lbry-desktop/ui/util/remark-timestamp.js

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import visit from 'unist-util-visit';
const TIMESTAMP_NODE_TYPE = 'timestamp';
// ***************************************************************************
// Tokenize timestamp
// ***************************************************************************
function findNextTimestamp(value, fromIndex, strictlyFromIndex) {
let begin = 0;
while (begin < value.length) {
// Start with a rough match
const match = value.substring(begin).match(/[0-9:]+/);
if (!match) {
return null;
}
// Compensate 'substring' index. 'match.index' is relative to 'value' from now on.
match.index += begin;
if (strictlyFromIndex && match.index !== fromIndex) {
if (match.index > fromIndex) {
// Already gone past desired index. Skip the rest.
return null;
} else {
// Next match might fit 'fromIndex'.
begin = match.index + match[0].length;
continue;
}
}
// Exclude trailing colons to allow "0:12: Start of section", for example.
const str = match[0].replace(/:+$/, '');
let isValidTimestamp;
switch (str.length) {
case 4: // "9:59"
isValidTimestamp = /^[0-9]:[0-5][0-9]$/.test(str);
break;
case 5: // "59:59"
isValidTimestamp = /^[0-5][0-9]:[0-5][0-9]$/.test(str);
break;
case 7: // "9:59:59"
isValidTimestamp = /^[0-9]:[0-5][0-9]:[0-5][0-9]$/.test(str);
break;
case 8: // "23:59:59"
isValidTimestamp = /^[0-2][0-3]:[0-5][0-9]:[0-5][0-9]$/.test(str);
break;
default:
// Reject
isValidTimestamp = false;
break;
}
if (isValidTimestamp) {
// Profit!
return {
text: str,
index: match.index,
};
}
if (strictlyFromIndex && match.index >= fromIndex) {
return null; // Since it failed and we've gone past the desired index, skip the rest.
}
begin = match.index + match[0].length;
}
return null;
}
function locateTimestamp(value, fromIndex) {
const ts = findNextTimestamp(value, fromIndex, false);
return ts ? ts.index : -1;
}
// Generate 'timestamp' markdown node
const createTimestampNode = (text) => ({
type: TIMESTAMP_NODE_TYPE,
value: text,
children: [{ type: 'text', value: text }],
});
// Generate a markdown link from timestamp
function tokenizeTimestamp(eat, value, silent) {
if (silent) {
return true;
}
const ts = findNextTimestamp(value, 0, true);
if (ts) {
try {
const text = ts.text;
return eat(text)(createTimestampNode(text));
} catch (err) {
// Do nothing
}
}
}
tokenizeTimestamp.locator = locateTimestamp;
tokenizeTimestamp.notInList = true; // Flag doesn't work? It'll always tokenizes in List and never in Bullet.
tokenizeTimestamp.notInLink = true;
tokenizeTimestamp.notInBlock = true;
export function inlineTimestamp() {
const Parser = this.Parser;
const tokenizers = Parser.prototype.inlineTokenizers;
const methods = Parser.prototype.inlineMethods;
// Add an inline tokenizer (defined in the following example).
tokenizers.timestamp = tokenizeTimestamp;
// Run it just before `text`.
methods.splice(methods.indexOf('text'), 0, 'timestamp');
}
// ***************************************************************************
// Format timestamp
// ***************************************************************************
function strToSeconds(stime) {
const tt = stime.split(':').reverse();
return (tt.length >= 3 ? +tt[2] : 0) * 60 * 60 + (tt.length >= 2 ? +tt[1] : 0) * 60 + (tt.length >= 1 ? +tt[0] : 0);
}
const transformer = (node, index, parent) => {
if (node.type === TIMESTAMP_NODE_TYPE && parent && parent.type === 'paragraph') {
const timestampStr = node.value;
const seconds = strToSeconds(timestampStr);
node.type = 'link';
node.url = `?t=${seconds}`;
node.title = timestampStr;
node.children = [{ type: 'text', value: timestampStr }];
}
};
const transform = (tree) => {
visit(tree, [TIMESTAMP_NODE_TYPE], transformer);
};
export const formattedTimestamp = () => transform;