scroll/src/common/document.ts

import { chars } from './utils.ts';
import { getRuntime } from './runtime.ts';

export class Row {
	chars: string[] = [];

	constructor(s: string = '') {
		this.chars = chars(s);
	}

	public toString(): string {
		return this.chars.join('');
	}
}

export class Document {
	#rows: Row[];

	private constructor() {
		this.#rows = [];
	}

	get numRows(): number {
		return this.#rows.length;
	}

	public static empty(): Document {
		return new Document();
	}

	public isEmpty(): boolean {
		return this.#rows.length === 0;
	}

	public async open(filename: string): Promise<Document> {
		const { file } = await getRuntime();

		// Clear any existing rows
		if (!this.isEmpty()) {
			this.#rows = [];
		}

		const rawFile = await file.openFile(filename);
		rawFile.split(/\r?\n/)
			.forEach((row) => this.appendRow(row));

		return this;
	}

	public row(i: number): Row | null {
		if (this.#rows[i] !== undefined) {
			return this.#rows[i];
		}

		return null;
	}

	protected appendRow(s: string): void {
		this.#rows.push(new Row(s));
	}
}

export default Document;