/* global hexo */

'use strict';

hexo.extend.helper.register('next_tagcloud', function(options) {
  let tags = this.site.tags;

  if (!tags || !tags.length) return '';
  options = options || {};

  const min = options.min_font || 10;
  const max = options.max_font || 20;
  const orderby = options.orderby || 'name';
  const order = options.order || 1;
  const unit = options.unit || 'px';
  const { transform } = options;
  const separator = options.separator || ' ';
  const result = [];

  // Sort the tags
  if (orderby === 'random' || orderby === 'rand') {
    tags = tags.random();
  } else {
    tags = tags.sort(orderby, order);
  }

  // Limit the number of tags
  if (options.amount) {
    tags = tags.limit(options.amount);
  }

  const sizes = [];

  tags.sort('length').forEach(tag => {
    const { length } = tag;
    if (sizes.includes(length)) return;

    sizes.push(length);
  });

  const length = sizes.length - 1;

  tags.forEach(tag => {
    const ratio = length ? sizes.indexOf(tag.length) / length : 0;
    const size = min + ((max - min) * ratio);
    let style = `font-size: ${parseFloat(size.toFixed(2))}${unit};`;

    result.push(
      `<a href="${this.url_for(tag.path)}" style="${style}" class="tag-cloud-${Math.round(ratio * 10)}">${transform ? transform(tag.name) : tag.name}</a>`
    );
  });

  return result.join(separator);
});