import { fileURLToPath } from "node:url";
import type { ExtensionUIContext } from "@earendil-works/pi-coding-agent";
import { visibleWidth } from "@earendil-works/pi-tui";
import { afterEach, describe, expect, it, vi } from "vitest";
import {
	createPiSession,
	type PiSession,
} from "../../../test/fixture/create-pi-session.ts";
import { __test } from "../index.ts";
import type { ProducerBridge } from "./producer.ts";

const footerPath = fileURLToPath(new URL("../index.ts", import.meta.url));
const producerPath = fileURLToPath(new URL("./producer.ts", import.meta.url));

interface UiCall {
	args: unknown[];
}

/**
 * Records `setFooter` factories by capturing each `setFooter` call, and stands
 * in for the interactive UI so `hasUI` is true once mounted.
 */
function createRecordingUi() {
	const setFooterCalls: UiCall[] = [];
	const ui = {
		setFooter: (factory: unknown) => {
			setFooterCalls.push({ args: [factory] });
		},
		notify: () => {},
	};
	return { ui: ui as unknown as ExtensionUIContext, setFooterCalls };
}

function setBridge(bridge: ProducerBridge): void {
	(globalThis as Record<string, unknown>)["__footerProducerBridge"] = bridge;
}

describe("footer contract", () => {
	let session: PiSession | undefined;

	afterEach(async () => {
		vi.restoreAllMocks();
		(globalThis as Record<string, unknown>)["__footerProducerBridge"] =
			undefined;
		await session?.dispose();
		session = undefined;
	});

	async function mountTui(
		active: PiSession,
		ui: ExtensionUIContext,
	): Promise<void> {
		const runner = active.session.extensionRunner;
		runner.setUIContext(ui, "tui");
		await runner.emit({ type: "session_start", reason: "startup" });
	}

	it("loads in real Pi extension runtime", async () => {
		session = await createPiSession({ extensionPaths: [footerPath] });

		expect(session.extensions).toHaveLength(1);
		expect(session.extensions[0]!.path).toBe(footerPath);
	});

	it("acknowledges and retains pre-mount updates without polling", async () => {
		let accepted = 0;
		let offer: ((id: string) => void) | undefined;
		setBridge({
			onLoad: (emit) => {
				offer = (id) =>
					emit({
						id,
						text: "ready",
						zone: "llm",
						accept: () => accepted++,
					});
				offer("early");
			},
		});
		const setTimeoutSpy = vi.spyOn(globalThis, "setTimeout");
		session = await createPiSession({
			extensionPaths: [footerPath, producerPath],
		});
		const { ui, setFooterCalls } = createRecordingUi();

		expect(accepted).toBe(1);
		expect(setFooterCalls).toHaveLength(0);

		const runner = session.session.extensionRunner;
		runner.setUIContext(ui, "rpc");
		await runner.emit({ type: "session_start", reason: "startup" });
		expect(setFooterCalls).toHaveLength(0);
		offer?.("rpc");
		expect(accepted).toBe(1);

		await mountTui(session, ui);
		expect(accepted).toBe(1);
		expect(setTimeoutSpy.mock.calls.some(([, delay]) => delay === 50)).toBe(
			false,
		);
		setTimeoutSpy.mockRestore();

		const factory = setFooterCalls.at(-1)?.args[0] as
			| ((
					tui: { requestRender(): void },
					theme: { fg(style: string, text: string): string },
					data: {
						onBranchChange(callback: () => void): () => void;
						getExtensionStatuses(): ReadonlyMap<string, string>;
					},
			  ) => { render(width: number): string[] })
			| undefined;
		const component = factory?.(
			{ requestRender() {} },
			{ fg: (_style, text) => text },
			{
				onBranchChange: () => () => {},
				getExtensionStatuses: () => new Map(),
			},
		);
		expect(component?.render(80).join("\n")).toContain("ready");
	});

	it("isolates acknowledgements from a nested non-TUI runtime", async () => {
		let parentAccepted = 0;
		setBridge({
			onLoad: (emit) => {
				emit({
					id: "parent",
					text: "ready",
					zone: "llm",
					accept: () => parentAccepted++,
				});
			},
		});
		session = await createPiSession({
			extensionPaths: [footerPath, producerPath],
		});
		const { ui } = createRecordingUi();
		await mountTui(session, ui);
		expect(parentAccepted).toBe(1);

		const nested = await createPiSession({ extensionPaths: [footerPath] });
		try {
			const runner = nested.session.extensionRunner;
			const { ui: nestedUi } = createRecordingUi();
			runner.setUIContext(nestedUi, "rpc");
			await runner.emit({ type: "session_start", reason: "startup" });
			await runner.emit({ type: "session_shutdown", reason: "quit" });
			expect(parentAccepted).toBe(1);
		} finally {
			await nested.dispose();
		}
	});

	it("keeps valid segments when a producer emits malformed data", async () => {
		const bridge: ProducerBridge = {};
		setBridge(bridge);
		session = await createPiSession({
			extensionPaths: [footerPath, producerPath],
		});
		const emitSegment = bridge.emit;
		const { ui, setFooterCalls } = createRecordingUi();
		await mountTui(session, ui);
		const factory = setFooterCalls.at(-1)?.args[0] as
			| ((
					tui: { requestRender(): void },
					theme: { fg(style: string, text: string): string },
					data: {
						onBranchChange(callback: () => void): () => void;
						getExtensionStatuses(): ReadonlyMap<string, string>;
					},
			  ) => { render(width: number): string[] })
			| undefined;
		const component = factory?.(
			{ requestRender() {} },
			{
				fg: (style, text) => {
					if (style === "not-a-theme-color") throw new Error("bad color");
					return text;
				},
			},
			{
				onBranchChange: () => () => {},
				getExtensionStatuses: () => new Map(),
			},
		);

		let accepted = 0;
		emitSegment?.({
			id: "good",
			text: "healthy",
			zone: "llm",
			accept: () => accepted++,
		});
		emitSegment?.({
			id: "good",
			text: 42,
			zone: "llm",
			accept: () => accepted++,
		});
		expect(accepted).toBe(1);
		emitSegment?.({
			id: "good",
			text: "poison",
			zone: "llm",
			color: "not-a-theme-color",
			accept: () => accepted++,
		});
		expect(accepted).toBe(1);
		expect(component?.render(80).join("\n")).toContain("healthy");
		expect(component?.render(80).join("\n")).not.toContain("poison");
	});

	it("keeps later LLM components visible as earlier values grow", async () => {
		const bridge: ProducerBridge = {};
		setBridge(bridge);
		session = await createPiSession({
			extensionPaths: [footerPath, producerPath],
		});
		const emitSegment = bridge.emit;
		const { ui, setFooterCalls } = createRecordingUi();
		await mountTui(session, ui);

		const factory = setFooterCalls.at(-1)?.args[0] as
			| ((
					tui: { requestRender(): void },
					theme: { fg(style: string, text: string): string },
					data: {
						onBranchChange(callback: () => void): () => void;
						getExtensionStatuses(): ReadonlyMap<string, string>;
					},
			  ) => {
					render(width: number): string[];
					dispose(): void;
			  })
			| undefined;
		expect(factory).toBeTypeOf("function");
		const component = factory?.(
			{ requestRender() {} },
			{ fg: (_style, text) => text },
			{
				onBranchChange: () => () => {},
				getExtensionStatuses: () => new Map(),
			},
		);
		expect(component).toBeDefined();

		emitSegment?.({ id: "model", text: "sol:medium", zone: "llm", order: 0 });
		emitSegment?.({ id: "tokens", text: "↑0", zone: "llm", order: 2 });
		emitSegment?.({ id: "tps", text: "50.0/s", zone: "llm", order: 4 });
		const initial = component?.render(32) ?? [];
		expect(initial).toHaveLength(2);
		expect(initial.join("\n")).toContain("50.0/s");

		emitSegment?.({
			id: "tokens",
			text: "↑12k ↓3.4k",
			zone: "llm",
			order: 2,
		});
		const grown = component?.render(32) ?? [];
		expect(grown).toHaveLength(3);
		expect(grown.join("\n")).toContain("50.0/s");
		expect(grown.every((line) => visibleWidth(line) <= 32)).toBe(true);

		emitSegment?.({ id: "tokens", text: "↑0", zone: "llm", order: 2 });
		const shrunk = component?.render(32) ?? [];
		expect(shrunk).toHaveLength(2);
		expect(shrunk.join("\n")).toContain("50.0/s");

		emitSegment?.({
			id: "provider",
			text: "provider",
			zone: "llm",
			group: "model-route",
			order: -0.5,
		});
		emitSegment?.({
			id: "model",
			text: "sol:medium",
			zone: "llm",
			group: "model-route",
			gap: 2,
			order: 0,
		});
		expect(component?.render(80).join("\n")).toContain("provider  sol:medium");
		component?.dispose();
	});

	it.each([
		[true, "tui", true],
		[true, "rpc", false],
		[false, "json", false],
		[false, "print", false],
		[false, "tui", false],
	] as const)(
		"requires UI and TUI mode when hasUI=%s and mode=%s",
		(hasUI, mode, expected) => {
			expect(__test.canRenderFooter({ hasUI, mode })).toBe(expected);
		},
	);

	it("keeps equal-priority order stable after removal and reinsertion", () => {
		const quota = {
			id: "quota:anthropic",
			text: "quota",
			zone: "llm",
			order: 4,
		} as const;
		const tps = {
			id: "tps",
			text: "tps",
			zone: "llm",
			order: 4,
		} as const;
		const segments = new Map<string, typeof tps | typeof quota>([
			[tps.id, tps],
			[quota.id, quota],
		]);
		segments.delete(tps.id);
		segments.set(tps.id, tps);

		expect([...segments.values()].sort(__test.compareSegments)).toEqual([
			quota,
			tps,
		]);
	});

	it("renders nothing and schedules no retries when hidden", async () => {
		const bridge: ProducerBridge = {};
		setBridge(bridge);
		session = await createPiSession({
			extensionPaths: [footerPath, producerPath],
		});
		const emitSegment = bridge.emit;
		const { ui, setFooterCalls } = createRecordingUi();
		await mountTui(session, ui);
		const runner = session.session.extensionRunner;
		await session.extensions[0]?.commands
			.get("footer")
			?.handler("", runner.createCommandContext());
		const factory = setFooterCalls.at(-1)?.args[0] as
			| ((
					tui: { requestRender(force?: boolean): void },
					theme: { fg(style: string, text: string): string },
					data: {
						getGitBranch(): string | null;
						onBranchChange(callback: () => void): () => void;
						getExtensionStatuses(): ReadonlyMap<string, string>;
					},
			  ) => {
					render(width: number): string[];
			  })
			| undefined;
		expect(
			factory?.(
				{ requestRender() {} },
				{ fg: (_style, text) => text },
				{
					getGitBranch: () => null,
					onBranchChange: () => () => {},
					getExtensionStatuses: () => new Map(),
				},
			).render(80),
		).toEqual([]);

		const setTimeoutSpy = vi.spyOn(globalThis, "setTimeout");
		emitSegment?.({ id: "tps", text: "50/s", zone: "llm" });
		expect(setTimeoutSpy).not.toHaveBeenCalled();
		setTimeoutSpy.mockRestore();
	});

	it("re-publishes Pi branch changes as footer:branch-change", async () => {
		const bridge: ProducerBridge = {};
		setBridge(bridge);
		session = await createPiSession({
			extensionPaths: [footerPath, producerPath],
		});
		const received: unknown[] = [];
		bridge.listen?.("footer:branch-change", (data) => received.push(data));
		const { ui, setFooterCalls } = createRecordingUi();
		await mountTui(session, ui);

		type Factory = (
			tui: { requestRender(force?: boolean): void },
			theme: { fg(style: string, text: string): string },
			data: {
				getGitBranch(): string | null;
				onBranchChange(callback: () => void): () => void;
				getExtensionStatuses(): ReadonlyMap<string, string>;
			},
		) => { dispose(): void };
		let branch: string | null = "main";
		let unsubscribed = 0;
		const mountWithBranchData = () => {
			let notify: (() => void) | undefined;
			const factory = setFooterCalls.at(-1)?.args[0] as Factory | undefined;
			const component = factory?.(
				{ requestRender() {} },
				{ fg: (_style, text) => text },
				{
					getGitBranch: () => branch,
					onBranchChange: (callback) => {
						notify = callback;
						return () => unsubscribed++;
					},
					getExtensionStatuses: () => new Map(),
				},
			);
			return { component, notify: () => notify?.() };
		};

		const visible = mountWithBranchData();
		visible.notify();
		expect(received).toEqual([{ branch: "main" }]);

		branch = null;
		visible.notify();
		expect(received).toEqual([{ branch: "main" }, { branch: null }]);

		visible.component?.dispose();
		expect(unsubscribed).toBe(1);

		// Hidden footer still forwards branch changes.
		const runner = session.session.extensionRunner;
		await session.extensions[0]?.commands
			.get("footer")
			?.handler("", runner.createCommandContext());
		branch = "feature";
		const hiddenFooter = mountWithBranchData();
		hiddenFooter.notify();
		expect(received.at(-1)).toEqual({ branch: "feature" });
		hiddenFooter.component?.dispose();
		expect(unsubscribed).toBe(2);
	});

	it("right-aligns statuses beside the workspace row", () => {
		expect(__test.alignLeftAndRight("workspace", "busy", 16)).toBe(
			"workspace   busy",
		);
	});

	it("preserves the workspace row when statuses exceed the remaining space", () => {
		const line = __test.alignLeftAndRight("workspace", "very long status", 12);

		expect(visibleWidth(line)).toBe(12);
		expect(line.startsWith("workspace ")).toBe(true);
	});

	it("uses the first row when its first group is oversized", () => {
		const [first, second] = __test.flowLines(
			["oversized-model-route", "tokens"],
			" | ",
			8,
		);

		expect(first).not.toBe("");
		expect(second).toBe("tokens");
	});

	it("keeps adjacent members of a named segment group atomic", () => {
		const model = { id: "model", text: "sol:medium", zone: "llm" } as const;
		const fast = {
			id: "fast",
			text: "",
			zone: "llm",
			group: "model-route",
		} as const;
		const angel = {
			id: "angel",
			text: "astra:max",
			zone: "llm",
			group: "model-route",
		} as const;
		const tokens = { id: "tokens", text: "1k", zone: "llm" } as const;

		expect(
			__test.groupSegments([
				{ ...model, group: "model-route" },
				fast,
				angel,
				tokens,
			]),
		).toEqual([[{ ...model, group: "model-route" }, fast, angel], [tokens]]);
	});
});