import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
import type { ReclaimClient } from '@reclaimprotocol/client/api'
import type {
	IOperationArgs,
	IOperationId
} from '@reclaimprotocol/client/openapi'
import { remapErrorAsResponse } from '../remap_errors.ts'
import { MCP_TOOLS } from './operations.gen.ts'

/**
 * The generated `MCP_TOOLS` are keyed by OpenAPI `operationId` (PascalCase,
 * For example, `GetMe`). MCP tools are conventionally snake_case, matching the
 * hand-written tools in this server. Convert the public tool name here while
 * still dispatching to the API with the original operationId — doing this in
 * the (non-generated) registration keeps it from being reverted on regen.
 */
function toSnakeCase(name: string): string {
	return name
		.replace(/([a-z0-9])([A-Z])/g, '$1_$2')
		.replace(/([A-Z]+)([A-Z][a-z])/g, '$1_$2')
		.toLowerCase()
}

export function registerTools(server: McpServer, client: ReclaimClient) {
	for(const [opId, shape] of Object.entries(MCP_TOOLS)) {
		// snake_case to match the hand-written tools. A name that collides with
		// a hand-written tool throws here at startup — intentional: hand-written
		// and generated names must stay disjoint (see start.ts), so a clash is a
		// bug to surface, not silently shadow.
		server.registerTool(
			toSnakeCase(opId),
			shape,
			async(args: unknown) => {
				try {
					const result = await client.call(
						opId as IOperationId,
						args as IOperationArgs<IOperationId>,
					)
					return {
						content: [{
							type: 'text' as const, text: JSON.stringify(result.data, null, 2)
						}],
					}
				} catch(err) {
					return remapErrorAsResponse(err)
				}
			},
		)
	}
}