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

from datetime import datetime, timedelta
from pytz import timezone, UTC

from odoo import fields, models, _
from odoo.exceptions import UserError


class HrLeaveGenerateMultiWizard(models.TransientModel):
    _name = "hr.leave.generate.multi.wizard"
    _description = 'Generate time off for multiple employees'

    name = fields.Char("Description")
    holiday_status_id = fields.Many2one(
        "hr.leave.type", string="Time Off Type", required=True,
        domain="[('company_id', 'in', [company_id, False])]")
    allocation_mode = fields.Selection([
        ('employee', 'By Employee'),
        ('company', 'By Company'),
        ('department', 'By Department'),
        ('category', 'By Employee Tag')],
        string='Allocation Mode', readonly=False, required=True, default='employee',
        help="Allow to create requests in batchs:\n- By Employee: for a specific employee"
             "\n- By Company: all employees of the specified company"
             "\n- By Department: all employees of the specified department"
             "\n- By Employee Tag: all employees of the specific employee group category")
    employee_ids = fields.Many2many('hr.employee', string='Employees', domain="[('company_id', '=', company_id)]")
    company_id = fields.Many2one('res.company', default=lambda self: self.env.company, required=True)
    department_id = fields.Many2one('hr.department')
    category_id = fields.Many2one('hr.employee.category', string='Employee Tag')
    date_from = fields.Date('Start Date', required=True)
    date_to = fields.Date('End Date', required=True)

    def _get_employees_from_allocation_mode(self):
        self.ensure_one()
        if self.allocation_mode == 'employee':
            employees = self.employee_ids
        elif self.allocation_mode == 'category':
            employees = self.category_id.employee_ids.filtered(lambda e: e.company_id in self.env.companies)
        elif self.allocation_mode == 'company':
            employees = self.env['hr.employee'].search([('company_id', '=', self.company_id.id)])
        else:
            employees = self.department_id.member_ids
        return employees

    def _prepare_employees_holiday_values(self, employees, date_from_tz, date_to_tz):
        self.ensure_one()
        work_days_data = employees._get_work_days_data_batch(date_from_tz, date_to_tz)
        return [{
            'name': self.name,
            'holiday_status_id': self.holiday_status_id.id,
            'date_from': date_from_tz,
            'date_to': date_to_tz,
            'request_date_from': self.date_from,
            'request_date_to': self.date_to,
            'number_of_days': work_days_data[employee.id]['days'],
            'employee_id': employee.id,
            'state': 'validate',
        } for employee in employees if work_days_data[employee.id]['days']]

    def action_generate_time_off(self):
        self.ensure_one()
        employees = self._get_employees_from_allocation_mode()

        tz = timezone(self.company_id.resource_calendar_id.tz or self.env.user.tz or 'UTC')
        date_from_tz = tz.localize(datetime.combine(self.date_from, datetime.min.time())).astimezone(UTC).replace(tzinfo=None)
        date_to_tz = tz.localize(datetime.combine(self.date_to, datetime.max.time())).astimezone(UTC).replace(tzinfo=None)

        conflicting_leaves = self.env['hr.leave'].with_context(
            tracking_disable=True,
            mail_activity_automation_skip=True,
            leave_fast_create=True
        ).search([
            ('date_from', '<=', date_to_tz),
            ('date_to', '>', date_from_tz),
            ('state', 'not in', ['cancel', 'refuse']),
            ('employee_id', 'in', employees.ids)])

        if conflicting_leaves:
            # YTI: More complex use cases could be managed later
            invalid_time_off = conflicting_leaves.filtered(lambda l: l.leave_type_request_unit == 'hour')
            if invalid_time_off:
                raise UserError(_('Automatic time off spliting during batch generation is not managed for ovelapping time off declared in hours. Conflicting time off:\n%s', '\n'.join(f"- {l.display_name}" for l in invalid_time_off)))

            conflicting_leaves._split_leaves(self.date_from, self.date_to + timedelta(days=1))

        vals_list = self._prepare_employees_holiday_values(employees, date_from_tz, date_to_tz)
        leaves = self.env['hr.leave'].with_context(
            tracking_disable=True,
            mail_activity_automation_skip=True,
            leave_fast_create=True,
            no_calendar_sync=True,
            leave_skip_state_check=True,
            # date_from and date_to are computed based on the employee tz
            # If _compute_date_from_to is used instead, it will trigger _compute_number_of_days
            # and create a conflict on the number of days calculation between the different leaves
            leave_compute_date_from_to=True,
        ).create(vals_list)
        leaves._validate_leave_request()

        return {
            'type': 'ir.actions.act_window',
            'name': _('Generated Time Off'),
            "views": [[self.env.ref('hr_holidays.hr_leave_view_tree').id, "list"], [self.env.ref('hr_holidays.hr_leave_view_form_manager').id, "form"]],
            'view_mode': 'list',
            'res_model': 'hr.leave',
            'domain': [('id', 'in', leaves.ids)]
        }