export default class ClassBuilder {
  constructor(block, customDefaults) {
    this.block = `mdc-${block}`
    this.customDefaults = customDefaults //will be ignored when building custom classes
  }

  // classParams: {modifiers:[] (mdc), custom:[] (bbmd), extra:[] (any)}
  blocks(classParams) {
    let base = this.block
    if (classParams == undefined) return base
    return this.buildClass(base, classParams)
  }

  //elementName: string, classParams: {}
  elements(elementName, classParams) {
    let base = `${this.block}__${elementName}`
    if (classParams == undefined) return base
    return this.buildClass(base, classParams)
  }

  buildClass(base, classParams) {
    let cls = base
    const { modifiers, customs, extras } = classParams
    if (modifiers) cls += modifiers.map(m => ` ${base}--${m}`).join(" ")
    if (customs)
      cls += Object.entries(customs)
        .map(([property, value]) => {
          //disregard falsy and values set by customDefaults constructor param
          if (!!value && !this.customDefaults.includes(value)) {
            //custom scss name convention = bbmd-[block | element]--[property]-[value]
            return ` bbmd-${base}--${property}-${value}`
          }
        })
        .join("")
    if (extras) cls += ` ${extras.join(" ")}`
    return cls.trim()
  }
}