I need to modify the sales report to add profit of each item or atleast add the cost of the items. At the end It should lits total ammount for sale , and cost/profit.

I am using the odoo.com version and have enabled the developer tools.

Technical->User Interface->Views->report_saledetails then I will edit the view 

Can some one please guide me what changes I need to do there ?

EDIT 1:

So if I check the code its as follows

<?xml version="1.0"?>
<t t-name="point_of_sale.report_saledetails">
    <t t-set="company" t-value="env.company"/>
    <t t-call="web.html_container">
    <t t-call="web.internal_layout">
        <div class="page">

            <div class="text-center">
                <h2>Sales Details</h2>

                <strong><t t-esc="date_start" t-options="{'widget': 'datetime'}"/> - <t t-esc="date_stop" t-options="{'widget': 'datetime'}"/></strong>
            </div>

            <!-- Orderlines -->
            <h3>Products</h3>
            <table class="table table-sm">
                <thead><tr>
                    <th>Product</th>
                    <th>Quantity</th>
                    <th>Price Unit</th>
                  </tr></thead>
                <tbody>
                <tr t-foreach="products" t-as="line">
                    <t t-set="internal_reference" t-value="line['code'] and '[%s] ' % line['code'] or ''"/>
                    <td><t t-esc="internal_reference"/><t t-esc="line['product_name']"/></td>
                    <td>
                        <t t-esc="line['quantity']"/>
                        <t t-if="line[&quot;uom&quot;] != &quot;Units&quot;">
                            <t t-esc="line[&quot;uom&quot;]"/> 
                        </t>
                    </td>
                    <td>
                        <t t-esc="line[&quot;price_unit&quot;]"/>
                    <t t-if="line[&quot;discount&quot;] != 0">
                        Disc: <t t-esc="line[&quot;discount&quot;]"/>%
                    </t>
                    </td>
                     </tr>
                </tbody>
            </table>

            <br/>

            <h3>Payments</h3>
            <table class="table table-sm">
                <thead><tr>
                    <th>Name</th>
                    <th>Total</th>
                </tr></thead>
                <tbody>
                <tr t-foreach="payments" t-as="payment">
                    <td><t t-esc="payment['name']"/></td>
                    <td><t t-esc="payment['total']" t-options="{'widget': 'float', 'precision': currency_precision}"/></td>
                </tr>
                </tbody>
            </table>

            <br/>

            <h3>Taxes</h3>
            <table class="table table-sm">
                <thead><tr>
                    <th>Name</th>
                    <th>Tax Amount</th>
                    <th>Base Amount</th>
                </tr></thead>
                <tbody>
                <tr t-foreach="taxes" t-as="tax">
                    <td><t t-esc="tax['name']"/></td>
                    <td><t t-esc="tax['tax_amount']" t-options="{'widget': 'float', 'precision': currency_precision}"/></td>
                    <td><t t-esc="tax['base_amount']" t-options="{'widget': 'float', 'precision': currency_precision}"/></td>
                </tr>
                </tbody>
            </table>

            <br/>
            <br/>

            <strong>Total: <t t-esc="total_paid" t-options="{'widget': 'float', 'precision': currency_precision}"/></strong>

        </div>
    </t>
    </t>
</t>

The Line  object has product id and the price . How can I get the cost of the product in this page !