purchase invoice taxes and totals calculations with test cases
diff --git a/accounts/doctype/purchase_invoice/purchase_invoice.py b/accounts/doctype/purchase_invoice/purchase_invoice.py
index 8b65e0d..8512b01 100644
--- a/accounts/doctype/purchase_invoice/purchase_invoice.py
+++ b/accounts/doctype/purchase_invoice/purchase_invoice.py
@@ -32,7 +32,6 @@
 		self.tname = 'Purchase Invoice Item'
 		self.fname = 'entries'
 
-
 # ************************** Trigger Functions ****************************
 
 	# Credit To
diff --git a/accounts/doctype/purchase_invoice/test_purchase_invoice.py b/accounts/doctype/purchase_invoice/test_purchase_invoice.py
index 8757788..8ad66fc 100644
--- a/accounts/doctype/purchase_invoice/test_purchase_invoice.py
+++ b/accounts/doctype/purchase_invoice/test_purchase_invoice.py
@@ -19,154 +19,41 @@
 import unittest
 import webnotes
 import webnotes.model
-from webnotes.utils import nowdate
-
-from stock.doctype.purchase_receipt import test_purchase_receipt
-
-company = webnotes.conn.get_default("company")
-abbr = webnotes.conn.get_value("Company", company, "abbr")
-
-def load_data():
-	test_purchase_receipt.load_data()
-	
-	webnotes.insert({"doctype": "Account", "account_name": "Cost for Goods Sold",
-		"parent_account": "Expenses - %s" % abbr, "company": company,
-		"group_or_ledger": "Ledger"})
-	
-	webnotes.insert({"doctype": "Account", "account_name": "Excise Duty",
-		"parent_account": "_Test Tax Assets - %s" % abbr, "company": company,
-		"group_or_ledger": "Ledger"})
-	
-	webnotes.insert({"doctype": "Account", "account_name": "Education Cess",
-		"parent_account": "_Test Tax Assets - %s" % abbr, "company": company,
-		"group_or_ledger": "Ledger"})
-	
-	webnotes.insert({"doctype": "Account", "account_name": "S&H Education Cess",
-		"parent_account": "_Test Tax Assets - %s" % abbr, "company": company,
-		"group_or_ledger": "Ledger"})
-		
-	webnotes.insert({"doctype": "Account", "account_name": "CST",
-		"parent_account": "Direct Expenses - %s" % abbr, "company": company,
-		"group_or_ledger": "Ledger"})
-		
-	webnotes.insert({"doctype": "Account", "account_name": "Discount",
-		"parent_account": "Direct Expenses - %s" % abbr, "company": company,
-		"group_or_ledger": "Ledger"})
-		
-	from webnotes.model.doc import Document
-	item = Document("Item", "Home Desktop 100")
-	
-	# excise duty
-	item_tax = item.addchild("item_tax", "Item Tax")
-	item_tax.tax_type = "Excise Duty - %s" % abbr
-	item_tax.tax_rate = 10
-	item_tax.save()
-
 import json	
-purchase_invoice_doclist = [
-	# parent
-	{
-		"doctype": "Purchase Invoice", 
-		"credit_to": "East Wind Inc. - %s" % abbr,
-		"supplier_name": "East Wind Inc.",
-		"naming_series": "BILL", "posting_date": nowdate(),
-		"company": company, "fiscal_year": webnotes.conn.get_default("fiscal_year"), 
-		"currency": webnotes.conn.get_default("currency"), "conversion_rate": 1,
-		'net_total': 1250.00, 'grand_total': 1512.30, 'grand_total_import': 1512.30, 
-	},
-	# items
-	{
-		"doctype": "Purchase Invoice Item", 
-		"item_code": "Home Desktop 100", "qty": 10, "import_rate": 50, "rate": 50,
-		"amount": 500, "import_amount": 500, "parentfield": "entries", 
-		"uom": "Nos", "item_tax_rate": json.dumps({"Excise Duty - %s" % abbr: 10}),
-		"expense_head": "Cost for Goods Sold - %s" % abbr, 
-		"cost_center": "Default Cost Center - %s" % abbr
-	},
-	{
-		"doctype": "Purchase Invoice Item", 
-		"item_code": "Home Desktop 200", "qty": 5, "import_rate": 150, "rate": 150, 
-		"amount": 750, "import_amount": 750, "parentfield": "entries", "uom": "Nos", 
-		"expense_head": "Cost for Goods Sold - %s" % abbr, 
-		"cost_center": "Default Cost Center - %s" % abbr
-	},
-	# taxes
-	{
-		"doctype": "Purchase Taxes and Charges", "charge_type": "Actual",
-		"account_head": "Shipping Charges - %s" % abbr, "rate": 100, "tax_amount": 100, 
-		"category": "Valuation and Total", "parentfield": "purchase_tax_details",
-		"cost_center": "Default Cost Center - %s" % abbr, "add_deduct_tax": "Add"
-	},
-	{
-		"doctype": "Purchase Taxes and Charges", "charge_type": "On Net Total",
-		"account_head": "Customs Duty - %s" % abbr, "rate": 10, "tax_amount": 125.00,
-		"category": "Valuation", "parentfield": "purchase_tax_details",
-		"cost_center": "Default Cost Center - %s" % abbr, "add_deduct_tax": "Add"
-	},
-	{
-		"doctype": "Purchase Taxes and Charges", "charge_type": "On Net Total",
-		"account_head": "Excise Duty - %s" % abbr, "rate": 12, "tax_amount": 140.00, 
-		"category": "Total", "parentfield": "purchase_tax_details", "add_deduct_tax": "Add"
-	},
-	{
-		"doctype": "Purchase Taxes and Charges", "charge_type": "On Previous Row Amount",
-		"account_head": "Education Cess - %s" % abbr, "rate": 2, "row_id": 3, "tax_amount": 2.80,
-		"category": "Total", "parentfield": "purchase_tax_details", "add_deduct_tax": "Add"
-	},
-	{
-		"doctype": "Purchase Taxes and Charges", "charge_type": "On Previous Row Amount",
-		"account_head": "S&H Education Cess - %s" % abbr, "rate": 1, "row_id": 3, 
-		"tax_amount": 1.4, "category": "Total", "parentfield": "purchase_tax_details",
-		"add_deduct_tax": "Add"
-	},
-	{
-		"doctype": "Purchase Taxes and Charges", "charge_type": "On Previous Row Total",
-		"account_head": "CST - %s" % abbr, "rate": 2, "row_id": 5, "tax_amount": 29.88, 
-		"category": "Total", "parentfield": "purchase_tax_details",
-		"cost_center": "Default Cost Center - %s" % abbr, "add_deduct_tax": "Add"
-	},
-	{
-		"doctype": "Purchase Taxes and Charges", "charge_type": "On Net Total",
-		"account_head": "VAT - Test - %s" % abbr, "rate": 12.5, "tax_amount": 156.25, 
-		"category": "Total", "parentfield": "purchase_tax_details", "add_deduct_tax": "Add"
-	},
-	{
-		"doctype": "Purchase Taxes and Charges", "charge_type": "On Previous Row Total",
-		"account_head": "Discount - %s" % abbr, "rate": 10, "row_id": 7, "tax_amount": 168.03, 
-		"category": "Total", "parentfield": "purchase_tax_details",
-		"cost_center": "Default Cost Center - %s" % abbr, "add_deduct_tax": "Deduct"
-	},
-]
 
 class TestPurchaseInvoice(unittest.TestCase):
 	def setUp(self):
 		webnotes.conn.begin()
-		load_data()
-		# webnotes.conn.set_value("Global Defaults", None, "automatic_inventory_accounting", 1)
 		self.load_test_data()
+		# webnotes.conn.set_value("Global Defaults", None, 
+		# 	"automatic_inventory_accounting", 1)
+		
+	def tearDown(self):
+		webnotes.conn.rollback()
 		
 	def load_test_data(self):
 		from webnotes.test_runner import make_test_records
+		webnotes.test_objects = {}
 		make_test_records("Cost Center", verbose=0)
 		make_test_records("Item", verbose=0)
 		make_test_records("Purchase Invoice", verbose=0)
 		
-	def atest_gl_entries(self):
-		wrapper = webnotes.model_wrapper(purchase_invoice_doclist).insert()
+	def test_gl_entries(self):
+		wrapper = webnotes.model_wrapper(self.get_test_doclist()).insert()
 		wrapper.submit()
 		wrapper.load_from_db()
 		dl = wrapper.doclist
 		
 		expected_gl_entries = {
-			"East Wind Inc. - %s" % abbr : [0, 1512.30],
-			"Cost for Goods Sold - %s" % abbr : [1250, 0],
-			"Shipping Charges - %s" % abbr : [100, 0],
-			"Excise Duty - %s" % abbr : [140, 0],
-			"Education Cess - %s" % abbr : [2.8, 0],
-			"S&H Education Cess - %s" % abbr : [1.4, 0],
-			"CST - %s" % abbr : [29.88, 0],
-			"VAT - Test - %s" % abbr : [156.25, 0],
-			"Discount - %s" % abbr : [0, 168.03],
+			"_Test Supplier - _TC": [0, 1512.30],
+			"_Test Account Cost for Goods Sold - _TC": [1250, 0],
+			"_Test Account Shipping Charges - _TC": [100, 0],
+			"_Test Account Excise Duty - _TC": [140, 0],
+			"_Test Account Education Cess - _TC": [2.8, 0],
+			"_Test Account S&H Education Cess - _TC": [1.4, 0],
+			"_Test Account CST - _TC": [29.88, 0],
+			"_Test Account VAT - _TC": [156.25, 0],
+			"_Test Account Discount - _TC": [0, 168.03],
 		}
 		gl_entries = webnotes.conn.sql("""select account, debit, credit from `tabGL Entry`
 			where voucher_type = 'Purchase Invoice' and voucher_no = %s""", dl[0].name, as_dict=1)
@@ -174,7 +61,39 @@
 			self.assertEqual([d.debit, d.credit], expected_gl_entries.get(d.account))
 			
 	def test_purchase_invoice_calculation(self):
-		test_doclist = [
+		wrapper = webnotes.model_wrapper(self.get_test_doclist()).insert()
+		wrapper.load_from_db()
+		
+		self.assertEqual(wrapper.doclist[0].net_total, 1250)
+		
+		# tax amounts
+		expected_values = [
+			["_Test Account Shipping Charges - _TC", 100, 1350],
+			["_Test Account Customs Duty - _TC", 125, 1350],
+			["_Test Account Excise Duty - _TC", 140, 1490],
+			["_Test Account Education Cess - _TC", 2.8, 1492.8],
+			["_Test Account S&H Education Cess - _TC", 1.4, 1494.2],
+			["_Test Account CST - _TC", 29.88, 1524.08],
+			["_Test Account VAT - _TC", 156.25, 1680.33],
+			["_Test Account Discount - _TC", 168.03, 1512.30],
+		]
+		
+		for i, tax in enumerate(wrapper.doclist.get({"parentfield": "purchase_tax_details"})):
+			self.assertEqual(tax.account_head, expected_values[i][0])
+			self.assertEqual(tax.tax_amount, expected_values[i][1])
+			self.assertEqual(tax.total, expected_values[i][2])
+			# print tax.account_head, tax.tax_amount, tax.item_wise_tax_detail
+
+		expected_values = [
+			["_Test Item Home Desktop 100", 90],
+			["_Test Item Home Desktop 200", 135]
+		]
+		for i, item in enumerate(wrapper.doclist.get({"parentfield": "entries"})):
+			self.assertEqual(item.item_code, expected_values[i][0])
+			self.assertEqual(item.item_tax_amount, expected_values[i][1])
+			
+	def get_test_doclist(self):
+		return [
 			# parent
 			{
 				"doctype": "Purchase Invoice",
@@ -183,7 +102,7 @@
 				"credit_to": "_Test Supplier - _TC",
 				"bill_no": "NA",
 				"posting_date": "2013-02-03",
-				"fiscal_year": "_Test Fiscal Year",
+				"fiscal_year": "_Test Fiscal Year 2013",
 				"company": "_Test Company",
 				"currency": "INR",
 				"conversion_rate": 1,
@@ -199,7 +118,7 @@
 				"import_rate": 50,
 				"import_amount": 500,
 				"rate": 50,
-				"amount": 50,
+				"amount": 500,
 				"uom": "_Test UOM",
 				"item_tax_rate": json.dumps({"_Test Account Excise Duty - _TC": 10}),
 				"expense_head": "_Test Account Cost for Goods Sold - _TC",
@@ -313,37 +232,4 @@
 				"rate": 10,
 				"row_id": 7
 			},
-		]
-				
-		wrapper = webnotes.model_wrapper(test_doclist).insert()
-		wrapper.load_from_db()
-		
-		# tax amounts
-		expected_values = [
-			["_Test Account Shipping Charges - _TC", 100, 1350],
-			["_Test Account Customs Duty - _TC", 125, 1350],
-			["_Test Account Excise Duty - _TC", 140, 1490],
-			["_Test Account Education Cess - _TC", 2.8, 1492.8],
-			["_Test Account S&H Education Cess - _TC", 1.4, 1494.2],
-			["_Test Account CST - _TC", 29.88, 1524.08],
-			["_Test Account VAT - _TC", 156.25, 1680.33],
-			["_Test Account Discount - _TC", 168.03, 1512.30],
-		]
-		
-		for i, tax in enumerate(wrapper.doclist.get({"parentfield": "purchase_tax_details"})):
-			self.assertEqual(tax.account_head, expected_values[i][0])
-			self.assertEqual(tax.tax_amount, expected_values[i][1])
-			self.assertEqual(tax.total, expected_values[i][2])
-
-		expected_values = [
-			["_Test Item Home Desktop 100", 90],
-			["_Test Item Home Desktop 200", 135]
-		]
-		for i, item in enumerate(wrapper.doclist.get({"parentfield": "entries"})):
-			self.assertEqual(item.item_code, expected_values[i][0])
-			self.assertEqual(item.item_tax_amount, expected_values[i][1])
-			
-		# self.assertEqual(dl[0].net_total, 1250)
-
-	def tearDown(self):
-		webnotes.conn.rollback()
\ No newline at end of file
+		]
\ No newline at end of file
diff --git a/accounts/doctype/purchase_invoice_item/purchase_invoice_item.txt b/accounts/doctype/purchase_invoice_item/purchase_invoice_item.txt
index 2891a12..ecd981d 100755
--- a/accounts/doctype/purchase_invoice_item/purchase_invoice_item.txt
+++ b/accounts/doctype/purchase_invoice_item/purchase_invoice_item.txt
@@ -1,8 +1,8 @@
 [
  {
-  "creation": "2013-01-28 10:05:58", 
+  "creation": "2013-01-29 20:53:00", 
   "docstatus": 0, 
-  "modified": "2013-01-29 16:28:04", 
+  "modified": "2013-02-08 14:06:17", 
   "modified_by": "Administrator", 
   "owner": "Administrator"
  }, 
@@ -269,6 +269,20 @@
   "report_hide": 1
  }, 
  {
+  "doctype": "DocField", 
+  "fieldname": "item_tax_amount", 
+  "fieldtype": "Currency", 
+  "hidden": 1, 
+  "label": "Item Tax Amount", 
+  "no_copy": 1, 
+  "options": "Company:company:default_currency", 
+  "print_hide": 1, 
+  "print_width": "150px", 
+  "read_only": 1, 
+  "search_index": 0, 
+  "width": "150px"
+ }, 
+ {
   "allow_on_submit": 1, 
   "doctype": "DocField", 
   "fieldname": "page_break", 
diff --git a/controllers/buying_controller.py b/controllers/buying_controller.py
index 511ca17..d825908 100644
--- a/controllers/buying_controller.py
+++ b/controllers/buying_controller.py
@@ -17,10 +17,12 @@
 from __future__ import unicode_literals
 import webnotes
 from webnotes import _, msgprint
-from webnotes.utils import flt
+from webnotes.utils import flt, cint
+import json
 
 from buying.utils import get_item_details
 from setup.utils import get_company_currency
+from webnotes.model.utils import round_floats_in_doc
 
 from controllers.accounts_controller import AccountsController
 
@@ -32,7 +34,10 @@
 			
 			if self.doc.price_list_name and self.doc.price_list_currency:
 				self.validate_conversion_rate("price_list_currency", "plc_conversion_rate")
-				
+			
+			# IMPORTANT: enable this only when client side code is similar to this one
+			self.calculate_taxes_and_totals()
+			
 			# set total in words
 			self.set_total_in_words()
 		
@@ -87,11 +92,246 @@
 		
 	def calculate_taxes_and_totals(self):
 		self.doc.conversion_rate = flt(self.doc.conversion_rate)
+		self.item_doclist = self.doclist.get({"parentfield": self.fname})
+		self.tax_doclist = self.doclist.get({"parentfield": "purchase_tax_details"})
 		
-		# self.calculate_item_values()
-		# self.initialize_taxes()
-		# self.calculate_net_total()
-		# self.calculate_taxes()
-		# self.calculate_totals()
-		# self.set_total_in_words()
-		
\ No newline at end of file
+		self.calculate_item_values()
+		self.initialize_taxes()
+		self.calculate_net_total()
+		self.calculate_taxes()
+		self.calculate_totals()
+		self.calculate_outstanding_amount()
+		
+		self._cleanup()
+		
+	def calculate_item_values(self):
+		def _set_base(item, print_field, base_field):
+			"""set values in base currency"""
+			item.fields[base_field] = flt((flt(item.fields[print_field],
+				self.precision.item[print_field]) * self.doc.conversion_rate),
+				self.precision.item[base_field])
+
+		for item in self.item_doclist:
+			round_floats_in_doc(item, self.precision.item)
+
+			if item.discount == 100:
+				if not item.import_ref_rate:
+					item.import_ref_rate = item.import_rate
+				item.import_rate = 0
+			else:
+				if item.import_ref_rate:
+					item.import_rate = flt(item.import_ref_rate *
+						(1.0 - (item.discount_rate / 100.0)),
+						self.precision.item.import_rate)
+				else:
+					# assume that print rate and discount are specified
+					item.import_ref_rate = flt(item.import_rate / 
+						(1.0 - (item.discount_rate / 100.0)),
+						self.precision.item.import_ref_rate)
+
+			item.import_amount = flt(item.import_rate * item.qty,
+				self.precision.item.import_amount)
+
+			_set_base(item, "import_ref_rate", "purchase_ref_rate")
+			_set_base(item, "import_rate", "rate")
+			_set_base(item, "import_amount", "amount")
+		
+	def initialize_taxes(self):
+		for tax in self.tax_doclist:
+			# initialize totals to 0
+			tax.tax_amount = tax.total = 0.0
+			
+			# temporary fields
+			tax.tax_amount_for_current_item = tax.grand_total_for_current_item = 0.0
+			
+			tax.item_wise_tax_detail = {}
+			
+			self.validate_on_previous_row(tax)
+			
+			round_floats_in_doc(tax, self.precision.tax)
+		
+	def calculate_net_total(self):
+		self.doc.net_total = 0
+		self.doc.net_total_import = 0
+
+		for item in self.item_doclist:
+			self.doc.net_total += item.amount
+			self.doc.net_total_import += item.import_amount
+			
+		self.doc.net_total = flt(self.doc.net_total, self.precision.main.net_total)
+		self.doc.net_total_import = flt(self.doc.net_total_import,
+			self.precision.main.net_total_import)
+		
+	def calculate_taxes(self):
+		for item in self.item_doclist:
+			item_tax_map = self._load_item_tax_rate(item.item_tax_rate)
+			item.item_tax_amount = 0
+
+			for i, tax in enumerate(self.tax_doclist):
+				# tax_amount represents the amount of tax for the current step
+				current_tax_amount = self.get_current_tax_amount(item, tax, item_tax_map)
+
+				self.set_item_tax_amount(item, tax, current_tax_amount)
+
+				# case when net total is 0 but there is an actual type charge
+				# in this case add the actual amount to tax.tax_amount
+				# and tax.grand_total_for_current_item for the first such iteration
+				if not (current_tax_amount or self.doc.net_total or tax.tax_amount) and \
+						tax.charge_type=="Actual":
+					zero_net_total_adjustment = flt(tax.rate, self.precision.tax.tax_amount)
+					current_tax_amount += zero_net_total_adjustment
+
+				# store tax_amount for current item as it will be used for
+				# charge type = 'On Previous Row Amount'
+				tax.tax_amount_for_current_item = current_tax_amount
+
+				# accumulate tax amount into tax.tax_amount
+				tax.tax_amount += tax.tax_amount_for_current_item
+
+				if tax.category == "Valuation":
+					# if just for valuation, do not add the tax amount in total
+					# hence, setting it as 0 for further steps
+					current_tax_amount = 0
+				else:
+					current_tax_amount *= tax.add_deduct_tax == "Deduct" and -1.0 or 1.0
+
+				# Calculate tax.total viz. grand total till that step
+				# note: grand_total_for_current_item contains the contribution of 
+				# item's amount, previously applied tax and the current tax on that item
+				if i==0:
+					tax.grand_total_for_current_item = flt(item.amount +
+						current_tax_amount, self.precision.tax.total)
+
+				else:
+					tax.grand_total_for_current_item = \
+						flt(self.tax_doclist[i-1].grand_total_for_current_item +
+							current_tax_amount, self.precision.tax.total)
+
+				# in tax.total, accumulate grand total of each item
+				tax.total += tax.grand_total_for_current_item
+
+				# store tax_breakup for each item
+				# DOUBT: should valuation type amount also be stored?
+				tax.item_wise_tax_detail[item.item_code] = current_tax_amount
+		
+	def calculate_totals(self):
+		if self.tax_doclist:
+			self.doc.grand_total = flt(self.tax_doclist[-1].total,
+				self.precision.main.grand_total)
+			self.doc.grand_total_import = flt(
+				self.doc.grand_total / self.doc.conversion_rate,
+				self.precision.main.grand_total_import)
+		else:
+			self.doc.grand_total = flt(self.doc.net_total,
+				self.precision.main.grand_total)
+			self.doc.grand_total_print = flt(
+				self.doc.grand_total / self.doc.conversion_rate,
+				self.precision.main.grand_total_import)
+
+		self.doc.total_tax = \
+			flt(self.doc.grand_total - self.doc.net_total,
+			self.precision.main.total_tax)
+
+		if self.meta.get_field("rounded_total"):
+			self.doc.rounded_total = round(self.doc.grand_total)
+		
+		if self.meta.get_field("rounded_total_import"):
+			self.doc.rounded_total_import = round(self.doc.grand_total_import)
+			
+	def calculate_outstanding_amount(self):
+		if self.doc.doctype == "Purchase Invoice" and self.doc.docstatus == 0:
+			self.doc.total_advance = flt(self.doc.total_advance,
+				self.precision.main.total_advance)
+			self.doc.outstanding_amount = flt(self.doc.grand_total - self.doc.total_advance,
+				self.precision.main.outstanding_amount)
+			
+	def _cleanup(self):
+		for tax in self.tax_doclist:
+			del tax.fields["grand_total_for_current_item"]
+			del tax.fields["tax_amount_for_current_item"]
+			tax.item_wise_tax_detail = json.dumps(tax.item_wise_tax_detail)
+		
+		# except in purchase invoice, rate field is purchase_rate
+		if self.doc.doctype != "Purchase Invoice":
+			for item in self.item_doclist:
+				item.purchase_rate = item.rate
+				del item.fields["rate"]
+		
+	def validate_on_previous_row(self, tax):
+		"""
+			validate if a valid row id is mentioned in case of
+			On Previous Row Amount and On Previous Row Total
+		"""
+		if tax.charge_type in ["On Previous Row Amount", "On Previous Row Total"] and \
+				(not tax.row_id or cint(tax.row_id) >= tax.idx):
+			msgprint((_("Row") + " # %(idx)s [%(taxes_doctype)s]: " + \
+				_("Please specify a valid") + " %(row_id_label)s") % {
+					"idx": tax.idx,
+					"taxes_doctype": tax.parenttype,
+					"row_id_label": self.meta.get_label("row_id",
+						parentfield="purchase_tax_details")
+				}, raise_exception=True)
+				
+	def _load_item_tax_rate(self, item_tax_rate):
+		if not item_tax_rate:
+			return {}
+		return json.loads(item_tax_rate)
+		
+	def get_current_tax_amount(self, item, tax, item_tax_map):
+		tax_rate = self._get_tax_rate(tax, item_tax_map)
+
+		if tax.charge_type == "Actual":
+			# distribute the tax amount proportionally to each item row
+			actual = flt(tax.rate, self.precision.tax.tax_amount)
+			current_tax_amount = (self.doc.net_total
+				and ((item.amount / self.doc.net_total) * actual)
+				or 0)
+		elif tax.charge_type == "On Net Total":
+			current_tax_amount = (tax_rate / 100.0) * item.amount
+		elif tax.charge_type == "On Previous Row Amount":
+			current_tax_amount = (tax_rate / 100.0) * \
+				self.tax_doclist[cint(tax.row_id) - 1].tax_amount_for_current_item
+		elif tax.charge_type == "On Previous Row Total":
+			current_tax_amount = (tax_rate / 100.0) * \
+				self.tax_doclist[cint(tax.row_id) - 1].grand_total_for_current_item
+
+		return flt(current_tax_amount, self.precision.tax.tax_amount)
+		
+	def _get_tax_rate(self, tax, item_tax_map):
+		if item_tax_map.has_key(tax.account_head):
+			return flt(item_tax_map.get(tax.account_head), self.precision.tax.rate)
+		else:
+			return tax.rate
+			
+	def set_item_tax_amount(self, item, tax, current_tax_amount):
+		"""
+			item_tax_amount is the total tax amount applied on that item
+			stored for valuation 
+			
+			TODO: rename item_tax_amount to valuation_tax_amount
+		"""
+		if tax.category in ["Valuation", "Valuation and Total"] and \
+				item.item_code in self.stock_items:
+			item.item_tax_amount += flt(current_tax_amount,
+				self.precision.item.item_tax_amount)
+	
+	@property
+	def stock_items(self):
+		if not hasattr(self, "_stock_items"):
+			item_codes = list(set(item.item_code for item in self.item_doclist))
+			self._stock_items = [r[0] for r in webnotes.conn.sql("""select name
+				from `tabItem` where name in (%s) and is_stock_item='Yes'""" % \
+				(", ".join((["%s"]*len(item_codes))),), item_codes)]
+
+		return self._stock_items
+		
+	@property
+	def precision(self):
+		if not hasattr(self, "_precision"):
+			self._precision = webnotes._dict()
+			self._precision.main = self.meta.get_precision_map()
+			self._precision.item = self.meta.get_precision_map(parentfield = self.fname)
+			if self.meta.get_field("purchase_tax_details"):
+				self._precision.tax = self.meta.get_precision_map(parentfield = \
+					"purchase_tax_details")
+		return self._precision
diff --git a/stock/doctype/purchase_receipt_item/purchase_receipt_item.txt b/stock/doctype/purchase_receipt_item/purchase_receipt_item.txt
index 2e5b219..fd73c87 100755
--- a/stock/doctype/purchase_receipt_item/purchase_receipt_item.txt
+++ b/stock/doctype/purchase_receipt_item/purchase_receipt_item.txt
@@ -1,8 +1,8 @@
 [
  {
-  "creation": "2013-01-30 12:49:56", 
+  "creation": "2013-02-07 08:28:23", 
   "docstatus": 0, 
-  "modified": "2013-02-07 10:50:00", 
+  "modified": "2013-02-08 14:06:15", 
   "modified_by": "Administrator", 
   "owner": "Administrator"
  }, 
@@ -407,7 +407,7 @@
   "print_width": "150px", 
   "read_only": 1, 
   "reqd": 0, 
-  "search_index": 1, 
+  "search_index": 0, 
   "width": "150px"
  }, 
  {