lbry-redux/src/lbryURI.js

const channelNameMinLength = 1;
const claimIdMaxLength = 40;

// see https://spec.lbry.com/#urls
export const regexInvalidURI = /[ =&#:$@%?;/\\"<>%{}|^~[\]`\u{0000}-\u{0008}\u{000b}-\u{000c}\u{000e}-\u{001F}\u{D800}-\u{DFFF}\u{FFFE}-\u{FFFF}]/u;
export const regexAddress = /^(b|r)(?=[^0OIl]{32,33})[0-9A-Za-z]{32,33}$/;

/**
 * Parses a LBRY name into its component parts. Throws errors with user-friendly
 * messages for invalid names.
 *
 * N.B. that "name" indicates the value in the name position of the URI. For
 * claims for channel content, this will actually be the channel name, and
 * the content name is in the path (e.g. lbry://@channel/content)
 *
 * In most situations, you'll want to use the contentName and channelName keys
 * and ignore the name key.
 *
 * Returns a dictionary with keys:
 *   - name (string): The value in the "name" position in the URI. Note that this
 *                    could be either content name or channel name; see above.
 *   - path (string, if persent)
 *   - claimSequence (int, if present)
 *   - bidPosition (int, if present)
 *   - claimId (string, if present)
 *   - isChannel (boolean)
 *   - contentName (string): For anon claims, the name; for channel claims, the path
 *   - channelName (string, if present): Channel name without @
 */
export function parseURI(URI, requireProto = false) {
  // Break into components. Empty sub-matches are converted to null
  const componentsRegex = new RegExp(
    '^((?:lbry://)?)' + // protocol
    '([^:$#/]*)' + // claim name (stops at the first separator or end)
    '([:$#]?)([^/]*)' + // modifier separator, modifier (stops at the first path separator or end)
      '(/?)(.*)' // path separator, path
  );
  const [proto, claimName, modSep, modVal, pathSep, path] = componentsRegex
    .exec(URI)
    .slice(1)
    .map(match => match || null);

  let contentName;

  // Validate protocol
  if (requireProto && !proto) {
    throw new Error(__('LBRY URIs must include a protocol prefix (lbry://).'));
  }

  // Validate and process name
  if (!claimName) {
    throw new Error(__('URI does not include name.'));
  }

  const isChannel = claimName.startsWith('@');
  const channelName = isChannel ? claimName.slice(1) : claimName;

  if (isChannel) {
    if (!channelName) {
      throw new Error(__('No channel name after @.'));
    }

    if (channelName.length < channelNameMinLength) {
      throw new Error(__(`Channel names must be at least %s characters.`, channelNameMinLength));
    }

    contentName = path;
  }

  const nameBadChars = (channelName || claimName).match(regexInvalidURI);
  if (nameBadChars) {
    throw new Error(
      __(
        `Invalid character %s in name: %s.`,
        nameBadChars.length === 1 ? '' : 's',
        nameBadChars.join(', ')
      )
    );
  }

  // Validate and process modifier (claim ID, bid position or claim sequence)
  let claimId;
  let claimSequence;
  let bidPosition;
  if (modSep) {
    if (!modVal) {
      throw new Error(__(`No modifier provided after separator %s.`, modSep));
    }

    if (modSep === '#') {
      claimId = modVal;
    } else if (modSep === ':') {
      claimSequence = modVal;
    } else if (modSep === '$') {
      bidPosition = modVal;
    }
  }

  if (claimId && (claimId.length > claimIdMaxLength || !claimId.match(/^[0-9a-f]+$/))) {
    throw new Error(__(`Invalid claim ID %s.`, claimId));
  }

  if (claimSequence && !claimSequence.match(/^-?[1-9][0-9]*$/)) {
    throw new Error(__('Claim sequence must be a number.'));
  }

  if (bidPosition && !bidPosition.match(/^-?[1-9][0-9]*$/)) {
    throw new Error(__('Bid position must be a number.'));
  }

  // Validate and process path
  if (path) {
    if (!isChannel) {
      throw new Error(__('Only channel URIs may have a path.'));
    }

    const pathBadChars = path.match(regexInvalidURI);
    if (pathBadChars) {
      throw new Error(__(`Invalid character in path: %s`, pathBadChars.join(', ')));
    }

    contentName = path;
  } else if (pathSep) {
    throw new Error(__('No path provided after /'));
  }

  return {
    claimName,
    path,
    isChannel,
    ...(contentName ? { contentName } : {}),
    ...(channelName ? { channelName } : {}),
    ...(claimSequence ? { claimSequence: parseInt(claimSequence, 10) } : {}),
    ...(bidPosition ? { bidPosition: parseInt(bidPosition, 10) } : {}),
    ...(claimId ? { claimId } : {}),
    ...(path ? { path } : {}),
  };
}

/**
 * Takes an object in the same format returned by parse() and builds a URI.
 *
 * The channelName key will accept names with or without the @ prefix.
 */
export function buildURI(URIObj, includeProto = true, protoDefault = 'lbry://') {
  const { claimId, claimSequence, bidPosition, contentName, channelName } = URIObj;

  let { claimName, path } = URIObj;

  if (channelName) {
    const channelNameFormatted = channelName.startsWith('@') ? channelName : `@${channelName}`;
    if (!claimName) {
      claimName = channelNameFormatted;
    } else if (claimName !== channelNameFormatted) {
      throw new Error(
        __(
          'Received a channel content URI, but claim name and channelName do not match. "name" represents the value in the name position of the URI (lbry://name...), which for channel content will be the channel name. In most cases, to construct a channel URI you should just pass channelName and contentName.'
        )
      );
    }
  }

  if (contentName) {
    if (!claimName) {
      claimName = contentName;
    } else if (!path) {
      path = contentName;
    }
    if (path && path !== contentName) {
      throw new Error(
        __(
          'Path and contentName do not match. Only one is required; most likely you wanted contentName.'
        )
      );
    }
  }

  return (
    (includeProto ? protoDefault : '') +
    claimName +
    (claimId ? `#${claimId}` : '') +
    (claimSequence ? `:${claimSequence}` : '') +
    (bidPosition ? `${bidPosition}` : '') +
    (path ? `/${path}` : '')
  );
}

/* Takes a parseable LBRY URI and converts it to standard, canonical format */
export function normalizeURI(URI) {
  const { claimName, path, bidPosition, claimSequence, claimId } = parseURI(URI);
  return buildURI({ claimName, path, claimSequence, bidPosition, claimId });
}

export function isURIValid(URI) {
  let parts;
  try {
    parts = parseURI(normalizeURI(URI));
  } catch (error) {
    return false;
  }
  return parts && parts.claimName;
}

export function isNameValid(claimName) {
  return !regexInvalidURI.test(claimName);
}

export function isURIClaimable(URI) {
  let parts;
  try {
    parts = parseURI(normalizeURI(URI));
  } catch (error) {
    return false;
  }
  return (
    parts &&
    parts.claimName &&
    !parts.claimId &&
    !parts.bidPosition &&
    !parts.claimSequence &&
    !parts.isChannel &&
    !parts.path
  );
}

export function convertToShareLink(URI) {
  const { claimName, path, bidPosition, claimSequence, claimId } = parseURI(URI);
  return buildURI(
    { claimName, path, claimSequence, bidPosition, claimId },
    true,
    'https://open.lbry.com/'
  );
}