import type {
	ModuleContributionDescriptor,
	ModuleUiApiClient,
	ModuleUiContributions,
	ModuleUiHostContext,
	MountedModuleContribution,
	MountModuleContributionOptions,
} from "@ekklesia/module-ui-sdk";

/**
 * A host, as a module's artifact actually experiences one.
 *
 * Requests are matched on the **relative** path a module asks for, which is what proves the artifact
 * never builds `/api/v1/modules/signage/...`: a route table keyed on Ekklesia's private prefix would
 * simply never match.
 */
export interface FakeHostRoute {
	readonly method: string;
	readonly path: string | RegExp;
	readonly respond: (request: {
		readonly path: string;
		readonly init: RequestInit | undefined;
	}) => Response | Promise<Response>;
}

export interface FakeHost {
	readonly context: ModuleUiHostContext;
	readonly requests: { method: string; path: string }[];
	/** Contributions this host published against Signage's renderer capability. */
	readonly mounted: { contributionId: string; input: unknown }[];
}

export function jsonResponse(body: unknown, status = 200): Response {
	return new Response(JSON.stringify(body), {
		headers: { "content-type": "application/json" },
		status,
	});
}

export function errorResponse(
	code: string,
	message: string,
	status = 400,
): Response {
	return jsonResponse({ code, message }, status);
}

export interface FakeHostOptions {
	readonly permissions: readonly string[];
	readonly routes: readonly FakeHostRoute[];
	readonly contributions?: readonly ModuleContributionDescriptor[];
	readonly displayUrl?: string;
	readonly principal?: ModuleUiHostContext["principal"];
	readonly mount?: (
		options: MountModuleContributionOptions,
	) => Promise<MountedModuleContribution> | MountedModuleContribution;
}

export function createFakeHost(options: FakeHostOptions): FakeHost {
	const requests: { method: string; path: string }[] = [];
	const mounted: { contributionId: string; input: unknown }[] = [];

	const api: ModuleUiApiClient = {
		async request(path, init) {
			const method = (init?.method ?? "GET").toUpperCase();
			const normalized = path.replace(/^\//u, "");
			requests.push({ method, path: normalized });
			for (const route of options.routes) {
				const matches =
					typeof route.path === "string"
						? route.path === normalized.split("?")[0]
						: route.path.test(normalized);
				if (route.method === method && matches) {
					return route.respond({ init, path: normalized });
				}
			}
			return errorResponse(
				"SIGNAGE_NOT_FOUND",
				"The requested resource was not found.",
				404,
			);
		},
	};

	const contributions: ModuleUiContributions = {
		list: (capabilityId) =>
			capabilityId === "signage.slide-renderer"
				? (options.contributions ?? [])
				: [],
		async mount(mountOptions) {
			mounted.push({
				contributionId: mountOptions.contributionId,
				input: mountOptions.input,
			});
			if (options.mount) {
				return options.mount(mountOptions);
			}
			return {
				contributionId: mountOptions.contributionId,
				mounted: true,
				unmount: () => Promise.resolve(),
				update: () => Promise.resolve(),
				version: "1.0.0",
			};
		},
	};

	return {
		context: {
			api,
			contributions,
			display: {
				url: options.displayUrl ?? "https://api.example.test/display/signage",
			},
			moduleId: "signage",
			permissions: {
				has: (permission) => options.permissions.includes(permission),
			},
			principal: options.principal ?? { kind: "anonymous" },
			realtime: { subscribe: () => ({ close: () => undefined }) },
		},
		mounted,
		requests,
	};
}

/** The settings payload every screen loads first. */
export const FAKE_SETTINGS = Object.freeze({
	crossfadeMs: 1000,
	moduleVersion: "0.1.2",
	nativeImageDurationMs: 7000,
	nativePresentation: {
		backgroundColor: "#000000",
		backgroundDarkened: false,
		backgroundMode: "blurred",
		blurPixels: 20,
	},
	rendererInputVersion: "1.0.0",
	timezone: "America/Chicago",
	uploads: {
		batchMaxFiles: 20,
		concurrency: 3,
		maxBytes: 26_214_400,
		maxPixels: 40_000_000,
	},
});