[16.0][ADD] pms: price a room type by its occupancy

pms/README.rst

@@ -56,6 +56,22 @@ You will find the hotel settings in PMS Management > Configuration > Properties
 
 This module required additional configuration for company, accounting, invoicing and user privileges.
 
+Children and room capacity
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+By default children take no place in the room, so only the adults are checked
+against its capacity. Properties that want to count them can set the system
+parameter ``pms.children_occupy_capacity`` to ``True``, in Settings > Technical
+> System Parameters.
+
+Once it is on, children take the regular places of the room first and only
+overflow into its children places, the ones where only a child can sleep, such
+as child bunk beds. Adults never occupy those, so a room with free children
+places can still be full.
+
+Mind that turning it on refuses reservations that the property may have been
+taking until then.
+
 Usage
 =====
 

pms/__manifest__.py

@@ -4,7 +4,7 @@
 {
     "name": "PMS (Property Management System)",
     "summary": "A property management system",
-    "version": "16.0.4.24.0",
+    "version": "16.0.4.26.0",
     "development_status": "Beta",
     "category": "Generic Modules/Property Management System",
     "website": "https://github.com/OCA/pms",

pms/demo/pms_master_data_no_update.xml

@@ -326,34 +326,39 @@
             <field name="room_type_id" ref="pms_room_type_single" />
             <field name="ubication_id" ref="pms_ubication_1st_floor" />
             <field name="capacity">1</field>
+            <field name="children_capacity">1</field>
             <field name="pms_property_id" ref="pms.main_pms_property" />
         </record>
         <record id="pms_room_single_02" model="pms.room">
             <field name="name">Single-107</field>
             <field name="room_type_id" ref="pms_room_type_single" />
             <field name="ubication_id" ref="pms_ubication_1st_floor" />
             <field name="capacity">1</field>
+            <field name="children_capacity">1</field>
             <field name="pms_property_id" ref="pms.main_pms_property" />
         </record>
         <record id="pms_room_single_03" model="pms.room">
             <field name="name">Single-108</field>
             <field name="room_type_id" ref="pms_room_type_single" />
             <field name="ubication_id" ref="pms_ubication_1st_floor" />
             <field name="capacity">1</field>
+            <field name="children_capacity">1</field>
             <field name="pms_property_id" ref="pms.main_pms_property" />
         </record>
         <record id="pms_room_single_04" model="pms.room">
             <field name="name">Single-109</field>
             <field name="room_type_id" ref="pms_room_type_single" />
             <field name="ubication_id" ref="pms_ubication_1st_floor" />
             <field name="capacity">1</field>
+            <field name="children_capacity">1</field>
             <field name="pms_property_id" ref="pms.main_pms_property" />
         </record>
         <record id="pms_room_single_05" model="pms.room">
             <field name="name">Single-110</field>
             <field name="room_type_id" ref="pms_room_type_single" />
             <field name="ubication_id" ref="pms_ubication_1st_floor" />
             <field name="capacity">1</field>
+            <field name="children_capacity">1</field>
             <field name="pms_property_id" ref="pms.main_pms_property" />
         </record>
         <!-- double rooms (My Property) -->

pms/migrations/16.0.4.25.0/pre-migration.py

@@ -0,0 +1,21 @@
+# Copyright 2026 Commit [Sun]
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+from openupgradelib import openupgrade
+
+# children_occupying held the children taking a place in the room, apart from
+# children, which held them all. Nothing kept both in sync, so a reservation
+# could declare an occupying child without counting it in children. Those
+# children are folded into children before the column goes away, or they would
+# be lost.
+_FOLD_CHILDREN_OCCUPYING = """
+    UPDATE pms_reservation
+    SET children = children_occupying
+    WHERE children_occupying > COALESCE(children, 0)
+"""
+
+
+@openupgrade.migrate()
+def migrate(env, version):
+    if openupgrade.column_exists(env.cr, "pms_reservation", "children_occupying"):
+        openupgrade.logged_query(env.cr, _FOLD_CHILDREN_OCCUPYING)
+        openupgrade.drop_columns(env.cr, [("pms_reservation", "children_occupying")])

pms/models/__init__.py

@@ -27,6 +27,7 @@
 from . import pms_checkin_partner
 from . import product_pricelist
 from . import product_pricelist_item
+from . import pms_pricelist_occupancy
 from . import res_partner
 from . import pms_sale_channel
 from . import mail_compose_message

pms/models/pms_pricelist_occupancy.py

@@ -0,0 +1,136 @@
+# Copyright 2026 Commit [Sun]
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+from odoo import _, api, fields, models
+from odoo.exceptions import ValidationError
+
+
+class PmsPricelistOccupancy(models.Model):
+    _name = "pms.pricelist.occupancy"
+    _description = "Occupancy price modifiers of a pricelist for a room type"
+    _check_pms_properties_auto = True
+
+    pricelist_id = fields.Many2one(
+        string="Pricelist",
+        help="Pricelist these modifiers belong to",
+        comodel_name="product.pricelist",
+        required=True,
+        index=True,
+        ondelete="cascade",
+        check_pms_properties=True,
+    )
+    room_type_id = fields.Many2one(
+        string="Room Type",
+        help="Room type these modifiers apply to",
+        comodel_name="pms.room.type",
+        required=True,
+        index=True,
+        ondelete="cascade",
+        check_pms_properties=True,
+    )
+    pms_property_ids = fields.Many2many(
+        string="Properties",
+        help="Properties of the room type these modifiers apply to",
+        comodel_name="pms.property",
+        related="room_type_id.pms_property_ids",
+    )
+    increase_mode = fields.Selection(
+        help="How to charge each guest above the default occupancy",
+        selection=[("percent", "Percentage"), ("amount", "Fixed amount")],
+        default="percent",
+        required=True,
+    )
+    increase_value = fields.Float(
+        string="Increase",
+        help="Charged for each guest above the default occupancy of the room "
+        "type. Zero to charge the same price no matter how many they are",
+        digits=("Product Price"),
+    )
+    decrease_mode = fields.Selection(
+        help="How to discount each guest below the default occupancy",
+        selection=[("percent", "Percentage"), ("amount", "Fixed amount")],
+        default="percent",
+        required=True,
+    )
+    decrease_value = fields.Float(
+        string="Decrease",
+        help="Discounted for each guest below the default occupancy of the "
+        "room type. Zero to charge the same price no matter how many they are",
+        digits=("Product Price"),
+    )
+    summary = fields.Char(
+        string="Per Guest",
+        help="What each guest of difference changes in the price",
+        compute="_compute_summary",
+    )
+
+    _sql_constraints = [
+        (
+            "pricelist_room_type_uniq",
+            "unique(pricelist_id, room_type_id)",
+            "A room type can only have one occupancy configuration per " "pricelist.",
+        )
+    ]
+
+    @api.depends("increase_mode", "increase_value", "decrease_mode", "decrease_value")
+    def _compute_summary(self):
+        """A one-liner for the list, so the form holds the detail."""
+        for record in self:
+            parts = record._summary_parts()
+            record.summary = " / ".join(parts) if parts else _("Same price")
+
+    def _summary_parts(self):
+        """The pieces of the summary, one per modifier that is set."""
+        self.ensure_one()
+        parts = []
+        if self.increase_value:
+            modifier = self._format_modifier(self.increase_mode, self.increase_value)
+            parts.append(f"+{modifier}")
+        if self.decrease_value:
+            modifier = self._format_modifier(self.decrease_mode, self.decrease_value)
+            parts.append(f"-{modifier}")
+        return parts
+
+    def _format_modifier(self, mode, value):
+        self.ensure_one()
+        if mode == "percent":
+            return f"{value:g}%"
+        return f"{value:g} {self.pricelist_id.currency_id.symbol or ''}"
+
+    @api.constrains("increase_value", "decrease_value")
+    def _check_values_not_negative(self):
+        """The direction is given by the field, so the value is an amount.
+
+        A negative increase would silently discount, and the other way round.
+        """
+        for record in self:
+            if record.increase_value < 0 or record.decrease_value < 0:
+                raise ValidationError(
+                    _("Occupancy increase and decrease can't be negative.")
+                )
+
+    def _apply(self, price, difference):
+        """Price for an occupancy differing by `difference` guests.
+
+        The modifier is linear: it applies once per guest of difference, which
+        is what channel managers derive from a default occupancy as well.
+        """
+        self.ensure_one()
+        if difference > 0:
+            mode, value, guests, sign = (
+                self.increase_mode,
+                self.increase_value,
+                difference,
+                1,
+            )
+        else:
+            mode, value, guests, sign = (
+                self.decrease_mode,
+                self.decrease_value,
+                -difference,
+                -1,
+            )
+        if not value:
+            return price
+        if mode == "percent":
+            return price * (1 + sign * value * guests / 100)
+        return price + sign * value * guests

pms/models/pms_reservation.py

@@ -356,12 +356,9 @@ class PmsReservation(models.Model):
         compute="_compute_adults",
         tracking=True,
     )
-    children_occupying = fields.Integer(
-        help="Number of children there in guest list whose presence counts",
-    )
     children = fields.Integer(
-        help="Number total of children there in guest list,"
-        "whose presence counts or not",
+        help="Number of children there in guest list. They take the regular "
+        "places of the room first, and only overflow into its children places",
         readonly=False,
         tracking=True,
     )
@@ -1031,7 +1028,9 @@ def _compute_user_id(self):
                     else:
                         res.user_id = active_user_id or res.pms_property_id.user_id
 
-    @api.depends("pricelist_id", "room_type_id")
+    @api.depends(
+        lambda self: ["pricelist_id", "room_type_id", *self._occupancy_price_fields()]
+    )
     def _compute_show_update_pricelist(self):
         for reservation in self:
             if (
@@ -1044,6 +1043,10 @@ def _compute_show_update_pricelist(self):
                     reservation.room_type_id
                     and reservation._origin.room_type_id != reservation.room_type_id
                 )
+                or any(
+                    reservation._origin[field] != reservation[field]
+                    for field in reservation._occupancy_price_fields()
+                )
             ):
                 reservation.show_update_pricelist = True
             else:
@@ -2215,9 +2218,10 @@ def write(self, vals):
 
         for record in self:
             record._check_services(vals)
-            # Only check if adult to avoid to check capacity in intermediate states
-            # (p.e. flush) that not take access to possible extra beds service in vals
-            if "adults" in vals:
+            # Only check on occupancy changes to avoid checking capacity in
+            # intermediate states (p.e. flush) that not take access to possible
+            # extra beds service in vals
+            if "adults" in vals or "children" in vals:
                 record._check_capacity()
             # The room of the lines is recomputed from the preferred room, so
             # that write does not go through pms.reservation.line.write and the
@@ -2311,6 +2315,17 @@ def get_services_to_update_channel(self, vals):
                     services_to_update_channel += service
         return services_to_update_channel
 
+    def _occupancy_price_fields(self):
+        """Fields the price of a night is derived from, besides the pricelist
+        and the room type.
+
+        Changing them leaves the prices of the nights outdated, the same as
+        changing the pricelist or the room type does: the nights keep the price
+        they have and the reservation flags it, so that they are updated on
+        purpose. Modules pricing on more than the adults staying add their own.
+        """
+        return ["adults"]
+
     def update_prices(self):
         self.ensure_one()
         for line in self.reservation_line_ids:

pms/models/pms_reservation_line.py

@@ -231,20 +231,32 @@ def _get_pricelist_price(self):
         qty = 1.0
         uom = product.uom_id
         currency = self.currency_id or self.order_id.company_id.currency_id
-        consumption_date = self.date
 
         price = pricelist_rule._compute_consumption_price(
             product,
             qty,
             uom,
             order_date,
             currency=currency,
-            consumption_date=consumption_date,
-            pms_property_id=self.pms_property_id.id,
+            **self._get_price_kwargs(),
         )
 
         return price
 
+    def _get_price_kwargs(self):
+        """What the pricelist resolves the price of this night with.
+
+        Kept apart so that modules pricing on more than the adults staying can
+        add to it without repeating how a night is priced.
+        """
+        self.ensure_one()
+        return {
+            "consumption_date": self.date,
+            "pms_property_id": self.pms_property_id.id,
+            "occupancy": self.reservation_id.adults,
+            "pricelist": self.reservation_id.pricelist_id,
+        }
+
     def _get_product_price_context(self):
         """Gives the context for product price computation.
 
@@ -685,23 +697,31 @@ def _check_room_capacity(self):
         of the room (capacity + allowed extra beds) instead of the extra beds
         actually sold, to avoid false positives in intermediate states where
         the extra bed service is not created yet.
+
+        Children count too: they take regular places first and only overflow
+        into the children places of the room.
         """
         if self.env.context.get("avoid_capacity_check"):
             return
         for record in self:
             reservation = record.reservation_id
-            if not record.room_id or reservation.reservation_type == "out":
+            room = record.room_id
+            if not room or reservation.reservation_type == "out":
                 continue
-            occupancy = reservation.adults + reservation.children_occupying
-            max_capacity = record.room_id.capacity + record.room_id.extra_beds_allowed
-            if occupancy > max_capacity:
+            if not room.fits_occupancy(
+                reservation.adults, reservation.children, room.extra_beds_allowed
+            ):
                 raise ValidationError(
                     _(
-                        "The room %(room)s can't hold %(occupancy)s guests "
-                        "(maximum capacity: %(capacity)s) (%(reservation)s)",
-                        room=record.room_id.display_name,
-                        occupancy=occupancy,
-                        capacity=max_capacity,
+                        "The room %(room)s can't hold %(adults)s adults and "
+                        "%(children)s children (capacity: %(capacity)s, "
+                        "children places: %(children_capacity)s) "
+                        "(%(reservation)s)",
+                        room=room.display_name,
+                        adults=reservation.adults,
+                        children=reservation.children,
+                        capacity=room.capacity + room.extra_beds_allowed,
+                        children_capacity=room.children_capacity,
                         reservation=reservation.name,
                     )
                 )