Major refactorings.

Introduce summaries.

services/summary.go

@@ -0,0 +1,74 @@
+package services
+
+import (
+	"math"
+	"time"
+
+	"github.com/jinzhu/gorm"
+	"github.com/n1try/wakapi/models"
+)
+
+type SummaryService struct {
+	Config           *models.Config
+	Db               *gorm.DB
+	HeartbeatService *HeartbeatService
+}
+
+func (srv *SummaryService) GetSummary(from, to time.Time, user *models.User) (*models.Summary, error) {
+	heartbeats, err := srv.HeartbeatService.GetAllWithin(from, to, user)
+	if err != nil {
+		return nil, err
+	}
+
+	summary := &models.Summary{
+		UserID:           user.ID,
+		FromTime:         &from,
+		ToTime:           &to,
+		Projects:         srv.aggregateBy(heartbeats, models.SummaryProject),
+		Languages:        srv.aggregateBy(heartbeats, models.SummaryLanguage),
+		Editors:          srv.aggregateBy(heartbeats, models.SummaryEditor),
+		OperatingSystems: srv.aggregateBy(heartbeats, models.SummaryOS),
+	}
+
+	return summary, nil
+}
+
+func (srv *SummaryService) aggregateBy(heartbeats []*models.Heartbeat, aggregationType uint8) []models.SummaryItem {
+	durations := make(map[string]time.Duration)
+
+	for i, h := range heartbeats {
+		var key string
+		switch aggregationType {
+		case models.SummaryProject:
+			key = h.Project
+		case models.SummaryEditor:
+			key = h.Editor
+		case models.SummaryLanguage:
+			key = h.Language
+		case models.SummaryOS:
+			key = h.OperatingSystem
+		}
+
+		if _, ok := durations[key]; !ok {
+			durations[key] = time.Duration(0)
+		}
+
+		if i == 0 {
+			continue
+		}
+
+		timePassed := h.Time.Time().Sub(heartbeats[i-1].Time.Time())
+		timeThresholded := math.Min(float64(timePassed), float64(time.Duration(2)*time.Minute))
+		durations[key] += time.Duration(int64(timeThresholded))
+	}
+
+	items := make([]models.SummaryItem, 0)
+	for k, v := range durations {
+		items = append(items, models.SummaryItem{
+			Key:   k,
+			Total: v / time.Second,
+		})
+	}
+
+	return items
+}