/*
Copyright (C) 2017  Cloudbase Solutions SRL
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

// @flow

class DomUtils {
  static getScrollableParent(element: HTMLElement, includeHidden?: boolean): HTMLElement {
    let style = getComputedStyle(element)
    let excludeStaticParent = style.position === 'absolute'
    let overflowRegex = includeHidden ? /(auto|scroll|hidden)/ : /(auto|scroll)/

    if (style.position === 'fixed') {
      return window
    }
    /* eslint no-cond-assign: off */
    for (let parent = element; (parent = parent.parentElement);) {
      style = getComputedStyle(parent)
      if (excludeStaticParent && style.position === 'static') {
        /* eslint no-continue: off */
        continue
      }
      if (overflowRegex.test(style.overflow + style.overflowY + style.overflowX)) {
        let htmlEl: any = parent
        return htmlEl
      }
    }

    return window
  }

  static isElementInViewport(el: HTMLElement, scrollableParent: any): boolean {
    let rect = el.getBoundingClientRect()
    let scrollableRect = scrollableParent.getBoundingClientRect ? scrollableParent.getBoundingClientRect() : {
      top: 0,
      left: 0,
      bottom: scrollableParent.innerHeight ? scrollableParent.innerHeight : window.innerHeight,
      right: scrollableParent.innerWidth ? scrollableParent.innerWidth : window.innerWidth,
    }

    return (
      rect.top + rect.height >= scrollableRect.top &&
      rect.left >= scrollableRect.left &&
      rect.bottom - rect.height <= scrollableRect.bottom &&
      rect.right <= scrollableRect.right
    )
  }

  static getEventPath(event: Event): HTMLElement[] {
    let path = []
    let node = event.target
    // $FlowIgnore
    while (node !== document.body && node.parentNode) {
      path.push(node)
      // $FlowIgnore
      node = node.parentNode
    }

    // $FlowIgnore
    return path
  }

  /**
   * Copies specified text to clipboard
   * @param {string} text The text to copy
   * @return True if successful, false otherwise
   */
  static copyTextToClipboard(text: string): boolean {
    let textArea = document.createElement('textarea')
    textArea.style.position = 'fixed'
    textArea.style.top = '0'
    textArea.style.left = '0'
    textArea.style.width = '2em'
    textArea.style.height = '2em'
    textArea.style.padding = '0'
    textArea.style.border = 'none'
    textArea.style.outline = 'none'
    textArea.style.boxShadow = 'none'
    textArea.style.background = 'transparent'

    textArea.value = text

    if (document.body) document.body.appendChild(textArea)

    textArea.select()

    let successful

    try {
      successful = document.execCommand('copy')
    } catch (e) {
      successful = false
    } finally {
      if (document.body) document.body.removeChild(textArea)
    }
    return successful
  }

  static get urlHashPrefix() {
    return window.env.ENV === 'development' ? '#/' : ''
  }

  static download(text: string, fileName: string) {
    let href: string = `data:text/json;charset=utf-8,${encodeURIComponent(text)}`
    let downloadAnchorNode = document.createElement('a')
    downloadAnchorNode.setAttribute('href', href)
    downloadAnchorNode.setAttribute('download', fileName)
    if (document.body) {
      document.body.appendChild(downloadAnchorNode) // required for firefox
    }
    downloadAnchorNode.click()
    downloadAnchorNode.remove()
  }
  static jsonSyntaxHighlight(json: any) {
    json = json.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
    return json.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+-]?\d+)?)/g, (match) => {
      let cls = 'number'
      if (/^"/.test(match)) {
        if (/:$/.test(match)) {
          cls = 'key'
        } else {
          cls = 'string'
        }
      } else if (/true|false/.test(match)) {
        cls = 'boolean'
      } else if (/null/.test(match)) {
        cls = 'null'
      }
      return `<span class="${cls}">${match}</span>`
    })
  }
}

export default DomUtils