enhance timeline data

apps/api/internal/service/event.go

@@ -10,6 +10,7 @@ import (
 	"net/http"
 	"slices"
 	"sort"
+	"time"
 
 	"github.com/google/uuid"
 
@@ -121,21 +122,24 @@ func (s *Event) fetchAvatar(ctx context.Context, url string) (*http.Response, er
 
 func (s *Event) calculateDailyFollowerChanges(events []model.AggregatedEvent) []dto.DailyFollowerChange {
 	dailyChangesMap := s.calculateDailyFollowerChangesMap(events)
+	startDate := events[0].Date
+	endDate := time.Now()
+	fullChangesMap := s.fillDailyFollowerChangesGaps(startDate, endDate, dailyChangesMap)
 
-	result := slices.Collect(maps.Values(dailyChangesMap))
+	result := slices.Collect(maps.Values(fullChangesMap))
 	sort.Slice(result, func(i, j int) bool {
 		return result[i].Date.Before(result[j].Date)
 	})
 
 	return result
 }
 
-func (s *Event) calculateDailyFollowerChangesMap(events []model.AggregatedEvent) map[int64]dto.DailyFollowerChange {
+func (s *Event) calculateDailyFollowerChangesMap(events []model.AggregatedEvent) map[string]dto.DailyFollowerChange {
 	totalFollowers := 0
-	dailyChanges := make(map[int64]dto.DailyFollowerChange, len(events))
+	dailyChanges := make(map[string]dto.DailyFollowerChange, len(events))
 
 	for _, event := range events {
-		index := event.Date.Unix()
+		index := event.Date.Format("2006-01-02")
 
 		change, ok := dailyChanges[index]
 		if !ok {
@@ -159,3 +163,30 @@ func (s *Event) calculateDailyFollowerChangesMap(events []model.AggregatedEvent)
 
 	return dailyChanges
 }
+
+func (s *Event) fillDailyFollowerChangesGaps(
+	startDate time.Time,
+	endDate time.Time,
+	dailyChanges map[string]dto.DailyFollowerChange,
+) map[string]dto.DailyFollowerChange {
+	timeline := make(map[string]dto.DailyFollowerChange)
+	lastTotalFollowers := 0
+
+	for currentDate := startDate; !currentDate.After(endDate); currentDate = currentDate.AddDate(0, 0, 1) {
+		dateKey := currentDate.Format("2006-01-02")
+
+		if change, exists := dailyChanges[dateKey]; exists {
+			timeline[dateKey] = change
+			lastTotalFollowers = change.Total
+
+			continue
+		}
+
+		timeline[dateKey] = dto.DailyFollowerChange{
+			Date:  currentDate,
+			Total: lastTotalFollowers,
+		}
+	}
+
+	return timeline
+}

libs/chart/src/components/axis.ts

@@ -18,15 +18,16 @@ function addAxis(
     .attr('transform', `translate(0,${height - margins.bottom})`)
     .call(
       d3
-        .axisBottom(xScale)
-        .ticks(width / 80)
+        .axisBottom<Date>(xScale)
+        .ticks(width / 50)
+        .tickFormat(d3.timeFormat('%d %b'))
         .tickSizeOuter(0)
     );
 
   svg
     .append('g')
     .attr('transform', `translate(${margins.left},0)`)
-    .call(d3.axisLeft(yScale).ticks(height / 40));
+    .call(d3.axisLeft(yScale).ticks(height / 50));
 }
 
 export { addAxis };