/* @flow */

import React from 'react';
import { Component, PropTypes } from '../../libs';
import Cover from './Cover';
import type { IframeUploadState } from './Types';

export default class IframeUpload extends Component {
  state: IframeUploadState;

  static defaultProps = {
    name: 'file'
  };

  constructor(props: Object) {
    super(props);
    this.state = {
      dragOver: false,
      file: null,
      disabled: false,
      frameName: 'frame-' + Date.now()
    };
  }

  componentDidMount() {
    const { action, onSuccess, onError } = this.props;
    const { file } = this.state;
    window.addEventListener(
      'message',
      event => {
        const { origin } = new URL(action);
        if (event.origin !== origin) return false;
        const response = event.data;
        if (response.result === 'success') {
          onSuccess(response, file);
        } else if (response.result === 'failed') {
          onError(response, file);
        }
      },
      false
    );
  }

  onload(): void {
    this.setState({ disabled: false });
  }

  onDrop(e: SyntheticDragEvent): void {
    e.preventDefault();
    this.setState({ dragOver: false });
    this.uploadFiles(e.dataTransfer.files); // TODO
  }

  handleChange(e: SyntheticInputEvent): void {
    if (e.target instanceof HTMLInputElement) {
      const file: File = e.target.files[0];
      if (file) {
        this.uploadFiles(file);
      }
    }
  }

  uploadFiles(file: File): void {
    if (this.state.disabled) return;
    this.setState({ disabled: false, file });
    this.props.onStart && this.props.onStart(file);
    const formNode = this.refs.form;
    const dataSpan = this.refs.data;
    let data = this.props.data;
    if (typeof data === 'function') {
      data = data(file);
    }
    const inputs = Object.keys(data).map(
      key => `<input name="${key}" value="${data[key]}"/>`
    );

    dataSpan.innerHTML = inputs.join('');
    formNode.submit();
    dataSpan.innerHTML = '';
  }

  handleClick(): void {
    if (!this.state.disabled) {
      this.refs.input.click();
    }
  }

  handleDragover(e: SyntheticDragEvent): void {
    e.preventDefault();
    this.setState({ onDrop: true });
  }

  handleDragleave(e: SyntheticDragEvent): void {
    e.preventDefault();
    this.setState({ onDrop: false });
  }

  render(): React.Element<any> {
    const { drag, action, name, accept, listType } = this.props;
    const { frameName } = this.state;
    const classes = this.classNames({
      'el-upload': true,
      [`el-upload--${listType}`]: true
    });
    return (
      <div
        className={classes}
        onClick={() => this.handleClick()}
        onDrop={e => this.onDrop(e)}
        onDragOver={e => this.handleDragover(e)}
        onDragLeave={e => this.handleDragleave(e)}
      >
        <iframe onLoad={() => this.onload()} ref="iframe" name={frameName} />
        <form
          ref="form"
          action={action}
          target={frameName}
          encType="multipart/form-data"
          method="POST"
        >
          <input
            className="el-upload__input"
            type="file"
            ref="input"
            name={name}
            onChange={e => this.handleChange(e)}
            accept={accept}
          />
          <input type="hidden" name="documentDomain" value={document.domain} />
          <span ref="data" />
        </form>
        {drag
          ? <Cover onFile={file => this.uploadFiles(file)}>
              {this.props.children}
            </Cover>
          : this.props.children}
      </div>
    );
  }
}

IframeUpload.propTypes = {
  drag: PropTypes.bool,
  data: PropTypes.object,
  action: PropTypes.string.isRequired,
  name: PropTypes.string,
  accept: PropTypes.string,
  onStart: PropTypes.func,
  onSuccess: PropTypes.func,
  onError: PropTypes.func,
  listType: PropTypes.string
};