/**
  This controller handles displaying of history

  @class HistoryController
  @extends Discourse.ObjectController
  @namespace Discourse
  @uses Discourse.ModalFunctionality
  @module Discourse
**/
Discourse.HistoryController = Discourse.ObjectController.extend(Discourse.ModalFunctionality, {
  loading: false,
  viewMode: "side_by_side",
  revisionsTextKey: "post.revisions.controls.comparing_previous_to_current_out_of_total",

  refresh: function(postId, postVersion) {
    this.set("loading", true);

    var self = this;
    Discourse.Post.loadRevision(postId, postVersion).then(function (result) {
      self.setProperties({ loading: false, model: result });
    });
  },

  createdAtDate: function() { return moment(this.get("created_at")).format("LLLL"); }.property("created_at"),

  previousVersion: function() { return this.get("version") - 1; }.property("version"),

  displayGoToFirst: Em.computed.gt("version", 3),
  displayGoToPrevious: Em.computed.gt("version", 2),
  displayRevisions: Em.computed.gt("revisions_count", 2),
  displayGoToNext: function() { return this.get("version") < this.get("revisions_count"); }.property("version", "revisions_count"),
  displayGoToLast: function() { return this.get("version") < this.get("revisions_count") - 1; }.property("version", "revisions_count"),

  displayingInline: Em.computed.equal("viewMode", "inline"),
  displayingSideBySide: Em.computed.equal("viewMode", "side_by_side"),
  displayingSideBySideMarkdown: Em.computed.equal("viewMode", "side_by_side_markdown"),

  category_diff: function() {
    var viewMode = this.get("viewMode");
    var changes = this.get("category_changes");

    if (changes === null) { return; }

    var prevCategory = Discourse.Category.findById(changes.previous_category_id);
    var curCategory = Discourse.Category.findById(changes.current_category_id);

    var raw = "";
    var opts = { allowUncategorized: true };
    prevCategory = Discourse.HTML.categoryBadge(prevCategory, opts);
    curCategory = Discourse.HTML.categoryBadge(curCategory, opts);

    if(viewMode === "side_by_side_markdown" || viewMode === "side_by_side") {
      raw = "<div class='span8'>" + prevCategory +  "</div> <div class='span8 offset1'>" + curCategory +  "</div>";
    } else {
      var diff = "<del>" + prevCategory + "</del> " + "<ins>" + curCategory + "</ins>";
      raw = "<div class='inline-diff'>" + diff +  "</div>";
    }

    return raw;

  }.property("viewMode", "category_changes"),

  title_diff: function() {
    var viewMode = this.get("viewMode");
    if(viewMode === "side_by_side_markdown") {
      viewMode = "side_by_side";
    }
    return this.get("title_changes." + viewMode);
  }.property("viewMode", "title_changes"),

  body_diff: function() {
    return this.get("body_changes." + this.get("viewMode"));
  }.property("viewMode", "body_changes"),

  actions: {
    loadFirstVersion: function() { this.refresh(this.get("post_id"), 2); },
    loadPreviousVersion: function() { this.refresh(this.get("post_id"), this.get("version") - 1); },
    loadNextVersion: function() { this.refresh(this.get("post_id"), this.get("version") + 1); },
    loadLastVersion: function() { this.refresh(this.get("post_id"), this.get("revisions_count")); },

    displayInline: function() { this.set("viewMode", "inline"); },
    displaySideBySide: function() { this.set("viewMode", "side_by_side"); },
    displaySideBySideMarkdown: function() { this.set("viewMode", "side_by_side_markdown"); }
  }
});