import React, { Component, PropTypes } from 'react';
import { Map } from 'immutable';
import { Schema } from 'prosemirror-model';
import { EditorState } from 'prosemirror-state';
import { EditorView } from 'prosemirror-view';
import history from 'prosemirror-history';
import {
  blockQuoteRule, orderedListRule, bulletListRule, codeBlockRule, headingRule,
  inputRules, allInputRules,
} from 'prosemirror-inputrules';
import { keymap } from 'prosemirror-keymap';
import { schema as markdownSchema, defaultMarkdownSerializer } from 'prosemirror-markdown';
import { baseKeymap, setBlockType, toggleMark } from 'prosemirror-commands';
import registry from '../../../../lib/registry';
import { createAssetProxy } from '../../../../valueObjects/AssetProxy';
import { buildKeymap } from './keymap';
import createMarkdownParser from './parser';
import Toolbar from '../Toolbar';
import ToolbarPlugins from '../ToolbarPlugins';
import { Sticky } from '../../../UI/Sticky/Sticky';
import styles from './index.css';

function processUrl(url) {
  if (url.match(/^(https?:\/\/|mailto:|\/)/)) {
    return url;
  }
  if (url.match(/^[^/]+\.[^/]+/)) {
    return `https://${ url }`;
  }
  return `/${ url }`;
}

const ruleset = {
  blockquote: [blockQuoteRule],
  ordered_list: [orderedListRule],
  bullet_list: [bulletListRule],
  code_block: [codeBlockRule],
  heading: [headingRule, 6],
};

function buildInputRules(schema) {
  return Map(ruleset)
    .filter(rule => schema.nodes[rule])
    .map(rule => rule[0].apply(rule[0].slice(1)))
    .toArray();
}

function markActive(state, type) {
  const { from, to, empty } = state.selection;
  if (empty) {
    return type.isInSet(state.storedMarks || state.doc.marksAt(from));
  }
  return state.doc.rangeHasMark(from, to, type);
}

function schemaWithPlugins(schema, plugins) {
  let nodeSpec = schema.nodeSpec;
  plugins.forEach((plugin) => {
    const attrs = {};
    plugin.get('fields').forEach((field) => {
      attrs[field.get('name')] = { default: null };
    });
    nodeSpec = nodeSpec.addToEnd(`plugin_${ plugin.get('id') }`, {
      attrs,
      group: 'block',
      parseDOM: [{
        tag: 'div[data-plugin]',
        getAttrs(dom) {
          return JSON.parse(dom.getAttribute('data-plugin'));
        },
      }],
      toDOM(node) {
        return ['div', { 'data-plugin': JSON.stringify(node.attrs) }, plugin.get('label')];
      },
    });
  });

  return new Schema({
    nodes: nodeSpec,
    marks: schema.markSpec,
  });
}

function createSerializer(schema, plugins) {
  const serializer = Object.create(defaultMarkdownSerializer);
  plugins.forEach((plugin) => {
    serializer.nodes[`plugin_${ plugin.get('id') }`] = (state, node) => {
      const toBlock = plugin.get('toBlock');
      state.write(`${ toBlock.call(plugin, node.attrs) }\n\n`);
    };
  });
  return serializer;
}

export default class Editor extends Component {
  constructor(props) {
    super(props);
    const plugins = registry.getEditorComponents();
    const schema = schemaWithPlugins(markdownSchema, plugins);
    this.state = {
      plugins,
      schema,
      parser: createMarkdownParser(schema, plugins),
      serializer: createSerializer(schema, plugins),
    };
  }

  componentDidMount() {
    const { schema, parser } = this.state;
    const doc = parser.parse(this.props.value || '');
    this.view = new EditorView(this.ref, {
      state: EditorState.create({
        doc,
        schema,
        plugins: [
          inputRules({
            rules: allInputRules.concat(buildInputRules(schema)),
          }),
          keymap(buildKeymap(schema)),
          keymap(baseKeymap),
          history.history(),
          keymap({
            'Mod-z': history.undo,
            'Mod-y': history.redo,
          }),
        ],
      }),
      onAction: this.handleAction,
    });
  }

  handleAction = (action) => {
    const { serializer } = this.state;
    const newState = this.view.state.applyAction(action);
    const md = serializer.serialize(newState.doc);
    this.props.onChange(md);
    this.view.updateState(newState);
    if (newState.selection !== this.state.selection) {
      this.handleSelection(newState);
    }
    this.view.focus();
  };

  handleSelection = (state) => {
    const { schema, selection } = state;
    if (selection.from === selection.to) {
      const { $from } = selection;
      if ($from.parent && $from.parent.type === schema.nodes.paragraph && $from.parent.textContent === '') {
        const pos = this.view.coordsAtPos(selection.from);
        const editorPos = this.view.content.getBoundingClientRect();
        const selectionPosition = { top: pos.top - editorPos.top, left: pos.left - editorPos.left };
        this.setState({ selectionPosition });
      }
    } else {
      const pos = this.view.coordsAtPos(selection.from);
      const editorPos = this.view.content.getBoundingClientRect();
      const selectionPosition = { top: pos.top - editorPos.top, left: pos.left - editorPos.left };
      this.setState({ selectionPosition });
    }
  };

  handleRef = (ref) => {
    this.ref = ref;
  };

  handleHeader = level => (
    () => {
      const { schema } = this.state;
      const state = this.view.state;
      const { $from, to, node } = state.selection;
      let nodeType = schema.nodes.heading;
      let attrs = { level };
      let inHeader = node && node.hasMarkup(nodeType, attrs);
      if (!inHeader) {
        inHeader = to <= $from.end() && $from.parent.hasMarkup(nodeType, attrs);
      }
      if (inHeader) {
        nodeType = schema.nodes.paragraph;
        attrs = {};
      }

      const command = setBlockType(nodeType, { level });
      command(state, this.handleAction);
    }
  );

  handleBold = () => {
    const command = toggleMark(this.state.schema.marks.strong);
    command(this.view.state, this.handleAction);
  };

  handleItalic = () => {
    const command = toggleMark(this.state.schema.marks.em);
    command(this.view.state, this.handleAction);
  };

  handleLink = () => {
    let url = null;
    if (!markActive(this.view.state, this.state.schema.marks.link)) {
      url = prompt('Link URL:'); // eslint-disable-line no-alert
    }
    const command = toggleMark(this.state.schema.marks.link, { href: url ? processUrl(url) : null });
    command(this.view.state, this.handleAction);
  };

  handlePlugin = (plugin, data) => {
    const { schema } = this.state;
    const nodeType = schema.nodes[`plugin_${ plugin.get('id') }`];
    this.view.props.onAction(this.view.state.tr.replaceSelectionWith(nodeType.create(data.toJS())).action());
  };

  handleDragEnter = (e) => {
    e.preventDefault();
    this.setState({ dragging: true });
  };

  handleDragLeave = (e) => {
    e.preventDefault();
    this.setState({ dragging: false });
  };

  handleDragOver = (e) => {
    e.preventDefault();
  };

  handleDrop = (e) => {
    e.preventDefault();

    this.setState({ dragging: false });

    const { schema } = this.state;

    const nodes = [];

    if (e.dataTransfer.files && e.dataTransfer.files.length) {
      Array.from(e.dataTransfer.files).forEach((file) => {
        createAssetProxy(file.name, file)
        .then((assetProxy) => {
          this.props.onAddAsset(assetProxy);
          if (file.type.split('/')[0] === 'image') {
            nodes.push(
              schema.nodes.image.create({ src: assetProxy.public_path, alt: file.name })
            );
          } else {
            nodes.push(
              schema.marks.link.create({ href: assetProxy.public_path, title: file.name })
            );
          }
        });
      });
    } else {
      nodes.push(schema.nodes.paragraph.create({}, e.dataTransfer.getData('text/plain')));
    }

    nodes.forEach((node) => {
      this.view.props.onAction(this.view.state.tr.replaceSelectionWith(node).action());
    });
  };

  handleToggle = () => {
    this.props.onMode('raw');
  };

  render() {
    const { onAddAsset, onRemoveAsset, getAsset } = this.props;
    const { plugins, selectionPosition, dragging } = this.state;
    const classNames = [styles.editor];
    if (dragging) {
      classNames.push(styles.dragging);
    }

    return (<div
      className={classNames.join(' ')}
      onDragEnter={this.handleDragEnter}
      onDragLeave={this.handleDragLeave}
      onDragOver={this.handleDragOver}
      onDrop={this.handleDrop}
    >
      <Sticky className={styles.editorControlBar} fillContainerWidth={true}>
        <Toolbar
          selectionPosition={selectionPosition}
          onH1={this.handleHeader(1)}
          onH2={this.handleHeader(2)}
          onBold={this.handleBold}
          onItalic={this.handleItalic}
          onLink={this.handleLink}
          onToggleMode={this.handleToggle}
        />
        <ToolbarPlugins
          selectionPosition={selectionPosition}
          plugins={plugins}
          onPlugin={this.handlePlugin}
          onAddAsset={onAddAsset}
          onRemoveAsset={onRemoveAsset}
          getAsset={getAsset}
        />
      </Sticky>
      <div ref={this.handleRef} />
      <div className={styles.shim} />
    </div>);
  }
}

Editor.propTypes = {
  onAddAsset: PropTypes.func.isRequired,
  onRemoveAsset: PropTypes.func.isRequired,
  getAsset: PropTypes.func.isRequired,
  onChange: PropTypes.func.isRequired,
  onMode: PropTypes.func.isRequired,
  value: PropTypes.node,
};