import TextBuffer from "../src/text-buffer.js";

import { describe, test, expect } from "vitest";

describe("TextBuffer – word‑wise navigation & deletion", () => {

test("wordRight moves to end‑of‑line when no further boundary", () => {

const tb = new TextBuffer("hello");

// Move the caret inside the word (index 3)

tb.move("right");

tb.move("right");

tb.move("right");

tb.move("wordRight");

const [, col] = tb.getCursor();

expect(col).toBe(5); // end of the word / line

});

test("Ctrl+Backspace on raw byte deletes previous word", () => {

const tb = new TextBuffer("hello world");

const vp = { height: 10, width: 80 } as const;

// Place caret at end

tb.move("end");

// Simulate terminal sending DEL (0x7f) byte with ctrl modifier – Ink

// usually does *not* set `key.backspace` in this path.

tb.handleInput("\x7f", { ctrl: true }, vp);

expect(tb.getText()).toBe("hello ");

});

test("Option/Alt+Backspace deletes previous word", () => {

const tb = new TextBuffer("foo bar baz");

const vp = { height: 10, width: 80 } as const;

// caret at end

tb.move("end");

// Simulate Option+Backspace (alt): Ink sets key.backspace = true, key.alt = true (no raw byte)

tb.handleInput(undefined, { backspace: true, alt: true }, vp);

expect(tb.getText()).toBe("foo bar ");

});

test("Option/Alt+Delete deletes previous word (matches shells)", () => {

const tb = new TextBuffer("foo bar baz");

const vp = { height: 10, width: 80 } as const;

// Place caret at end so we can test backward deletion.

tb.move("end");

// Simulate Option+Delete (parsed as alt-modified Delete on some terminals)

tb.handleInput(undefined, { delete: true, alt: true }, vp);

expect(tb.getText()).toBe("foo bar ");

});

test("wordLeft eventually reaches column 0", () => {

const tb = new TextBuffer("hello world");

// Move to end of line first

tb.move("end");

// two wordLefts should land at start of line

tb.move("wordLeft");

tb.move("wordLeft");

const [, col] = tb.getCursor();

expect(col).toBe(0);

});

test("wordRight jumps over a delimiter into the next word", () => {

const tb = new TextBuffer("hello world");

tb.move("wordRight"); // from start – should land after "hello" (between space & w)

let [, col] = tb.getCursor();

expect(col).toBe(5);

// Next wordRight should move to end of line (after "world")

tb.move("wordRight");

[, col] = tb.getCursor();

expect(col).toBe(11);

});

test("deleteWordLeft after trailing space only deletes the last word, not the whole line", () => {

const tb = new TextBuffer("I want you to refactor my view ");

tb.move("end"); // Place caret after the space

tb.deleteWordLeft();

expect(tb.getText()).toBe("I want you to refactor my ");

const [, col] = tb.getCursor();

expect(col).toBe("I want you to refactor my ".length);

});

test("deleteWordLeft removes the previous word and positions the caret correctly", () => {

const tb = new TextBuffer("hello world");

// Place caret at end of line

tb.move("end");

// Act

tb.deleteWordLeft();

expect(tb.getText()).toBe("hello ");

const [, col] = tb.getCursor();

expect(col).toBe(6); // after the space

});

test("deleteWordRight removes the following word", () => {

const tb = new TextBuffer("hello world");

// Move caret to start of "world"

tb.move("wordRight"); // caret after "hello"

tb.move("right"); // skip the space, now at index 6 (start of world)

// Act

tb.deleteWordRight();

expect(tb.getText()).toBe("hello ");

const [, col] = tb.getCursor();

expect(col).toBe(6);

});

test("Shift+Option/Alt+Delete deletes next word", () => {

const tb = new TextBuffer("foo bar baz");

const vp = { height: 10, width: 80 } as const;

// Move caret between first and second word (after space)

tb.move("wordRight"); // after foo

tb.move("right"); // skip space -> start of bar

// Shift+Option+Delete should now remove "bar "

tb.handleInput(undefined, { delete: true, alt: true, shift: true }, vp);

expect(tb.getText()).toBe("foo baz");

});

});