streamlined error handling and misc minor fixes

3 files changed, 148 insertions, 93 deletions

diff --git a/http.go b/http.go
index b348604..7cf3ad2 100644
--- a/http.go
+++ b/http.go
@@ -1,47 +1,19 @@
 package main
 
 import (
-	"context"
 	"crypto/sha256"
 	"fmt"
 	"io/ioutil"
 	"log"
 	"net/http"
 	"os"
-	"strings"
 	"time"
 
 	"github.com/gorilla/mux"
 )
 
-// Attaches a request's IP address to the request's context
-func newCtxUserIP(ctx context.Context, r *http.Request) context.Context {
-	base := strings.Split(r.RemoteAddr, ":")
-	uip := base[0]
-	return context.WithValue(ctx, ctxKey, uip)
-}
-
-// Retrieves a request's IP address from the request's context
-func getIPFromCtx(ctx context.Context) string {
-	uip, ok := ctx.Value(ctxKey).(string)
-	if !ok {
-		log.Printf("Couldn't retrieve IP from request\n")
-	}
-	return uip
-}
-
-// Shim function to modify/pass context value to a handler
-func ipMiddleware(hop http.Handler) http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		ctx := newCtxUserIP(r.Context(), r)
-		hop.ServeHTTP(w, r.WithContext(ctx))
-	})
-}
-
 // handles "/"
 func indexHandler(w http.ResponseWriter, r *http.Request) {
-	uip := getIPFromCtx(r.Context())
-	log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL)
 
 	// Stat the index template to get the mod time
 	var etag string
@@ -61,63 +33,72 @@ func indexHandler(w http.ResponseWriter, r *http.Request) {
 	// then send it to the client.
 	err := tmpls.ExecuteTemplate(w, "index.html", confObj.Instance)
 	if err != nil {
-		log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		log500(w, r, err)
 		return
 	}
 
+	log200(r)
 }
 
 // handles "/api"
 func apiBaseHandler(w http.ResponseWriter, r *http.Request) {
-	uip := getIPFromCtx(r.Context())
-	log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL)
 
 	timerfc3339, err := time.Now().MarshalText()
 	if err != nil {
 		log.Printf("Couldn't format time as RFC3339: %v\n", err)
 	}
+
 	etag := fmt.Sprintf("%x", sha256.Sum256(timerfc3339))
+
 	w.Header().Set("ETag", etag)
 	w.Header().Set("Content-Type", txtutf8)
+
 	pathdata := []byte("\n\n" + r.URL.Path)
 	timerfc3339 = append(timerfc3339, pathdata...)
+
 	n, err := w.Write(timerfc3339)
 	if err != nil || n == 0 {
-		log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		log500(w, r, err)
+		return
 	}
+
+	log200(r)
 }
 
 // handles "/api/plain"
 // maybe add json/xml support later
 func apiFormatHandler(w http.ResponseWriter, r *http.Request) {
-	uip := getIPFromCtx(r.Context())
-	log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL)
 
 	vars := mux.Vars(r)
 	format := vars["format"]
 
 	w.Header().Set("Content-Type", txtutf8)
+
 	n, err := w.Write([]byte(format + "\n"))
 	if err != nil || n == 0 {
-		log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		log500(w, r, err)
+		return
 	}
+
+	log200(r)
 }
 
 // handles "/api/plain/(users|mentions|tweets)"
 func apiEndpointHandler(w http.ResponseWriter, r *http.Request) {
-	uip := getIPFromCtx(r.Context())
-	log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL)
 
 	err := r.ParseForm()
-	if err == nil && (r.FormValue("q") != "" || r.FormValue("url") != "") {
-		apiEndpointQuery(w, r)
+	if err != nil {
+		log500(w, r, err)
 		return
-	} else if err != nil {
-		log.Printf("Error parsing query from %v :: %v %v :: %v\n", uip, r.Method, r.URL, err)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+
+	if r.FormValue("q") != "" || r.FormValue("url") != "" {
+		err := apiEndpointQuery(w, r)
+		if err != nil {
+			log500(w, r, err)
+			return
+		}
+		log200(r)
 		return
 	}
 
@@ -125,80 +106,84 @@ func apiEndpointHandler(w http.ResponseWriter, r *http.Request) {
 
 	n, err := w.Write([]byte(r.URL.String()))
 	if err != nil || n == 0 {
-		log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		log500(w, r, err)
+		return
 	}
+
+	log200(r)
 }
 
 // handles POST for "/api/plain/users"
 func apiEndpointPOSTHandler(w http.ResponseWriter, r *http.Request) {
+
 	vars := mux.Vars(r)
 	format := vars["format"]
 	endpoint := vars["endpoint"]
 
-	uip := getIPFromCtx(r.Context())
-	log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL)
-
 	w.Header().Set("Content-Type", htmlutf8)
-	n, err := w.Write([]byte(format + "/" + endpoint))
-	if err != nil || n == 0 {
-		log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+
+	_, err := w.Write([]byte(format + "/" + endpoint))
+	if err != nil {
+		log500(w, r, err)
+		return
 	}
 
+	log200(r)
 }
 
 // handles "/api/plain/tags"
 func apiTagsBaseHandler(w http.ResponseWriter, r *http.Request) {
+
 	vars := mux.Vars(r)
 	format := vars["format"]
 
-	uip := getIPFromCtx(r.Context())
-	log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL)
-
 	w.Header().Set("Content-Type", htmlutf8)
+
 	n, err := w.Write([]byte("api/" + format + "/tags"))
 	if err != nil || n == 0 {
-		log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		log500(w, r, err)
+		return
 	}
 
+	log200(r)
 }
 
 // handles "/api/plain/tags/[a-zA-Z0-9]+"
 func apiTagsHandler(w http.ResponseWriter, r *http.Request) {
+
 	vars := mux.Vars(r)
-	format := vars["format"]
 	tags := vars["tags"]
 
-	uip := getIPFromCtx(r.Context())
-	log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL)
+	out, err := twtxtCache.QueryInStatus(tags)
+	if err != nil {
+		log500(w, r, err)
+		return
+	}
 
-	w.Header().Set("Content-Type", htmlutf8)
-	n, err := w.Write([]byte("api/" + format + "/tags/" + tags))
-	if err != nil || n == 0 {
-		log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+	data := parseQueryOut(out)
+
+	w.Header().Set("Content-Type", txtutf8)
+	_, err = w.Write(data)
+	if err != nil {
+		log500(w, r, err)
+		return
 	}
 
+	log200(r)
 }
 
 // Serving the stylesheet virtually because
 // files aren't served directly.
 func cssHandler(w http.ResponseWriter, r *http.Request) {
-	uip := getIPFromCtx(r.Context())
-	log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL)
 
 	// read the raw bytes of the stylesheet
 	css, err := ioutil.ReadFile("assets/style.css")
 	if err != nil {
 		if os.IsNotExist(err) {
-			log.Printf("CSS file does not exist: /css request 404\n")
-			http.Error(w, err.Error(), http.StatusNotFound)
+			log404(w, r, err)
 			return
 		}
-		log.Printf("500: %v\n", err)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		log500(w, r, err)
 		return
 	}
 
@@ -213,9 +198,12 @@ func cssHandler(w http.ResponseWriter, r *http.Request) {
 
 	w.Header().Set("ETag", "\""+etag+"\"")
 	w.Header().Set("Content-Type", cssutf8)
+
 	n, err := w.Write(css)
 	if err != nil || n == 0 {
-		log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		log500(w, r, err)
+		return
 	}
+
+	log200(r)
 }
diff --git a/httpmeta.go b/httpmeta.go
new file mode 100644
index 0000000..2a733aa
--- /dev/null
+++ b/httpmeta.go
@@ -0,0 +1,60 @@
+package main
+
+import (
+	"context"
+	"log"
+	"net/http"
+	"strings"
+)
+
+// Attaches a request's IP address to the request's context
+func newCtxUserIP(ctx context.Context, r *http.Request) context.Context {
+
+	base := strings.Split(r.RemoteAddr, ":")
+	uip := base[0]
+
+	return context.WithValue(ctx, ctxKey, uip)
+}
+
+// Retrieves a request's IP address from the request's context
+func getIPFromCtx(ctx context.Context) string {
+
+	uip, ok := ctx.Value(ctxKey).(string)
+	if !ok {
+		log.Printf("Couldn't retrieve IP from request\n")
+	}
+
+	return uip
+}
+
+// Shim function to modify/pass context value to a handler
+func ipMiddleware(hop http.Handler) http.Handler {
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		ctx := newCtxUserIP(r.Context(), r)
+		hop.ServeHTTP(w, r.WithContext(ctx))
+	})
+}
+
+// log output for 200s
+func log200(r *http.Request) {
+
+	uip := getIPFromCtx(r.Context())
+	log.Printf("*** %v :: 200 :: %v %v\n", uip, r.Method, r.URL)
+}
+
+// log output for 404s
+func log404(w http.ResponseWriter, r *http.Request, err error) {
+
+	uip := getIPFromCtx(r.Context())
+	log.Printf("*** %v :: 404 :: %v %v :: %v\n", uip, r.Method, r.URL, err)
+	http.Error(w, err.Error(), http.StatusNotFound)
+}
+
+// log output for 500s
+func log500(w http.ResponseWriter, r *http.Request, err error) {
+
+	uip := getIPFromCtx(r.Context())
+	log.Printf("*** %v :: 500 :: %v %v :: %v\n", uip, r.Method, r.URL, err)
+	http.Error(w, err.Error(), http.StatusInternalServerError)
+}
diff --git a/query.go b/query.go
index 63deb55..c47cfb0 100644
--- a/query.go
+++ b/query.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"log"
 	"net/http"
 	"strings"
@@ -11,23 +12,33 @@ import (
 func apiErrCheck(err error, r *http.Request) {
 	if err != nil {
 		uip := getIPFromCtx(r.Context())
-		log.Printf("%v :: %v %v :: %v\n", uip, r.Method, r.URL, err)
+		log.Printf("*** %v :: %v %v :: %v\n", uip, r.Method, r.URL, err)
 	}
 }
 
-func apiErrCheck500(err error, w http.ResponseWriter, r *http.Request) {
-	if err != nil {
-		uip := getIPFromCtx(r.Context())
-		log.Printf("%v :: %v %v :: %v\n", uip, r.Method, r.URL, err)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+// Takes the output of queries and formats it for
+// an HTTP response. Iterates over the string slice,
+// appending each entry to a byte slice, and adding
+// newlines where appropriate.
+func parseQueryOut(out []string) []byte {
+	var data []byte
+
+	for _, e := range out {
+		data = append(data, []byte(e)...)
+
+		if !strings.HasSuffix(e, "\n") {
+			data = append(data, byte('\n'))
+		}
 	}
+
+	return data
 }
 
 // apiUserQuery is called via apiEndpointHandler when
 // the endpoint is "users" and r.FormValue("q") is not empty.
 // It queries the registry cache for users or user URLs
 // matching the term supplied via r.FormValue("q")
-func apiEndpointQuery(w http.ResponseWriter, r *http.Request) {
+func apiEndpointQuery(w http.ResponseWriter, r *http.Request) error {
 	query := r.FormValue("q")
 	urls := r.FormValue("url")
 	var out []string
@@ -64,20 +75,16 @@ func apiEndpointQuery(w http.ResponseWriter, r *http.Request) {
 		apiErrCheck(err, r)
 
 	default:
-		http.Error(w, "500", http.StatusInternalServerError)
+		return fmt.Errorf("endpoint query, no cases match")
 	}
 
-	// iterate over the output. if there aren't
-	// explicit newlines, add them.
-	var data []byte
-	for _, e := range out {
-		data = append(data, []byte(e)...)
-		if !strings.HasSuffix(e, "\n") {
-			data = append(data, byte('\n'))
-		}
-	}
+	data := parseQueryOut(out)
 
 	w.Header().Set("Content-Type", txtutf8)
 	_, err = w.Write(data)
-	apiErrCheck500(err, w, r)
+	if err != nil {
+		return err
+	}
+
+	return nil
 }