From 989dd670309eea785e7cccb73327cf9715763073 Mon Sep 17 00:00:00 2001
From: cspark <git@cspark.dev>
Date: Tue, 6 May 2025 01:49:13 +0100
Subject: [PATCH] Implement request body handling on abstraction

---
 main.go | 54 +++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 41 insertions(+), 13 deletions(-)

diff --git a/main.go b/main.go
index 1fa8345..a67b1a2 100644
--- a/main.go
+++ b/main.go
@@ -3,11 +3,13 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"log"
 	"net/http"
 	"os"
 	"os/signal"
 	"reflect"
+	"strings"
 	"syscall"
 	"time"
 )
@@ -43,32 +45,58 @@ type http_status_code int; const (
 	BAD_REQUEST http_status_code = http.StatusBadRequest
 )
 
-func http_new_route[T any](method http_method, route string, handle_func func(request *http.Request) (T, http_status_code)) {
+type empty_request_body struct {}
+/* T Representing any request body struct
+   S Representing any response body struct */
+func http_new_route[T any, S any](method http_method, route string, handle_func func(body T, raw_request *http.Request) (S, http_status_code)) {
 	http.HandleFunc(method.to_string() + " /" + route, func(response http.ResponseWriter, request *http.Request) {
-		body, status_code := handle_func(request)
-		result, err := json.Marshal(body)
+		request_body_bytes, err := io.ReadAll(request.Body)
 		if err != nil {
-			log.Fatal(err)
+			response.WriteHeader(int(INTERNAL_SERVER_ERROR))
+			log.Panicln(err)
+			return
+		}
+		var decode_result T
+		if len(request_body_bytes) != 0 {
+			decoder := json.NewDecoder(strings.NewReader(string(request_body_bytes)))
+			decoder.DisallowUnknownFields()
+			err = decoder.Decode(&decode_result)
+			if err != nil {
+				response.WriteHeader(int(BAD_REQUEST))
+				response.Write([]byte(err.Error()))
+				log.Println(err)
+				return
+			}
+		}
+
+		body, status_code := handle_func(decode_result, request)
+		encode_result, err := json.Marshal(body)
+		if err != nil {
+			response.WriteHeader(int(INTERNAL_SERVER_ERROR))
+			log.Panicln(err)
+			return
 		}
 		fmt.Println(reflect.VisibleFields(reflect.TypeOf(body)))
 
 		response.WriteHeader(int(status_code))
-		response.Write(result)
+		response.Write(encode_result)
 	})
 
 }
 
 func main() {
+	type foo_request_body struct {
+		Arg1 int
+		Arg2 int
+	}
 	type foo_response_body struct {
 		Field1 string
-		Field2 http.Header
+		Field2 int
 	}
-	foo_route_handler := func(request *http.Request) (foo_response_body, http_status_code) {
-		fmt.Println(request.Header)
-
-		return foo_response_body{
+	foo_route_handler := func(body foo_request_body, raw_request *http.Request) (foo_response_body, http_status_code) {
+		return foo_response_body {
 			Field1: "hi there on foo!",
-			Field2: request.Header,
+			Field2: body.Arg1 + body.Arg2,
 		}, OK
 	}
 	http_new_route(GET, "foo", foo_route_handler)
@@ -77,8 +105,8 @@ func main() {
 		Response int
 		Message string
 	}
-	bar_route_handler := func(request *http.Request) (bar_response_body, http_status_code) {
-		return bar_response_body{
+	bar_route_handler := func(body empty_request_body, raw_request *http.Request) (bar_response_body, http_status_code) {
+		return bar_response_body {
 			Response: 400,
 			Message: "hi there on bar!",
 		}, INTERNAL_SERVER_ERROR