.user_has_groups('hr_holidays.group_hr_holidays_user')

    def get_mandatory_days(self, start_date, end_date):
        all_days = {}

        self = self or self.env.user.employee_id

        mandatory_days = self._get_mandatory_days(start_date, end_date)
        for mandatory_day in mandatory_days:
            num_days = (mandatory_day.end_date - mandatory_day.start_date).days
            for d in range(num_days + 1):
                all_days[str(mandatory_day.start_date + relativedelta(days=d))] = mandatory_day.color

        return all_days

    @api.model
    def get_special_days_data(self, date_start, date_end):
        return {
            'mandatoryDays': self.get_mandatory_days_data(date_start, date_end),
            'bankHolidays': self.get_public_holidays_data(date_start, date_end),
        }

    @api.model
    def get_public_holidays_data(self, date_start, date_end):
        self = self._get_contextual_employee()
        employee_tz = pytz.timezone(self._get_tz() if self else self.env.user.tz or 'utc')
        public_holidays = self._get_public_holidays(date_start, date_end).sorted('date_from')
        return list(map(lambda bh: {
            'id': -bh.id,
            'colorIndex': 0,
            'end': datetime.combine(bh.date_to.astimezone(employee_tz), datetime.max.time()).isoformat(),
            'endType': "datetime",
            'isAllDay': True,
            'start': datetime.combine(bh.date_from.astimezone(employee_tz), datetime.min.time()).isoformat(),
            'startType': "datetime",
            'title': bh.name,
        }, public_holidays))

    def _get_public_holidays(self, date_start, date_end):
        domain = [
            ('resource_id', '=', False),
            ('company_id', 'in', self.env.companies.ids),
            ('date_from', '<=', date_end),
            ('date_to', '>=', date_start),
            '|',
            ('calendar_id', '=', False),
            ('calendar_id', '=', self.resource_calendar_id.id),
        ]

        return self.env['resource.calendar.leaves'].search(domain)

    @api.model
    def get_mandatory_days_data(self, date_start, date_end):
        self = self._get_contextual_employee()
        mandatory_days = self._get_mandatory_days(date_start, date_end).sorted('start_date')
        return list(map(lambda sd: {
            'id': -sd.id,
            'colorIndex': sd.color,
            'end': datetime.combine(sd.end_date, datetime.max.time()).isoformat(),
            'endType': "datetime",
            'isAllDay': True,
            'start': datetime.combine(sd.start_date, datetime.min.time()).isoformat(),
            'startType': "datetime",
            'title': sd.name,
        }, mandatory_days))

    def _get_mandatory_days(self, start_date, end_date):
        domain = [
            ('start_date', '<=', end_date),
            ('end_date', '>=', start_date),
            ('company_id', 'in', self.env.companies.ids),
            '|',
            ('resource_calendar_id', '=', False),
            ('resource_calendar_id', '=', self.resource_calendar_id.id),
        ]

        if self.department_id:
            domain += [
                '|',
                ('department_ids', '=', False),
                ('department_ids', 'parent_of', self.department_id.id),
            ]
        else:
            domain += [('department_ids', '=', False)]

        return self.env['hr.leave.mandatory.day'].search(domain)

    @api.model
    def _get_contextual_employee(self):
        ctx = self.env.context
        if self.env.context.get('employee_id') is not None:
            return self.browse(ctx.get('employee_id'))
        if self.env.context.get('default_employee_id') is not None:
            return self.browse(ctx.get('default_employee_id'))
        return self.env.user.employee_id

    def _get_consumed_leaves(self, leave_types, target_date=False, ignore_future=False):
        employees = self or self._get_contextual_employee()
        leaves_domain = [
            ('holiday_status_id', 'in', leave_types.ids),
            ('employee_id', 'in', employees.ids),
            ('state', 'in', ['confirm', 'validate1', 'validate']),
        ]
        if self.env.context.get('ignored_leave_ids'):
            leaves_domain.append(('id', 'not in', self.env.context.get('ignored_leave_ids')))

        if not target_date:
            target_date = fields.Date.today()
        if ignore_future:
            leaves_domain.append(('date_from', '<=', target_date))
        leaves = self.env['hr.leave'].search(leaves_domain)
        leaves_per_employee_type = defaultdict(lambda: defaultdict(lambda: self.env['hr.leave']))
        for leave in leaves:
            leaves_per_employee_type[leave.employee_id][leave.holiday_status_id] |= leave

        allocations = self.env['hr.leave.allocation'].with_context(active_test=False).search([
            ('employee_id', 'in', employees.ids),
            ('holiday_status_id', 'in', leave_types.ids),
            ('state', '=', 'validate'),
        ]).filtered(lambda al: al.active or not al.employee_id.active)
        allocations_per_employee_type = defaultdict(lambda: defaultdict(lambda: self.env['hr.leave.allocation']))
        for allocation in allocations:
            allocations_per_employee_type[allocation.employee_id][allocation.holiday_status_id] |= allocation

        # _get_consumed_leaves returns a tuple of two dictionnaries.
        # 1) The first is a dictionary to map the number of days/hours of leaves taken per allocation
        # The structure is the following:
        # - KEYS:
        # allocation_leaves_consumed
        #  |--employee_id
        #      |--holiday_status_id
        #          |--allocation
        #              |--virtual_leaves_taken
        #              |--leaves_taken
        #              |--virtual_remaining_leaves
        #              |--remaining_leaves
        #              |--max_leaves
        #              |--accrual_bonus
        # - VALUES:
        # Integer representing the number of (virtual) remaining leaves, (virtual) leaves taken or max leaves
        # for each allocation.
        # leaves_taken and remaining_leaves only take into account validated leaves, while the "virtual" equivalent are
        # also based on leaves in "confirm" or "validate1" state.
        # Accrual bonus gives the amount of additional leaves that will have been granted at the given
        # target_date in comparison to today.
        # The unit is in hour or days depending on the leave type request unit
        # 2) The second is a dictionary mapping the remaining days per employee and per leave type that are either
        # not taken into account by the allocations, mainly because accruals don't take future leaves into account.
        # This is used to warn the user if the leaves they takes bring them above their available limit.
        # - KEYS:
        # allocation_leaves_consumed
        #  |--employee_id
        #      |--holiday_status_id
        #          |--to_recheck_leaves
        #          |--excess_days
        #          |--exceeding_duration
        # - VALUES:
        # "to_recheck_leaves" stores every leave that is not yet taken into account by the "allocation_leaves_consumed" dictionary.
        # "excess_days" represents the excess amount that somehow isn't taken into account by the first dictionary.
        # "exceeding_duration" sum up the to_recheck_leaves duration and compares it to the maximum allocated for that time period.
        allocations_leaves_consumed = defaultdict(lambda: defaultdict(lambda: defaultdict(lambda: defaultdict(lambda: 0))))

        to_recheck_leaves_per_leave_type = defaultdict(lambda:
            defaultdict(lambda: {
                'excess_days': defaultdict(lambda: {
                    'amount': 0,
                    'is_virtual': True,
                }),
                'exceeding_duration': 0,
                'to_recheck_leaves': self.env['hr.leave']
            })
        )
        for allocation in allocations:
            allocation_data = allocations_leaves_consumed[allocation.employee_id][allocation.holiday_status_id][allocation]
            future_leaves = 0
            if allocation.allocation_type == 'accrual':
                future_leaves = allocation._get_future_leaves_on(target_date)
            max_leaves = allocation.number_of_hours_display\
                if allocation.type_request_unit in ['hour']\
                else allocation.number_of_days_display
            max_leaves += future_leaves
            allocation_data.update({
                'max_leaves': max_leaves,
                'accrual_bonus': future_leaves,
                'virtual_remaining_leaves': max_leaves,
                'remaining_leaves': max_leaves,
                'leaves_taken': 0,
                'virtual_leaves_taken': 0,
            })

        for employee in employees:
            for leave_type in leave_types:
                allocations_with_date_to = self.env['hr.leave.allocation']
                allocations_without_date_to = self.env['hr.leave.allocation']
                for leave_allocation in allocations_per_employee_type[employee][leave_type]:
                    if leave_allocation.date_to:
                        allocations_with_date_to |= leave_allocation
                    else:
                        allocations_without_date_to |= leave_allocation
                sorted_leave_allocations = allocations_with_date_to.sorted(key='date_to') + allocations_without_date_to

                if leave_type.request_unit in ['day', 'half_day']:
                    leave_duration_field = 'number_of_days'
                    leave_unit = 'days'
                else:
                    leave_duration_field = 'number_of_hours_display'
                    leave_unit = 'hours'

                leave_type_data = allocations_leaves_consumed[employee][leave_type]
                for leave in leaves_per_employee_type[employee][leave_type].sorted('date_from'):
                    leave_duration = leave[leave_duration_field]
                    skip_excess = False

                    if sorted_leave_allocations.filtered(lambda alloc: alloc.allocation_type == 'accrual') and leave.date_from.date() > target_date:
                        to_recheck_leaves_per_leave_type[employee][leave_type]['to_recheck_leaves'] |= leave
                        skip_excess = True
                        continue

                    if leave_type.requires_allocation == 'yes':
                        for allocation in sorted_leave_allocations:
                            # We don't want to include future leaves linked to accruals into the total count of available leaves.
                            # However, we'll need to check if those leaves take more than what will be accrued in total of those days
                            # to give a warning if the total exceeds what will be accrued.
                            if allocation.date_from > leave.date_to.date() or (allocation.date_to and allocation.date_to < leave.date_from.date()):
                                continue
                            interval_start = max(
                                leave.date_from,
                                datetime.combine(allocation.date_from, time.min)
                            )
                            interval_end = min(
                                leave.date_to,
                                datetime.combine(allocation.date_to, time.max)
                                if allocation.date_to else leave.date_to
                            )
                            duration = leave[leave_duration_field]
                            if leave.date_from != interval_start or leave.date_to != interval_end:
                                duration_info = employee._get_calendar_attendances(interval_start.replace(tzinfo=pytz.UTC), interval_end.replace(tzinfo=pytz.UTC))
                                duration = duration_info['hours' if leave_unit == 'hours' else 'days']
                            max_allowed_duration = min(
                                duration,
                                leave_type_data[allocation]['virtual_remaining_leaves']
                            )

                            if not max_allowed_duration:
                                continue

                            allocated_time = min(max_allowed_duration, leave_duration)
                            leave_type_data[allocation]['virtual_leaves_taken'] += allocated_time
                            leave_type_data[allocation]['virtual_remaining_leaves'] -= allocated_time
                            if leave.state == 'validate':
                                leave_type_data[allocation]['leaves_taken'] += allocated_time
                                leave_type_data[allocation]['remaining_leaves'] -= allocated_time

                            leave_duration -= allocated_time
                            if not leave_duration:
                                break
                        if round(leave_duration, 2) > 0 and not skip_excess:
                            to_recheck_leaves_per_leave_type[employee][leave_type]['excess_days'][leave.date_to.date()] = {
                                'amount': leave_duration,
                                'is_virtual': leave.state != 'validate',
                                'leave_id': leave.id,
                            }
                    else:
                        if leave_unit == 'hours':
                            allocated_time = leave.number_of_hours_display
                        else:
                            allocated_time = leave.number_of_days_display
                        leave_type_data[False]['virtual_leaves_taken'] += allocated_time
                        leave_type_data[False]['virtual_remaining_leaves'] = 0
                        leave_type_data[False]['remaining_leaves'] = 0
                        if leave.state == 'validate':
                            leave_type_data[False]['leaves_taken'] += allocated_time

        for employee in to_recheck_leaves_per_leave_type:
            for leave_type in to_recheck_leaves_per_leave_type[employee]:
                content = to_recheck_leaves_per_leave_type[employee][leave_type]
                consumed_content = allocations_leaves_consumed[employee][leave_type]
                if content['to_recheck_leaves']:
                    date_to_simulate = max(content['to_recheck_leaves'].mapped('date_from')).date()
                    latest_accrual_bonus = 0
                    date_accrual_bonus = 0
                    virtual_remaining = 0
                    additional_leaves_duration = 0
                    for allocation in consumed_content:
                        latest_accrual_bonus += allocation and allocation._get_future_leaves_on(date_to_simulate)
                        date_accrual_bonus += consumed_content[allocation]['accrual_bonus']
                        virtual_remaining += consumed_content[allocation]['virtual_remaining_leaves']
                    for leave in content['to_recheck_leaves']:
                        additional_leaves_duration += leave.number_of_hours if leave_type.request_unit == 'hours' else leave.number_of_days
                    latest_remaining = virtual_remaining - date_accrual_bonus + latest_accrual_bonus
                    content['exceeding_duration'] = round(min(0, latest_remaining - additional_leaves_duration), 2)

        return (allocations_leaves_consumed, to_recheck_leaves_per_leave_type)
