Advanced MCP Features

import { spawn } from 'node:child_process' import fs from 'node:fs/promises' import { userInfo } from 'node:os' const subscribers = new Set<() => void>() export async function listVideos() { const videos = await fs.readdir('./videos').catch(() => []) return videos } export async function getVideoBase64(videoId: string) { let video: Buffer try { video = await fs.readFile(`./videos/${videoId}`) } catch (err: any) { if (err.code === 'ENOENT') { throw new Error(`Video with ID "${videoId}" not found.`) } throw err } return video.toString('base64') } export function subscribe(subscriber: () => void) { subscribers.add(subscriber) return () => { subscribers.delete(subscriber) } } function notifySubscribers() { for (const subscriber of subscribers) { subscriber() } } export async function createWrappedVideo({ entries, tags, year, mockTime, onProgress, signal, }: { entries: Array<{ id: number; content: string; title: string }> tags: Array<{ id: number; name: string }> year: number mockTime?: number onProgress?: (progress: number) => void signal?: AbortSignal }) { const videoFilename = `wrapped-${year}.mp4` if (signal?.aborted) { throw new Error(`Creating Wrapped Video for ${year} was cancelled`) } if (mockTime && mockTime > 0) { const step = mockTime / 10 for (let i = 0; i < mockTime; i += step) { if (signal?.aborted) { throw new Error(`Creating Wrapped Video for ${year} was cancelled`) } const progress = i / mockTime if (progress >= 1) break onProgress?.(progress) await new Promise((resolve) => setTimeout(resolve, step)) } onProgress?.(1) return `epicme://videos/${videoFilename}` } const longestEntry = entries.reduce((longest, entry) => { return entry.content.length > (longest?.content.length ?? 0) ? entry : longest }, entries[0]) const shortestEntry = entries.reduce((shortest, entry) => { return entry.content.length < (shortest?.content.length ?? 0) ? entry : shortest }, entries[0]) const totalDurationSeconds = 60 const texts = [ { text: `Hello ${userInfo().username}!`, color: '#FF1493', fontsize: 72, }, { text: `It is ${new Date().toLocaleDateString('en-US', { month: 'long', day: 'numeric', year: 'numeric', })}`, color: '#33FF99', fontsize: 72, }, { text: `Here is your EpicMe wrapped video for ${year}`, color: '#66CCFF', fontsize: 72, }, { text: `You wrote ${entries.length} entries in ${year}`, color: '#ff69b4', fontsize: 72, }, longestEntry ? { text: `Your longest entry was ${longestEntry?.content.length} characters\n"${longestEntry?.title}" `, color: '#FF0000', fontsize: 72, } : null, shortestEntry ? { text: `Your shortest entry was ${shortestEntry?.content.length} characters\n"${shortestEntry?.title}" `, color: '#B39DDB', fontsize: 72, } : null, entries.length < 1 ? { text: `You did not write any entries in ${year}`, color: '#D2B48C', fontsize: 72, } : null, tags.length > 0 ? { text: `And you created ${tags.length} tags in ${year}`, color: '#FFB300', fontsize: 72, } : { text: `You did not create any tags in ${year}`, color: '#D2B48C', fontsize: 72, }, { text: `Good job!`, color: 'red', fontsize: 72 }, { text: `Keep Journaling in ${year + 1}!`, color: '#ffa500', fontsize: 72, }, ].filter(Boolean) const outputFile = `./videos/${videoFilename}` await fs.mkdir('./videos', { recursive: true }) const fontPath = './other/caveat-variable-font.ttf' const numTexts = texts.length const perTextDuration = totalDurationSeconds / numTexts const timings = texts.map((_, i) => { const start = perTextDuration * i const end = perTextDuration * (i + 1) return { start, end } }) const drawtexts = texts.map((t, i) => { const { start, end } = timings[i]! const fadeInEnd = start + perTextDuration / 3 const fadeOutStart = end - perTextDuration / 3 const scrollExpr = `h-((t-${start})*(h+text_h)/${perTextDuration})` const fontcolor = t.color.startsWith('#') ? t.color.replace('#', '0x') : t.color // Properly handle newlines for ffmpeg drawtext: replace \n with actual newline escape and split into multiple drawtext filters if needed const lines = t.text.split('\n') const drawtextFilters = lines.map((line, lineIdx) => { const safeLine = line.replace(/\\/g, '\\\\').replace(/'/g, "'\\''") const yOffset = lineIdx * (t.fontsize + 12) // 10px line spacing return `drawtext=fontfile=${fontPath}:text='${safeLine}':fontcolor=${fontcolor}:fontsize=${t.fontsize}:x=(w-text_w)/2:y=${scrollExpr}+${yOffset}:alpha='if(lt(t,${start}),0,if(lt(t,${fadeInEnd}),1,if(lt(t,${fadeOutStart}),1,if(lt(t,${end}),((${end}-t)/${perTextDuration / 3}),0))))':shadowcolor=black:shadowx=4:shadowy=4` }) return drawtextFilters.join(',') }) let ffmpeg: ReturnType<typeof spawn> | undefined const ffmpegPromise = new Promise((resolve, reject) => { ffmpeg = spawn('ffmpeg', [ '-f', 'lavfi', '-i', `color=c=black:s=1280x720:d=${totalDurationSeconds}`, '-vf', drawtexts.join(','), '-c:v', 'libx264', '-preset', 'veryslow', // better compression '-crf', '32', // higher CRF = smaller file, lower quality '-pix_fmt', 'yuv420p', '-y', outputFile, ]) if (ffmpeg.stderr) { ffmpeg.stderr.on('data', (data) => { const str = data.toString() const timeMatch = str.match(/time=(\d{2}):(\d{2}):(\d{2})\.(\d{2})/) if (timeMatch) { const hours = Number(timeMatch[1]) const minutes = Number(timeMatch[2]) const seconds = Number(timeMatch[3]) const fraction = Number(timeMatch[4]) const currentSeconds = hours * 3600 + minutes * 60 + seconds + fraction / 100 const progress = Math.min(currentSeconds / totalDurationSeconds, 1) onProgress?.(progress) } }) } ffmpeg.on('close', (code) => { if (signal?.aborted) { reject(new Error(`Creating Wrapped Video for ${year} was cancelled`)) } else if (code === 0) { onProgress?.(1) resolve(outputFile) } else { reject(new Error(`ffmpeg exited with code ${code}`)) } }) }) signal?.addEventListener('abort', onAbort) function onAbort() { if (ffmpeg && !ffmpeg.killed) { ffmpeg.kill('SIGKILL') } } await ffmpegPromise.finally(() => { signal?.removeEventListener('abort', onAbort) }) notifySubscribers() const videoUri = `epicme://videos/${videoFilename}` return videoUri }