import { truncateToWidth, visibleWidth } from "@earendil-works/pi-tui";

import { sanitizeText } from "../utils/format";

import type { Component } from "@earendil-works/pi-tui";

interface InlineTextOptions {
  padding?: number;
  spacingChar?: string;
  ellipsis?: string;
}

const DEFAULT_INLINE_TEXT_OPTIONS: Required<InlineTextOptions> = {
  padding: 0,
  spacingChar: " ",
  ellipsis: "…",
};

/**
 * Text component that renders inline and truncates it to fit the given width.
 *
 * The given width is a budget, not a guaranteed rendered width. After rendering, callers should
 * check the result with visibleWidth(), because the rendered width may be smaller than the budget.
 */
export class InlineText implements Component {
  private text: string;

  private padding: number;
  private spacingChar: string;
  private ellipsis: string;

  constructor(text: string, options: InlineTextOptions = {}) {
    const spacingChar = options.spacingChar ?? DEFAULT_INLINE_TEXT_OPTIONS.spacingChar;
    if (visibleWidth(spacingChar) !== 1) throw new Error("spacingChar must have a visible width of 1");

    this.text = sanitizeText(text);

    this.padding = options.padding ?? DEFAULT_INLINE_TEXT_OPTIONS.padding;
    this.spacingChar = spacingChar;
    this.ellipsis = options.ellipsis ?? DEFAULT_INLINE_TEXT_OPTIONS.ellipsis;
  }

  invalidate(): void {
    // No-op
  }

  render(width: number): [string] {
    if (visibleWidth(this.text) <= 0) return [""];
    if (width < this.padding * 2 + visibleWidth(this.ellipsis)) return [""];

    const displayText = truncateToWidth(this.text, width - this.padding * 2, this.ellipsis);
    const paddingText = this.spacingChar.repeat(this.padding);

    return [`${paddingText}${displayText}${paddingText}`];
  }
}