Add ttl feature and redirection complete

root27 · Jun 24, 2024 · 748adc2 · 748adc2
1 parent 2669b26
commit 748adc2
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Showing 2 changed files with 195 additions and 18 deletions.
diff --git a/main.go b/main.go
@@ -1,23 +1,28 @@
 package main
 
 import (
-	"context"
-	"google.golang.org/api/sheets/v4"
+	"fmt"
 	"log"
+	"net/http"
 	"net/url"
+	"os"
 	"strings"
+	"sync"
 	"time"
 )
 
 type URLMap map[string]*url.URL
 
-type cached struct {
-	db        URLMap
-	updatedAt time.Time
+type server struct {
+	db *cached
 }
 
-func (c *cached) refreshData() error {
-
+type cached struct {
+	sync.RWMutex
+	value         URLMap
+	updatedAt     time.Time
+	ttl           time.Duration
+	sheetProvider *sheet
 }
 
 func GetUrls(data [][]interface{}) URLMap {
@@ -53,32 +58,153 @@ func GetUrls(data [][]interface{}) URLMap {
 
 	}
 
-	log.Println(output)
-
 	return output
 
 }
 
 func main() {
 
-	srv, err := sheets.NewService(context.TODO())
+	port := os.Getenv("PORT")
+
+	sheetId := os.Getenv("SHEETID")
+
+	sheetName := os.Getenv("SHEETNAME")
+
+	ttlValue := os.Getenv("TTL")
+
+	ttl := time.Second * 5
+
+	if ttlValue != "" {
+
+		v, err := time.ParseDuration(ttlValue)
+
+		if err != nil {
+
+			log.Fatalf("Error parsing time duration %v", err)
+		}
+
+		ttl = v
+
+	}
+
+	if port == "" {
+
+		port = "8080"
+	}
+
+	srv := &server{
+		db: &cached{
+			ttl: ttl,
+			sheetProvider: &sheet{
+				Name: sheetName,
+				Id:   sheetId,
+			},
+		},
+	}
+
+	http.HandleFunc("/", srv.Handler)
+
+	log.Printf("Server listening on port: %s", port)
+
+	http.ListenAndServe(":"+port, nil)
+
+}
+
+func (s *server) Handler(w http.ResponseWriter, r *http.Request) {
+
+	if r.URL.Path == "/" {
+
+		s.home(w)
+
+		return
+
+	}
+
+	s.redirector(w, r)
+
+}
+
+func (s *server) home(w http.ResponseWriter) {
+
+	w.WriteHeader(http.StatusNotFound)
+
+	fmt.Fprintf(w, `<!DOCTYPE html>
+<html><head><title>Not found</title></head><body><h1>Not found :(</h1>
+	<p>This is home page for a URL redirector service.</p>
+	<p>The URL is missing the shortcut in the path.</p>
+	</body></html>`)
+
+}
+
+func (c *cached) refreshData() error {
+
+	c.Lock()
+
+	defer c.Unlock()
+
+	if time.Since(c.updatedAt) <= c.ttl {
+
+		return nil
+	}
+
+	rows, err := c.sheetProvider.Query()
+
 	if err != nil {
-		log.Fatalf("Unable to retrieve Sheets client: %v", err)
+
+		return err
+
 	}
 
-	//NOTE: Set env variable
-	spreadsheetId := "1HUIYUXbSX21ZgR93l0ryA-Q_PMoNGeIUlAIlHzT9dNc"
-	readRange := "A:B"
-	resp, err := srv.Spreadsheets.Values.Get(spreadsheetId, readRange).Do()
+	c.value = GetUrls(rows)
+
+	c.updatedAt = time.Now()
+
+	return nil
+}
+
+func (c *cached) Get(query string) (*url.URL, error) {
+
+	if err := c.refreshData(); err != nil {
+
+		return nil, err
+	}
+
+	c.RLock()
+
+	defer c.RUnlock()
+
+	return c.value[query], nil
+
+}
+
+func (s *server) redirector(w http.ResponseWriter, r *http.Request) {
+
+	if r.Body != nil {
+		defer r.Body.Close()
+	}
+
+	path := strings.TrimPrefix(r.URL.Path, "/")
+
+	url, err := s.db.Get(path)
+
 	if err != nil {
-		log.Fatalf("Unable to retrieve data from sheet: %v", err)
+
+		http.Error(w, "Error querying data", http.StatusInternalServerError)
+
+		return
 	}
 
-	if len(resp.Values) == 0 {
+	if url == nil {
+
+		w.WriteHeader(http.StatusNotFound)
 
-		log.Println("No data available")
+		fmt.Fprintf(w, `404 Not Found`)
 
 		return
 	}
 
+	fmt.Printf("Redirecting %s to %s\n", r.URL, url)
+
+	http.Redirect(w, r, url.String(), http.StatusFound)
+
 }
diff --git a/sheet.go b/sheet.go
@@ -0,0 +1,51 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"google.golang.org/api/sheets/v4"
+
+	"log"
+)
+
+type sheet struct {
+	Name string
+	Id   string
+}
+
+func (s *sheet) Query() ([][]interface{}, error) {
+
+	srv, err := sheets.NewService(context.TODO())
+
+	if err != nil {
+		log.Fatalf("Unable to retrieve Sheets client: %v", err)
+	}
+
+	if s.Id == "" {
+
+		log.Fatal("Google Sheets ID not specified")
+
+		return nil, errors.New("Google Sheets ID not specified")
+
+	}
+
+	//NOTE: Set env variable
+	spreadsheetId := s.Id
+	readRange := "A:B"
+
+	if s.Name != "" {
+
+		readRange = s.Name + "!A:B"
+	}
+
+	resp, err := srv.Spreadsheets.Values.Get(spreadsheetId, readRange).Do()
+	if err != nil {
+		log.Fatalf("Unable to retrieve data from sheet: %v", err)
+
+		return nil, err
+	}
+
+	log.Printf("Number of quering rows: %d\n", len(resp.Values))
+
+	return resp.Values, nil
+}