#!/usr/bin/env bun
/**
 * Generates prelude metadata for the VSCode extension.
 * - Prelude names (for parser scope tracking)
 * - Function signatures (for autocomplete)
 */

import { writeFileSync } from 'fs'
import { join } from 'path'
import { globals } from '../../src/prelude'

// Extract parameter names from a function
const extractParams = (fn: Function): string[] => {
  const fnStr = fn.toString()
  const match = fnStr.match(/\(([^)]*)\)/)
  if (!match) return []

  const paramsStr = match[1]!.trim()
  if (!paramsStr) return []

  // Split by comma, but be careful of default values with commas
  const params: string[] = []
  let current = ''
  let inString = false
  let stringChar = ''

  for (let i = 0; i < paramsStr.length; i++) {
    const char = paramsStr[i]
    if ((char === '"' || char === "'") && (i === 0 || paramsStr[i - 1] !== '\\')) {
      if (!inString) {
        inString = true
        stringChar = char
      } else if (char === stringChar) {
        inString = false
      }
    }

    if (char === ',' && !inString) {
      params.push(current.trim())
      current = ''
    } else {
      current += char
    }
  }
  if (current.trim()) params.push(current.trim())

  return params
    .map((p) => p.split(/[=:]/)[0]!.trim()) // Handle defaults and types
    .filter((p) => p && p !== 'this')
}

// Generate metadata for a module
const generateModuleMetadata = (module: Record<string, any>) => {
  const metadata: Record<string, { params: string[] }> = {}

  for (const [name, value] of Object.entries(module)) {
    if (typeof value === 'function') {
      metadata[name] = { params: extractParams(value) }
    }
  }

  return metadata
}

// Generate names list
const names = Object.keys(globals).sort()

// Generate module metadata
const moduleMetadata: Record<string, any> = {}
for (const [name, value] of Object.entries(globals)) {
  if (typeof value === 'object' && value !== null && name !== '$') {
    moduleMetadata[name] = generateModuleMetadata(value)
  }
}

// Generate dollar metadata
const dollarMetadata: Record<string, { params: string[] }> = {}
if (globals.$ && typeof globals.$ === 'object') {
  for (const key of Object.keys(globals.$)) {
    dollarMetadata[key] = { params: [] }
  }
}

// Write prelude-names.ts
const namesOutput = `// Auto-generated by scripts/generate-prelude-metadata.ts
// Do not edit manually - run 'bun run generate-prelude-metadata' to regenerate

export const PRELUDE_NAMES = ${JSON.stringify(names, null, 2)} as const
`

const namesPath = join(import.meta.dir, '../server/src/metadata/prelude-names.ts')
writeFileSync(namesPath, namesOutput)

// Write prelude-completions.ts
const completionsOutput = `// Auto-generated by scripts/generate-prelude-metadata.ts
// Do not edit manually - run 'bun run generate-prelude-metadata' to regenerate

export type CompletionMetadata = {
  params: string[]
  description?: string
}

export const completions = {
  modules: ${JSON.stringify(moduleMetadata, null, 2)},
  dollar: ${JSON.stringify(dollarMetadata, null, 2)},
} as const
`

const completionsPath = join(import.meta.dir, '../server/src/metadata/prelude-completions.ts')
writeFileSync(completionsPath, completionsOutput)

console.log(`✓ Generated ${names.length} prelude names to server/src/metadata/prelude-names.ts`)
console.log(
  `✓ Generated completions for ${
    Object.keys(moduleMetadata).length
  } modules to server/src/metadata/prelude-completions.ts`,
)