/**
* Tool: read_slide
* Reads slide content from a Marp presentation file by slide ID or returns all slides.
*/
import { z } from "zod";
import { promises as fs } from "fs";
import { extractSlideId, ensureSlideId } from "../utils/slide-id.js";
import { validateFilePath } from "../utils/path-validator.js";
import { parseFrontmatter, splitSlides } from "../utils/frontmatter.js";
import { MAX_FILE_SIZE } from "../utils/constants.js";
import { createErrorResponse, createSuccessResponse } from "../utils/response.js";
import type { ToolResponse } from "../types/common.js";
export const readSlideSchema = z.object({
filePath: z.string().describe("Absolute path to the Marp markdown file"),
slideId: z
.string()
.optional()
.describe("Optional slide ID to read a specific slide. If omitted, returns all slides."),
});
/**
* MCP Tool: Reads slide content from a Marp presentation file.
* Returns a specific slide by ID, or all slides with their IDs and positions.
*
* @param {object} options - The read options
* @param {string} options.filePath - Absolute path to the Marp markdown file
* @param {string} [options.slideId] - Optional slide ID to read a specific slide
* @returns {Promise<ToolResponse>} Slide content with metadata
*/
export async function readSlide({
filePath,
slideId,
}: z.infer<typeof readSlideSchema>): Promise<ToolResponse> {
// Validate file path
const pathError = validateFilePath(filePath);
if (pathError) {
return createErrorResponse(pathError);
}
let existingContent: string;
try {
existingContent = await fs.readFile(filePath, "utf-8");
} catch (error) {
return createErrorResponse(
`Could not read file at ${filePath}: ${error instanceof Error ? error.message : String(error)}`
);
}
if (existingContent.length > MAX_FILE_SIZE) {
return createErrorResponse(
`File too large (${existingContent.length} bytes, max ${MAX_FILE_SIZE} bytes)`
);
}
const { frontmatter, body } = parseFrontmatter(existingContent);
const slides = splitSlides(body);
// Ensure all slides have IDs (for consistent output)
const slidesWithIds = slides.map(slide => ensureSlideId(slide));
if (slideId) {
// Find specific slide by ID
const found = slidesWithIds.find(s => s.id === slideId);
if (!found) {
return createErrorResponse(`Slide with ID "${slideId}" not found`);
}
const position = slidesWithIds.findIndex(s => s.id === slideId) + 1;
return createSuccessResponse({
slideId,
position,
totalSlides: slidesWithIds.length,
content: found.content,
file: filePath,
});
}
// Return all slides
const allSlides = slidesWithIds.map((s, index) => ({
slideId: s.id,
position: index + 1,
content: s.content,
}));
return createSuccessResponse({
totalSlides: allSlides.length,
slides: allSlides,
file: filePath,
});
}
