import json
from datetime import datetime, time, timedelta

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


class Task(models.Model):
    _name = "beesdoo.shift.shift"

    _inherit = ["mail.thread"]

    _order = "start_time asc"

    ##################################
    # Method to override             #
    # to have different state        #
    # on the shift                   #
    ##################################
    def _get_selection_status(self):
        return [
            ("open", "Confirmed"),
            ("done", "Attended"),
            ("absent", "Absent"),
            ("excused", "Excused"),
            ("cancel", "Cancelled"),
        ]

    def _get_color_mapping(self, state):
        return {
            "draft": 0,
            "open": 1,
            "done": 5,
            "absent": 2,
            "excused": 3,
            "cancel": 9,
        }[state]

    def _get_final_state(self):
        return ["done", "absent", "excused"]

    name = fields.Char(track_visibility="always")
    task_template_id = fields.Many2one("beesdoo.shift.template")
    planning_id = fields.Many2one(
        related="task_template_id.planning_id", store=True
    )
    task_type_id = fields.Many2one("beesdoo.shift.type", string="Task Type")
    worker_id = fields.Many2one(
        "res.partner",
        track_visibility="onchange",
        domain=[
            ("is_worker", "=", True),
            ("working_mode", "in", ("regular", "irregular")),
            ("state", "not in", ("unsubscribed", "resigning")),
        ],
    )
    start_time = fields.Datetime(
        track_visibility="always", index=True, required=True
    )
    end_time = fields.Datetime(track_visibility="always", required=True)
    state = fields.Selection(
        selection=_get_selection_status,
        default="open",
        required=True,
        track_visibility="onchange",
        group_expand="_expand_states",
    )
    color = fields.Integer(compute="_compute_color")
    super_coop_id = fields.Many2one(
        "res.users",
        string="Super Cooperative",
        domain=[("partner_id.super", "=", True)],
        track_visibility="onchange",
    )
    is_regular = fields.Boolean(default=False, string="Regular shift")
    is_compensation = fields.Boolean(
        default=False, string="Compensation shift"
    )
    replaced_id = fields.Many2one(
        "res.partner",
        track_visibility="onchange",
        domain=[
            ("eater", "=", "worker_eater"),
            ("working_mode", "=", "regular"),
            ("state", "not in", ("unsubscribed", "resigning")),
        ],
    )
    revert_info = fields.Text(copy=False)
    working_mode = fields.Selection(related="worker_id.working_mode")

    def _expand_states(self, states, domain, order):
        return [key for key, val in self._fields["state"].selection]

    @api.depends("state")
    def _compute_color(self):
        for rec in self:
            rec.color = self._get_color_mapping(rec.state)

    def _compensation_validation(self, task):
        """
        Raise a validation error if the fields is_regular and
        is_compensation are not properly set.
        """
        if task.is_regular == task.is_compensation or not (
            task.is_regular or task.is_compensation
        ):
            raise ValidationError(
                "You must choose between Regular Shift or "
                "Compensation Shift."
            )

    @api.constrains("state")
    def _lock_future_task(self):
        if datetime.now() < self.start_time:
            if self.state in self._get_final_state():
                raise UserError(
                    _(
                        "Shift state of a future shift "
                        "can't be set to 'present' or 'absent'."
                    )
                )

    @api.constrains("is_regular", "is_compensation")
    def _check_compensation(self):
        for task in self:
            if task.working_mode == "regular":
                self._compensation_validation(task)

    @api.constrains("worker_id")
    def _check_worker_id(self):
        """
        When worker_id changes we need to check whether is_regular
        and is_compensation are set correctly.
        When worker_id is set to a worker that doesn't need field
        is_regular and is_compensation, these two fields are set to
        False.
        """
        for task in self:
            if task.working_mode == "regular":
                self._compensation_validation(task)
            else:
                task.write({"is_regular": False, "is_compensation": False})
            if task.worker_id:
                if task.worker_id == task.replaced_id:
                    raise UserError("A worker cannot replace himself.")

    def message_auto_subscribe(self, updated_fields, values=None):
        self._add_follower(values)
        return super(Task, self).message_auto_subscribe(
            updated_fields, values=values
        )

    def _add_follower(self, vals):
        if vals.get("worker_id"):
            worker = self.env["res.partner"].browse(vals["worker_id"])
            self.message_subscribe(partner_ids=worker.ids)

    # TODO button to replaced someone
    @api.model
    def unsubscribe_from_today(
        self, worker_ids, today=None, end_date=None, now=None
    ):
        """
        Unsubscribe workers from *worker_ids* from all shift that start *today* and later.
        If *end_date* is given, unsubscribe workers from shift between *today* and *end_date*.
        If *now* is given workers are unsubscribed from all shifts starting *now* and later.
        If *now* is given, *end_date* is not taken into account.

        :type today: date
        :type end_date: date
        :type now: datetime
        """
        if now:
            if not isinstance(now, datetime):
                raise UserError(_("'Now' must be a datetime."))
            date_domain = [("start_time", ">", now)]
        else:
            today = today or fields.Date.today()
            today = datetime.combine(today, time())
            date_domain = [("start_time", ">", today)]
            if end_date:
                end_date = datetime.combine(
                    end_date, time(hour=23, minute=59, second=59)
                )
                date_domain.append(("end_time", "<=", end_date))

        to_unsubscribe = self.search(
            [("worker_id", "in", worker_ids)] + date_domain
        )
        to_unsubscribe.write({"worker_id": False})

        # Remove worker, replaced_id and regular
        to_unsubscribe_replace = self.search(
            [("replaced_id", "in", worker_ids)] + date_domain
        )
        to_unsubscribe_replace.write(
            {"worker_id": False, "replaced_id": False}
        )

        # If worker is Super cooperator, remove it from planning
        super_coop_ids = (
            self.env["res.users"]
            .search([("partner_id", "in", worker_ids), ("super", "=", True)])
            .ids
        )

        if super_coop_ids:
            to_unsubscribe_super_coop = self.search(
                [("super_coop_id", "in", super_coop_ids)] + date_domain
            )
            to_unsubscribe_super_coop.write({"super_coop_id": False})

    @api.multi
    def write(self, vals):
        """
            Overwrite write to track state change
            If worker is changer:
               Revert for the current worker
               Change the worker info
               Compute state change for the new worker
        """
        if "worker_id" in vals:
            for rec in self:
                if rec.worker_id.id != vals["worker_id"]:
                    rec._revert()
                    # To satisfy the constrains on worker_id, it must be
                    # accompanied by the change in is_regular and
                    # is_compensation field.
                    super(Task, rec).write(
                        {
                            "worker_id": vals["worker_id"],
                            "is_regular": vals.get(
                                "is_regular", rec.is_regular
                            ),
                            "is_compensation": vals.get(
                                "is_compensation", rec.is_compensation
                            ),
                        }
                    )
                    rec._update_state(rec.state)
        if "state" in vals:
            for rec in self:
                if vals["state"] != rec.state:
                    rec._update_state(vals["state"])
        return super(Task, self).write(vals)

    def _set_revert_info(self, data, status):
        data_new = {
            "status_id": status.id,
            "data": {
                k: data.get(k, 0) * -1
                for k in ["sr", "sc", "irregular_absence_counter"]
            },
        }
        if data.get("irregular_absence_date"):
            data_new["data"]["irregular_absence_date"] = False

        self.write({"revert_info": json.dumps(data_new)})

    def _revert(self):
        if not self.revert_info:
            return
        data = json.loads(self.revert_info)
        self.env["cooperative.status"].browse(
            data["status_id"]
        ).sudo()._change_counter(data["data"])
        self.revert_info = False

    def _update_state(self, new_state):
        self.ensure_one()
        self._revert()

        if (
            not (self.worker_id or self.replaced_id)
            and new_state in self._get_final_state()
        ):
            raise UserError(
                _(
                    "You cannot change to the status %s if no worker is defined for the shift"
                )
                % new_state
            )

        always_update = int(
            self.env["ir.config_parameter"]
            .sudo()
            .get_param("always_update", False)
        )
        if always_update or not (self.worker_id or self.replaced_id):
            return

        if not (self.worker_id.working_mode in ["regular", "irregular"]):
            raise UserError(
                _(
                    "Working mode is not properly defined. Please check if the worker is subscribed"
                )
            )

        data, status = self._get_counter_date_state_change(new_state)
        if status:
            status.sudo()._change_counter(data)
            self._set_revert_info(data, status)

    @api.model
    def _cron_send_weekly_emails(self):
        """
        Send a summary email for all workers
        if they have a shift planned during the week.
        """
        tasks = self.env["beesdoo.shift.shift"]
        shift_summary_mail_template = self.env.ref(
            "beesdoo_shift.email_template_shift_summary", False
        )

        start_time = datetime.now() + timedelta(days=1)
        end_time = datetime.now() + timedelta(days=7)

        confirmed_tasks = tasks.search(
            [
                ("start_time", ">", start_time),
                ("start_time", "<", end_time),
                ("worker_id", "!=", False),
                ("state", "=", "open"),
            ]
        )

        for rec in confirmed_tasks:
            shift_summary_mail_template.send_mail(rec.id, True)

    ########################################################
    #                   Method to override                 #
    #           To define the behavior of the status       #
    #                                                      #
    #       By default: everyone is always up to date      #
    ########################################################

    def _get_counter_date_state_change(self, new_state):
        """
        Return the cooperator_status of the cooperator that need to be
        change and data that need to be change. It does not perform the
        change directly. The cooperator_status will be changed by the
        _change_counter function.

        Check has been done to ensure that worker is legitimate.
        """
        data = {}
        status = None
        return data, status