/* istanbul ignore file */
'use strict'

const appRoot = require( 'app-root-path' )
const sharp = require( 'sharp' )
const xmlescape = require( 'xml-escape' )
var pixelWidth = require( 'string-pixel-width' )

module.exports = {

  async makeOgImage( previewBufferOrFilename, streamName ) {
    let imgWidth = 1200
    let imgHeight = 627

    let panelPadding = 20
    let panelWidth = imgWidth - 2 * panelPadding
    let panelHeight = 80

    let title = '/ ' + streamName
    let maxTitleSize = 750
    if ( pixelWidth( title, { font: 'open sans', size: 48 } ) > maxTitleSize ) {
      while ( pixelWidth( title, { font: 'open sans', size: 48 } ) > maxTitleSize ) {
        title = title.slice( 0, -1 )
      }
      title += '...'
    }
    // console.log( streamName, pixelWidth( title, { font: 'open sans', size: 48 } ), ' / ', imgWidth - 2 * panelPadding - 305 )

    const logo = await sharp( `${appRoot}/modules/previews/assets/speckle_logo_and_text.png` ).resize( { height: panelHeight } ).toBuffer()

    const topPanel = Buffer.from( `
      <svg width="${imgWidth}" height="${panelHeight + 2 * panelPadding}">
        <defs>
          <filter id="dropshadow" height="130%">
            <feGaussianBlur in="SourceAlpha" stdDeviation="3"/> 
            <feOffset dx="0" dy="5" result="offsetblur"/>
            <feComponentTransfer>
              <feFuncA type="linear" slope="0.3"/>
            </feComponentTransfer>
            <feMerge> 
              <feMergeNode/>
              <feMergeNode in="SourceGraphic"/> 
            </feMerge>
          </filter>
        </defs>
  
        <rect x="${panelPadding}" y="${panelPadding}" width="${panelWidth}" height="${panelHeight}" fill="#fff" rx="15" filter="url(#dropshadow)" />
        <text x="${panelPadding + 305}" y="${panelPadding + 60}" fill="#000" font-family="DejaVu Sans, sans-serif" font-size="48px">
          ${xmlescape( title )}
        </text>  
      </svg>
    ` )
    //<text x="50%" y="50%" dy="0.3em" fill="#000" text-anchor="middle" font-family="Arial, Helvetica, sans-serif" font-size="48px">

    return await sharp( previewBufferOrFilename ).resize( { width: imgWidth, height: imgHeight } ).composite( [
      { input: topPanel, top: 0, left: 0 },
      { input: logo, left: panelPadding + 10, top: panelPadding },
    ] ).png().toBuffer()
  }
}