Revert changes to computation of _immediately_usable_qty

Commit 6c16913 changed the way we compute the immediately_usable_qty: instead of using the virtual stock, we used the sum of quants without reservations. But a quant may actually be reserved and still be available (for example it may be reserved for an internal move).
Fixes OCA#79

Remove loop and use correct decorator

Restore the features of stock_available_immediately

The previous fix restored stock_available but then there was no way to exclude the incomming moves from the count. This belongs in stock_available_immediately, restoring it cleanly.
This commit also takes care to respect the distinction between templates and variants, so it should fix OCA#73 too.

Restore the qty avail. to promise on variant treeview

PEP8

stock_available/__init__.py

@@ -18,5 +18,4 @@
 #
 ##############################################################################
 
-from . import product
-from . import res_config
+from . import models

stock_available/__openerp__.py

@@ -26,7 +26,8 @@
     'depends': ['stock'],
     'license': 'AGPL-3',
     'data': [
-        'product_view.xml',
-        'res_config_view.xml',
-    ]
+        'views/product_template_view.xml',
+        'views/product_product_view.xml',
+        'views/res_config_view.xml',
+    ],
 }

stock_available/models/__init__.py

@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+##############################################################################
+#
+#    This module is copyright (C) 2014 Numérigraphe SARL. All Rights Reserved.
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+
+from . import product_template
+from . import product_product
+from . import res_config

stock_available/product.py → stock_available/models/product_product.py

@@ -22,45 +22,29 @@
 from openerp.addons import decimal_precision as dp
 
 
-class ProductTemplate(models.Model):
+class ProductProduct(models.Model):
     """Add a field for the stock available to promise.
     Useful implementations need to be installed through the Settings menu or by
     installing one of the modules stock_available_*
     """
-    _inherit = 'product.template'
+    _inherit = 'product.product'
 
-    # immediately usable quantity caluculated with the quant method
-    @api.multi
+    @api.one
     @api.depends('virtual_available')
     def _immediately_usable_qty(self):
-        stock_location_obj = self.env['stock.location']
-        internal_locations = stock_location_obj.search([
-            ('usage', '=', 'internal')])
-        sublocations = self.env['stock.location']
-        for location in internal_locations:
-            sublocations += stock_location_obj.search(
-                [('id', 'child_of', location.id)])
-        for product_template in self:
-            products = self.env['product.product'].search([
-                ('product_tmpl_id', '=', product_template.id)])
-            quant_obj = self.env['stock.quant']
-            quants = quant_obj.search([
-                ('location_id', 'in', sublocations.ids),
-                ('product_id', 'in', products.ids),
-                ('reservation_id', '=', False)])
-            availability = 0
-            if quants:
-                for quant in quants:
-                    availability += quant.qty
-            product_template.immediately_usable_qty = availability
+        """No-op implementation of the stock available to promise.
+
+        By default, available to promise = forecasted quantity.
+
+        Must be overridden by another module that actually implement
+        computations."""
+        self.immediately_usable_qty = self.virtual_available
 
     immediately_usable_qty = fields.Float(
         digits=dp.get_precision('Product Unit of Measure'),
         compute='_immediately_usable_qty',
-        string='Available to promise (quant calculation)',
+        string='Available to promise',
         help="Stock for this Product that can be safely proposed "
              "for sale to Customers.\n"
              "The definition of this value can be configured to suit "
-             "your needs , this number is obtained by using the new odoo 8 "
-             "quants, so it gives us the actual current quants  minus reserved"
-             "quants")
+             "your needs")

stock_available/models/product_template.py

@@ -0,0 +1,42 @@
+# -*- coding: utf-8 -*-
+##############################################################################
+#
+#    This module is copyright (C) 2014 Numérigraphe SARL. All Rights Reserved.
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+
+from openerp import models, fields, api
+from openerp.addons import decimal_precision as dp
+
+
+class ProductTemplate(models.Model):
+    _inherit = 'product.template'
+
+    @api.one
+    @api.depends('virtual_available')
+    def _immediately_usable_qty(self):
+        """Compute the quantity using all the variants"""
+        self.immediately_usable_qty = sum(
+            [v.immediately_usable_qty for v in self.product_variant_ids])
+
+    immediately_usable_qty = fields.Float(
+        digits=dp.get_precision('Product Unit of Measure'),
+        compute='_immediately_usable_qty',
+        string='Available to promise',
+        help="Stock for this Product that can be safely proposed "
+             "for sale to Customers.\n"
+             "The definition of this value can be configured to suit "
+             "your needs")

stock_available/views/product_product_view.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<openerp>
+    <data>
+        <record model="ir.ui.view" id="view_stock_available_tree_variant">
+            <field name="name">Quantity available to promise (variant tree)</field>
+            <field name="model">product.product</field>
+            <field name="inherit_id" ref="stock.view_stock_product_tree"/>
+            <field name="arch" type="xml">
+                <data>
+                    <tree position="attributes">
+                        <attribute name="colors">red:immediately_usable_qty&lt;0;blue:immediately_usable_qty&gt;=0 and state in ('draft', 'end', 'obsolete');black:immediately_usable_qty&gt;=0 and state not in ('draft', 'end', 'obsolete')</attribute>
+                    </tree>
+                       <field name="virtual_available" position="after">
+                       <field name="immediately_usable_qty" />
+                    </field>
+                </data>
+            </field>
+        </record>
+    </data>
+</openerp>