import { describe, expect, test } from "bun:test";
import type {
	ExtensionAPI,
	ExtensionContext,
} from "@earendil-works/pi-coding-agent";
import { refreshTranscriptOnSessionStart } from "../src/glue/tool-renderer.js";
import { importUpstream } from "../src/upstream.js";

describe("transcript refresh", () => {
	test("repaints a restored message after upstream initializes its context", async () => {
		const handlers = new Map<
			string,
			Array<(event: unknown, ctx: ExtensionContext) => void>
		>();
		const pi = {
			on(
				event: string,
				handler: (event: unknown, ctx: ExtensionContext) => void,
			) {
				const list = handlers.get(event) ?? [];
				list.push(handler);
				handlers.set(event, list);
			},
		} as unknown as ExtensionAPI;
		class UserMessage {
			contentBox = { paddingY: 1, setBgFn() {}, invalidateCache() {} };
			render(_width: number) {
				return ["hello"];
			}
		}
		const upstream = await importUpstream(
			"@vanillagreen/pi-tool-renderer/extensions/tool-renderer/messages.js",
		);
		upstream.installUserMessageRenderer(pi, UserMessage);
		refreshTranscriptOnSessionStart(pi);
		const message = new UserMessage();
		let cached: string[] | undefined;
		const render = () => (cached ??= message.render(40));
		const widgets = new Set<string>();
		let repaints = 0;
		const tui = {
			invalidate() {
				cached = undefined;
			},
			requestRender() {
				repaints++;
				render();
			},
		};
		const ctx = {
			mode: "tui",
			hasUI: true,
			cwd: process.cwd(),
			ui: {
				setWidget(key: string, factory?: (tui: unknown) => unknown) {
					if (factory) {
						factory(tui);
						widgets.add(key);
					} else widgets.delete(key);
				},
			},
		} as unknown as ExtensionContext;
		try {
			const before = [...render()];
			expect(before[0]).toBe("hello");
			for (const handler of handlers.get("session_start") ?? [])
				handler({ reason: "resume" }, ctx);
			expect(render()).not.toEqual(before);
			expect(render().join("\n")).toContain("hello");
			expect(repaints).toBe(1);
			expect(widgets.size).toBe(0);
		} finally {
			for (const handler of handlers.get("session_shutdown") ?? [])
				handler({}, ctx);
		}
	});

	test("does not use TUI factories in non-terminal modes", () => {
		let start: (event: unknown, ctx: ExtensionContext) => void = () => {};
		refreshTranscriptOnSessionStart({
			on(_event: string, handler: typeof start) {
				start = handler;
			},
		} as unknown as ExtensionAPI);
		for (const mode of ["rpc", "json", "print"] as const) {
			expect(() => start({}, { mode } as ExtensionContext)).not.toThrow();
		}
	});
});