feat: Initial Commit, Partial Functionality

This is the initial commit. The url-shortener is partially functional.
URLs can be shortened and stored for the runtime of the program. API
keys are not checked, nothing is persistent, and short URLs are size
limited to 4 alpha numeric characters.

3 files changed, 117 insertions, 0 deletions

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..cbace07
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module mcdonnell.dev/url-shortener
+
+go 1.26.1
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..11d7370
--- /dev/null
+++ b/main.go
@@ -0,0 +1,105 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"math/rand/v2"
+	"net/http"
+	"unicode/utf8"
+)
+
+const charSet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+const version = "0.0.1"
+
+var Table map[string]string = make(map[string]string)
+
+type Request struct {
+	URL string
+}
+
+type Response struct {
+	Version  string
+	Status   string
+	Original string
+	New      string
+}
+
+func NewRequest(r *http.Request) (Request, error) {
+	var request Request
+
+	err := json.NewDecoder(r.Body).Decode(&request)
+
+	return request, err
+}
+
+func log_header(r *http.Request) {
+	log.Println("Header {")
+	for k, v := range r.Header {
+		log.Printf("\t\"%s\": \"%s\"\n", k, v)
+	}
+	log.Println("}")
+}
+
+func redirect(w http.ResponseWriter, r *http.Request) {
+	log.Println("Request for:", r.URL.String())
+	log_header(r)
+
+	_, i := utf8.DecodeRuneInString(r.URL.String())
+	url := r.URL.String()[i:]
+
+	original, ok := Table[url]
+
+	if ok {
+		w.Header().Set("location", original)
+		http.Error(w, http.StatusText(301), 301)
+	} else {
+		http.Error(w, http.StatusText(404), 404)
+	}
+}
+
+func shorten(w http.ResponseWriter, r *http.Request) {
+	log.Println("Request to Shorten")
+	log_header(r)
+
+	request, err := NewRequest(r)
+	if err != nil {
+		http.Error(w, http.StatusText(500), 500)
+	}
+
+	url := GenerateString(4)
+	_, ok := Table[url]
+
+	for ok {
+		url = GenerateString(4)
+		_, ok = Table[url]
+	}
+
+	Table[url] = request.URL
+
+	response := Response{version, "ok", request.URL, url}
+
+	data, err := json.Marshal(response)
+	if err != nil {
+		http.Error(w, http.StatusText(500), 500)
+	}
+
+	fmt.Fprintf(w, "%s", string(data))
+}
+
+func GenerateString(size uint) string {
+	buffer := make([]rune, size)
+
+	for i := uint(0); i < size; i++ {
+		index := rand.Uint() % uint(len(charSet))
+		buffer[i] = []rune(charSet)[index]
+	}
+
+	return string(buffer)
+}
+
+func main() {
+	http.HandleFunc("/shorten", shorten)
+	http.HandleFunc("/", redirect)
+	log.Fatal(http.ListenAndServe(":8000", nil))
+}
diff --git a/test.sh b/test.sh
new file mode 100755
index 0000000..c2cc156
--- /dev/null
+++ b/test.sh
@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+RES=$(curl -X 'POST' \
+    -H 'accept: application/json' \
+    -H 'Content-Type: application/json' \
+    --data '{ "URL": "https://git.mcdonnell.dev/" }' \
+    http://localhost:8000/shorten 2>/dev/null)
+printf '%s\n' "$(echo "$RES" | json_pp)"
+