Following is the code of a controller which is giving a rfq comparison report

@http.route(['/purchase_comparison_chart/purchase_comparison/<model("purchase.requisition"):purchase_requisition_id>'], type='http', auth='public', website=True)

def purchase_comparison(self, purchase_requisition_id, **post):
    supplier_ids = []; product_ids=[]; values = []; amt = []; number = []; supplier_id = []
    counts = 1
    for record in request.env['purchase.order'].sudo().search([('requisition_id', '=', purchase_requisition_id.id)]):
        # Append supplier
        supplier_ids.append({'supplier_id':record.partner_id.id, 'sname':record.partner_id.name})
        supplier_id.append(record.partner_id.id)
        number.append(counts)
        # Append Products and quantity
        counts +=1
        for line in record.order_line:
            if values:
                if line.product_id.id not in product_ids:
                    product_ids.append(line.product_id.id)
                    values.append({'product_id':line.product_id.id, 'product_name':line.product_id.name, 'price':line.price_unit, 'uom':line.product_id.uom_po_id.name, 'qty':line.product_qty})
            else:
                product_ids.append(line.product_id.id)
                values.append({'product_id':line.product_id.id,'product_name':line.product_id.name, 'price':line.price_unit, 'uom':line.product_id.uom_po_id.name,'qty':line.product_qty})

    count = 0; supplier_amount_total = []; no_of_col = 2 ; even_number = [] ; odd_number = []
    # Append amount based on the products and supplier
    for separate_values in values:
        for suppliers in supplier_ids:
            for record in request.env['purchase.order'].sudo().search([('requisition_id', '=', purchase_requisition_id.id),('partner_id', '=',suppliers['supplier_id'])]):
                for po_line in request.env['purchase.order.line'].search([('order_id', '=', record.id),('product_id', '=',separate_values['product_id'])]):
                    amt.append({'total_amount':(po_line.product_qty * po_line.price_unit), 'price':po_line.price_unit})
        values[count]['amt'] = amt
        count +=1
        amt = []
    # Generate number to create rows and columns
    total_supplier = len(number)
    if total_supplier >= 2:
        increase_by_supplier = total_supplier * no_of_col
    else:
        increase_by_supplier = no_of_col
    if total_supplier > 1:
        total_no = range(1, increase_by_supplier + 1)
        supplier_amount_total_1 = list(range(1, increase_by_supplier + 1))
    else:
        total_no = range(1, increase_by_supplier)
        supplier_amount_total_1 = list(range(1, increase_by_supplier))
    for c_number in total_no:
        if c_number%2 ==0:
            even_number.append(c_number)
        else:
            odd_number.append(c_number)
    for record in request.env['purchase.order'].sudo().search([('requisition_id', '=', purchase_requisition_id.id)]):
        supplier_amount_total.append(record.amount_total)
    # Update the amount in even number position
    tcount = 1
    for i in even_number:
        supplier_amount_total_1[i-1] = supplier_amount_total[tcount-1]
        tcount +=1
    # Update the supplier id in odd number position
    scount = 1
    for odd_no in odd_number:
        for total in total_no:
            if total == odd_no:
                supplier_amount_total_1[odd_no-1] = supplier_id[scount-1]
                scount +=1
    global result
    global check
    check = 'Hello world'
    result = request.render('purchase_comparison_chart.purchase_comparison', {'data':values, 'supplier':supplier_ids,'purchase_requisition_id':purchase_requisition_id,
                                                           'number':number, 'to_no':total_no, 'column_no':even_number, 'supplier_amount_total':supplier_amount_total,
                                                            'supplier_amount_total_1':supplier_amount_total_1, 'odd_number':odd_number})

    
    return result

Now i want to download this web report too. I know the code for that too but i dont know how to call the above controller code i am using is following

@http.route(['/purchase_comparison_chart/purchase_comparison'], type='http', auth='public', website=True)
def invoice_print(self, date_start=False, date_stop=False, **kw):
    r = kw['purchase_comparison']
    pdf = request.env['report'].sudo().get_pdf([r], 'purchase_comparison_chart.action_purchase_id', data=None)

    pdfhttpheaders = [('Content-Type', 'application/pdf'), ('Content-Length', len(pdf))]

    return request.make_response(pdf, headers=pdfhttpheaders)
​

This is giving me a pdf which i am unable to open kindly tell what should i do