#!/usr/bin/env node

const sharp = require('sharp')

function parseArgs(argv) {
  const parsed = {}
  for (let i = 2; i < argv.length; i += 1) {
    const key = argv[i]
    const value = argv[i + 1]
    if (key === '--width' && value) {
      parsed.width = Number(value)
      i += 1
      continue
    }
    if (key === '--height' && value) {
      parsed.height = Number(value)
      i += 1
    }
  }
  return parsed
}

async function main() {
  const args = parseArgs(process.argv)
  const chunks = []

  process.stdin.on('data', (chunk) => {
    chunks.push(chunk)
  })

  process.stdin.on('end', async () => {
    try {
      const svgBuffer = Buffer.concat(chunks)
      if (!svgBuffer.length) {
        throw new Error('empty svg input')
      }

      const width = Number.isFinite(args.width) && args.width > 0 ? Math.round(args.width) : null
      const height = Number.isFinite(args.height) && args.height > 0 ? Math.round(args.height) : null

      let pipeline = sharp(svgBuffer, { density: 300 })
      if (width || height) {
        pipeline = pipeline.resize({
          width: width || undefined,
          height: height || undefined,
          fit: 'contain',
          background: { r: 255, g: 255, b: 255, alpha: 1 },
          withoutEnlargement: false,
        })
      }

      const pngBuffer = await pipeline.png({ compressionLevel: 9 }).toBuffer()
      process.stdout.write(pngBuffer)
    } catch (error) {
      process.stderr.write(`svg_to_png_error: ${error && error.message ? error.message : String(error)}\n`)
      process.exit(1)
    }
  })
}

main()