Add PL/pgSQL functions to add and edit products

I am going to add similar functions for invoices, as i will need to
add the taxes for their products and their own taxes, thus the Go code
will begin to be “too much work” and i feel better if that is in
PL/pgSQL.

If i have these functions for invoices, there is no point on having to
do almost the same work, albeit less, for products.

deploy/add_product.sql

@@ -0,0 +1,39 @@
+-- Deploy numerus:add_product to pg
+-- requires: schema_numerus
+-- requires: product
+-- requires: product_tax
+-- requires: parse_price
+-- requires: company
+-- requires: currency
+
+begin;
+
+set search_path to numerus, public;
+
+create or replace function add_product(company_id integer, name text, description text, price text, taxes integer[]) returns uuid
+as $$
+declare
+	pid integer;
+	pslug uuid;
+begin
+	insert into product (company_id, name, description, price)
+	select add_product.company_id, add_product.name, add_product.description, parse_price(add_product.price, decimal_digits)
+	from company
+	join currency using (currency_code)
+	where company.company_id = add_product.company_id
+	returning product_id, slug
+	into pid, pslug;
+
+	insert into product_tax (product_id, tax_id)
+	select pid, tax_id
+	from unnest(taxes) as tax(tax_id);
+
+	return pslug;
+end;
+$$ language plpgsql;
+
+revoke execute on function add_product(integer, text, text, text, integer[]) from public;
+grant execute on function add_product(integer, text, text, text, integer[]) to invoicer;
+grant execute on function add_product(integer, text, text, text, integer[]) to admin;
+
+commit;

deploy/edit_product.sql

@@ -0,0 +1,47 @@
+-- Deploy numerus:edit_product to pg
+-- requires: schema_numerus
+-- requires: product
+-- requires: product_tax
+-- requires: parse_price
+-- requires: company
+-- requires: currency
+
+begin;
+
+set search_path to numerus, public;
+
+create or replace function edit_product(slug uuid, name text, description text, price text, taxes integer[]) returns boolean
+as $$
+declare
+	pid integer;
+begin
+	update product
+	set name = edit_product.name
+	  , description = edit_product.description
+	  , price = parse_price(edit_product.price, decimal_digits)
+	from company
+	join currency using (currency_code)
+	where product.company_id = company.company_id
+	  and product.slug = edit_product.slug
+	returning product_id
+	into pid;
+
+	if pid is null then
+		return false;
+	end if;
+
+	delete from product_tax where product_id = pid;
+
+	insert into product_tax(product_id, tax_id)
+	select pid, tax_id
+	from unnest(taxes) as tax(tax_id);
+
+	return true;
+end;
+$$ language plpgsql;
+
+revoke execute on function edit_product(uuid, text, text, text, integer[]) from public;
+grant execute on function edit_product(uuid, text, text, text, integer[]) to invoicer;
+grant execute on function edit_product(uuid, text, text, text, integer[]) to admin;
+
+commit;

pkg/db.go

@@ -90,6 +90,14 @@ func (c *Conn) MustGetText(ctx context.Context, def string, sql string, args ...
 	return result
 }
 
+func (c *Conn) MustGetBool(ctx context.Context, sql string, args ...interface{}) bool {
+	var result bool
+	if err := c.Conn.QueryRow(ctx, sql, args...).Scan(&result); err != nil {
+		panic(err)
+	}
+	return result
+}
+
 func (c *Conn) MustExec(ctx context.Context, sql string, args ...interface{}) {
 	if _, err := c.Conn.Exec(ctx, sql, args...); err != nil {
 		panic(err)

pkg/products.go

@@ -8,6 +8,7 @@ import (
 	"html/template"
 	"math"
 	"net/http"
+	"strconv"
 )
 
 type ProductEntry struct {
@@ -89,27 +90,31 @@ func HandleAddProduct(w http.ResponseWriter, r *http.Request, _ httprouter.Param
 		mustRenderNewProductForm(w, r, form)
 		return
 	}
-	tx := conn.MustBegin(r.Context())
+	taxes := mustSliceAtoi(form.Tax.Selected)
-	productId := tx.MustGetInteger(r.Context(), "insert into product (company_id, name, description, price) select company_id, $2, $3, parse_price($4, decimal_digits) from company join currency using (currency_code) where company_id = $1 returning product_id", company.Id, form.Name, form.Description, form.Price)
+	conn.MustExec(r.Context(), "select add_product($1, $2, $3, $4, $5)", company.Id, form.Name, form.Description, form.Price, taxes)
-	if len(form.Tax.Selected) > 0 {
-		batch := &pgx.Batch{}
-		for _, tax := range form.Tax.Selected {
-			batch.Queue("insert into product_tax(product_id, tax_id) values ($1, $2)", productId, tax)
-		}
-		br := tx.SendBatch(r.Context(), batch)
-		for range form.Tax.Selected {
-			if _, err := br.Exec(); err != nil {
-				panic(err)
-			}
-		}
-		if err := br.Close(); err != nil {
-			panic(err)
-		}
-	}
-	tx.MustCommit(r.Context())
 	http.Redirect(w, r, companyURI(company, "/products"), http.StatusSeeOther)
 }
 
+func sliceAtoi(s []string) ([]int, error) {
+	i := []int{}
+	for _, vs := range s {
+		vi, err := strconv.Atoi(vs)
+		if err != nil {
+			return i, err
+		}
+		i = append(i, vi)
+	}
+	return i, nil
+}
+
+func mustSliceAtoi(s []string) []int {
+	i, err := sliceAtoi(s)
+	if err != nil {
+		panic(err)
+	}
+	return i
+}
+
 func HandleUpdateProduct(w http.ResponseWriter, r *http.Request, params httprouter.Params) {
 	conn := getConn(r)
 	locale := getLocale(r)
@@ -128,28 +133,11 @@ func HandleUpdateProduct(w http.ResponseWriter, r *http.Request, params httprout
 		mustRenderEditProductForm(w, r, form)
 		return
 	}
-	tx := conn.MustBegin(r.Context())
 	slug := params[0].Value
-	productId := tx.MustGetIntegerOrDefault(r.Context(), 0, "update product set name = $1, description = $2, price = parse_price($3, decimal_digits) from company join currency using (currency_code) where product.company_id = company.company_id and product.slug = $4 returning product_id", form.Name, form.Description, form.Price, slug)
+	taxes := mustSliceAtoi(form.Tax.Selected)
-	if productId == 0 {
+	if ok := conn.MustGetBool(r.Context(), "select edit_product($1, $2, $3, $4, $5)", slug, form.Name, form.Description, form.Price, taxes); !ok {
-		tx.MustRollback(r.Context())
 		http.NotFound(w, r)
 	}
-	batch := &pgx.Batch{}
-	batch.Queue("delete from product_tax where product_id = $1", productId)
-	for _, tax := range form.Tax.Selected {
-		batch.Queue("insert into product_tax(product_id, tax_id) values ($1, $2)", productId, tax)
-	}
-	br := tx.SendBatch(r.Context(), batch)
-	for i := 0; i < batch.Len(); i++ {
-		if _, err := br.Exec(); err != nil {
-			panic(err)
-		}
-	}
-	if err := br.Close(); err != nil {
-		panic(err)
-	}
-	tx.MustCommit(r.Context())
 	http.Redirect(w, r, companyURI(company, "/products/"+slug), http.StatusSeeOther)
 }
 

revert/add_product.sql

@@ -0,0 +1,7 @@
+-- Revert numerus:add_product from pg
+
+begin;
+
+drop function if exists numerus.add_product(integer, text, text, text, integer[]);
+
+commit;

revert/edit_product.sql

@@ -0,0 +1,7 @@
+-- Revert numerus:edit_product from pg
+
+begin;
+
+drop function if exists numerus.edit_product(uuid, text, text, text, integer[]);
+
+commit;

sqitch.plan

@@ -49,3 +49,5 @@ product_tax [schema_numerus product tax] 2023-02-08T11:36:49Z jordi fita mas <jo
 invoice [schema_numerus company contact invoice_status currency] 2023-02-09T09:52:21Z jordi fita mas <jordi@tandem.blog> # Add relation for invoice
 discount_rate [schema_numerus] 2023-02-10T17:22:40Z jordi fita mas <jordi@tandem.blog> # Add domain for discount rates
 invoice_product [schema_numerus invoice discount_rate] 2023-02-10T17:07:08Z jordi fita mas <jordi@tandem.blog> # Add relation for invoice product
+add_product [schema_numerus product product_tax parse_price company currency] 2023-02-14T10:32:18Z jordi fita mas <jordi@tandem.blog> # Add function to add new products
+edit_product [schema_numerus product product_tax parse_price company currency] 2023-02-14T11:06:03Z jordi fita mas <jordi@tandem.blog> # Add function to edit products

test/add_product.sql

@@ -0,0 +1,80 @@
+-- Test add_product
+set client_min_messages to warning;
+create extension if not exists pgtap;
+reset client_min_messages;
+
+begin;
+
+select plan(14);
+
+set search_path to auth, numerus, public;
+
+select has_function('numerus', 'add_product', array ['integer', 'text', 'text', 'text', 'integer[]']);
+select function_lang_is('numerus', 'add_product', array ['integer', 'text', 'text', 'text', 'integer[]'], 'plpgsql');
+select function_returns('numerus', 'add_product', array ['integer', 'text', 'text', 'text', 'integer[]'], 'uuid');
+select isnt_definer('numerus', 'add_product', array ['integer', 'text', 'text', 'text', 'integer[]']);
+select volatility_is('numerus', 'add_product', array ['integer', 'text', 'text', 'text', 'integer[]'], 'volatile');
+select function_privs_are('numerus', 'add_product', array ['integer', 'text', 'text', 'text', 'integer[]'], 'guest', array []::text[]);
+select function_privs_are('numerus', 'add_product', array ['integer', 'text', 'text', 'text', 'integer[]'], 'invoicer', array ['EXECUTE']);
+select function_privs_are('numerus', 'add_product', array ['integer', 'text', 'text', 'text', 'integer[]'], 'admin', array ['EXECUTE']);
+select function_privs_are('numerus', 'add_product', array ['integer', 'text', 'text', 'text', 'integer[]'], 'authenticator', array []::text[]);
+
+
+set client_min_messages to warning;
+truncate product_tax cascade;
+truncate product cascade;
+truncate tax cascade;
+truncate company cascade;
+reset client_min_messages;
+
+
+insert into company (company_id, business_name, vatin, trade_name, phone, email, web, address, city, province, postal_code, country_code, currency_code)
+values (1, 'Company 2', 'XX123', '', '555-555-555', 'a@a', '', '', '', '', '', 'ES', 'EUR')
+     , (2, 'Company 4', 'XX234', '', '666-666-666', 'b@b', '', '', '', '', '', 'FR', 'USD')
+;
+
+insert into tax (tax_id, company_id, name, rate)
+values (3, 1, 'IRPF -15 %', -0.15)
+     , (4, 1, 'IVA 21 %', 0.21)
+     , (5, 2, 'IRPF -7 %', -0.07)
+     , (6, 2, 'IVA 10 %', 0.10)
+;
+
+
+select lives_ok(
+	$$ select add_product(1, 'Product 1', 'Description 1', '12.12', array[3, 4]) $$,
+	'Should be able to add product to first company'
+);
+
+select lives_ok(
+	$$ select add_product(2, 'Product 2', 'Description 2', '24.24', array[6]) $$,
+	'Should be able to add product to second company'
+);
+
+select lives_ok(
+	$$ select add_product(2, 'Product 3', 'Description 3', '36.36', array[]::integer[]) $$,
+	'Should be able to add product without taxes'
+);
+
+select bag_eq(
+	$$ select company_id, name, description, price, created_at from product $$,
+	$$ values (1, 'Product 1', 'Description 1', 1212, current_timestamp)
+	        , (2, 'Product 2', 'Description 2', 2424, current_timestamp)
+		, (2, 'Product 3', 'Description 3', 3636, current_timestamp)
+	$$,
+	'Should have added all three products'
+);
+
+select bag_eq(
+	$$ select tax_id, name from product_tax join product using (product_id) $$,
+	$$ values (3, 'Product 1')
+	        , (4, 'Product 1')
+		, (6, 'Product 2')
+	$$,
+	'Should have added the taxes for the products we told to'
+);
+
+select *
+from finish();
+
+rollback;

test/edit_product.sql

@@ -0,0 +1,101 @@
+-- Test edit_product
+set client_min_messages to warning;
+create extension if not exists pgtap;
+reset client_min_messages;
+
+begin;
+
+select plan(15);
+
+set search_path to auth, numerus, public;
+
+select has_function('numerus', 'edit_product', array ['uuid', 'text', 'text', 'text', 'integer[]']);
+select function_lang_is('numerus', 'edit_product', array ['uuid', 'text', 'text', 'text', 'integer[]'], 'plpgsql');
+select function_returns('numerus', 'edit_product', array ['uuid', 'text', 'text', 'text', 'integer[]'], 'boolean');
+select isnt_definer('numerus', 'edit_product', array ['uuid', 'text', 'text', 'text', 'integer[]']);
+select volatility_is('numerus', 'edit_product', array ['uuid', 'text', 'text', 'text', 'integer[]'], 'volatile');
+select function_privs_are('numerus', 'edit_product', array ['uuid', 'text', 'text', 'text', 'integer[]'], 'guest', array []::text[]);
+select function_privs_are('numerus', 'edit_product', array ['uuid', 'text', 'text', 'text', 'integer[]'], 'invoicer', array ['EXECUTE']);
+select function_privs_are('numerus', 'edit_product', array ['uuid', 'text', 'text', 'text', 'integer[]'], 'admin', array ['EXECUTE']);
+select function_privs_are('numerus', 'edit_product', array ['uuid', 'text', 'text', 'text', 'integer[]'], 'authenticator', array []::text[]);
+
+
+set client_min_messages to warning;
+truncate product_tax cascade;
+truncate product cascade;
+truncate tax cascade;
+truncate company cascade;
+reset client_min_messages;
+
+
+insert into company (company_id, business_name, vatin, trade_name, phone, email, web, address, city, province, postal_code, country_code, currency_code)
+values (1, 'Company 2', 'XX123', '', '555-555-555', 'a@a', '', '', '', '', '', 'ES', 'EUR')
+     , (2, 'Company 4', 'XX234', '', '666-666-666', 'b@b', '', '', '', '', '', 'FR', 'USD')
+;
+
+insert into tax (tax_id, company_id, name, rate)
+values (3, 1, 'IRPF -15 %', -0.15)
+     , (4, 1, 'IVA 21 %', 0.21)
+     , (5, 2, 'IRPF -7 %', -0.07)
+     , (6, 2, 'IVA 10 %', 0.10)
+;
+
+insert into product (product_id, company_id, slug, name, description, price)
+values (7, 1, 'd2300404-bd23-48b3-8e2b-2bbf86dc7bd6', 'Product 01', 'Description01', 1200)
+     , (8, 2, '2f085b8b-da90-41fe-b8cf-6ba8d94cfa38', 'Product 02', 'Description02', 2400)
+     , (9, 2, '84044d0b-af33-442a-95a6-21efc77260d5', 'Product 03', 'Description03', 3600)
+;
+
+insert into product_tax (product_id, tax_id)
+values (7, 3)
+     , (8, 5)
+     , (9, 5)
+     , (9, 6)
+;
+
+select is(
+	edit_product('d2300404-bd23-48b3-8e2b-2bbf86dc7bd6', 'Product 1', 'Description 1', '12.12', array[3, 4]),
+	true,
+	'Should be able to edit product from first company'
+);
+
+select is(
+	edit_product('2f085b8b-da90-41fe-b8cf-6ba8d94cfa38', 'Product 2', 'Description 2', '24.24', array[6]),
+	true,
+	'Should be able to edit product from second company'
+);
+
+select is(
+	edit_product('84044d0b-af33-442a-95a6-21efc77260d5', 'Product 3', 'Description 3', '36.36', array[]::integer[]),
+	true,
+	'Should be able to edit a product a remove all taxes'
+);
+
+select is(
+	edit_product('87e158d1-a0f5-48a7-854b-b86d7b4bb21c', 'Product 4', 'Description 4', '48.48', array[]::integer[]),
+	false,
+	'Should return false when the product does not exist'
+);
+
+select bag_eq(
+	$$ select product_id, company_id, name, description, price from product $$,
+	$$ values (7, 1, 'Product 1', 'Description 1', 1212)
+	        , (8, 2, 'Product 2', 'Description 2', 2424)
+		, (9, 2, 'Product 3', 'Description 3', 3636)
+	$$,
+	'Should have edited all three products'
+);
+
+select bag_eq(
+	$$ select product_id, tax_id from product_tax $$,
+	$$ values (7, 3)
+	        , (7, 4)
+		, (8, 6)
+	$$,
+	'Should have updated the taxes for the products we told to'
+);
+
+select *
+from finish();
+
+rollback;

test/product_tax.sql

@@ -33,8 +33,8 @@ select col_hasnt_default('product_tax', 'tax_id');
 
 
 set client_min_messages to warning;
-truncate product cascade;
 truncate product_tax cascade;
+truncate product cascade;
 truncate tax cascade;
 truncate company_user cascade;
 truncate company cascade;

verify/add_product.sql

@@ -0,0 +1,7 @@
+-- Verify numerus:add_product on pg
+
+begin;
+
+select has_function_privilege('numerus.add_product(integer, text, text, text, integer[])', 'execute');
+
+rollback;

verify/edit_product.sql

@@ -0,0 +1,7 @@
+-- Verify numerus:edit_product on pg
+
+begin;
+
+select has_function_privilege('numerus.edit_product(uuid, text, text, text, integer[])', 'execute');
+
+rollback;