From 10bd39d915c7b069020d3e1ca546b6fd45d56571 Mon Sep 17 00:00:00 2001
From: Erik Winter <e@ewintr.nl>
Date: Sat, 13 May 2023 13:03:48 +0200
Subject: [PATCH] handler index

---
 handler/handler.go    | 47 ++++++++++++++++++++++++++
 handler/server.go     | 78 +++++++++++++++++++++++++++++++++++++++++++
 handler/server.go].go |  1 -
 service.go            | 15 ++++++++-
 4 files changed, 139 insertions(+), 2 deletions(-)
 create mode 100644 handler/server.go
 delete mode 100644 handler/server.go].go

diff --git a/handler/handler.go b/handler/handler.go
index abeebd1..287a80a 100644
--- a/handler/handler.go
+++ b/handler/handler.go
@@ -1 +1,48 @@
 package handler
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+func Index(w http.ResponseWriter) {
+	Message(w, http.StatusOK, "yogai index")
+}
+
+func Message(w http.ResponseWriter, status int, message string, details ...any) {
+	w.WriteHeader(status)
+	response := struct {
+		Message string `json:"message"`
+		Details []any  `json:"details,omitempty"`
+	}{
+		Message: message,
+		Details: details,
+	}
+	body, marshalErr := json.Marshal(response)
+	if marshalErr != nil {
+		fmt.Fprintf(w, fmt.Sprintf(`{"message": %q, "details":%q}`, message, marshalErr.Error()))
+		return
+	}
+	fmt.Fprintf(w, string(body))
+}
+
+func Error(w http.ResponseWriter, status int, message string, err error, details ...any) {
+	w.WriteHeader(status)
+	response := struct {
+		Message string `json:"message"`
+		Error   string `json:"error"`
+		Details []any  `json:"details,omitempty"`
+	}{
+		Message: message,
+		Error:   err.Error(),
+		Details: details,
+	}
+	body, marshalErr := json.Marshal(response)
+	if marshalErr != nil {
+		fmt.Fprintf(w, fmt.Sprintf(`{"message": %q, "error": %q, "details":%q}`, message, err.Error(), marshalErr.Error()))
+		return
+	}
+
+	fmt.Fprintf(w, string(body))
+}
diff --git a/handler/server.go b/handler/server.go
new file mode 100644
index 0000000..b0e583f
--- /dev/null
+++ b/handler/server.go
@@ -0,0 +1,78 @@
+package handler
+
+import (
+	"fmt"
+	"golang.org/x/exp/slog"
+	"miniflux.app/logger"
+	"net/http"
+	"net/http/httptest"
+	"path"
+	"strings"
+)
+
+type Server struct {
+	apis   map[string]http.Handler
+	logger *slog.Logger
+}
+
+func NewServer(logger *slog.Logger) *Server {
+	return &Server{
+		apis:   map[string]http.Handler{},
+		logger: logger,
+	}
+}
+
+func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	originalPath := r.URL.Path
+	rec := httptest.NewRecorder() // records the response to be able to mix writing headers and content
+
+	w.Header().Add("Content-Type", "application/json")
+
+	// route to api
+	head, tail := ShiftPath(r.URL.Path)
+	if len(head) == 0 {
+		Index(rec)
+		returnResponse(w, rec)
+		return
+	}
+	api, ok := s.apis[head]
+	if !ok {
+		Error(rec, http.StatusNotFound, "Not found", fmt.Errorf("%s is not a valid path", r.URL.Path))
+	} else {
+		r.URL.Path = tail
+		api.ServeHTTP(rec, r)
+	}
+
+	returnResponse(w, rec)
+	logger.Info("request served", "path", originalPath, "status", rec.Code)
+}
+
+func returnResponse(w http.ResponseWriter, rec *httptest.ResponseRecorder) {
+	w.WriteHeader(rec.Code)
+	for k, v := range rec.Header() {
+		w.Header()[k] = v
+	}
+	w.Write(rec.Body.Bytes())
+}
+
+// ShiftPath splits off the first component of p, which will be cleaned of
+// relative components before processing. head will never contain a slash and
+// tail will always be a rooted path without trailing slash.
+// See https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
+func ShiftPath(p string) (string, string) {
+	p = path.Clean("/" + p)
+
+	// restore iri prefixes that might be mangled by path.Clean
+	for k, v := range map[string]string{
+		"http:/":  "http://",
+		"https:/": "https://",
+	} {
+		p = strings.Replace(p, k, v, -1)
+	}
+
+	i := strings.Index(p[1:], "/") + 1
+	if i <= 0 {
+		return p[1:], "/"
+	}
+	return p[1:i], p[i:]
+}
diff --git a/handler/server.go].go b/handler/server.go].go
deleted file mode 100644
index abeebd1..0000000
--- a/handler/server.go].go
+++ /dev/null
@@ -1 +0,0 @@
-package handler
diff --git a/service.go b/service.go
index aa9ca97..a04e7a7 100644
--- a/service.go
+++ b/service.go
@@ -3,18 +3,23 @@ package main
 import (
 	"context"
 	"ewintr.nl/yogai/fetcher"
+	"ewintr.nl/yogai/handler"
 	"ewintr.nl/yogai/storage"
+	"fmt"
 	"golang.org/x/exp/slog"
 	"google.golang.org/api/option"
 	"google.golang.org/api/youtube/v3"
+	"net/http"
 	"os"
 	"os/signal"
+	"strconv"
 	"time"
 )
 
 func main() {
 	ctx := context.Background()
 	logger := slog.New(slog.NewTextHandler(os.Stderr))
+
 	postgres, err := storage.NewPostgres(storage.PostgresInfo{
 		Host:     getParam("POSTGRES_HOST", "localhost"),
 		Port:     getParam("POSTGRES_PORT", "5432"),
@@ -50,7 +55,15 @@ func main() {
 
 	fetcher := fetcher.NewFetch(videoRepo, mflx, fetchInterval, yt, openAIClient, logger)
 	go fetcher.Run()
-	logger.Info("service started")
+	logger.Info("fetch service started")
+
+	port, err := strconv.Atoi(getParam("API_PORT", "8080"))
+	if err != nil {
+		logger.Error("invalid port", err)
+		os.Exit(1)
+	}
+	go http.ListenAndServe(fmt.Sprintf(":%d", port), handler.NewServer(logger))
+	logger.Info("http server started")
 
 	done := make(chan os.Signal)
 	signal.Notify(done, os.Interrupt)