import type { DiscoveredCapability } from "./discover.js";

/**
 * Generate the app entry module for a set of discovered capabilities.
 *
 * The module uses only static imports so that the bundler can bundle the
 * whole app into a single file. It is written to `.notion/entry.ts` in
 * the app project, so imports are relative to that location.
 */
export function generateEntry(capabilities: readonly DiscoveredCapability[]): string {
	const imports: string[] = [];
	const registrations: string[] = [];
	const registryEntries = new Map<string, string[]>();
	// A workflow's key comes from its file name, so the entry records it for
	// `context.workflows`, which receives the imported workflow object.
	const workflowKeyBindings: string[] = [];

	capabilities
		.filter((capability) => capability.runtime !== "build")
		.forEach((capability, index) => {
			const binding = `capability_${index}`;
			imports.push(
				`import ${binding} from ${JSON.stringify(`../${capability.sourcePath}`)};`,
			);
			if (capability.type === "sync") {
				registrations.push(
					`bindSyncCapabilityKey(${binding}, ${JSON.stringify(capability.key)});`,
				);
			}

			if (capability.type === "workflow") {
				workflowKeyBindings.push(
					`bindWorkflowKey(${binding}, ${JSON.stringify(capability.key)});`,
				);
			}

			const entries = registryEntries.get(capability.type) ?? [];
			entries.push(`\t\t${JSON.stringify(capability.key)}: ${binding},`);
			registryEntries.set(capability.type, entries);
		});

	const registry = Array.from(registryEntries.entries())
		.map(([type, entries]) => `\t${JSON.stringify(type)}: {\n${entries.join("\n")}\n\t},`)
		.join("\n");

	const syncBindingImport =
		registrations.length === 0
			? ""
			: 'import { bindSyncCapabilityKey } from "@notionhq/apps/sync";\n';
	const workflowBindingImport =
		workflowKeyBindings.length === 0
			? ""
			: 'import { bindWorkflowKey } from "@notionhq/apps/workflow";\n';

	return `// Generated by \`notion-apps build\`. Do not edit.
${syncBindingImport}${workflowBindingImport}${imports.join("\n")}
${[...registrations, ...workflowKeyBindings].join("\n")}

type Handler = (context?: unknown, options?: { concreteOutput?: true }) => Promise<unknown>;

export const capabilities: Record<string, Record<string, { handler: Handler }>> = {
${registry}
};

// The platform dispatches a workflow's synchronous webhook verify run under its
// own invocation type. It resolves to the same capability, which tells a verify
// invocation from a trigger event by the shape of its input.
const invocationTypes: Record<string, string | undefined> = {
	workflowWebhookVerify: "workflow",
};

export async function run(
	type: string,
	key: string,
	context?: unknown,
	options?: { concreteOutput?: true },
): Promise<unknown> {
	const capabilityType = invocationTypes[type] ?? type;
	const capability = capabilities[capabilityType]?.[key];

	if (!capability) {
		throw new Error(\`Capability "\${capabilityType}/\${key}" not found\`);
	}

	return capability.handler(context, options);
}
`;
}

/**
 * Generate the build-only metadata entry. Dynamic imports run after the
 * recorder starts and remain isolated from the deployed Worker entry.
 */
export function generateMetadataEntry(capabilities: readonly DiscoveredCapability[]): string {
	const imports = [...capabilities]
		.sort(
			(left, right) =>
				Number(right.type === "custom_block") - Number(left.type === "custom_block"),
		)
		.map(
			(capability) =>
				`await withMetadataCapabilityKey(${capability.type === "custom_block" ? JSON.stringify(capability.key) : "undefined"}, () => import(${JSON.stringify(`../${capability.sourcePath}`)}));`,
		)
		.join("\n");

	return `// Generated by \`notion-apps build\`. Do not edit.
import {
	finishMetadataRecording,
	startMetadataRecording,
	withMetadataCapabilityKey,
} from "@notionhq/apps/notion-as-code/recorder";

const recorder = startMetadataRecording();
${imports}
export default finishMetadataRecording(recorder);
`;
}

/** Evaluate block declarations only while building, separately from the Worker. */
export function generateBlocksEntry(capabilities: readonly DiscoveredCapability[]): string {
	const entries = capabilities.filter((capability) => capability.runtime === "build");
	return (
		entries
			.map(
				(capability, index) =>
					`import block_${index} from ${JSON.stringify(`../${capability.sourcePath}`)};`,
			)
			.join("\n") +
		`\nexport const capabilities = { custom_block: {${entries.map((capability, index) => `${JSON.stringify(capability.key)}: block_${index}`).join(",")}} };\n`
	);
}