const DEFAULT_COLORS = [
  'rgb(59, 130, 246)',
  'rgb(239, 68, 68)',
  'rgb(34, 197, 94)',
  'rgb(234, 179, 8)',
  'rgb(168, 85, 247)',
  'rgb(236, 72, 153)',
  'rgb(14, 165, 233)',
  'rgb(249, 115, 22)',
]

const hasOwn = (object, key) => Object.prototype.hasOwnProperty.call(object, key)

export function buildChartDatasets(data, { isTrafficChart, dualAxis, colors = DEFAULT_COLORS }) {
  return data.datasets.map((dataset, index) => {
    const color = colors[index % colors.length]
    const baseConfig = {
      ...dataset,
      borderColor: color,
      backgroundColor: color.replace('rgb', 'rgba').replace(')', ', 0.2)'),
      borderWidth: 2,
      tension: 0.4,
      pointRadius: 0,
      pointHoverRadius: 4,
    }

    if (dualAxis && dataset.yAxisID === 'y1') {
      baseConfig.stepped = 'before'
      baseConfig.tension = 0
      baseConfig.fill = 'origin'
      baseConfig.borderWidth = 1
      baseConfig.borderColor = 'rgb(34, 197, 94)'
      baseConfig.backgroundColor = 'rgba(34, 197, 94, 0.1)'
      return baseConfig
    }

    if (hasOwn(dataset, 'fill')) {
      baseConfig.fill = dataset.fill
      return baseConfig
    }

    baseConfig.fill = isTrafficChart ? 'origin' : false
    return baseConfig
  })
}