import React from 'react';

import Input from './Input.jsx';
import Panel from './Panel.jsx';
import * as key from './keyboard';

const { PropTypes } = React;

export function isCategoryItemValid(i) {
  return typeof i === 'string' && i.trim().length > 0;
}

export function isCategoryValid(c) {
  return typeof c === 'object'
    && c.id
    && c.title
    && c.items
    && Array.isArray(c.items)
    && c.items.every(isCategoryItemValid)
    && (c.type || c.single);
}

const CategorizedTagInput = React.createClass({
  propTypes: {
    addNew: PropTypes.bool,
    categories: PropTypes.arrayOf(PropTypes.object).isRequired,
    transformTag: PropTypes.func,
    value: PropTypes.arrayOf(PropTypes.object),
    onBlur: PropTypes.func,
    onChange: PropTypes.func,
    placeholder: PropTypes.string,
    getTagStyle: PropTypes.func,
    getCreateNewText: PropTypes.func
  },

  getInitialState() {
    return {
      value: '',
      selection: {
        item: 0,
        category: 0
      },
      panelOpened: false,
      categories: [],
      addNew: this.props.addNew === undefined ? true : this.props.addNew
    };
  },

  getDefaultProps() {
      return {
          onChange(newTags){
            // do nothing
          }
      };
  },

  componentWillMount() {
    if (!this.props.categories.every(isCategoryValid)) {
      throw new Error('invalid categories source provided for react-categorized-tag-input');
    }
  },

  componentWillUnmount() {
    if (this.timeout) {
      clearTimeout(this.timeout);
    }
  },

  filterCategories(input) {
    let categories = this.props.categories.map(c => {
      c = Object.assign({}, c, {
        items: c.items.filter(this.filterItems(input))
      });
      return (c.items.length === 0 && (!this.state.addNew || c.single)) ? null : c;
    }).filter(c => c !== null);

    let selection = this.state.selection;
    if (this.state.selection.category >= categories.length) {
      selection = {
        category: 0,
        item: 0
      };
    } else {
      if (selection.item >= categories[selection.category].items.length) {
        selection.item = 0;
      }
    }

    this.setState({
      categories,
      selection
    });
  },

  filterItems(input) {
    return function (i) {
      if (input.length === 1) {
        return i.toLowerCase().trim() === input;
      }
      return i.toLowerCase().indexOf(input.trim().toLowerCase()) >= 0;
    };
  },

  openPanel() {
    this.setState({ panelOpened: true });
  },

  closePanel() {
    // Prevent the panel from hiding before the click action takes place
    if (this.timeout) {
      clearTimeout(this.timeout);
    }
    this.timeout = setTimeout(() => {
      this.timeout = undefined;
      this.setState({ panelOpened: false });
    }, 150);
  },

  onValueChange(e) {
    let value = e.target.value;
    this.setState({ value, panelOpened: value.trim().length > 0 || !isNaN(Number(value.trim())) });
    this.filterCategories(value);
  },

  onTagDeleted(i) {
    const newTags = this.props.value.slice()
    newTags.splice(i, 1)
    this.props.onChange(newTags)
  },

  onAdd(newTag) {  
    const newTags = this.props.value.concat([newTag]);
    this.setState({
      value: '',
      panelOpened: true
    });

    this.refs.input.focusInput();
    this.props.onChange(newTags);
  },

  addSelectedTag() {
    if (!(this.state.panelOpened && this.state.value.length > 0)) {
      return;
    }

    const category = this.state.categories[this.state.selection.category];
    const title = category.items[this.state.selection.item];
    this.onAdd({
      category: category.id,
      title: title || this.state.value
    });
  },

  handleBackspace(e) {
    if (this.state.value.trim().length === 0) {
      e.preventDefault();
      this.onTagDeleted(this.props.value.length - 1);
    }
  },

  handleArrowLeft() {
    let result = this.state.selection.item - 1;
    this.setState({selection: {
      category: this.state.selection.category,
      item: result >= 0 ? result : 0
    }});
  },

  handleArrowUp() {
    let result = this.state.selection.category - 1;
    this.setState({selection: {
      category: result >= 0 ? result : 0,
      item: 0
    }});
  },

  handleArrowRight() {
    let result = this.state.selection.item + 1;
    let cat = this.state.categories[this.state.selection.category];
    this.setState({selection: {
      category: this.state.selection.category,
      item: result <= cat.items.length ? result : cat.items.length
    }});
  },

  handleArrowDown() {
    let result = this.state.selection.category + 1;
    let cats = this.state.categories;
    this.setState({selection: {
      category: result < cats.length ? result : cats.length - 1,
      item: 0
    }});
  },

  onKeyDown(e) {
    let result;
    switch (e.keyCode) {
    case key.TAB:
    case key.ENTER:
      if (!this.state.value){
        // enable normal tab/enter behavior
        // (don't preventDefault)
        break;
      }
    case key.COMMA:
      e.preventDefault();
      this.addSelectedTag();
      break;
    case key.BACKSPACE:
      this.handleBackspace(e);
      break;
    case key.LEFT:
      this.handleArrowLeft();
      break;
    case key.UP:
      this.handleArrowUp();
      break;
    case key.RIGHT:
      this.handleArrowRight();
      break;
    case key.DOWN:
      this.handleArrowDown();
      break;
    }
  },

  render() {
    return (
      <div className='cti__root'>
        <Input openPanel={this.openPanel} closePanel={this.closePanel}
          onValueChange={this.onValueChange} onTagDeleted={this.onTagDeleted}
          onKeyDown={this.onKeyDown} placeholder={this.props.placeholder} value={this.state.value}
          getTagStyle={this.props.getTagStyle}
          tags={this.props.value}
          transformTag={this.props.transformTag}
          onBlur={this.props.onBlur} ref='input' />
        {this.state.panelOpened && this.state.value.length > 0 ? <Panel categories={this.state.categories}
          selection={this.state.selection} onAdd={this.onAdd}
          input={this.state.value}
          getCreateNewText={this.props.getCreateNewText}
          addNew={this.props.addNew === undefined ? true : this.props.addNew} /> : ''}
      </div>
    );
  }
});

export default CategorizedTagInput;