// TODO(sadovsky): Maybe update to the new Meteor Todos UI.
// https://github.com/meteor/simple-todos

'use strict';

/* jshint newcap: false */

var _ = require('lodash');
var page = require('page');
var React = require('react');
var url = require('url');
var vanadium = require('vanadium');

var defaults = require('./defaults');
var h = require('./util').h;

////////////////////////////////////////
// Constants

var DISP_TYPE_COLLECTION = 'collection';
var DISP_TYPE_SYNCBASE = 'syncbase';

////////////////////////////////////////
// Global state

var disp;  // type Dispatcher

////////////////////////////////////////
// Helpers

function noop() {}

function activateInput(input) {
  input.focus();
  input.select();
}

function okCancelEvents(callbacks) {
  var ok = callbacks.ok || noop;
  var cancel = callbacks.cancel || noop;
  function done(ev) {
    var value = ev.target.value;
    if (value) {
      ok(value, ev);
    } else {
      cancel(ev);
    }
  }
  return {
    onKeyDown: function(ev) {
      if (ev.which === 27) {  // esc
        cancel(ev);
      }
    },
    onKeyUp: function(ev) {
      if (ev.which === 13) {  // enter
        done(ev);
      }
    },
    onBlur: function(ev) {
      done(ev);
    }
  };
}

////////////////////////////////////////
// Components

var TagFilter = React.createFactory(React.createClass({
  displayName: 'TagFilter',
  render: function() {
    var that = this;
    var tagFilter = this.props.tagFilter;
    var tagInfos = [], totalCount = 0;
    _.each(this.props.todos, function(todo) {
      _.each(todo.tags, function(tag) {
        var tagInfo = _.find(tagInfos, function(x) {
          return x.tag === tag;
        });
        if (!tagInfo) {
          tagInfos.push({tag: tag, count: 1, selected: tagFilter === tag});
        } else {
          tagInfo.count++;
        }
      });
      totalCount++;
    });
    tagInfos = _.sortBy(tagInfos, 'tag');
    // Add "All items" tag.
    tagInfos.unshift({
      tag: null,
      count: totalCount,
      selected: tagFilter === null
    });
    return h('div#tag-filter.tag-list', [
      h('div.label', 'Show:')
    ].concat(_.map(tagInfos, function(tagInfo) {
      var count = h('span.count', '(' + tagInfo.count + ')');
      return h('div.tag' + (tagInfo.selected ? '.selected' : ''), {
        onMouseDown: function() {
          var newTagFilter = tagFilter === tagInfo.tag ? null : tagInfo.tag;
          that.props.setTagFilter(newTagFilter);
        }
      }, [tagInfo.tag === null ? 'All items' : tagInfo.tag, ' ', count]);
    })));
  }
}));

var Tags = React.createFactory(React.createClass({
  displayName: 'Tags',
  getInitialState: function() {
    return {
      addingTag: false
    };
  },
  componentDidUpdate: function() {
    if (this.state.addingTag) {
      activateInput(this.getDOMNode().querySelector('#edittag-input'));
    }
  },
  render: function() {
    var that = this;
    var children = [];
    _.each(this.props.tags, function(tag) {
      // Note, we must specify the "key" prop so that React doesn't reuse the
      // opacity=0 node after a tag is removed.
      children.push(h('div.tag.removable_tag', {key: tag}, [
        h('div.name', tag),
        h('div.remove', {
          onClick: function(ev) {
            ev.target.parentNode.style.opacity = 0;
            // Wait for CSS animation to finish.
            window.setTimeout(function() {
              // TODO(sadovsky): If no other todos have the removed tag, maybe
              // set tagFilter to null.
              disp.removeTag(that.props.todoId, tag);
            }, 200);
          }
        })
      ]));
    });
    if (this.state.addingTag) {
      children.push(h('div.tag.edittag', h('input#edittag-input', _.assign({
        type: 'text',
        defaultValue: ''
      }, okCancelEvents({
        ok: function(value) {
          disp.addTag(that.props.todoId, value);
          that.setState({addingTag: false});
        },
        cancel: function() {
          that.setState({addingTag: false});
        }
      })))));
    } else {
      children.push(h('div.tag.addtag', {
        onClick: function() {
          that.setState({addingTag: true});
        }
      }, '+tag'));
    }
    return h('div.item-tags', children);
  }
}));

var Todo = React.createFactory(React.createClass({
  displayName: 'Todo',
  getInitialState: function() {
    return {
      editingText: false
    };
  },
  componentDidUpdate: function() {
    if (this.state.editingText) {
      activateInput(this.getDOMNode().querySelector('#todo-input'));
    }
  },
  render: function() {
    var that = this;
    var todo = this.props.todo, children = [];
    if (this.state.editingText) {
      children.push(h('div.edit', h('input#todo-input', _.assign({
        type: 'text',
        defaultValue: todo.text
      }, okCancelEvents({
        ok: function(value) {
          disp.editTodoText(todo._id, value);
          that.setState({editingText: false});
        },
        cancel: function() {
          that.setState({editingText: false});
        }
      })))));
    } else {
      children.push(h('div.destroy', {
        onClick: function() {
          disp.removeTodo(todo._id);
        }
      }));
      children.push(h('div.display', [
        h('input.check', {
          type: 'checkbox',
          checked: todo.done,
          onClick: function() {
            disp.markTodoDone(todo._id, !todo.done);
          }
        }),
        h('div.todo-text', {
          onDoubleClick: function() {
            that.setState({editingText: true});
          }
        }, todo.text)
      ]));
    }
    children.push(Tags({todoId: todo._id, tags: todo.tags}));
    return h('li.todo' + (todo.done ? '.done' : ''), children);
  }
}));

var Todos = React.createFactory(React.createClass({
  displayName: 'Todos',
  render: function() {
    var that = this;
    if (!this.props.listId) {
      return null;
    }
    var children = [];
    if (this.props.todos === null) {
      children.push('Loading...');
    } else {
      var tagFilter = this.props.tagFilter, items = [];
      _.each(this.props.todos, function(todo) {
        if (tagFilter === null || _.contains(todo.tags, tagFilter)) {
          items.push(Todo({todo: todo}));
        }
      });
      children.push(h('div#new-todo-box', h('input#new-todo', _.assign({
        type: 'text',
        placeholder: 'New item'
      }, okCancelEvents({
        ok: function(value, ev) {
          disp.addTodo(that.props.listId, {
            text: value,
            tags: tagFilter ? [tagFilter] : [],
            done: false,
            timestamp: Date.now()
          });
          ev.target.value = '';
        }
      })))));
      children.push(h('ul#item-list', items));
    }
    return h('div#items-view', children);
  }
}));

var List = React.createFactory(React.createClass({
  displayName: 'List',
  getInitialState: function() {
    return {
      editingName: false
    };
  },
  componentDidUpdate: function() {
    if (this.state.editingName) {
      activateInput(this.getDOMNode().querySelector('#list-name-input'));
    }
  },
  render: function() {
    var that = this;
    var list = this.props.list, child;
    // http://facebook.github.io/react/docs/forms.html#controlled-components
    if (this.state.editingName) {
      child = h('div.edit', h('input#list-name-input', _.assign({
        type: 'text',
        defaultValue: list.name
      }, okCancelEvents({
        ok: function(value) {
          disp.editListName(list._id, value);
          that.setState({editingName: false});
        },
        cancel: function() {
          that.setState({editingName: false});
        }
      }))));
    } else {
      child = h('div.display', h('a.list-name' + (list.name ? '' : '.empty'), {
        href: '/lists/' + list._id,
        onClick: function(ev) {
          ev.preventDefault();
        }
      }, list.name));
    }
    return h('div.list' + (list.selected ? '.selected' : ''), {
      onMouseDown: function() {
        that.props.setListId(list._id);
      },
      onDoubleClick: function() {
        that.setState({editingName: true});
      }
    }, child);
  }
}));

var Lists = React.createFactory(React.createClass({
  displayName: 'Lists',
  render: function() {
    var that = this;
    var children = [h('h3', 'Todo Lists')];
    if (this.props.lists === null) {
      children.push(h('div#lists', 'Loading...'));
    } else {
      var lists = [];
      _.each(this.props.lists, function(list) {
        list.selected = that.props.listId === list._id;
        lists.push(List({
          list: list,
          setListId: that.props.setListId
        }));
      });
      children.push(h('div#lists', lists));
      children.push(h('div#createList', h('input#new-list', _.assign({
        type: 'text',
        placeholder: 'New list'
      }, okCancelEvents({
        ok: function(value, ev) {
          disp.addList({name: value}, function(err, listId) {
            if (err) throw err;
            that.props.setListId(listId);
          });
          ev.target.value = '';
        }
      })))));
    }
    return h('div', children);
  }
}));

var DispType = React.createFactory(React.createClass({
  render: function() {
    var that = this;
    return h('div.disp-type.' + this.props.dispType, {
      onClick: function() {
        that.props.toggleDispType();
      }
    }, this.props.dispType);
  }
}));

var Page = React.createFactory(React.createClass({
  displayName: 'Page',
  getInitialState: function() {
    return {
      lists: null,  // all lists
      todos: null,  // all todos for current listId
      listId: this.props.initialListId,  // current list
      tagFilter: null  // current tag
    };
  },
  getLists_: function(cb) {
    disp.getLists(function(err, lists) {
      if (err) return cb(err);
      // Sort lists by name in the UI.
      return cb(null, _.sortBy(lists, 'name'));
    });
  },
  getTodos_: function(listId, cb) {
    if (!listId) {
      return process.nextTick(cb);
    }
    disp.getTodos(listId, function(err, todos) {
      if (err) return cb(err);
      // Sort todos by timestamp in the UI.
      return cb(null, _.sortBy(todos, 'timestamp'));
    });
  },
  updateURL: function() {
    var listId = this.state.listId;
    var pathname = !listId ? '/' : '/lists/' + listId;
    // Note, this doesn't trigger a re-render; it's purely visual.
    window.history.replaceState({}, '', pathname + window.location.search);
  },
  componentDidMount: function() {
    var that = this;

    // TODO(sadovsky): Only update what's needed based on what changed.
    disp.on('change', function() {
      var listId = that.state.listId;
      that.getLists_(function(err, lists) {
        if (err) throw err;
        that.getTodos_(listId, function(err, todos) {
          if (err) throw err;
          // TODO(sadovsky): Maybe don't call setState if a newer change has
          // been observed.
          var nextState = {lists: lists};
          if (that.state.listId === listId) {
            nextState.todos = todos;
          }
          that.setState(nextState);
        });
      });
    });

    that.getLists_(function(err, lists) {
      if (err) throw err;
      var listId = that.state.listId;
      if ((!listId || !_.includes(_.pluck(lists, '_id'), listId)) &&
          lists.length > 0) {
        listId = lists[0]._id;
      }
      that.getTodos_(listId, function(err, todos) {
        if (err) throw err;
        that.setState({
          lists: lists,
          todos: todos,
          listId: listId
        });
      });
    });
  },
  componentWillUpdate: function(nextProps, nextState) {
    if (false) {
      console.log(this.props, nextProps);
      console.log(this.state, nextState);
    }
  },
  componentDidUpdate: function() {
    this.updateURL();
  },
  render: function() {
    var that = this;
    return h('div', [
      DispType({
        dispType: this.props.dispType,
        toggleDispType: function() {
          var newDispType = DISP_TYPE_SYNCBASE;
          if (that.props.dispType === DISP_TYPE_SYNCBASE) {
            newDispType = DISP_TYPE_COLLECTION;
          }
          // TODO(sadovsky): Retain other query params, namely 'n'.
          window.location.href = '/?d=' + newDispType;
        }
      }),
      h('div#top-tag-filter', TagFilter({
        todos: this.state.todos,
        tagFilter: this.state.tagFilter,
        setTagFilter: function(tagFilter) {
          that.setState({tagFilter: tagFilter});
        }
      })),
      h('div#main-pane', Todos({
        todos: this.state.todos,
        listId: this.state.listId,
        tagFilter: this.state.tagFilter
      })),
      h('div#side-pane', Lists({
        lists: this.state.lists,
        listId: this.state.listId,
        setListId: function(listId) {
          if (listId !== that.state.listId) {
            that.setState({
              todos: null,
              listId: listId,
              tagFilter: null
            }, function() {
              // Run getTodos_ in the setState callback to ensure that it will
              // execute after the 'change' event handler executes when a list
              // is created locally.
              // TODO(sadovsky): Maybe hold all todos (for all lists) in memory
              // so that we don't show a brief "loading" message on every list
              // change.
              that.getTodos_(listId, function(err, todos) {
                if (err) throw err;
                if (listId === that.state.listId) {
                  that.setState({todos: todos});
                }
              });
            });
          }
        }
      }))
    ]);
  }
}));

////////////////////////////////////////
// Initialization

var u = url.parse(window.location.href, true);

var rc;  // React component
function render(props) {
  console.assert(!rc);
  rc = React.render(Page(props), document.getElementById('page'));
}

function initDispatcher(dispType, syncbaseName, cb) {
  if (dispType === 'collection') {
    defaults.initCollectionDispatcher(cb);
  } else if (dispType === 'syncbase') {
    var vanadiumConfig = {
      logLevel: vanadium.vlog.levels.INFO,
      namespaceRoots: u.query.mounttable ? [u.query.mounttable] : undefined,
      proxy: u.query.proxy
    };
    vanadium.init(vanadiumConfig, function(err, rt) {
      if (err) return cb(err);
      defaults.initSyncbaseDispatcher(rt, syncbaseName, cb);
    });
  } else {
    process.nextTick(function() {
      cb(new Error('unknown dispType: ' + dispType));
    });
  }
}

function main(ctx) {
  console.assert(!rc);
  var dispType = u.query.d || 'collection';
  var syncbaseName = u.query.n || '/localhost:8200';
  var props = {
    initialListId: ctx.params.listId,
    dispType: dispType,
    syncbaseName: syncbaseName
  };
  initDispatcher(dispType, syncbaseName, function(err, resDisp) {
    if (err) throw err;
    disp = resDisp;
    defaults.initData(disp, function(err) {
      if (err) throw err;
      render(props);
    });
  });
}

page('/', main);
page('/lists/:listId', main);
page({click: false});