import { stripVTControlCharacters } from "node:util";
import { visibleWidth } from "@earendil-works/pi-tui";
import { describe, expect, it } from "vitest";
import {
	compactChunkBudget,
	fullFooterFitsAligned,
	packCompactChunks,
	reflowFullFooter,
} from "../extensions/zentui/footer-layout";

const chunk = (text: string, boundary: "space" | "separator" = "space") => ({
	text,
	boundary,
});

describe("responsive footer layout", () => {
	it("models centered-middle placement and its floor bias", () => {
		expect(fullFooterFitsAligned({ left: "LLLLL", middle: "MMMM", right: "" }, 10)).toBe(false);
		expect(fullFooterFitsAligned({ left: "LLLLL", middle: "MMMM", right: "" }, 11)).toBe(true);
		expect(fullFooterFitsAligned({ left: "", middle: "MMMM", right: "RRRRR" }, 10)).toBe(true);
		expect(fullFooterFitsAligned({ left: "LLLL", middle: "MMM", right: "RRRR" }, 13)).toBe(true);
		expect(fullFooterFitsAligned({ left: "LLLL", middle: "MMM", right: "RRRR" }, 12)).toBe(false);
	});

	it("measures ANSI and Nerd Font content by visible terminal cells", () => {
		const zones = { left: "\u001b[31mLL\u001b[0m", middle: "\ue0a0", right: "RR" };
		expect(fullFooterFitsAligned(zones, 7)).toBe(true);
		expect(fullFooterFitsAligned(zones, 6)).toBe(false);
	});

	it("prefers left / middle+right and falls back to left+middle / right", () => {
		expect(reflowFullFooter({ left: "LLLL", middle: "MM", right: "RR" }, 5)).toEqual([
			"LLLL",
			"MM RR",
		]);
		expect(reflowFullFooter({ left: "L", middle: "MMMM", right: "RRRR" }, 6)).toEqual([
			"L MMMM",
			"RRRR",
		]);
		expect(reflowFullFooter({ left: "LLLLLL", middle: "MMMM", right: "RRRR" }, 6)).toBeUndefined();
	});

	it("collapses empty reflow zones without blank rows or stray spaces", () => {
		expect(reflowFullFooter({ left: "L", middle: "", right: "R" }, 2)).toEqual(["L", "R"]);
		expect(reflowFullFooter({ left: "", middle: "M", right: "R" }, 3)).toEqual(["M R"]);
		expect(reflowFullFooter({ left: "L", middle: "M", right: "" }, 3)).toEqual(["L", "M"]);
	});

	it("uses the exact half-row compact budget", () => {
		expect(compactChunkBudget(47)).toBe(23);
		expect(compactChunkBudget(19)).toBe(9);
		expect(compactChunkBudget(17)).toBe(8);
		expect(compactChunkBudget(8)).toBe(8);
		expect(compactChunkBudget(5)).toBe(8);
	});

	it("packs chunks with boundary-aware same-row joins and no divider at breaks", () => {
		expect(packCompactChunks([chunk("one"), chunk("two")], 7, 2, " | ")).toEqual(["one two"]);
		expect(packCompactChunks([chunk("one"), chunk("two", "separator")], 9, 2, " | ")).toEqual([
			"one | two",
		]);
		expect(packCompactChunks([chunk("one"), chunk("two", "separator")], 8, 2, " | ")).toEqual([
			"one",
			"two",
		]);
		expect(
			packCompactChunks([chunk("one"), chunk(""), chunk("  "), chunk("two")], 7, 2, " | "),
		).toEqual(["one two"]);
	});

	it("retains the next surviving chunk's incoming boundary", () => {
		expect(
			packCompactChunks([chunk("A"), chunk("", "separator"), chunk("B", "space")], 5, 2, " | "),
		).toEqual(["A B"]);
		expect(
			packCompactChunks([chunk("A"), chunk("", "space"), chunk("B", "separator")], 5, 2, " | "),
		).toEqual(["A | B"]);
	});

	it("supports every finite line limit and unlimited rows", () => {
		const chunks = [chunk("one"), chunk("two"), chunk("three")];
		expect(packCompactChunks(chunks, 5, 1, " | ")).toEqual(["one…"]);
		expect(packCompactChunks(chunks, 7, 2, " | ")).toEqual(["one two", "three"]);
		expect(packCompactChunks(chunks, 5, 3, " | ")).toEqual(["one", "two", "three"]);
		expect(packCompactChunks(chunks, 5, "unlimited", " | ")).toEqual(["one", "two", "three"]);
	});

	it("marks finite-cap omissions with exactly one ellipsis", () => {
		expect(
			packCompactChunks([chunk("12345"), chunk("later")], 5, 1, " | ").map(
				stripVTControlCharacters,
			),
		).toEqual(["1234…"]);
		expect(
			packCompactChunks([chunk("123456789"), chunk("later")], 5, 1, " | ").map(
				stripVTControlCharacters,
			),
		).toEqual(["1234…"]);
	});

	it("keeps every ANSI and wide-glyph row within width, even below the compact budget", () => {
		const rows = packCompactChunks(
			[chunk("\u001b[31mabcdef\u001b[0m"), chunk("界界界"), chunk("\ue0a0")],
			5,
			3,
			" | ",
		);
		expect(rows.every((row) => visibleWidth(row) <= 5)).toBe(true);
		expect(
			packCompactChunks([chunk("abcdefgh")], 5, 1, " | ").every((row) => visibleWidth(row) <= 5),
		).toBe(true);
	});
});