chore: added model delete related to #2

utils.go

@@ -1,7 +1,150 @@
 package main
 
-import "net/url"
+import (
+	"errors"
+	"io"
+	"mime"
+	"net/http"
+	"net/url"
+
+	"github.com/google/uuid"
+)
 
 func checkEmpty(f url.Values, path string) bool {
-    return !f.Has(path) || f.Get(path) == ""
+	return !f.Has(path) || f.Get(path) == ""
+}
+
+func checkId(f url.Values, path string) bool {
+    return !checkEmpty(f, path) && isValidUUID(f.Get(path))
+}
+
+func isValidUUID(u string) bool {
+	_, err := uuid.Parse(u)
+	return err == nil
+}
+
+func getIdFromUrl(r *http.Request, target string) (string, error) {
+	if !r.URL.Query().Has(target) {
+        return "", errors.New("Query does not have " + target)
+	}
+
+	id := r.URL.Query().Get("id")
+	if len(id) == 0 {
+        return "", errors.New("Query is empty for " + target)
+	}
+
+	if !isValidUUID(id) {
+        return "", errors.New("Value of query is not a valid uuid for " + target)
+	}
+
+    return id, nil
+}
+
+type maxBytesReader struct {
+	w   http.ResponseWriter
+	r   io.ReadCloser // underlying reader
+	i   int64         // max bytes initially, for MaxBytesError
+	n   int64         // max bytes remaining
+	err error         // sticky error
+}
+
+type MaxBytesError struct {
+	Limit int64
+}
+
+func (e *MaxBytesError) Error() string {
+	// Due to Hyrum's law, this text cannot be changed.
+	return "http: request body too large"
+}
+
+func (l *maxBytesReader) Read(p []byte) (n int, err error) {
+	if l.err != nil {
+		return 0, l.err
+	}
+	if len(p) == 0 {
+		return 0, nil
+	}
+	// If they asked for a 32KB byte read but only 5 bytes are
+	// remaining, no need to read 32KB. 6 bytes will answer the
+	// question of the whether we hit the limit or go past it.
+	// 0 < len(p) < 2^63
+	if int64(len(p))-1 > l.n {
+		p = p[:l.n+1]
+	}
+	n, err = l.r.Read(p)
+
+	if int64(n) <= l.n {
+		l.n -= int64(n)
+		l.err = err
+		return n, err
+	}
+
+	n = int(l.n)
+	l.n = 0
+
+	// The server code and client code both use
+	// maxBytesReader. This "requestTooLarge" check is
+	// only used by the server code. To prevent binaries
+	// which only using the HTTP Client code (such as
+	// cmd/go) from also linking in the HTTP server, don't
+	// use a static type assertion to the server
+	// "*response" type. Check this interface instead:
+	type requestTooLarger interface {
+		requestTooLarge()
+	}
+	if res, ok := l.w.(requestTooLarger); ok {
+		res.requestTooLarge()
+	}
+	l.err = &MaxBytesError{l.i}
+	return n, l.err
+}
+
+func (l *maxBytesReader) Close() error {
+	return l.r.Close()
+}
+
+func MyParseForm(r *http.Request) (vs url.Values, err error) {
+	if r.Body == nil {
+		err = errors.New("missing form body")
+		return
+	}
+	ct := r.Header.Get("Content-Type")
+	// RFC 7231, section 3.1.1.5 - empty type
+	//   MAY be treated as application/octet-stream
+	if ct == "" {
+		ct = "application/octet-stream"
+	}
+	ct, _, err = mime.ParseMediaType(ct)
+	switch {
+	case ct == "application/x-www-form-urlencoded":
+		var reader io.Reader = r.Body
+		maxFormSize := int64(1<<63 - 1)
+		if _, ok := r.Body.(*maxBytesReader); !ok {
+			maxFormSize = int64(10 << 20) // 10 MB is a lot of text.
+			reader = io.LimitReader(r.Body, maxFormSize+1)
+		}
+		b, e := io.ReadAll(reader)
+		if e != nil {
+			if err == nil {
+				err = e
+			}
+			break
+		}
+		if int64(len(b)) > maxFormSize {
+			err = errors.New("http: POST too large")
+			return
+		}
+		vs, e = url.ParseQuery(string(b))
+		if err == nil {
+			err = e
+		}
+	case ct == "multipart/form-data":
+		// handled by ParseMultipartForm (which is calling us, or should be)
+		// TODO(bradfitz): there are too many possible
+		// orders to call too many functions here.
+		// Clean this up and write more tests.
+		// request_test.go contains the start of this,
+		// in TestParseMultipartFormOrder and others.
+	}
+	return
 }