import type { ManifestDataSource } from "@notionhq/custom-blocks";

import type { DataSourceHandle, SingleSourceDatabaseHandle } from "./notion-as-code/database.js";
import { getCurrentMetadataCapabilityKey } from "./notion-as-code/recorder.js";
import { toCustomBlockDefaultBinding, toCustomBlockDataSource } from "./translate.js";

export type CustomBlockDefaultBinding = {
	dataSourceResourceId: string;
	propertyResourceIdsByKey: Record<string, string>;
};

export type CustomBlockHandle = {
	readonly key?: string;
	readonly config: {
		readonly defaultBindings?: Readonly<Record<string, CustomBlockDefaultBinding>>;
	};
};

type CustomBlockDataSource = ManifestDataSource | DataSourceHandle | SingleSourceDatabaseHandle;

export type CustomBlockOptions = {
	path: string;
	name?: string;
	description?: string;
	slashCommand?: string;
	dataSources?: Record<string, CustomBlockDataSource>;
} & (
	| { static: true; command?: never; output?: never }
	| { static?: false; command?: string; output?: string }
);

/** Declare a browser project. Its filename under src/customBlocks supplies its key. */
export function customBlock(options: CustomBlockOptions) {
	if (typeof options.path !== "string" || options.path.trim() === "") {
		throw new Error("customBlock requires a non-empty path relative to the app root");
	}
	const slashCommand = options.slashCommand?.replace(/^\//, "");
	if (slashCommand !== undefined && !/^[a-z0-9][a-z0-9_-]{0,63}$/.test(slashCommand)) {
		throw new Error(
			"Custom block slashCommand must be 1–64 lowercase letters, numbers, hyphens or underscores, starting with a letter or number",
		);
	}
	const { dataSources, defaultBindings } = lowerDataSources(options.dataSources ?? {});
	const key = getCurrentMetadataCapabilityKey();
	return {
		_tag: "custom_block" as const,
		...(key === undefined ? {} : { key }),
		config: {
			source: options.static
				? { type: "static" as const, path: options.path }
				: {
						type: "project" as const,
						path: options.path,
						command: options.command ?? "npx vite build",
						output: options.output ?? "dist",
					},
			manifest: {
				version: 1 as const,
				...(options.name === undefined ? {} : { name: options.name }),
				...(options.description === undefined ? {} : { description: options.description }),
				...(slashCommand === undefined ? {} : { slashCommand }),
				dataSources,
			},
			...(Object.keys(defaultBindings).length === 0 ? {} : { defaultBindings }),
		},
	};
}

function lowerDataSources(dataSources: Record<string, CustomBlockDataSource>) {
	const manifestDataSources: Record<string, ManifestDataSource> = {};
	const defaultBindings: Record<string, CustomBlockDefaultBinding> = {};

	for (const [key, dataSource] of Object.entries(dataSources)) {
		const handle = isSingleSourceDatabaseHandle(dataSource)
			? dataSource.dataSource
			: dataSource;
		if (isDataSourceHandle(handle)) {
			manifestDataSources[key] = toCustomBlockDataSource(handle);
			defaultBindings[key] = toCustomBlockDefaultBinding(handle);
		} else {
			manifestDataSources[key] = handle;
		}
	}

	return { dataSources: manifestDataSources, defaultBindings };
}

function isSingleSourceDatabaseHandle(
	value: CustomBlockDataSource,
): value is SingleSourceDatabaseHandle {
	return "dataSource" in value;
}

function isDataSourceHandle(
	value: ManifestDataSource | DataSourceHandle,
): value is DataSourceHandle {
	return "resourceId" in value && "schema" in value && "database" in value;
}