Initial QSfera import

Server/services/collaboration/pkg/wopisrc/wopisrc.go

@@ -0,0 +1,72 @@
+package wopisrc
+
+import (
+	"errors"
+	"net/url"
+	"path"
+
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/qsfera/server/services/collaboration/pkg/config"
+)
+
+// GenerateWopiSrc generates a WOPI src URL for the given file reference.
+// If a proxy URL and proxy secret are configured, the URL will be generated
+// as a jwt token that is signed with the proxy secret and contains the file reference
+// and the WOPI src URL.
+// Example:
+// https://cloud.proxy.com/wopi/files/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1IjoiaHR0cHM6Ly9vY2lzLnRlYW0vd29waS9maWxlcy8iLCJmIjoiMTIzNDU2In0.6ol9PQXGKktKfAri8tsJ4X_a9rIeosJ7id6KTQW6Ui0
+//
+// If no proxy URL and proxy secret are configured, the URL will be generated
+// as a direct URL that contains the file reference.
+// Example:
+// https:/cloud.example.test/wopi/files/12312678470610632091729803710923
+func GenerateWopiSrc(fileRef string, cfg *config.Config) (*url.URL, error) {
+	wopiSrcURL, err := url.Parse(cfg.Wopi.WopiSrc)
+	if err != nil {
+		return nil, err
+	}
+	if wopiSrcURL.Host == "" {
+		return nil, errors.New("invalid WopiSrc URL")
+	}
+
+	if cfg.Wopi.ProxyURL != "" && cfg.Wopi.ProxySecret != "" {
+		return generateProxySrc(fileRef, cfg.Wopi.ProxyURL, cfg.Wopi.ProxySecret, wopiSrcURL)
+	}
+
+	return generateDirectSrc(fileRef, wopiSrcURL)
+}
+
+func generateDirectSrc(fileRef string, wopiSrcURL *url.URL) (*url.URL, error) {
+	wopiSrcURL.Path = path.Join("wopi", "files", fileRef)
+	return wopiSrcURL, nil
+}
+
+func generateProxySrc(fileRef string, proxyUrl string, proxySecret string, wopiSrcURL *url.URL) (*url.URL, error) {
+	proxyURL, err := url.Parse(proxyUrl)
+	if err != nil {
+		return nil, err
+	}
+	if proxyURL.Host == "" {
+		return nil, errors.New("invalid proxy URL")
+	}
+
+	wopiSrcURL.Path = path.Join("wopi", "files")
+
+	type tokenClaims struct {
+		URL    string `json:"u"`
+		FileID string `json:"f"`
+		jwt.RegisteredClaims
+	}
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, tokenClaims{
+		FileID: fileRef,
+		// the string value from the URL package always ends with a slash
+		// the office365 proxy assumes that we have a trailing slash
+		URL: wopiSrcURL.String() + "/",
+	})
+	tokenString, err := token.SignedString([]byte(proxySecret))
+	if err != nil {
+		return nil, err
+	}
+	proxyURL.Path = path.Join("wopi", "files", tokenString)
+	return proxyURL, nil
+}