import type { NotionAsCodeIcon } from "./intents.js";

/** Page icons cannot refer to workspace custom emoji or uploaded files. */
export type PageIcon = Exclude<NotionAsCodeIcon, { type: "file" }>;

const NOTION_ICON_COLORS = new Set([
	"gray",
	"lightgray",
	"brown",
	"yellow",
	"orange",
	"green",
	"blue",
	"purple",
	"pink",
	"red",
]);

/** Validate icon values before they enter a provisioning artifact. */
export function assertPageIcon(icon: unknown): asserts icon is PageIcon {
	if (typeof icon !== "object" || icon === null || !("type" in icon)) {
		throw new Error("Page icons must use a standard emoji or a Notion icon.");
	}
	if (icon.type === "emoji") {
		if (
			!("emoji" in icon) ||
			typeof icon.emoji !== "string" ||
			!/^(?:\p{RGI_Emoji}|\p{Extended_Pictographic})$/v.test(icon.emoji)
		) {
			throw new Error(
				"Page icons must use a single standard emoji, not workspace custom emoji.",
			);
		}
		return;
	}
	if (icon.type === "notion_icon") {
		if (
			!("description" in icon) ||
			typeof icon.description !== "string" ||
			icon.description.trim().length === 0
		) {
			throw new Error("Notion page icons need a nonempty description.");
		}
		if (
			"color" in icon &&
			icon.color !== undefined &&
			(typeof icon.color !== "string" || !NOTION_ICON_COLORS.has(icon.color))
		) {
			throw new Error(
				`Notion page icon colors must be one of: ${[...NOTION_ICON_COLORS].join(", ")}.`,
			);
		}
		return;
	}
	throw new Error(
		"Page icons must use a standard emoji or a Notion icon, not custom emoji or files.",
	);
}