Recipe Generator

Task: Edit bot2.js

bot2.js now does the following:
(Done)Input: a link or file
(Done)Process 1: Convert to transcript
Process 2: Use Gemini to generate recipe
Process 3: Output the recipe to user

Note: GEMINI_API_TOKEN is saved on .env file

Gemini should use the prompt from "prompt.js"
and the prompt as follow:
(see the prompt section)

Code in NodeJS, CommomJS:
export the function as getTranscript(link)

Important:
- const fs = require('fs').promises; // Use fs.promises for async operations
- const fsSync = require('fs'); // Use fsSync for synchronous operations like checking file existence
- Use as few npm package as possible. Use fluent-ffmpeg,axios,fs,path,ytdl-core
- Provide a usage example with sample audio URL: https://filedn.com/lvpQyX5dxsK7TR0Vaa6Pr1k/Gemini%20%E7%AA%81%E7%84%B6%E7%9C%9F%E9%A6%99%E4%BA%86%20%E5%A6%82%E4%BD%95%E7%94%A8%E5%A5%BD%E7%94%A8%E9%80%8FGemini.mp3
- My cloudflare account: 6cef0b2f126356a3dee567e091e44d0f

Func:
download audio from link, or youtube link
split the audio into X part,
call cloudflare's whisper-large-v3-turbo API,
obtain each transcript,
Combine Transcript
return as string

Input: Audio file URL / Youtube link
Output: String of transcipt

Steps:
1. If the link is youtube url, download the file using ytdl, add .mp3 extention to the file.
2. If the link is general URL, Download audio file from URL
3. if audio file is not mp3, convert into mp3 using toMP3()
4. If the audio is less than 150s*16, split into 150s each, else split evenly into 16 chunks
5. Store their path in "files" array
6. Use map to transcribe() "files" array
7. get back a array of strings
8. Combine those strings and return a single string

toMP3():
use node-ffmpeg to convert any audio file into mp3

convert(X):
use node-ffmpeg to
1. Splite MP3 into X MP3 files
2. return arrays of string containes file paths.

transcribe():
1. use axios, use get method with JSON body
2. 'audio' string required, Base64 encoded value of the audio data.
3. WHISPER_API_URL = `https://api.cloudflare.com/client/v4/accounts/${CLOUDFLARE_ACCOUNT_ID}/ai/run/@cf/openai/whisper-large-v3-turbo`;
ref:https://developers.cloudflare.com/workers-ai/models/whisper-large-v3-turbo/
4. If the segment transcribe failed, retry one more time

const getPrompt = (cleanTranscript, videoDescription) => `
# Role and Objective
- Generate a recipe using a structured Markdown template based on the provided source details.

# Instructions
- Keep the recipe within 2000 characters.
- Use Chinese or English, transcript language is preferred.
- If any required information is missing, write N/A in the corresponding placeholder.
- Use SI units (grams, milliliters) by default for all ingredient amounts, unless otherwise specified.
- Produce output strictly in Markdown format.
- Begin with a concise checklist (3-7 bullets) of what you will do; keep items conceptual, not implementation-level.
- Output the Recipe only, no additional output.

## Recipe Template

# {FOOD_NAME} Recipe:
- For {NUM} Serves.
- Prep Time: {X mins}
- Cook Time: {Y mins}

## Ingredients
- Create a section for each ingredient part (e.g., 'Main Ingredient', 'Sauce', 'Garnish'), following the order in the source.
- For each part, list each ingredient in the format:
  
  {PART NAME}:
  - {Item}, ({Prep State: e.g., Diced/Minced, or N/A}): {Amount in SI unit or as described}

- If there are more than two ingredient parts, add additional sections (e.g., "Part C: Garnish").
- If any specific detail is missing for an item, enter N/A for that field.

## Steps
- List recipe steps as sequentially numbered sections, in the exact order found in the source.
- Do not limit to only two steps—include every step from the source.
- Groups step together. One Step can contain multiple sub-steps.
- For each step, use the following format:
  
  ## Step {step_number}:
  - {List instruction in bullet points, bolding keywords}

## Key Notes and Tips
- **Chef's Tip:** {List important tips or advice. If absent, write N/A.}
- **Substitution:** {Provide alternative ingredients/equipment, or N/A if not provided.}
- **Storage:** {Instructions for leftovers, or N/A if not mentioned.}

---
Video Transcript:
${cleanTranscript}

---
Video Description:
${videoDescription}

## Example Output

# Tomato Soup Recipe:
- For 4 Serves.
- Prep Time: 10 mins
- Cook Time: 30 mins

## Ingredients
Main Ingredient:
- Tomato, (Chopped): 500 grams
- Onion, (Diced): 50 grams

Sauce:
- Olive oil, (N/A): 2 tablespoons

Garnish:
- Basil leaves, (N/A): 5 grams

## Step 1:
- **Heat** olive oil in a pot.
- **Add** onions and sauté until translucent.

## Step 2:
- **Add** tomatoes and **cook** for 20 minutes.

## Step 3:
- **Blend** the mixture until smooth, then **season** to taste.

## Key Notes and Tips
- **Chef's Tip:** Use ripe tomatoes for better flavor.
- **Substitution:** Use sunflower oil if olive oil unavailable.
- **Storage:** Refrigerate for up to 3 days.
`;

module.exports = getPrompt;