Implemented the hardware service

+ Started working on web interface

lib/svc/service.go

@@ -0,0 +1,131 @@
+package svc
+
+import (
+	"encoding/gob"
+	"fmt"
+	"io"
+	"os"
+	"time"
+
+	"tea.chunkbyte.com/kato/drive-health/lib/config"
+	"tea.chunkbyte.com/kato/drive-health/lib/hardware"
+)
+
+// The path to where the snapshot database is located
+const SNAPSHOT_LIST_PATH = "./snapshots.dat"
+
+// A simple in-memory buffer for the history of snapshots
+var snapShotBuffer []*HardwareSnapshot
+
+// A snapshot in time of the current state of the harddrives
+type HardwareSnapshot struct {
+	TimeStamp time.Time
+	HDD       []*hardware.HardDrive
+}
+
+type Snapshots struct {
+	List []*HardwareSnapshot
+}
+
+// The function itterates through all hard disks and takes a snapshot of their state,
+// returns a struct which contains metadata as well as the harddrives themselves.
+func TakeHardwareSnapshot() (*HardwareSnapshot, error) {
+	drives, err := hardware.GetSystemHardDrives()
+	if err != nil {
+		return nil, err
+	}
+
+	snapShot := &HardwareSnapshot{
+		TimeStamp: time.Now(),
+		HDD:       []*hardware.HardDrive{},
+	}
+
+	for _, hdd := range drives {
+		hdd.GetTemperature(true)
+		snapShot.HDD = append(snapShot.HDD, hdd)
+	}
+
+	// Append to the in-memory listing
+	snapShotBuffer = append(snapShotBuffer, snapShot)
+
+	// Return the snapshot just in case there is any need to modify it,
+	// any modification to it will also affect the current buffer from memory.
+	return snapShot, nil
+}
+
+// The function wil check if the `.dat` file is present, if it is then it will load it into memory
+func UpdateHardwareSnapshotsFromFile() {
+	file, err := os.Open(SNAPSHOT_LIST_PATH)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return // File does not exist, no snapshots to load
+		}
+		panic(err) // Handle error according to your error handling policy
+	}
+	defer file.Close()
+
+	decoder := gob.NewDecoder(file)
+	var snapshots Snapshots
+	if err := decoder.Decode(&snapshots); err != nil {
+		if err == io.EOF {
+			return // End of file reached
+		}
+		panic(err) // Handle error according to your error handling policy
+	}
+
+	snapShotBuffer = snapshots.List
+
+	fmt.Printf("Loaded %v snapshots from .dat", len(snapShotBuffer))
+}
+
+// Get the list of snapshots that have been buffered in memory
+func GetHardwareSnapshot() []*HardwareSnapshot {
+	return snapShotBuffer
+}
+
+// Dump the current snapshot history from memory to file
+func SaveSnapshotsToFile() error {
+	file, err := os.Create(SNAPSHOT_LIST_PATH)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	encoder := gob.NewEncoder(file)
+	snapshots := Snapshots{List: snapShotBuffer}
+	if err := encoder.Encode(snapshots); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func RunService() {
+
+	// Snapshot taking routine
+	go func() {
+		for {
+			time.Sleep(time.Duration(config.GetConfiguration().DiskFetchFrequency) * time.Second)
+			data, err := TakeHardwareSnapshot()
+			if err != nil {
+				fmt.Printf("Hardware Fetch Error: %s", err)
+			} else {
+				fmt.Println("Got Snapshot for " + data.TimeStamp.Format("02/01/2006"))
+				for _, hdd := range data.HDD {
+					fmt.Printf("%s[%s]: %v\n", hdd.Model, hdd.Size, hdd.Temperature)
+				}
+			}
+		}
+	}()
+
+	// Periodic saving routine
+	go func() {
+		for {
+			time.Sleep(time.Duration(config.GetConfiguration().MemoryDumpFrequency) * time.Second)
+			err := SaveSnapshotsToFile()
+			if err != nil {
+				fmt.Printf("Memory Dump Error: %s", err)
+			}
+		}
+	}()
+}