add gross income and net tax to income page

internal/server/income.go

@@ -15,13 +15,25 @@ type Income struct {
 	Postings []posting.Posting `json:"postings"`
 }
 
+type Tax struct {
+	StartDate time.Time         `json:"start_date"`
+	EndDate   time.Time         `json:"end_date"`
+	Postings  []posting.Posting `json:"postings"`
+}
+
 func GetIncome(db *gorm.DB) gin.H {
-	var postings []posting.Posting
-	result := db.Where("account like ?", "Income:%").Order("date ASC").Find(&postings)
+	var incomePostings []posting.Posting
+	result := db.Where("account like ?", "Income:%").Order("date ASC").Find(&incomePostings)
 	if result.Error != nil {
 		log.Fatal(result.Error)
 	}
-	return gin.H{"income_timeline": computeIncomeTimeline(postings)}
+
+	var taxPostings []posting.Posting
+	result = db.Where("account = ?", "Tax").Order("date ASC").Find(&taxPostings)
+	if result.Error != nil {
+		log.Fatal(result.Error)
+	}
+	return gin.H{"income_timeline": computeIncomeTimeline(incomePostings), "tax_timeline": computeTaxTimeline(taxPostings)}
 }
 
 func computeIncomeTimeline(postings []posting.Posting) []Income {
@@ -45,3 +57,26 @@ func computeIncomeTimeline(postings []posting.Posting) []Income {
 	}
 	return incomes
 }
+
+func computeTaxTimeline(postings []posting.Posting) []Tax {
+	var taxes []Tax = make([]Tax, 0)
+
+	if len(postings) == 0 {
+		return taxes
+	}
+
+	var p posting.Posting
+	end := time.Now()
+	for start := utils.BeginningOfFinancialYear(postings[0].Date); start.Before(end); start = start.AddDate(1, 0, 0) {
+		yearEnd := utils.EndOfFinancialYear(start)
+		var currentMonthPostings []posting.Posting = make([]posting.Posting, 0)
+		for len(postings) > 0 && (postings[0].Date.Before(yearEnd) || postings[0].Date.Equal(start)) {
+			p, postings = postings[0], postings[1:]
+			currentMonthPostings = append(currentMonthPostings, p)
+		}
+
+		taxes = append(taxes, Tax{StartDate: start, EndDate: yearEnd, Postings: currentMonthPostings})
+
+	}
+	return taxes
+}

internal/utils/utils.go

@@ -15,6 +15,19 @@ func BTreeDescendFirstLessOrEqual[I btree.Item](tree *btree.BTree, item I) I {
 	return hit
 }
 
+func BeginningOfFinancialYear(date time.Time) time.Time {
+	beginningOfMonth := BeginningOfMonth(date)
+	if beginningOfMonth.Month() < time.April {
+		return beginningOfMonth.AddDate(-1, int(time.April-beginningOfMonth.Month()), 0)
+	} else {
+		return beginningOfMonth.AddDate(0, -int(beginningOfMonth.Month()-time.April), 0)
+	}
+}
+
+func EndOfFinancialYear(date time.Time) time.Time {
+	return EndOfMonth(BeginningOfFinancialYear(date).AddDate(0, 11, 0))
+}
+
 func BeginningOfMonth(date time.Time) time.Time {
 	return date.AddDate(0, 0, -date.Day()+1)
 }

web/src/income.ts

@@ -9,14 +9,26 @@ import {
   Income,
   Posting,
   restName,
+  setHtml,
   skipTicks,
   tooltip
 } from "./utils";
 
 export default async function () {
-  const { income_timeline: incomes } = await ajax("/api/income");
+  const { income_timeline: incomes, tax_timeline: taxes } = await ajax(
+    "/api/income"
+  );
   _.each(incomes, (i) => (i.timestamp = dayjs(i.date)));
   renderMonthlyInvestmentTimeline(incomes);
+
+  const grossIncome = _.sumBy(incomes, (i) =>
+    _.sumBy(i.postings, (p) => -p.amount)
+  );
+
+  const netTax = _.sumBy(taxes, (t) => _.sumBy(t.postings, (p) => p.amount));
+
+  setHtml("gross-income", formatCurrency(grossIncome));
+  setHtml("net-tax", formatCurrency(netTax));
 }
 
 function renderMonthlyInvestmentTimeline(incomes: Income[]) {

web/src/utils.ts

@@ -55,6 +55,12 @@ export interface Income {
   timestamp: dayjs.Dayjs;
 }
 
+export interface Tax {
+  start_date: string;
+  end_date: string;
+  postings: Posting[];
+}
+
 export function ajax(
   route: "/api/investment"
 ): Promise<{ postings: Posting[] }>;
@@ -74,6 +80,7 @@ export function ajax(route: "/api/allocation"): Promise<{
 }>;
 export function ajax(route: "/api/income"): Promise<{
   income_timeline: Income[];
+  tax_timeline: Tax[];
 }>;
 export async function ajax(route: string) {
   const response = await fetch(route);

web/static/index.html

@@ -129,6 +129,24 @@
         </div>
       </div>
     </section>
+    <section class="section tab-income">
+      <div class="container">
+        <nav class="level">
+          <div class="level-item has-text-centered">
+            <div>
+              <p class="heading">Gross Income</p>
+              <p class="d3-gross-income title"></p>
+            </div>
+          </div>
+          <div class="level-item has-text-centered">
+            <div>
+              <p class="heading">Net Tax</p>
+              <p class="d3-net-tax title"></p>
+            </div>
+          </div>
+        </nav>
+      </div>
+    </section>
     <section class="section tab-income">
       <div class="container is-fluid">
         <div class="columns">