/**
 * apeman react package for file upload components.
 * @class ApUpload
 */

'use strict'

import React, { PropTypes as types } from 'react'
import classnames from 'classnames'
import async from 'async'
import path from 'path'
import uuid from 'uuid'
import { ApImage } from 'apeman-react-image'
import { ApSpinner } from 'apeman-react-spinner'
import { ApButton } from 'apeman-react-button'

/** @lends ApUpload */
const ApUpload = React.createClass({

  // --------------------
  // Specs
  // --------------------

  propTypes: {
    /** Name of input */
    name: types.string,
    /** DOM id of input */
    id: types.string,
    /** Allow multiple upload */
    multiple: types.bool,
    /** Handler for change event */
    onChange: types.func,
    /** Handler for load event */
    onLoad: types.func,
    /** Handler for error event */
    onError: types.func,
    /** Image width */
    width: types.number,
    /** Image height */
    height: types.number,
    /** Guide text */
    text: types.string,
    /** Accept file type */
    accept: types.string,
    /** Guide icon */
    icon: types.string,
    /** Icon for close images */
    closeIcon: types.string,
    /** Spinner theme */
    spinner: types.string,
    /** Value of input */
    value: types.oneOfType([
      types.string,
      types.array
    ])
  },

  mixins: [],

  statics: {
    readFile (file, callback) {
      let reader = new window.FileReader()
      reader.onerror = function onerror (err) {
        callback(err)
      }
      reader.onload = function onload (ev) {
        callback(null, ev.target.result)
      }
      reader.readAsDataURL(file)
    },
    isImageUrl (url) {
      const imageExtensions = [
        '.jpg',
        '.jpeg',
        '.svg',
        '.gif',
        '.png'
      ]
      return /^data:image/.test(url) || !!~imageExtensions.indexOf(path.extname(url))
    }
  },

  getInitialState () {
    const s = this
    let { props } = s
    let hasValue = props.value && props.value.length > 0
    return {
      spinning: false,
      error: null,
      urls: hasValue ? [].concat(props.value) : null
    }
  },

  getDefaultProps () {
    return {
      name: null,
      id: `ap-upload-${uuid.v4()}`,
      multiple: false,
      width: 180,
      height: 180,
      accept: null,
      text: 'Upload file',
      icon: 'fa fa-cloud-upload',
      closeIcon: 'fa fa-close',
      spinnerIcon: ApSpinner.DEFAULT_THEME,
      onChange: null,
      onLoad: null,
      onError: null
    }
  },

  render () {
    const s = this
    let { state, props } = s
    let { width, height } = props
    return (
      <div className={classnames('ap-upload', props.className)}
           style={Object.assign({}, props.style)}>
        <input type='file'
               className='ap-upload-input'
               multiple={ props.multiple }
               name={ props.name }
               id={ props.id }
               accept={ props.accept }
               onChange={s.handleChange}
               style={{ width, height }}
        />
        <label className='ap-upload-label' htmlFor={ props.id }>
                    <span className='ap-upload-aligner'>
                    </span>
          <span className='ap-upload-label-inner'>
                        <i className={ classnames('ap-upload-icon', props.icon) }/>
                        <span className='ap-upload-text'>{props.text}</span>
            { props.children }
                    </span>
        </label>
        { s._renderPreviewImage(state.urls, width, height) }
        { s._renderRemoveButton(!!(state.urls && state.urls.length > 0), props.closeIcon) }
        { s._renderSpinner(state.spinning, props.spinner) }
      </div>
    )
  },

  // --------------------
  // Lifecycle
  // --------------------

  componentWillReceiveProps (nextProps) {
    const s = this
    const { props } = s
    let { value } = nextProps
    let hasValue = value && value.length > 0
    if (hasValue && (props.value !== value)) {
      s.setState({ urls: [].concat(value) })
    }
  },

  // ------------------
  // Custom
  // ------------------

  handleChange (e) {
    const s = this
    let { props } = s
    let { target } = e
    let files = Array.prototype.slice.call(target.files, 0)
    let { onChange, onError, onLoad } = props

    s.setState({ spinning: true })
    if (onChange) {
      onChange(e)
    }
    async.concat(files, ApUpload.readFile, (error, urls) => {
      s.setState({
        spinning: false,
        error,
        urls
      })
      if (error) {
        if (onError) {
          onError(error)
        }
      } else {
        if (onLoad) {
          let loaded = Object.assign({ urls, target })
          onLoad(loaded)
        }
      }
    })
  },

  handleRemove () {
    const s = this
    let { props } = s
    let { onLoad } = props
    s.setState({
      error: null,
      urls: null
    })
    if (onLoad) {
      onLoad([])
    }
  },

  // ------------------
  // Private
  // ------------------

  _renderSpinner (spinning, theme) {
    const s = this
    return (
      <ApSpinner enabled={spinning} theme={theme}>
      </ApSpinner>
    )
  },

  _renderRemoveButton (removable, icon) {
    const s = this
    if (!removable) {
      return null
    }
    return (
      <ApButton onTap={ s.handleRemove } className='ap-upload-remove-button'>
        <i className={ classnames('ap-upload-remove-icon', icon) }/>
      </ApButton>
    )
  },

  _renderPreviewImage (urls, width, height) {
    if (!urls) {
      return null
    }
    const s = this
    return urls
      .filter((url) => ApUpload.isImageUrl(url))
      .map((url, i) => (
        <ApImage key={ url }
                 src={ url }
                 height={ height }
                 width={ width }
                 className={ classnames('ap-upload-preview-image') }
                 style={ { left: `${i * 10}%`, top: `${i * 10}%` } }
                 scale='fit'>
        </ApImage>
      ))
  }
})

export default ApUpload