import { afterEach, describe, expect, it } from "bun:test";
import { getEditorCommand } from "../src/utils/external-editor";

interface MutableProcess {
	platform: NodeJS.Platform;
}

function setPlatform(value: NodeJS.Platform): void {
	(process as unknown as MutableProcess).platform = value;
}

describe("getEditorCommand", () => {
	const originalPlatform = process.platform;
	const originalVisual = Bun.env.VISUAL;
	const originalEditor = Bun.env.EDITOR;

	afterEach(() => {
		setPlatform(originalPlatform);
		if (originalVisual === undefined) delete Bun.env.VISUAL;
		else Bun.env.VISUAL = originalVisual;
		if (originalEditor === undefined) delete Bun.env.EDITOR;
		else Bun.env.EDITOR = originalEditor;
	});

	it("prefers $VISUAL over $EDITOR and the platform default", () => {
		Bun.env.VISUAL = "nvim";
		Bun.env.EDITOR = "nano";
		setPlatform("win32");
		expect(getEditorCommand()).toBe("nvim");
	});

	it("falls back to $EDITOR when $VISUAL is unset", () => {
		delete Bun.env.VISUAL;
		Bun.env.EDITOR = "nano";
		expect(getEditorCommand()).toBe("nano");
	});

	it("trims whitespace so an accidentally padded value still works", () => {
		Bun.env.VISUAL = "  code --wait  ";
		delete Bun.env.EDITOR;
		expect(getEditorCommand()).toBe("code --wait");
	});

	it("treats a whitespace-only $VISUAL as unset and consults $EDITOR", () => {
		Bun.env.VISUAL = "   ";
		Bun.env.EDITOR = "vim";
		expect(getEditorCommand()).toBe("vim");
	});

	it("defaults to notepad on Windows when neither variable is set", () => {
		delete Bun.env.VISUAL;
		delete Bun.env.EDITOR;
		setPlatform("win32");
		expect(getEditorCommand()).toBe("notepad");
	});

	it("returns undefined on POSIX when neither variable is set", () => {
		delete Bun.env.VISUAL;
		delete Bun.env.EDITOR;
		setPlatform("linux");
		expect(getEditorCommand()).toBeUndefined();
	});
});