Add functions for building and parsing new-style URIs

ui/js/uri.js

@@ -0,0 +1,118 @@
+const CHANNEL_NAME_MIN_LEN = 4;
+const CLAIM_ID_MAX_LEN = 40;
+
+const uri = {};
+
+/**
+ * Parses a LBRY name into its component parts. Throws errors with user-friendly
+ * messages for invalid names.
+ *
+ * Returns a dictionary with keys:
+ *   - name (string)
+ *   - properName (string; strips off @ for channels)
+ *   - isChannel (boolean)
+ *   - claimSequence (int, if present)
+ *   - bidPosition (int, if present)
+ *   - claimId (string, if present)
+ *   - path (string, if persent)
+ */
+uri.parseLbryUri = function(lbryUri, requireProto=false) {
+  // Break into components. Empty sub-matches are converted to null
+  const componentsRegex = new RegExp(
+    '^((?:lbry:\/\/)?)' + // protocol
+    '([^:$#/]*)' +        // name (stops at the first separator or end)
+    '([:$#]?)([^/]*)' +   // modifier separator, modifier (stops at the first path separator or end)
+    '(/?)(.*)'            // path separator, path
+  );
+  const [proto, name, modSep, modVal, pathSep, path] = componentsRegex.exec(lbryUri).slice(1).map(match => match || null);
+
+  // Validate protocol
+  if (requireProto && !proto) {
+    throw new Error('LBRY URIs must include a protocol prefix (lbry://).');
+  }
+
+  // Validate and process name
+  if (!name) {
+    throw new Error('URI does not include name.');
+  }
+
+  const isChannel = name[0] == '@';
+  const properName = isChannel ? name.substr(1) : name;
+
+  if (isChannel) {
+    if (!properName) {
+      throw new Error('No channel name after @.');
+    }
+
+    if (properName.length < CHANNEL_NAME_MIN_LEN) {
+      throw new Error(`Channel names must be at least ${CHANNEL_NAME_MIN_LEN} characters.`);
+    }
+  }
+
+  const nameBadChars = properName.match(/[^A-Za-z0-9-]/g);
+  if (nameBadChars) {
+    throw new Error(`Invalid character${nameBadChars.length == 1 ? '' : 's'} in name: ${nameBadChars.join(', ')}.`);
+  }
+
+  // Validate and process modifier (claim ID, bid position or claim sequence)
+  let claimId, claimSequence, bidPosition;
+  if (modSep) {
+    if (!modVal) {
+      throw new Error(`No modifier provided after separator ${modSep}.`);
+    }
+
+    if (modSep == '#') {
+      claimId = modVal;
+    } else if (modSep == ':') {
+      claimSequence = modVal;
+    } else if (modSep == '$') {
+      bidPosition = modVal;
+    }
+  }
+
+  if (claimId && (claimId.length > CLAIM_ID_MAX_LEN || !claimId.match(/^[0-9a-f]+$/))) {
+    throw new Error(`Invalid claim ID ${claimId}.`);
+  }
+
+  if (bidPosition && !bidPosition.match(/^-?[1-9][0-9]+$/)) {
+    throw new Error('Bid position must be a number.');
+  }
+
+  if (claimSequence && !claimSequence.match(/^-?[1-9][0-9]+$/)) {
+    throw new Error('Claim sequence must be a number.');
+  }
+
+  // Validate path
+  if (path) {
+    if (!isChannel) {
+      throw new Error('Only channel URIs may have a path.');
+    }
+
+    const pathBadChars = path.match(/[^A-Za-z0-9-]/g);
+    if (pathBadChars) {
+      throw new Error(`Invalid character${count == 1 ? '' : 's'} in path: ${nameBadChars.join(', ')}`);
+    }
+  } else if (pathSep) {
+    throw new Error('No path provided after /');
+  }
+
+  return {
+    name, properName, isChannel,
+    ... claimSequence ? {claimSequence: parseInt(claimSequence)} : {},
+    ... bidPosition ? {bidPosition: parseInt(bidPosition)} : {},
+    ... claimId ? {claimId} : {},
+    ... path ? {path} : {},
+  };
+}
+
+uri.buildLbryUri = function(uriObj, includeProto=true) {
+  const {name, claimId, claimSequence, bidPosition, path} = uriObj;
+
+  return (includeProto ? 'lbry://' : '') + name +
+         (claimId ? `#${claimId}` : '') +
+         (claimSequence ? `:${claimSequence}` : '') +
+         (bidPosition ? `\$${bidPosition}` : '') +
+         (path ? `/${path}` : '');
+}
+
+export default uri;