Implemented frontend

+ Graph Generation as images for frontend performance
+ A new decent style

lib/svc/service.go

@@ -1,9 +1,11 @@
 package svc
 
 import (
+	"bytes"
 	"fmt"
 	"time"
 
+	"github.com/wcharczuk/go-chart/v2"
 	"gorm.io/driver/sqlite"
 	"gorm.io/gorm"
 	"tea.chunkbyte.com/kato/drive-health/lib/config"
@@ -66,3 +68,114 @@ func RunLoggerService() {
 		}
 	}()
 }
+
+func GetDiskGraphImage(hddID int, newerThan *time.Time, olderThan *time.Time) (*bytes.Buffer, error) {
+	var hdd hardware.HardDrive
+	// Fetch by a combination of fields
+	q := db.Where("id = ?", hddID)
+
+	if newerThan == nil && olderThan == nil {
+		q = q.Preload("Temperatures")
+	} else {
+		q = q.Preload("Temperatures", "time_stamp < ? AND time_stamp > ?", newerThan, olderThan)
+	}
+
+	// Query for the instance
+	result := q.First(&hdd)
+	if result.Error != nil {
+		return nil, result.Error
+	}
+
+	// Prepare slices for X (time) and Y (temperature) values
+	var xValues []time.Time
+	var yValues []float64
+	for _, temp := range hdd.Temperatures {
+		xValues = append(xValues, temp.TimeStamp)
+		yValues = append(yValues, float64(temp.Temperature))
+	}
+
+	// Allocate a buffer for the graph image
+	graphImageBuffer := bytes.NewBuffer([]byte{})
+
+	// TODO: Graph dark theme
+
+	// Generate the chart
+	graph := chart.Chart{
+		Title: fmt.Sprintf("%s:%s[%s]", hdd.Name, hdd.Serial, hdd.Size),
+		TitleStyle: chart.Style{
+			FontSize: 14,
+		},
+
+		// TODO: Implement customizable sizing
+		Width: 1280,
+
+		Background: chart.Style{
+			Padding: chart.Box{
+				Top: 20, Right: 20, Bottom: 20, Left: 20,
+			},
+		},
+
+		XAxis: chart.XAxis{
+			Name: "Time",
+			ValueFormatter: func(v interface{}) string {
+				if ts, isValidTime := v.(float64); isValidTime {
+					t := time.Unix(int64(ts/1e9), 0)
+
+					return t.Format("Jan 2 2006, 15:04")
+				}
+
+				return ""
+			},
+			Style: chart.Style{},
+			GridMajorStyle: chart.Style{
+				StrokeColor: chart.ColorAlternateGray,
+				StrokeWidth: 0.5,
+			},
+			GridMinorStyle: chart.Style{
+				StrokeColor: chart.ColorAlternateGray.WithAlpha(64),
+				StrokeWidth: 0.25,
+			},
+		},
+		YAxis: chart.YAxis{
+			Name:  "Temperature (C)",
+			Style: chart.Style{},
+			GridMajorStyle: chart.Style{
+				StrokeColor: chart.ColorAlternateGray,
+				StrokeWidth: 0.5,
+			},
+			GridMinorStyle: chart.Style{
+				StrokeColor: chart.ColorAlternateGray.WithAlpha(64),
+				StrokeWidth: 0.25,
+			},
+		},
+		Series: []chart.Series{
+			chart.TimeSeries{
+				Name:    "Temperature",
+				XValues: xValues,
+				YValues: yValues,
+				Style: chart.Style{
+					StrokeColor: chart.ColorCyan,
+					StrokeWidth: 2.0,
+				},
+			},
+		},
+	}
+
+	// Add a legend to the chart
+	graph.Elements = []chart.Renderable{
+		chart.Legend(&graph, chart.Style{
+			Padding: chart.Box{
+				Top: 5, Right: 5, Bottom: 5, Left: 5,
+			},
+			FontSize: 10,
+		}),
+	}
+
+	// Render the chart into the byte buffer
+	err := graph.Render(chart.PNG, graphImageBuffer)
+	if err != nil {
+		return nil, err
+	}
+
+	return graphImageBuffer, nil
+}