import srtParser2 from "srt-parser-2";
import { TextLoader } from "langchain/document_loaders/fs/text";
/**
 * A class that extends the `TextLoader` class. It represents a document
 * loader that loads documents from SRT (SubRip) subtitle files. It has a
 * constructor that takes a `filePathOrBlob` parameter representing the
 * path to the SRT file or a `Blob` object. The `parse()` method is
 * implemented to parse the SRT file and extract the text content of each
 * subtitle.
 * @example
 * ```typescript
 * const loader = new SRTLoader("path/to/file.srt");
 * const docs = await loader.load();
 * console.log({ docs });
 * ```
 */
export class SRTLoader extends TextLoader {
    constructor(filePathOrBlob) {
        super(filePathOrBlob);
    }
    /**
     * A protected method that takes a `raw` string as a parameter and returns
     * a promise that resolves to an array of strings. It parses the raw SRT
     * string using the `SRTParser2` class from the `srt-parser-2` module. It
     * retrieves the subtitle objects from the parsed SRT data and extracts
     * the text content from each subtitle object. It filters out any empty
     * text content and joins the non-empty text content with a space
     * separator.
     * @param raw The raw SRT string to be parsed.
     * @returns A promise that resolves to an array of strings representing the text content of each subtitle.
     */
    async parse(raw) {
        // eslint-disable-next-line new-cap
        const parser = new srtParser2();
        const srts = parser.fromSrt(raw);
        return [
            srts
                .map((srt) => srt.text)
                .filter(Boolean)
                .join(" "),
        ];
    }
}
