/**
 * query-docs tool handler
 *
 * Fetches documentation and code examples from TrueRef for a specific library.
 * Tool schema is identical to context7 for drop-in compatibility.
 */

import { z } from 'zod';
import { fetchContext } from '../client.js';

export const QueryDocsSchema = z.object({
	libraryId: z
		.string()
		.describe('The TrueRef library ID obtained from resolve-library-id, e.g. /facebook/react'),
	query: z
		.string()
		.describe('Specific question about the library to retrieve relevant documentation'),
	tokens: z.number().optional().describe('Maximum token budget for the response (default: 10000)'),
	searchMode: z
		.enum(['auto', 'keyword', 'semantic', 'hybrid'])
		.optional()
		.describe(
			"Retrieval mode: 'auto' (default), 'keyword' (FTS only), 'semantic' (vector only), or 'hybrid'"
		),
	alpha: z
		.number()
		.min(0)
		.max(1)
		.optional()
		.describe('Hybrid blend weight: 0.0 = keyword only, 1.0 = semantic only (default: 0.5)')
});

export type QueryDocsInput = z.infer<typeof QueryDocsSchema>;

export const QUERY_DOCS_TOOL = {
	name: 'query-docs',
	description: [
		'Fetches documentation and code examples from TrueRef for a specific library.',
		'Requires a library ID obtained from resolve-library-id.',
		'Returns relevant snippets formatted for LLM consumption.',
		'Call at most 3 times per user question.'
	].join(' '),
	inputSchema: {
		type: 'object' as const,
		properties: {
			libraryId: {
				type: 'string',
				description: 'TrueRef library ID, e.g. /facebook/react'
			},
			query: {
				type: 'string',
				description: 'Specific question about the library'
			},
			tokens: {
				type: 'number',
				description: 'Max token budget (default: 10000)'
			},
			searchMode: {
				type: 'string',
				enum: ['auto', 'keyword', 'semantic', 'hybrid'],
				description: "Retrieval mode: 'auto' (default), 'keyword', 'semantic', or 'hybrid'"
			},
			alpha: {
				type: 'number',
				minimum: 0,
				maximum: 1,
				description: 'Hybrid blend weight (0=keyword, 1=semantic, default: 0.5)'
			}
		},
		required: ['libraryId', 'query']
	}
};

export async function handleQueryDocs(args: unknown) {
	const { libraryId, query, tokens, searchMode, alpha } = QueryDocsSchema.parse(args);

	const response = await fetchContext({ libraryId, query, tokens, type: 'txt', searchMode, alpha });

	if (!response.ok) {
		const status = response.status;

		if (status === 404) {
			return {
				content: [
					{
						type: 'text' as const,
						text: `Library "${libraryId}" not found. Please run resolve-library-id first.`
					}
				],
				isError: true
			};
		}

		if (status === 503) {
			return {
				content: [
					{
						type: 'text' as const,
						text: `Library "${libraryId}" is currently being indexed. Please try again in a moment.`
					}
				],
				isError: true
			};
		}

		return {
			content: [
				{
					type: 'text' as const,
					text: `Error fetching documentation: ${response.status} ${response.statusText}`
				}
			],
			isError: true
		};
	}

	const text = await response.text();
	return {
		content: [{ type: 'text' as const, text }]
	};
}