Merge pull request #38298 from ruthra-kumar/simplied_purchase_cost_update

perf: optimize update_purchase_cost method 
diff --git a/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.py b/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.py
index d7c2361..c6ae937 100644
--- a/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.py
+++ b/erpnext/accounts/doctype/purchase_invoice/purchase_invoice.py
@@ -527,7 +527,11 @@
 		if self.update_stock == 1:
 			self.repost_future_sle_and_gle()
 
-		self.update_project()
+		if (
+			frappe.db.get_single_value("Buying Settings", "project_update_frequency") == "Each Transaction"
+		):
+			self.update_project()
+
 		update_linked_doc(self.doctype, self.name, self.inter_company_invoice_reference)
 		self.update_advance_tax_references()
 
@@ -1262,7 +1266,10 @@
 		if self.update_stock == 1:
 			self.repost_future_sle_and_gle()
 
-		self.update_project()
+		if (
+			frappe.db.get_single_value("Buying Settings", "project_update_frequency") == "Each Transaction"
+		):
+			self.update_project()
 		self.db_set("status", "Cancelled")
 
 		unlink_inter_company_doc(self.doctype, self.name, self.inter_company_invoice_reference)
@@ -1281,13 +1288,21 @@
 		self.update_advance_tax_references(cancel=1)
 
 	def update_project(self):
-		project_list = []
+		projects = frappe._dict()
 		for d in self.items:
-			if d.project and d.project not in project_list:
-				project = frappe.get_doc("Project", d.project)
-				project.update_purchase_costing()
-				project.db_update()
-				project_list.append(d.project)
+			if d.project:
+				if self.docstatus == 1:
+					projects[d.project] = projects.get(d.project, 0) + d.base_net_amount
+				elif self.docstatus == 2:
+					projects[d.project] = projects.get(d.project, 0) - d.base_net_amount
+
+		pj = frappe.qb.DocType("Project")
+		for proj, value in projects.items():
+			res = (
+				frappe.qb.from_(pj).select(pj.total_purchase_cost).where(pj.name == proj).for_update().run()
+			)
+			current_purchase_cost = res and res[0][0] or 0
+			frappe.db.set_value("Project", proj, "total_purchase_cost", current_purchase_cost + value)
 
 	def validate_supplier_invoice(self):
 		if self.bill_date:
diff --git a/erpnext/buying/doctype/buying_settings/buying_settings.json b/erpnext/buying/doctype/buying_settings/buying_settings.json
index 0599992..0af93bf 100644
--- a/erpnext/buying/doctype/buying_settings/buying_settings.json
+++ b/erpnext/buying/doctype/buying_settings/buying_settings.json
@@ -17,6 +17,7 @@
   "po_required",
   "pr_required",
   "blanket_order_allowance",
+  "project_update_frequency",
   "column_break_12",
   "maintain_same_rate",
   "set_landed_cost_based_on_purchase_invoice_rate",
@@ -172,6 +173,14 @@
    "fieldname": "blanket_order_allowance",
    "fieldtype": "Float",
    "label": "Blanket Order Allowance (%)"
+  },
+  {
+   "default": "Each Transaction",
+   "description": "How often should Project be updated of Total Purchase Cost ?",
+   "fieldname": "project_update_frequency",
+   "fieldtype": "Select",
+   "label": "Update frequency of Project",
+   "options": "Each Transaction\nManual"
   }
  ],
  "icon": "fa fa-cog",
@@ -179,7 +188,7 @@
  "index_web_pages_for_search": 1,
  "issingle": 1,
  "links": [],
- "modified": "2023-10-25 14:03:32.520418",
+ "modified": "2023-11-24 10:55:51.287327",
  "modified_by": "Administrator",
  "module": "Buying",
  "name": "Buying Settings",
diff --git a/erpnext/patches.txt b/erpnext/patches.txt
index 8e091d4..a73502d 100644
--- a/erpnext/patches.txt
+++ b/erpnext/patches.txt
@@ -351,5 +351,6 @@
 erpnext.patches.v15_0.set_reserved_stock_in_bin
 erpnext.patches.v14_0.create_accounting_dimensions_in_supplier_quotation
 erpnext.patches.v14_0.update_zero_asset_quantity_field
+execute:frappe.db.set_single_value("Buying Settings", "project_update_frequency", "Each Transaction")
 # below migration patch should always run last
 erpnext.patches.v14_0.migrate_gl_to_payment_ledger
diff --git a/erpnext/projects/doctype/project/project.js b/erpnext/projects/doctype/project/project.js
index f366f77..2dac399 100644
--- a/erpnext/projects/doctype/project/project.js
+++ b/erpnext/projects/doctype/project/project.js
@@ -68,6 +68,10 @@
 				frm.events.create_duplicate(frm);
 			}, __("Actions"));
 
+			frm.add_custom_button(__('Update Total Purchase Cost'), () => {
+				frm.events.update_total_purchase_cost(frm);
+			}, __("Actions"));
+
 			frm.trigger("set_project_status_button");
 
 
@@ -92,6 +96,22 @@
 
 	},
 
+	update_total_purchase_cost: function(frm) {
+		frappe.call({
+			method: "erpnext.projects.doctype.project.project.recalculate_project_total_purchase_cost",
+			args: {project: frm.doc.name},
+			freeze: true,
+			freeze_message: __('Recalculating Purchase Cost against this Project...'),
+			callback: function(r) {
+				if (r && !r.exc) {
+					frappe.msgprint(__('Total Purchase Cost has been updated'));
+					frm.refresh();
+				}
+			}
+
+		});
+	},
+
 	set_project_status_button: function(frm) {
 		frm.add_custom_button(__('Set Project Status'), () => {
 			let d = new frappe.ui.Dialog({
diff --git a/erpnext/projects/doctype/project/project.py b/erpnext/projects/doctype/project/project.py
index e9aed1a..4f2e395 100644
--- a/erpnext/projects/doctype/project/project.py
+++ b/erpnext/projects/doctype/project/project.py
@@ -4,11 +4,11 @@
 
 import frappe
 from email_reply_parser import EmailReplyParser
-from frappe import _
+from frappe import _, qb
 from frappe.desk.reportview import get_match_cond
 from frappe.model.document import Document
 from frappe.query_builder import Interval
-from frappe.query_builder.functions import Count, CurDate, Date, UnixTimestamp
+from frappe.query_builder.functions import Count, CurDate, Date, Sum, UnixTimestamp
 from frappe.utils import add_days, flt, get_datetime, get_time, get_url, nowtime, today
 from frappe.utils.user import is_website_user
 
@@ -249,12 +249,7 @@
 			self.per_gross_margin = (self.gross_margin / flt(self.total_billed_amount)) * 100
 
 	def update_purchase_costing(self):
-		total_purchase_cost = frappe.db.sql(
-			"""select sum(base_net_amount)
-			from `tabPurchase Invoice Item` where project = %s and docstatus=1""",
-			self.name,
-		)
-
+		total_purchase_cost = calculate_total_purchase_cost(self.name)
 		self.total_purchase_cost = total_purchase_cost and total_purchase_cost[0][0] or 0
 
 	def update_sales_amount(self):
@@ -695,3 +690,29 @@
 
 def get_users_email(doc):
 	return [d.email for d in doc.users if frappe.db.get_value("User", d.user, "enabled")]
+
+
+def calculate_total_purchase_cost(project: str | None = None):
+	if project:
+		pitem = qb.DocType("Purchase Invoice Item")
+		frappe.qb.DocType("Purchase Invoice Item")
+		total_purchase_cost = (
+			qb.from_(pitem)
+			.select(Sum(pitem.base_net_amount))
+			.where((pitem.project == project) & (pitem.docstatus == 1))
+			.run(as_list=True)
+		)
+		return total_purchase_cost
+	return None
+
+
+@frappe.whitelist()
+def recalculate_project_total_purchase_cost(project: str | None = None):
+	if project:
+		total_purchase_cost = calculate_total_purchase_cost(project)
+		frappe.db.set_value(
+			"Project",
+			project,
+			"total_purchase_cost",
+			(total_purchase_cost and total_purchase_cost[0][0] or 0),
+		)