import { EditState, insertTextAtSelection, toggleCodeBlock, toggleLinePrefix, toggleWrap, wrapWithLink } from './markdownEditing';

const state = (content: string, selectionStart: number, selectionEnd = selectionStart): EditState => {
	return { content, selectionStart, selectionEnd };
};

describe('markdownEditing', () => {
	test('insertTextAtSelection inserts at the cursor and moves it', () => {
		expect(insertTextAtSelection(state('ac', 1), 'b')).toEqual({
			content: 'abc',
			selectionStart: 2,
			selectionEnd: 2,
		});
	});

	test('insertTextAtSelection replaces the selection', () => {
		expect(insertTextAtSelection(state('aXYb', 1, 3), 'Z')).toEqual({
			content: 'aZb',
			selectionStart: 2,
			selectionEnd: 2,
		});
	});

	test('toggleWrap wraps and unwraps a selection', () => {
		const wrapped = toggleWrap(state('hello', 0, 5), '**', 'strong text');
		expect(wrapped).toEqual({ content: '**hello**', selectionStart: 2, selectionEnd: 7 });

		expect(toggleWrap(wrapped, '**', 'strong text')).toEqual({
			content: 'hello',
			selectionStart: 0,
			selectionEnd: 5,
		});
	});

	test('toggleWrap unwraps markers included in the selection', () => {
		expect(toggleWrap(state('**hello**', 0, 9), '**', 'strong text')).toEqual({
			content: 'hello',
			selectionStart: 0,
			selectionEnd: 5,
		});
	});

	test('toggleWrap inserts the placeholder when there is no selection', () => {
		expect(toggleWrap(state('', 0), '_', 'italic text')).toEqual({
			content: '_italic text_',
			selectionStart: 1,
			selectionEnd: 12,
		});
	});

	test('toggleLinePrefix adds and removes a prefix on the selected lines', () => {
		const prefixed = toggleLinePrefix(state('one\ntwo', 0, 7), { add: '- ', detect: /^[-*+] / });
		expect(prefixed.content).toBe('- one\n- two');

		expect(toggleLinePrefix(prefixed, { add: '- ', detect: /^[-*+] / }).content).toBe('one\ntwo');
	});

	test('toggleLinePrefix skips empty lines and keeps the cursor after the prefix', () => {
		const result = toggleLinePrefix(state('one\n\ntwo', 0, 8), { add: '- ', detect: /^[-*+] / });
		expect(result.content).toBe('- one\n\n- two');

		const cursor = toggleLinePrefix(state('one', 0), { add: '# ', detect: /^#{1,6} / });
		expect(cursor).toEqual({ content: '# one', selectionStart: 2, selectionEnd: 2 });
	});

	test('toggleLinePrefix only affects the line under the cursor', () => {
		expect(toggleLinePrefix(state('one\ntwo', 4), { add: '> ', detect: /^> ?/ }).content).toBe('one\n> two');
	});

	test('toggleLinePrefix shifts a selection that starts mid-line', () => {
		expect(toggleLinePrefix(state('one', 1, 3), { add: '- ', detect: /^[-*+] / })).toEqual({
			content: '- one',
			selectionStart: 3,
			selectionEnd: 5,
		});
	});

	test('toggleCodeBlock wraps a selection in a fenced block', () => {
		expect(toggleCodeBlock(state('code', 0, 4))).toEqual({
			content: '```\ncode\n```',
			selectionStart: 4,
			selectionEnd: 8,
		});
	});

	test('toggleCodeBlock inserts empty fences with the cursor inside', () => {
		expect(toggleCodeBlock(state('', 0))).toEqual({
			content: '```\n\n```',
			selectionStart: 4,
			selectionEnd: 4,
		});
	});

	test('wrapWithLink wraps the selection and keeps it selected', () => {
		expect(wrapWithLink(state('hello', 0, 5), 'https://example.com')).toEqual({
			content: '[hello](https://example.com)',
			selectionStart: 1,
			selectionEnd: 6,
		});
	});

	test('wrapWithLink places the cursor inside the brackets when empty', () => {
		expect(wrapWithLink(state('', 0), 'https://example.com')).toEqual({
			content: '[](https://example.com)',
			selectionStart: 1,
			selectionEnd: 1,
		});
	});
});