Hosts and settings

internal/app/hosts.go

@@ -0,0 +1,190 @@
+package app
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/wailsapp/wails/v2/pkg/runtime"
+	"go.mongodb.org/mongo-driver/mongo"
+	mongoOptions "go.mongodb.org/mongo-driver/mongo/options"
+)
+
+// {
+// 	"3b7e3926-03ce-4407-bc3f-85ed2f01ee42": {
+// 		"name": "Localhost",
+// 		"uri": "mongodb://localhost:27017"
+// 	}
+// }
+
+type Host struct {
+	Name string `json:"name"`
+	URI  string `json:"uri"`
+}
+
+func updateHostsFile(newData map[string]Host) error {
+	filePath, err := appDataFilePath("hosts.json")
+	if err != nil {
+		return err
+	}
+
+	jsonData, err := json.MarshalIndent(newData, "", "\t")
+	if err != nil {
+		return err
+	}
+
+	err = ioutil.WriteFile(filePath, jsonData, os.ModePerm)
+	return err
+}
+
+func (a *App) Hosts() (map[string]Host, error) {
+	filePath, err := appDataFilePath("hosts.json")
+	if err != nil {
+		fmt.Println(err.Error())
+		return nil, err
+	}
+
+	jsonData, err := ioutil.ReadFile(filePath)
+	if err != nil {
+		// It's ok if the file cannot be opened, for example if it is not accessible.
+		// Therefore no error is returned.
+		fmt.Println(err.Error())
+		return make(map[string]Host, 0), nil
+	}
+
+	if len(jsonData) == 0 {
+		return make(map[string]Host, 0), nil
+	} else {
+		var hosts map[string]Host
+		err = json.Unmarshal(jsonData, &hosts)
+
+		if err != nil {
+			fmt.Println(err.Error())
+			return nil, errors.New("host.json file contains malformatted JSON data")
+		}
+		return hosts, nil
+	}
+}
+
+func (a *App) AddHost(jsonData string) error {
+	hosts, err := a.Hosts()
+	if err != nil {
+		runtime.MessageDialog(a.ctx, runtime.MessageDialogOptions{
+			Type:  runtime.InfoDialog,
+			Title: "Could not retrieve hosts",
+		})
+		return errors.New("could not retrieve existing host list")
+	}
+
+	var newHost Host
+	err = json.Unmarshal([]byte(jsonData), &newHost)
+	if err != nil {
+		runtime.MessageDialog(a.ctx, runtime.MessageDialogOptions{
+			Type:  runtime.InfoDialog,
+			Title: "Malformed JSON",
+		})
+		return errors.New("could not retrieve existing host list")
+	}
+
+	id, err := uuid.NewRandom()
+	if err != nil {
+		runtime.MessageDialog(a.ctx, runtime.MessageDialogOptions{
+			Type:  runtime.InfoDialog,
+			Title: "Failed to generate a UUID",
+		})
+		return errors.New("could not generate a UUID")
+	}
+
+	fmt.Println(hosts)
+
+	hosts[id.String()] = newHost
+	err = updateHostsFile(hosts)
+	if err != nil {
+		runtime.MessageDialog(a.ctx, runtime.MessageDialogOptions{
+			Type:  runtime.InfoDialog,
+			Title: "Could not update host list",
+		})
+		return errors.New("could not update host list")
+	}
+
+	return nil
+}
+
+func (a *App) RemoveHost(key string) error {
+	hosts, err := a.Hosts()
+	if err != nil {
+		runtime.MessageDialog(a.ctx, runtime.MessageDialogOptions{
+			Type:  runtime.InfoDialog,
+			Title: "Could not retrieve hosts",
+		})
+		return errors.New("could not retrieve existing host list")
+	}
+
+	sure, _ := runtime.MessageDialog(a.ctx, runtime.MessageDialogOptions{
+		Title:         "Confirm",
+		Message:       "Are you sure you want to remove " + key + "?",
+		Buttons:       []string{"Yes", "No"},
+		DefaultButton: "Yes",
+		CancelButton:  "No",
+	})
+	if sure != "Yes" {
+		return errors.New("operation aborted")
+	}
+
+	delete(hosts, key)
+	err = updateHostsFile(hosts)
+
+	if err != nil {
+		runtime.MessageDialog(a.ctx, runtime.MessageDialogOptions{
+			Type:  runtime.InfoDialog,
+			Title: "Could not update host list",
+		})
+		return errors.New("could not update host list")
+	}
+	return nil
+}
+
+func (a *App) connectToHost(hostKey string) (*mongo.Client, context.Context, func(), error) {
+	hosts, err := a.Hosts()
+	if err != nil {
+		runtime.MessageDialog(a.ctx, runtime.MessageDialogOptions{
+			Type:  runtime.InfoDialog,
+			Title: "Could not retrieve hosts",
+		})
+		return nil, nil, nil, errors.New("could not retrieve hosts")
+	}
+
+	h := hosts[hostKey]
+	if len(h.URI) == 0 {
+		runtime.MessageDialog(a.ctx, runtime.MessageDialogOptions{
+			Type:    runtime.InfoDialog,
+			Title:   "Invalid uri",
+			Message: "You haven't specified a valid uri for the selected host.",
+		})
+		return nil, nil, nil, errors.New("invalid uri")
+	}
+
+	client, err := mongo.NewClient(mongoOptions.Client().ApplyURI(h.URI))
+
+	if err != nil {
+		fmt.Println(err.Error())
+		runtime.MessageDialog(a.ctx, runtime.MessageDialogOptions{
+			Type:    runtime.ErrorDialog,
+			Title:   "Could not connect",
+			Message: "Failed to establish a connection with " + h.Name,
+		})
+		return nil, nil, nil, errors.New("could not establish a connection with " + h.Name)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	client.Connect(ctx)
+	return client, ctx, func() {
+		client.Disconnect(ctx)
+		cancel()
+	}, nil
+}