# -*- coding: utf-8 -*-
# Part of Odoo. See LICENSE file for full copyright and licensing details.

import itertools

from collections import defaultdict
from datetime import datetime, timedelta
from functools import partial
from itertools import chain

from dateutil.relativedelta import relativedelta
from dateutil.rrule import rrule, DAILY
from pytz import timezone, utc

from odoo import api, fields, models, _
from odoo.addons.base.models.res_partner import _tz_get
from odoo.exceptions import ValidationError
from odoo.osv import expression
from odoo.tools.float_utils import float_round

from odoo.tools import date_utils, ormcache
from .utils import Intervals, float_to_time, make_aware, datetime_to_string, string_to_datetime
from odoo.addons.hr_work_entry_contract.models.hr_work_intervals import WorkIntervals


class ResourceCalendar(models.Model):
    """ Calendar model for a resource. It has

     - attendance_ids: list of resource.calendar.attendance that are a working
                       interval in a given weekday.
     - leave_ids: list of leaves linked to this calendar. A leave can be general
                  or linked to a specific resource, depending on its resource_id.

    All methods in this class use intervals. An interval is a tuple holding
    (begin_datetime, end_datetime). A list of intervals is therefore a list of
    tuples, holding several intervals of work or leaves. """
    _name = "resource.calendar"
    _description = "Resource Working Time"

    @api.model
    def default_get(self, fields):
        res = super().default_get(fields)
        if not res.get('name') and res.get('company_id'):
            res['name'] = _('Working Hours of %s', self.env['res.company'].browse(res['company_id']).name)
        if 'attendance_ids' in fields and not res.get('attendance_ids'):
            company_id = res.get('company_id', self.env.company.id)
            company = self.env['res.company'].browse(company_id)
            company_attendance_ids = company.resource_calendar_id.attendance_ids
            if not company.resource_calendar_id.two_weeks_calendar and company_attendance_ids:
                res['attendance_ids'] = [
                    (0, 0, {
                        'name': attendance.name,
                        'dayofweek': attendance.dayofweek,
                        'hour_from': attendance.hour_from,
                        'hour_to': attendance.hour_to,
                        'day_period': attendance.day_period,
                        'date_from': attendance.date_from,
                        'date_to': attendance.date_to,
                    })
                    for attendance in company_attendance_ids
                ]
            else:
                res['attendance_ids'] = [
                    (0, 0, {'name': _('Monday Morning'), 'dayofweek': '0', 'hour_from': 8, 'hour_to': 12, 'day_period': 'morning'}),
                    (0, 0, {'name': _('Monday Lunch'), 'dayofweek': '0', 'hour_from': 12, 'hour_to': 13, 'day_period': 'lunch'}),
                    (0, 0, {'name': _('Monday Afternoon'), 'dayofweek': '0', 'hour_from': 13, 'hour_to': 17, 'day_period': 'afternoon'}),
                    (0, 0, {'name': _('Tuesday Morning'), 'dayofweek': '1', 'hour_from': 8, 'hour_to': 12, 'day_period': 'morning'}),
                    (0, 0, {'name': _('Tuesday Lunch'), 'dayofweek': '1', 'hour_from': 12, 'hour_to': 13, 'day_period': 'lunch'}),
                    (0, 0, {'name': _('Tuesday Afternoon'), 'dayofweek': '1', 'hour_from': 13, 'hour_to': 17, 'day_period': 'afternoon'}),
                    (0, 0, {'name': _('Wednesday Morning'), 'dayofweek': '2', 'hour_from': 8, 'hour_to': 12, 'day_period': 'morning'}),
                    (0, 0, {'name': _('Wednesday Lunch'), 'dayofweek': '2', 'hour_from': 12, 'hour_to': 13, 'day_period': 'lunch'}),
                    (0, 0, {'name': _('Wednesday Afternoon'), 'dayofweek': '2', 'hour_from': 13, 'hour_to': 17, 'day_period': 'afternoon'}),
                    (0, 0, {'name': _('Thursday Morning'), 'dayofweek': '3', 'hour_from': 8, 'hour_to': 12, 'day_period': 'morning'}),
                    (0, 0, {'name': _('Thursday Lunch'), 'dayofweek': '3', 'hour_from': 12, 'hour_to': 13, 'day_period': 'lunch'}),
                    (0, 0, {'name': _('Thursday Afternoon'), 'dayofweek': '3', 'hour_from': 13, 'hour_to': 17, 'day_period': 'afternoon'}),
                    (0, 0, {'name': _('Friday Morning'), 'dayofweek': '4', 'hour_from': 8, 'hour_to': 12, 'day_period': 'morning'}),
                    (0, 0, {'name': _('Friday Lunch'), 'dayofweek': '4', 'hour_from': 12, 'hour_to': 13, 'day_period': 'lunch'}),
                    (0, 0, {'name': _('Friday Afternoon'), 'dayofweek': '4', 'hour_from': 13, 'hour_to': 17, 'day_period': 'afternoon'})
                ]
        return res

    name = fields.Char(required=True)
    active = fields.Boolean("Active", default=True,
                            help="If the active field is set to false, it will allow you to hide the Working Time without removing it.")
    company_id = fields.Many2one(
        'res.company', 'Company', domain=lambda self: [('id', 'in', self.env.companies.ids)],
        default=lambda self: self.env.company)
    attendance_ids = fields.One2many(
        'resource.calendar.attendance', 'calendar_id', 'Working Time',
        compute='_compute_attendance_ids', store=True, readonly=False, copy=True)
    leave_ids = fields.One2many(
        'resource.calendar.leaves', 'calendar_id', 'Time Off')
    global_leave_ids = fields.One2many(
        'resource.calendar.leaves', 'calendar_id', 'Global Time Off',
        compute='_compute_global_leave_ids', store=True, readonly=False,
        domain=[('resource_id', '=', False)], copy=True,
    )
    hours_per_day = fields.Float("Average Hour per Day", store=True, compute="_compute_hours_per_day", digits=(2, 2), readonly=False,
                                 help="Average hours per day a resource is supposed to work with this calendar.")
    tz = fields.Selection(
        _tz_get, string='Timezone', required=True,
        default=lambda self: self._context.get('tz') or self.env.user.tz or self.env.ref('base.user_admin').tz or 'UTC',
        help="This field is used in order to define in which timezone the resources will work.")
    tz_offset = fields.Char(compute='_compute_tz_offset', string='Timezone offset')
    two_weeks_calendar = fields.Boolean(string="Calendar in 2 weeks mode")
    two_weeks_explanation = fields.Char('Explanation', compute="_compute_two_weeks_explanation")
    flexible_hours = fields.Boolean(string="Flexible Hours",
                                    help="When enabled, it will allow employees to work flexibly, without relying on the company's working schedule (working hours).")
    full_time_required_hours = fields.Float(string="Company Full Time", help="Number of hours to work on the company schedule to be considered as fulltime.")

    @api.depends('attendance_ids', 'attendance_ids.hour_from', 'attendance_ids.hour_to', 'two_weeks_calendar', 'flexible_hours')
    def _compute_hours_per_day(self):
        for calendar in self:
            if calendar.flexible_hours:
                continue
            attendances = calendar._get_global_attendances()
            calendar.hours_per_day = calendar._get_hours_per_day(attendances)

    @api.depends('company_id')
    def _compute_attendance_ids(self):
        for calendar in self.filtered(lambda c: not c._origin or c._origin.company_id != c.company_id and c.company_id):
            company_calendar = calendar.company_id.resource_calendar_id
            calendar.update({
                'two_weeks_calendar': company_calendar.two_weeks_calendar,
                'tz': company_calendar.tz,
                'attendance_ids': [(5, 0, 0)] + [
                    (0, 0, attendance._copy_attendance_vals()) for attendance in company_calendar.attendance_ids if not attendance.resource_id]
            })

    @api.depends('company_id')
    def _compute_global_leave_ids(self):
        for calendar in self.filtered(lambda c: not c._origin or c._origin.company_id != c.company_id):
            calendar.update({
                'global_leave_ids': [(5, 0, 0)] + [
                    (0, 0, leave._copy_leave_vals()) for leave in calendar.company_id.resource_calendar_id.global_leave_ids]
            })

    @api.depends('tz')
    def _compute_tz_offset(self):
        for calendar in self:
            calendar.tz_offset = datetime.now(timezone(calendar.tz or 'GMT')).strftime('%z')

    def copy_data(self, default=None):
        vals_list = super().copy_data(default=default)
        return [dict(vals, name=self.env._("%s (copy)", calendar.name)) for calendar, vals in zip(self, vals_list)]

    @api.constrains('attendance_ids')
    def _check_attendance_ids(self):
        for resource in self:
            if (resource.two_weeks_calendar and
                    resource.attendance_ids.filtered(lambda a: a.display_type == 'line_section') and
                    not resource.attendance_ids.sorted('sequence')[0].display_type):
                raise ValidationError(_("In a calendar with 2 weeks mode, all periods need to be in the sections."))

    @api.depends('two_weeks_calendar')
    def _compute_two_weeks_explanation(self):
        today = fields.Date.today()
        week_type = self.env['resource.calendar.attendance'].get_week_type(today)
        week_type_str = _("second") if week_type else _("first")
        first_day = date_utils.start_of(today, 'week')
        last_day = date_utils.end_of(today, 'week')
        self.two_weeks_explanation = _(
            "The current week (from %(first_day)s to %(last_day)s) corresponds to week number %(number)s.",
            first_day=first_day,
            last_day=last_day,
            number=week_type_str,
        )

    def _get_global_attendances(self):
        return self.attendance_ids.filtered(lambda attendance:
            attendance.day_period != 'lunch'
            and not attendance.date_from and not attendance.date_to
            and not attendance.resource_id and not attendance.display_type)

    def _get_hours_per_day(self, attendances):
        """
        Calculate the average hours worked per workday.
        """
        if not attendances:
            return 0

        hour_count = 0.0
        for attendance in attendances:
            hour_count += attendance.hour_to - attendance.hour_from

        if self.two_weeks_calendar:
            number_of_days = len(set(attendances.filtered(lambda cal: cal.week_type == '1').mapped('dayofweek')))
            number_of_days += len(set(attendances.filtered(lambda cal: cal.week_type == '0').mapped('dayofweek')))
        else:
            number_of_days = len(set(attendances.mapped('dayofweek')))

        if not number_of_days:
            return 0

        return float_round(hour_count / float(number_of_days), precision_digits=2)

    def switch_calendar_type(self):
        if not self.two_weeks_calendar:
            self.attendance_ids.unlink()
            self.attendance_ids = [
                (0, 0, {
                    'name': 'First week',
                    'dayofweek': '0',
                    'sequence': '0',
                    'hour_from': 0,
                    'day_period': 'morning',
                    'week_type': '0',
                    'hour_to': 0,
                    'display_type':
                    'line_section'}),
                (0, 0, {
                    'name': 'Second week',
                    'dayofweek': '0',
                    'sequence': '25',
                    'hour_from': 0,
                    'day_period': 'morning',
                    'week_type': '1',
                    'hour_to': 0,
                    'display_type': 'line_section'}),
            ]

            self.two_weeks_calendar = True
            default_attendance = self.default_get(['attendance_ids'])['attendance_ids']
            for idx, att in enumerate(default_attendance):
                att[2]["week_type"] = '0'
                att[2]["sequence"] = idx + 1
            self.attendance_ids = default_attendance
            for idx, att in enumerate(default_attendance):
                att[2]["week_type"] = '1'
                att[2]["sequence"] = idx + 26
            self.attendance_ids = default_attendance
        else:
            self.two_weeks_calendar = False
            self.attendance_ids.unlink()
            self.attendance_ids = self.default_get(['attendance_ids'])['attendance_ids']

    @api.onchange('attendance_ids')
    def _onchange_attendance_ids(self):
        if not self.two_weeks_calendar:
            return

        even_week_seq = self.attendance_ids.filtered(lambda att: att.display_type == 'line_section' and att.week_type == '0')
        odd_week_seq = self.attendance_ids.filtered(lambda att: att.display_type == 'line_section' and att.week_type == '1')
        if len(even_week_seq) != 1 or len(odd_week_seq) != 1:
            raise ValidationError(_("You can't delete section between weeks."))

        even_week_seq = even_week_seq.sequence
        odd_week_seq = odd_week_seq.sequence

        for line in self.attendance_ids.filtered(lambda att: att.display_type is False):
            if even_week_seq > odd_week_seq:
                line.week_type = '1' if even_week_seq > line.sequence else '0'
            else:
                line.week_type = '0' if odd_week_seq > line.sequence else '1'

    def _check_overlap(self, attendance_ids):
        """ attendance_ids correspond to attendance of a week,
            will check for each day of week that there are no superimpose. """
        result = []
        for attendance in attendance_ids.filtered(lambda att: not att.date_from and not att.date_to):
            # 0.000001 is added to each start hour to avoid to detect two contiguous intervals as superimposing.
            # Indeed Intervals function will join 2 intervals with the start and stop hour corresponding.
            result.append((int(attendance.dayofweek) * 24 + attendance.hour_from + 0.000001, int(attendance.dayofweek) * 24 + attendance.hour_to, attendance))

        if len(Intervals(result)) != len(result):
            raise ValidationError(_("Attendances can't overlap."))

    @api.constrains('attendance_ids')
    def _check_attendance(self):
        # Avoid superimpose in attendance
        for calendar in self:
            attendance_ids = calendar.attendance_ids.filtered(lambda attendance: not attendance.resource_id and attendance.display_type is False)
            if calendar.two_weeks_calendar:
                calendar._check_overlap(attendance_ids.filtered(lambda attendance: attendance.week_type == '0'))
                calendar._check_overlap(attendance_ids.filtered(lambda attendance: attendance.week_type == '1'))
            else:
                calendar._check_overlap(attendance_ids)

    # --------------------------------------------------
    # Computation API
    # --------------------------------------------------

    def _attendance_intervals_batch(self, start_dt, end_dt, resources=None, domain=None, tz=None, lunch=False):
        assert start_dt.tzinfo and end_dt.tzinfo
        self.ensure_one()
        if not resources:
            resources = self.env['resource.resource']
            resources_list = [resources]
        else:
            resources_list = list(resources) + [self.env['resource.resource']]
        resource_ids = [r.id for r in resources_list]
        domain = domain if domain is not None else []
        domain = expression.AND([domain, [
            ('calendar_id', '=', self.id),
            ('resource_id', 'in', resource_ids),
            ('display_type', '=', False),
            ('day_period', '!=' if not lunch else '=', 'lunch'),
        ]])

        attendances = self.env['resource.calendar.attendance'].search(domain)
        # Since we only have one calendar to take in account
        # Group resources per tz they will all have the same result
        resources_per_tz = defaultdict(list)
        for resource in resources_list:
            resources_per_tz[tz or timezone((resource or self).tz)].append(resource)
        # Resource specific attendances
        attendance_per_resource = defaultdict(lambda: self.env['resource.calendar.attendance'])
        # Calendar attendances per day of the week
        # * 7 days per week * 2 for two week calendars
        attendances_per_day = [self.env['resource.calendar.attendance']] * 7 * 2
        weekdays = set()
        for attendance in attendances:
            if attendance.resource_id:
                attendance_per_resource[attendance.resource_id] |= attendance
            weekday = int(attendance.dayofweek)
            weekdays.add(weekday)
            if self.two_weeks_calendar:
                weektype = int(attendance.week_type)
                attendances_per_day[weekday + 7 * weektype] |= attendance
            else:
                attendances_per_day[weekday] |= attendance
                attendances_per_day[weekday + 7] |= attendance

        start = start_dt.astimezone(utc)
        end = end_dt.astimezone(utc)
        bounds_per_tz = {
            tz: (start_dt.astimezone(tz), end_dt.astimezone(tz))
            for tz in resources_per_tz.keys()
        }
        # Use the outer bounds from the requested timezones
        for tz, bounds in bounds_per_tz.items():
            start = min(start, bounds[0].replace(tzinfo=utc))
            end = max(end, bounds[1].replace(tzinfo=utc))
        # Generate once with utc as timezone
        days = rrule(DAILY, start.date(), until=end.date(), byweekday=weekdays)
        ResourceCalendarAttendance = self.env['resource.calendar.attendance']
        base_result = []
        per_resource_result = defaultdict(list)
        for day in days:
            week_type = ResourceCalendarAttendance.get_week_type(day)
            attendances = attendances_per_day[day.weekday() + 7 * week_type]
            for attendance in attendances:
                if (attendance.date_from and day.date() < attendance.date_from) or\
                    (attendance.date_to and attendance.date_to < day.date()):
                    continue
                day_from = datetime.combine(day, float_to_time(attendance.hour_from))
                day_to = datetime.combine(day, float_to_time(attendance.hour_to))
                if attendance.resource_id:
                    per_resource_result[attendance.resource_id].append((day_from, day_to, attendance))
                else:
                    base_result.append((day_from, day_to, attendance))


        # Copy the result localized once per necessary timezone
        # Strictly speaking comparing start_dt < time or start_dt.astimezone(tz) < time
        # should always yield the same result. however while working with dates it is easier
        # if all dates have the same format
        result_per_tz = {
            tz: [(max(bounds_per_tz[tz][0], tz.localize(val[0])),
                min(bounds_per_tz[tz][1], tz.localize(val[1])),
                val[2])
                    for val in base_result]
            for tz in resources_per_tz.keys()
        }
        result_per_resource_id = dict()
        for tz, resources in resources_per_tz.items():
            res = result_per_tz[tz]
            res_intervals = WorkIntervals(res)
            for resource in resources:
                if resource in per_resource_result:
                    resource_specific_result = [(max(bounds_per_tz[tz][0], tz.localize(val[0])), min(bounds_per_tz[tz][1], tz.localize(val[1])), val[2])
                        for val in per_resource_result[resource]]
                    result_per_resource_id[resource.id] = WorkIntervals(itertools.chain(res, resource_specific_result))
                else:
                    result_per_resource_id[resource.id] = res_intervals
        return result_per_resource_id

    def _leave_intervals(self, start_dt, end_dt, resource=None, domain=None, tz=None):
        if resource is None:
            resource = self.env['resource.resource']
        return self._leave_intervals_batch(
            start_dt, end_dt, resources=resource, domain=domain, tz=tz
        )[resource.id]

    def _leave_intervals_batch(self, start_dt, end_dt, resources=None, domain=None, tz=None, any_calendar=False):
        """ Return the leave intervals in the given datetime range.
            The returned intervals are expressed in specified tz or in the calendar's timezone.
        """
        assert start_dt.tzinfo and end_dt.tzinfo
        self.ensure_one()

        if not resources:
            resources = self.env['resource.resource']
            resources_list = [resources]
        else:
            resources_list = list(resources) + [self.env['resource.resource']]
        if domain is None:
            domain = [('time_type', '=', 'leave')]
        if not any_calendar:
            domain = domain + [('calendar_id', 'in', [False, self.id])]
        # for the computation, express all datetimes in UTC
        # Public leave don't have a resource_id
        domain = domain + [
            ('resource_id', 'in', [False] + [r.id for r in resources_list]),
            ('date_from', '<=', datetime_to_string(end_dt)),
            ('date_to', '>=', datetime_to_string(start_dt)),
        ]

        # retrieve leave intervals in (start_dt, end_dt)
        result = defaultdict(lambda: [])
        tz_dates = {}
        all_leaves = self.env['resource.calendar.leaves'].search(domain)
        for leave in all_leaves:
            leave_resource = leave.resource_id
            leave_company = leave.company_id
            leave_date_from = leave.date_from
            leave_date_to = leave.date_to
            for resource in resources_list:
                if leave_resource.id not in [False, resource.id] or (not leave_resource and resource and resource.company_id != leave_company):
                    continue
                tz = tz if tz else timezone((resource or self).tz)
                if (tz, start_dt) in tz_dates:
                    start = tz_dates[(tz, start_dt)]
                else:
                    start = start_dt.astimezone(tz)
                    tz_dates[(tz, start_dt)] = start
                if (tz, end_dt) in tz_dates:
                    end = tz_dates[(tz, end_dt)]
                else:
                    end = end_dt.astimezone(tz)
                    tz_dates[(tz, end_dt)] = end
                dt0 = string_to_datetime(leave_date_from).astimezone(tz)
                dt1 = string_to_datetime(leave_date_to).astimezone(tz)
                result[resource.id].append((max(start, dt0), min(end, dt1), leave))

        return {r.id: Intervals(result[r.id]) for r in resources_list}

    def _work_intervals_batch(self, start_dt, end_dt, resources=None, domain=None, tz=None, compute_leaves=True):
        """ Return the effective work intervals between the given datetimes. """
        if not resources:
            resources = self.env['resource.resource']
            resources_list = [resources]
        else:
            resources_list = list(resources) + [self.env['resource.resource']]

        attendance_intervals = self._attendance_intervals_batch(start_dt, end_dt, resources, tz=tz or self.env.context.get("employee_timezone"))
        if compute_leaves:
            leave_intervals = self._leave_intervals_batch(start_dt, end_dt, resources, domain, tz=tz)
            return {
                r.id: (attendance_intervals[r.id] - leave_intervals[r.id]) for r in resources_list
            }
        else:
            return {
                r.id: attendance_intervals[r.id] for r in resources_list
            }

    def _unavailable_intervals(self, start_dt, end_dt, resource=None, domain=None, tz=None):
        if resource is None:
            resource = self.env['resource.resource']
        return self._unavailable_intervals_batch(
            start_dt, end_dt, resources=resource, domain=domain, tz=tz
        )[resource.id]

    def _unavailable_intervals_batch(self, start_dt, end_dt, resources=None, domain=None, tz=None):
        """ Return the unavailable intervals between the given datetimes. """
        if not resources:
            resources = self.env['resource.resource']
            resources_list = [resources]
        else:
            resources_list = list(resources)

        resources_work_intervals = self._work_intervals_batch(start_dt, end_dt, resources, domain, tz)
        result = {}
        for resource in resources_list:
            if resource and resource._is_flexible():
                continue
            work_intervals = [(start, stop) for start, stop, meta in resources_work_intervals[resource.id]]
            # start + flatten(intervals) + end
            work_intervals = [start_dt] + list(chain.from_iterable(work_intervals)) + [end_dt]
            # put it back to UTC
            work_intervals = list(map(lambda dt: dt.astimezone(utc), work_intervals))
            # pick groups of two
            work_intervals = list(zip(work_intervals[0::2], work_intervals[1::2]))
            result[resource.id] = work_intervals
        return result

    # --------------------------------------------------
    # Private Methods / Helpers
    # --------------------------------------------------

    def _get_attendance_intervals_days_data(self, attendance_intervals):
        """
        helper function to compute duration of `intervals` that have
        'resource.calendar.attendance' records as payload (3rd element in tuple).
        expressed in days and hours.

        resource.calendar.attendance records have durations associated
        with them so this method merely calculates the proportion that is
        covered by the intervals.
        """
        day_hours = defaultdict(float)
        day_days = defaultdict(float)
        for start, stop, meta in attendance_intervals:
            # If the interval covers only a part of the original attendance, we
            # take durations in days proportionally to what is left of the interval.
            interval_hours = (stop - start).total_seconds() / 3600
            day_hours[start.date()] += interval_hours
            day_days[start.date()] += sum(meta.mapped('duration_days')) * interval_hours / sum(meta.mapped('duration_hours'))

        return {
            # Round the number of days to the closest 16th of a day.
            'days': float_round(sum(day_days[day] for day in day_days), precision_rounding=0.001),
            'hours': sum(day_hours.values()),
        }

    def _get_days_data(self, intervals, day_total):
        """
        helper function to compute duration of `intervals`
        expressed in days and hours.
        `day_total` is a dict {date: n_hours} with the number of hours for each day.
        """
        day_hours = defaultdict(float)
        for start, stop, meta in intervals:
            day_hours[start.date()] += (stop - start).total_seconds() / 3600

        # compute number of days the hours span over
        days = float_round(sum(
            day_hours[day] / day_total[day] if day_total[day] else 0
            for day in day_hours
        ), precision_rounding=0.001)
        return {
            'days': days,
            'hours': sum(day_hours.values()),
        }

    def _get_resources_day_total(self, from_datetime, to_datetime, resources=None):
        """
        @return dict with hours of attendance in each day between `from_datetime` and `to_datetime`
        """
        self.ensure_one()
        if not resources:
            resources = self.env['resource.resource']
            resources_list = [resources]
        else:
            resources_list = list(resources) + [self.env['resource.resource']]
        # total hours per day:  retrieve attendances with one extra day margin,
        # in order to compute the total hours on the first and last days
        from_full = from_datetime - timedelta(days=1)
        to_full = to_datetime + timedelta(days=1)
        intervals = self._attendance_intervals_batch(from_full, to_full, resources=resources)

        result = defaultdict(lambda: defaultdict(float))
        for resource in resources_list:
            day_total = result[resource.id]
            for start, stop, meta in intervals[resource.id]:
                day_total[start.date()] += (stop - start).total_seconds() / 3600
        return result

    def _get_closest_work_time(self, dt, match_end=False, resource=None, search_range=None, compute_leaves=True):
        """Return the closest work interval boundary within the search range.
        Consider only starts of intervals unless `match_end` is True. It will then only consider
        ends of intervals.
        :param dt: reference datetime
        :param match_end: wether to search for the begining of an interval or the end.
        :param search_range: time interval considered. Defaults to the entire day of `dt`
        :rtype: datetime | None
        """
        def interval_dt(interval):
            return interval[1 if match_end else 0]

        tz = resource.tz if resource else self.tz
        if resource is None:
            resource = self.env['resource.resource']

        if not dt.tzinfo or search_range and not (search_range[0].tzinfo and search_range[1].tzinfo):
            raise ValueError('Provided datetimes needs to be timezoned')

        dt = dt.astimezone(timezone(tz))

        if not search_range:
            range_start = dt + relativedelta(hour=0, minute=0, second=0)
            range_end = dt + relativedelta(days=1, hour=0, minute=0, second=0)
        else:
            range_start, range_end = search_range

        if not range_start <= dt <= range_end:
            return None
        work_intervals = sorted(
            self._work_intervals_batch(range_start, range_end, resource, compute_leaves=compute_leaves)[resource.id],
            key=lambda i: abs(interval_dt(i) - dt),
        )
        return interval_dt(work_intervals[0]) if work_intervals else None

    def _get_unusual_days(self, start_dt, end_dt, company_id=False):
        if not self:
            return {}
        self.ensure_one()
        if not start_dt.tzinfo:
            start_dt = start_dt.replace(tzinfo=utc)
        if not end_dt.tzinfo:
            end_dt = end_dt.replace(tzinfo=utc)

        domain = []
        if company_id:
            domain = [('company_id', 'in', (company_id.id, False))]
        works = {d[0].date() for d in self._work_intervals_batch(start_dt, end_dt, domain=domain)[False]}
        return {fields.Date.to_string(day.date()): (day.date() not in works) for day in rrule(DAILY, start_dt, until=end_dt)}

    # --------------------------------------------------
    # External API
    # --------------------------------------------------

    def get_work_hours_count(self, start_dt, end_dt, compute_leaves=True, domain=None):
        """
            `compute_leaves` controls whether or not this method is taking into
            account the global leaves.

            `domain` controls the way leaves are recognized.
            None means default value ('time_type', '=', 'leave')

            Counts the number of work hours between two datetimes.
        """
        self.ensure_one()
        # Set timezone in UTC if no timezone is explicitly given
        if not start_dt.tzinfo:
            start_dt = start_dt.replace(tzinfo=utc)
        if not end_dt.tzinfo:
            end_dt = end_dt.replace(tzinfo=utc)

        if compute_leaves:
            intervals = self._work_intervals_batch(start_dt, end_dt, domain=domain)[False]
        else:
            intervals = self._attendance_intervals_batch(start_dt, end_dt)[False]

        return sum(
            (stop - start).total_seconds() / 3600
            for start, stop, meta in intervals
        )

    def get_work_duration_data(self, from_datetime, to_datetime, compute_leaves=True, domain=None):
        """
            Get the working duration (in days and hours) for a given period, only
            based on the current calendar. This method does not use resource to
            compute it.

            `domain` is used in order to recognise the leaves to take,
            None means default value ('time_type', '=', 'leave')

            Returns a dict {'days': n, 'hours': h} containing the
            quantity of working time expressed as days and as hours.
        """
        # naive datetimes are made explicit in UTC
        from_datetime, dummy = make_aware(from_datetime)
        to_datetime, dummy = make_aware(to_datetime)

        # actual hours per day
        if compute_leaves:
            intervals = self._work_intervals_batch(from_datetime, to_datetime, domain=domain)[False]
        else:
            intervals = self._attendance_intervals_batch(from_datetime, to_datetime, domain=domain)[False]

        return self._get_attendance_intervals_days_data(intervals)

    def plan_hours(self, hours, day_dt, compute_leaves=False, domain=None, resource=None):
        """
        `compute_leaves` controls whether or not this method is taking into
        account the global leaves.

        `domain` controls the way leaves are recognized.
        None means default value ('time_type', '=', 'leave')

        Return datetime after having planned hours
        """
        day_dt, revert = make_aware(day_dt)

        if resource is None:
            resource = self.env['resource.resource']

        # which method to use for retrieving intervals
        if compute_leaves:
            get_intervals = partial(self._work_intervals_batch, domain=domain, resources=resource)
            resource_id = resource.id
        else:
            get_intervals = self._attendance_intervals_batch
            resource_id = False

        if hours >= 0:
            delta = timedelta(days=14)
            for n in range(100):
                dt = day_dt + delta * n
                for start, stop, meta in get_intervals(dt, dt + delta)[resource_id]:
                    interval_hours = (stop - start).total_seconds() / 3600
                    if hours <= interval_hours:
                        return revert(start + timedelta(hours=hours))
                    hours -= interval_hours
            return False
        else:
            hours = abs(hours)
            delta = timedelta(days=14)
            for n in range(100):
                dt = day_dt - delta * n
                for start, stop, meta in reversed(get_intervals(dt - delta, dt)[resource_id]):
                    interval_hours = (stop - start).total_seconds() / 3600
                    if hours <= interval_hours:
                        return revert(stop - timedelta(hours=hours))
                    hours -= interval_hours
            return False

    def plan_days(self, days, day_dt, compute_leaves=False, domain=None):
        """
        `compute_leaves` controls whether or not this method is taking into
        account the global leaves.

        `domain` controls the way leaves are recognized.
        None means default value ('time_type', '=', 'leave')

        Returns the datetime of a days scheduling.
        """
        day_dt, revert = make_aware(day_dt)

        # which method to use for retrieving intervals
        if compute_leaves:
            get_intervals = partial(self._work_intervals_batch, domain=domain)
        else:
            get_intervals = self._attendance_intervals_batch

        if days > 0:
            found = set()
            delta = timedelta(days=14)
            for n in range(100):
                dt = day_dt + delta * n
                for start, stop, meta in get_intervals(dt, dt + delta)[False]:
                    found.add(start.date())
                    if len(found) == days:
                        return revert(stop)
            return False

        elif days < 0:
            days = abs(days)
            found = set()
            delta = timedelta(days=14)
            for n in range(100):
                dt = day_dt - delta * n
                for start, stop, meta in reversed(get_intervals(dt - delta, dt)[False]):
                    found.add(start.date())
                    if len(found) == days:
                        return revert(start)
            return False

        else:
            return revert(day_dt)

    def _get_max_number_of_hours(self, start, end):
        self.ensure_one()
        if not self.attendance_ids:
            return 0
        mapped_data = defaultdict(lambda: 0)
        for attendance in self.attendance_ids.filtered(lambda a: a.day_period != 'lunch' and ((not a.date_from or not a.date_to) or (a.date_from <= end.date() and a.date_to >= start.date()))):
            mapped_data[(attendance.week_type, attendance.dayofweek)] += attendance.hour_to - attendance.hour_from
        return max(mapped_data.values())

    def _works_on_date(self, date):
        self.ensure_one()

        working_days = self._get_working_hours()
        dayofweek = str(date.weekday())
        if self.two_weeks_calendar:
            weektype = str(self.env['resource.calendar.attendance'].get_week_type(date))
            return working_days[weektype][dayofweek]
        return working_days[False][dayofweek]

    @ormcache('self.id')
    def _get_working_hours(self):
        self.ensure_one()

        working_days = defaultdict(lambda: defaultdict(lambda: False))
        for attendance in self.attendance_ids:
            working_days[attendance.week_type][attendance.dayofweek] = True
        return working_days