Create msova_server.go

Author: micsova

msova_server.go

@@ -0,0 +1,145 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/dynamodb"
+	"github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute"
+	"github.com/aws/aws-sdk-go/service/dynamodb/expression"
+	"github.com/gorilla/mux"
+	"net/http"
+	"os"
+	"strconv"
+)
+
+type Artist struct {
+	Name string `json:"name"`
+	HREF string `json:"href"`
+	ID   string `json:"id"`
+}
+
+type Album struct {
+	Name    string   `json:"name"`
+	Artists []Artist `json:"artists"`
+	ID      string   `json:"id"`
+	HREF    string   `json:"href"`
+}
+
+type Track struct {
+	Name     string   `json:"name"`
+	Artists  []Artist `json:"artists"`
+	Album    Album    `json:"album"`
+	TrackNum int      `json:"track_number"`
+	ID       string   `json:"id"`
+	HREF     string   `json:"href"`
+}
+
+type Playlist struct {
+	TableID     string `json:"unique_id"`
+	Name        string `json:"name"`
+	Description string `json:"description"`
+	TrackList   struct {
+		Items []struct {
+			Song Track `json:"track"`
+		} `json:"items"`
+	} `json:"tracks"`
+	//TrackList	Tracks		`json:"tracks"`
+	PlaylistID string `json:"id"`
+	HREF       string `json:"href"`
+	Followers  struct {
+		Total int `json:"total"`
+	} `json:"followers"`
+}
+
+type Item struct {
+	Playlists []Playlist `json:"items"`
+}
+
+var svc *dynamodb.DynamoDB
+
+func main() {
+	//Router setup
+	//Initialize
+	router := mux.NewRouter()
+	//Route handlers (endpoints)
+	router.HandleFunc("/msova/all", getAll).Methods("GET")
+	router.HandleFunc("/msova/status", getStatus).Methods("GET")
+	//Create a DynamoDB session
+	sess, err := session.NewSession(&aws.Config{
+		Region: aws.String("us-east-1")},
+	)
+	if err != nil {
+		fmt.Println("Error creating session:")
+		fmt.Println(err.Error())
+		os.Exit(1)
+	}
+	// Create DynamoDB client
+	svc = dynamodb.New(sess)
+	//Run server
+	if err := http.ListenAndServe(":8080", router); err != nil {
+		fmt.Println(err)
+	}
+}
+
+//Gets JSON representation of the entire table
+func getAll(w http.ResponseWriter, r *http.Request) {
+	//Define what you want to get
+	proj := expression.NamesList(expression.Name("name"),
+		expression.Name("description"), expression.Name("followers"), expression.Name("tracks"),
+		expression.Name("id"), expression.Name("href"), expression.Name("unique_id"))
+
+	expr, err := expression.NewBuilder().WithProjection(proj).Build()
+	if err != nil {
+		fmt.Println("Got error building expression:")
+		fmt.Println(err.Error())
+		os.Exit(1)
+	}
+
+	params := &dynamodb.ScanInput{
+		ExpressionAttributeNames:  expr.Names(),
+		ExpressionAttributeValues: expr.Values(),
+		ProjectionExpression:      expr.Projection(),
+		TableName:                 aws.String("SpotifyGrab"),
+	}
+
+	result, err := svc.Scan(params)
+	if err != nil {
+		fmt.Println(err.Error())
+		return
+	}
+
+	var playlists []Playlist
+	err = dynamodbattribute.UnmarshalListOfMaps(result.Items, &playlists)
+
+	ba, err := json.MarshalIndent(playlists, "", "   ")
+	w.Header().Set("Content-Type", "application/json")
+	_, _ = w.Write(ba)
+}
+
+//Gets status of the table
+func getStatus(w http.ResponseWriter, r *http.Request) {
+	result, err := svc.Scan(&dynamodb.ScanInput{
+		TableName: aws.String("SpotifyGrab"),
+	})
+
+	if err != nil {
+		fmt.Println(err.Error())
+		return
+	}
+
+	var playlists []Playlist
+	err = dynamodbattribute.UnmarshalListOfMaps(result.Items, &playlists)
+
+	//Create JSON-formatted string with table name and item count
+	info := []byte(`{"table":"SpotifyGrab","recordCount": `)
+	info = append(info, []byte(strconv.Itoa(len(playlists)))...)
+	info = append(info, []byte(`}`)...)
+	var prettyJson bytes.Buffer
+	_ = json.Indent(&prettyJson, info, "", "   ")
+
+	w.Header().Set("Content-Type", "application/json")
+	_, _ = w.Write(prettyJson.Bytes())
+}