konnoscron.ts112 lines · main
| 1 | import { codeBlock } from 'common-tags' |
| 2 | import { jsonrepair } from 'jsonrepair' |
| 3 | import type OpenAI from 'openai' |
| 4 | |
| 5 | import { ContextLengthError } from '../errors' |
| 6 | |
| 7 | // Responds to a natural language request for cron syntax. |
| 8 | export async function generateCron(openai: OpenAI, prompt: string) { |
| 9 | const initMessages: OpenAI.Chat.Completions.ChatCompletionMessageParam[] = [ |
| 10 | { |
| 11 | role: 'system', |
| 12 | content: codeBlock` |
| 13 | You are a cron syntax expert. Your purpose is to convert natural language time descriptions into valid cron expressions for pg_cron. |
| 14 | |
| 15 | Rules for responses: |
| 16 | - For standard intervals (minutes and above), output cron expressions in the 5-field format supported by pg_cron |
| 17 | - For second-based intervals, use the special pg_cron "x seconds" syntax |
| 18 | - Do not provide any explanation of what the cron expression does |
| 19 | - Format output as markdown with the cron expression in a code block |
| 20 | - Do not ask for clarification if you need it. Just output the cron expression. |
| 21 | |
| 22 | Example input: "Every Monday at 3am" |
| 23 | Example output: |
| 24 | \`\`\` |
| 25 | 0 3 * * 1 |
| 26 | \`\`\` |
| 27 | |
| 28 | Example input: "Every 30 seconds" |
| 29 | Example output: |
| 30 | \`\`\` |
| 31 | 30 seconds |
| 32 | \`\`\` |
| 33 | |
| 34 | Additional examples: |
| 35 | - Every minute: \`* * * * *\` |
| 36 | - Every 5 minutes: \`*/5 * * * *\` |
| 37 | - Every first of the month, at 00:00: \`0 0 1 * *\` |
| 38 | - Every night at midnight: \`0 0 * * *\` |
| 39 | - Every Monday at 2am: \`0 2 * * 1\` |
| 40 | - Every 15 seconds: \`15 seconds\` |
| 41 | - Every 45 seconds: \`45 seconds\` |
| 42 | |
| 43 | Field order for standard cron: |
| 44 | - minute (0-59) |
| 45 | - hour (0-23) |
| 46 | - day (1-31) |
| 47 | - month (1-12) |
| 48 | - weekday (0-6, Sunday=0) |
| 49 | |
| 50 | Important: pg_cron uses "x seconds" for second-based intervals, not "x * * * *". |
| 51 | If the user asks for seconds, do not use the 5-field format, instead use "x seconds". |
| 52 | |
| 53 | Here is the user's prompt: |
| 54 | ${prompt} |
| 55 | `, |
| 56 | }, |
| 57 | ] |
| 58 | |
| 59 | const completionFunction = { |
| 60 | name: 'generateCronSyntax', |
| 61 | description: 'Generates a cron expression for a given natural language description.', |
| 62 | parameters: { |
| 63 | type: 'object', |
| 64 | properties: { |
| 65 | cron_expression: { |
| 66 | type: 'string', |
| 67 | description: 'The generated cron expression.', |
| 68 | }, |
| 69 | }, |
| 70 | required: ['cron_expression'], |
| 71 | }, |
| 72 | } |
| 73 | |
| 74 | try { |
| 75 | const response = await openai.chat.completions.create({ |
| 76 | model: 'gpt-4o-mini-2024-07-18', |
| 77 | messages: initMessages, |
| 78 | max_tokens: 1024, |
| 79 | temperature: 0, |
| 80 | stream: false, |
| 81 | tool_choice: { |
| 82 | type: 'function', |
| 83 | function: { |
| 84 | name: completionFunction.name, |
| 85 | }, |
| 86 | }, |
| 87 | tools: [ |
| 88 | { |
| 89 | type: 'function', |
| 90 | function: completionFunction, |
| 91 | }, |
| 92 | ], |
| 93 | }) |
| 94 | |
| 95 | // Parse the JSON string in arguments using jsonrepair |
| 96 | const functionArgs = response?.choices?.[0]?.message?.tool_calls?.[0]?.function?.arguments |
| 97 | if (!functionArgs) { |
| 98 | throw new Error('No cron expression generated') |
| 99 | } |
| 100 | |
| 101 | // Use jsonrepair before parsing |
| 102 | const repairedJsonString = jsonrepair(functionArgs) |
| 103 | const args = JSON.parse(repairedJsonString) |
| 104 | |
| 105 | return args.cron_expression |
| 106 | } catch (error) { |
| 107 | if (error instanceof Error && 'code' in error && error.code === 'context_length_exceeded') { |
| 108 | throw new ContextLengthError() |
| 109 | } |
| 110 | throw error |
| 111 | } |
| 112 | } |