import { ENV_VARIABLES } from "../env-variables/index.js";

/**
 * List of telemetry events for typesafety.
 *
 * - prefix with `SDK` to avoid collisions with other apps
 * - use past tense to indicate that the event is completed
 */
type TelemetryEvent = "LIX-SDK lix opened";

/**
 * Capture an event.
 *
 * - manually calling the PostHog API because the SDKs were not platform angostic (and generally bloated)
 */
export const capture = async (
	event: TelemetryEvent,
	args: {
		lixId: string;
		accountId: string;
		/**
		 * The value of the telemetry key-value pair.
		 *
		 * @example
		 *   const telemetryKeyValue = await lix.db.selectFrom("key_value").select("value").where("key", "=", "lix_telemetry").executeTakeFirstOrThrow();
		 *   await capture("LIX-SDK opened lix", { lixId: "test", accountId: "test", telemetryKeyValue: telemetryKeyValue.value, properties: {} });
		 */
		telemetryKeyValue: string;
		/**
		 * Please use snake_case for property names.
		 */
		properties: Record<string, any>;
	}
): Promise<void> => {
	if (ENV_VARIABLES.LIX_SDK_POSTHOG_TOKEN === undefined) {
		return;
	} else if (args.telemetryKeyValue === "off") {
		return;
	}
	try {
		await fetch("https://eu.posthog.com/capture/", {
			method: "POST",
			body: JSON.stringify({
				api_key: ENV_VARIABLES.LIX_SDK_POSTHOG_TOKEN,
				event,
				distinct_id: args.accountId,
				properties: {
					$groups: { lix_id: args.lixId },
					...args.properties,
				},
			}),
		});
		await identifyLix({
			lixId: args.lixId,
			accountId: args.accountId,
			// using the id for now as a name but can be changed in the future
			// we need at least one property to make a project visible in the dashboard
			properties: { name: args.lixId },
		});
	} catch {
		//
	}
};

/**
 * Identifying a project is needed.
 *
 * Otherwise, the project will not be visible in the PostHog dashboard.
 */
const identifyLix = async (args: {
	lixId: string;
	accountId: string;
	properties: Record<string, string>;
}) => {
	// do not send events if the token is not set
	// (assuming this eases testing)
	if (ENV_VARIABLES.LIX_SDK_POSTHOG_TOKEN === undefined) {
		return;
	}
	try {
		await fetch("https://eu.posthog.com/capture/", {
			method: "POST",
			body: JSON.stringify({
				api_key: ENV_VARIABLES.LIX_SDK_POSTHOG_TOKEN,
				event: "$groupidentify",
				distinct_id: args.accountId,
				properties: {
					$group_type: "lix",
					$group_key: args.lixId,
					$group_set: {
						...args.properties,
					},
				},
			}),
		});
	} catch {
		//
	}
};