# -*- coding: utf-8 -*-
from odoo import fields, models, api
from datetime import timedelta

# 教学用：规定上班时间为 09:00。
# 注意：Odoo 数据库里的 Datetime 以 UTC 存储，这里直接用字段的“小时”做演示比较；
# 生产环境应先用 fields.Datetime.context_timestamp() 把时间转换到用户时区再判断。
WORK_START_HOUR = 9


class Attendance(models.Model):
    """教职工出勤记录。"""
    _name = 'yuthon.attendance'
    _description = '出勤记录'
    _order = 'date desc, employee_id'

    employee_id = fields.Many2one(
        'yuthon.employee',
        string='教职工',
        required=True,
        ondelete='cascade',
    )
    date = fields.Date(
        string='日期',
        required=True,
        default=fields.Date.today,
    )
    check_in = fields.Datetime(string='签到时间')
    check_out = fields.Datetime(string='签退时间')

    # ---- 计算字段 ----
    working_hours = fields.Float(
        string='工时(小时)',
        compute='_compute_working_hours',
        store=True,
    )
    status = fields.Selection(
        [
            ('normal', '正常'),
            ('late', '迟到'),
            ('absent', '缺勤'),
        ],
        string='状态',
        compute='_compute_status',
        store=True,
    )
    late_minutes = fields.Integer(
        string='迟到分钟',
        compute='_compute_status',
        store=True,
    )

    # ---- 约束 ----
    _sql_constraints = [
        ('uniq_employee_date', 'unique(employee_id, date)',
         '同一教职工一天只能有一条出勤记录！'),
    ]

    @api.constrains('check_in', 'check_out')
    def _check_time_order(self):
        for rec in self:
            if rec.check_in and rec.check_out and rec.check_out < rec.check_in:
                raise models.ValidationError('签退时间不能早于签到时间。')

    @api.depends('check_in', 'check_out')
    def _compute_working_hours(self):
        for rec in self:
            if rec.check_in and rec.check_out and rec.check_out >= rec.check_in:
                delta = rec.check_out - rec.check_in
                rec.working_hours = round(delta.total_seconds() / 3600.0, 2)
            else:
                rec.working_hours = 0.0

    @api.depends('check_in')
    def _compute_status(self):
        for rec in self:
            if not rec.check_in:
                rec.status = 'absent'
                rec.late_minutes = 0
                continue
            check_in_hour = rec.check_in.hour + rec.check_in.minute / 60.0
            if check_in_hour > WORK_START_HOUR:
                rec.status = 'late'
                threshold = rec.check_in.replace(
                    hour=WORK_START_HOUR, minute=0, second=0, microsecond=0)
                rec.late_minutes = max(0, int(
                    (rec.check_in - threshold).total_seconds() // 60))
            else:
                rec.status = 'normal'
                rec.late_minutes = 0


class Employee(models.Model):
    """通过 _inherit 反向扩展 yuthon.employee，把出勤记录挂上去。

    这是「模块组合」的关键示范：yuthon_attendance 不修改 yuthon_employee 的源码，
    而是继承它追加 One2many 反向关联，让两个模块保持解耦。
    """
    _inherit = 'yuthon.employee'

    attendance_ids = fields.One2many(
        'yuthon.attendance',
        'employee_id',
        string='出勤记录',
    )
    attendance_count = fields.Integer(
        string='出勤记录数',
        compute='_compute_attendance_count',
    )

    @api.depends('attendance_ids')
    def _compute_attendance_count(self):
        for rec in self:
            rec.attendance_count = len(rec.attendance_ids)