This is an augmented version of my earlier script that can be found here:
This time it features zigzag and channel lines, signal generation and filtering and performance testing. Signal generation and filtering procedures are used only for performance testing, not for the actual labelling. The labelling is governed by zigzag logic.
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.