pdf-tools/cli/prompts.ts

// deno-lint-disable-must-await-calls
import { log } from "util/logfile.ts";
import { Cursor } from "./cursor.ts";
import { colorize } from "./style.ts";
import { TerminalBlock, TerminalLayout } from "./TerminalLayout.ts";

export async function cliPrompt(
  message: string,
  block?: TerminalBlock,
): Promise<string> {
  const encoder = new TextEncoder();
  const input: string[] = [];
  let cursorPos = 0;

  await Deno.stdin.setRaw(true);

  const cursorVisible = Cursor["visible"];
  Cursor.show();

  let range: [number, number] = [0, 1];
  if (block) {
    range = block.setLines([message + " "]);
  } else {
    Deno.stdout.writeSync(encoder.encode(message + " "));
  }

  const render = () => {
    const line = message + " " + input.join("");
    const moveTo = `\x1b[${message.length + 2 + cursorPos}G`;

    if (block) {
      block.setPostRenderAction(function () {
        Deno.stdout.writeSync(
          encoder.encode(`\x1b[${this["lastRenderRow"]};1H`),
        );
        Deno.stdout.writeSync(encoder.encode(moveTo));
      });
      range = block.setLines([line], range);
    } else {
      Deno.stdout.writeSync(encoder.encode("\x1b[K" + line + moveTo));
    }
  };

  render();

  const buf = new Uint8Array(64); // large enough for most pastes
  while (true) {
    const n = await Deno.stdin.read(buf);
    if (n === null) break;

    for (let i = 0; i < n; i++) {
      const byte = buf[i];

      // Ctrl+C
      if (byte === 3) {
        block?.clear();
        block?.["layout"]?.clearAll();
        await Deno.stdin.setRaw(false);
        Deno.exit(130);
      }

      if (byte === 13) { // Enter
        break;
      }

      // Escape sequence?
      if (byte === 27 && i + 1 < n && buf[i + 1] === 91) {
        const third = buf[i + 2];
        if (third === 68 && cursorPos > 0) cursorPos--; // Left
        else if (third === 67 && cursorPos < input.length) cursorPos++; // Right
        else if (third === 51 && i + 3 < n && buf[i + 3] === 126) { // Delete
          if (cursorPos < input.length) input.splice(cursorPos, 1);
          i += 1; // consume tilde
        }
        i += 2; // consume ESC [ X
        continue;
      }

      // Backspace
      if (byte === 127 || byte === 8) {
        if (cursorPos > 0) {
          input.splice(cursorPos - 1, 1);
          cursorPos--;
        }
        continue;
      }

      // Delete (ASCII 46)
      if (byte === 46 && cursorPos < input.length) {
        input.splice(cursorPos, 1);
        continue;
      }

      // Printable
      if (byte >= 32 && byte <= 126) {
        input.splice(cursorPos, 0, String.fromCharCode(byte));
        cursorPos++;
      }

      // Other cases: ignore
    }

    render();
  }

  await Deno.stdin.setRaw(false);
  if (!cursorVisible) {
    Cursor.hide();
  }
  Deno.stdout.writeSync(encoder.encode("\n"));

  return input.join("");
}

export function cliConfirm(message: string, block?: TerminalBlock) {
  return cliPrompt(message + " (y/n)", block).then((v) =>
    v.toLowerCase() === "y"
  );
}

export function cliAlert(message: string, block?: TerminalBlock) {
  return cliPrompt(
    message + colorize(" Press Enter to continue", "gray"),
    block,
  ).then((v) => {
    return v;
  });
}

export function cliLog(
  message: string | object | Array<unknown>,
  block?: TerminalBlock,
) {
  if (!block) {
    console.log(message);
  } else {
    if (typeof message === "object") message = Deno.inspect(message);
    block.setLines(message.split("\n"));
  }
}

if (import.meta.main) {
  Cursor.hide();
  const layout = new TerminalLayout();
  const title = new TerminalBlock();
  const block = new TerminalBlock();
  const footer = new TerminalBlock();
  block.setPreserveHistory(true);
  // ScrollManager.enable(block);
  title.setLines(["Hello, World!"]);
  title.setFixedHeight(1);

  footer.setLines(["Press Ctrl+C to exit"]);
  footer.setFixedHeight(1);

  layout.register("title", title);
  layout.register("block", block);
  layout.register("footer", footer);

  Deno.addSignalListener("SIGINT", () => {
    layout.clearAll();
    // console.clear();
    Deno.exit(0);
  });
  const name = await cliPrompt("Enter your name:", block);
  cliLog(`Hello, ${name}!`, block);
  const single = await cliConfirm("Are you single?", block);
  cliLog(single ? "Do you want to go out with me?" : "Okay", block);
  // ScrollManager.enable(block);
  const loopingConvo = [
    "No response?",
    "I guess that's okay",
    "Maybe I'll see you next week?",
    "Wow, really not going to say anything to me?",
    "Well, if that's how you feel",
  ];
  let convo = 0;
  setInterval(() => {
    cliLog(loopingConvo[convo % loopingConvo.length], block);
    convo++;
  }, 2000);
  // setTimeout(async () => {
  //   await cliAlert("Well, if that's that...", block);
  //   Deno.exit(0);
  // }, 10000);
}