LogCommon.ts

import { padStart } from '@shared/Util';
import { ILogEntry, LogLevel } from '@shared/Log/interface';

export const timeChars = 11; // "[HH:MM:SS] "
const sourceChars = 19; // "Background Services" (sometimes used with +2 to add the length of ": ")

/** Create a HTML string of a number of entries */
export function stringifyLogEntries(entries: ILogEntry[], sourceFilter: { [key: string]: boolean } = {}, levelFilter: { [key in LogLevel]: boolean }): string {
  let str = '';
  let prevEntry: ILogEntry = { source: '', content: '', timestamp: 0, logLevel: -1 };
  for (let i = 0; i < entries.length; i++) {
    const entry = entries[i];

    if (!entry) { continue; } // Temp fix for array gaps

    if (sourceFilter[entry.source] === false || levelFilter[entry.logLevel] === false) { continue; }

    // E.G log__level-WARN, log__level-DEBUG
    str += `<span class="log__level-${LogLevel[entry.logLevel]}">${getLevelText(entry.logLevel)}</span> `;
    str += `<span class="log__time-stamp">[${formatTime(new Date(entry.timestamp))}]</span> `;
    if (entry.source) {
      str += (!prevEntry || entry.source !== prevEntry.source)
        ? `<span class="log__source log__source--${getClassModifier(entry.source)}">${padStart(escapeHTML(entry.source), sourceChars)}:</span> `
        : ' '.repeat(sourceChars + 2);
    }
    str += padLines(escapeHTML(entry.content), timeChars + sourceChars + 2);
    str += '\n';

    prevEntry = entry;
  }

  return str;
}

/** Create a HTML string of a number of entries */
export function stringifyLogEntriesRaw(entries: ILogEntry[], sourceFilter: { [key: string]: boolean } = {}, levelFilter: { [key in LogLevel]: boolean }): string {
  let str = '';
  let prevEntry: ILogEntry = { source: '', content: '', timestamp: 0, logLevel: -1 };

  for (let i = 0; i < entries.length; i++) {
    const entry = entries[i];

    if (sourceFilter[entry.source] === false || levelFilter[entry.logLevel] === false) { continue; }

    str += `${getLevelText(entry.logLevel)} `;
    str += `[${(new Date(entry.timestamp)).toLocaleString()}] `;
    if (entry.source) {
      str += (entry.source !== prevEntry.source)
        ? `${padStart(escapeHTML(entry.source), sourceChars)} | `
        : ' '.repeat(sourceChars + 2);
    }
    str += padLines(entry.content, timeChars + sourceChars + 2);
    str += '\n';

    prevEntry = entry;
  }

  return str;
}

function getLevelText(logLevel: LogLevel) {
  return LogLevel[logLevel].padEnd(5) || '?????';
}

/** Formats a date to a string in the format "HH:MM:SS" */
export function formatTime(date: Date): string {
  return (
    ('0'+date.getHours()  ).slice(-2)+':'+
    ('0'+date.getMinutes()).slice(-2)+':'+
    ('0'+date.getSeconds()).slice(-2)
  );
}

/** Mak a string safe to use as HTML content (only safe if used as "text" between tags, not inside a tag) */
export function escapeHTML(str: string): string {
  return str.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;');
}

/**
 * Create a CSS class "modifier" name from the name of a log entry source
 * (it just makes it lower-case, only alphabetical characters and replaces all spaces with "-")
 */
function getClassModifier(source: string): string {
  return (
    source
    .toLowerCase()
    .replace(/ /g, '-')
    .replace(/[^a-z-]/gi, '') // (Only allow a-z and "-")
  );
}

/** Pad all lines (except for the first one) by a number of spaces */
export function padLines(text: string, padding: number): string {
  return text.replace(/\n/g, '\n'+' '.repeat(padding));
}