/**
 * Freezes (or unfreezes) selected properties
 *
 * @author Zack Lovatt <zack@lova.tt>
 * @version 0.2.1
 */
(function freezeSelectedProperties() {
  var frozenText = "// FROZEN";

  function freezeProp(property) {
    if (!property.canSetExpression) {
      return;
    }

    var expression = property.expression;

    if (expression === "") {
      try {
        property.expression = generateExpression(property);
      } catch (e) {
        throw new Error(
          [
            "Property " + property.name + " not supported!",
            "Screenshot this and send to zack@lova.tt",
            e
          ].join("\n")
        );
      }
    } else {
      if (expression.indexOf(frozenText) > -1) {
        property.expression = "";
      } else {
        // prop has expression; skip!
      }
    }
  }

  /**
   * Freezes a given property
   *
   * @param {Property | Layer | PropertyGroup} property Property to freeze
   */
  function freeze(property) {
    if (skipProperty(property)) {
      return;
    }

    if (property instanceof Property) {
      freezeProp(property);
    } else if (
      property instanceof PropertyGroup ||
      property.matchName.indexOf("Layer") > -1
    ) {
      for (var ii = 1; ii <= property.numProperties; ii++) {
        var prop = property.property(ii);
        freeze(prop);
      }
    }
  }

  /**
   * Check whether to skip a given property
   *
   * @param {Property} property Property to check
   * @returns {boolean}         Whether to skip this prop
   */
  function skipProperty(property) {
    var depth = property.propertyDepth;

    if (depth > 1) {
      var layer = property.propertyGroup(depth);
      var rootGroup = property.propertyGroup(depth - 1);

      switch (rootGroup.matchName) {
        // skip any layer style data if not present
        case "ADBE Layer Styles":
          if (!layer.layerStyle.canSetEnabled) {
            return true;
          }

          // Handle style groups we can't see
          if (property instanceof PropertyGroup && !property.canSetEnabled) {
            return true;
          }
          break;

        // 2d layer? Skip Geometry and Materials groups
        case "ADBE Plane Options Group":
        case "ADBE Material Options Group":
        case "ADBE Extrsn Options Group":
          if (!layer.threeDLayer) {
            return true;
          }
          break;

        // Check audio
        case "ADBE Audio Group":
          if (!layer.hasAudio) {
            return true;
          }
          break;

        default:
          break;
      }
    }

    return false;
  }

  /**
   * Generates freeze expression based on property type
   *
   * @param {Property} property Property to generate expr for
   * @returns {string}          Freeze expression
   */
  function generateExpression(property) {
    var expression = [frozenText, "posterizeTime(0);"];

    switch (property.propertyValueType) {
      case PropertyValueType.ThreeD_SPATIAL:
      case PropertyValueType.ThreeD:
      case PropertyValueType.TwoD_SPATIAL:
      case PropertyValueType.TwoD:
      case PropertyValueType.COLOR:
        expression.push("[" + property.value.toString() + "];");
        break;
      case PropertyValueType.NO_VALUE:
      case PropertyValueType.CUSTOM_VALUE:
      case PropertyValueType.SHAPE:
      case PropertyValueType.TEXT_DOCUMENT:
        var compTime = property.propertyGroup(property.propertyDepth).time;
        expression.push("valueAtTime(" + compTime + ");");
        break;
      case PropertyValueType.OneD:
        expression.push(property.value.toString() + ";");
        break;
    }

    return expression.join("\n");
  }

  /**
   * Removes all redundant ancestor groups from a selection of properties
   *
   * @param {(Property|PropertyGroup)[]} props Props to prune
   * @return {(Property|PropertyGroup)[]}      Pruned group
   */
  function pruneAncestorGroups(props) {
    /**
     * Converts a given property to an array of property indices
     *
     * @param {Property | PropertyGroup} prop Prop to get path from
     * @return {number[]}                     Property index array
     */
    function getPropPath(prop) {
      var propPath = [prop.propertyIndex];

      var parentProp = prop.propertyGroup();

      while (parentProp.propertyDepth > 1) {
        propPath.unshift(parentProp.propertyIndex);
        parentProp = parentProp.propertyGroup();
      }

      // Add layer index
      propPath.unshift(prop.propertyGroup(prop.propertyDepth).index);

      return propPath;
    }

    /**
     * Checks whether an array is a subset of another array
     *
     * @param {number[]} arr1 Array to check
     * @param {number[]} arr2 Array to check against
     * @return {boolean}      Whether arr1 is a subset of arr2
     */
    function arrayIsSubsetOfArray(arr1, arr2) {
      for (var ii = 0, il = arr1.length; ii < il; ii++) {
        var propIndex = arr1[ii]; // [(1), 1]

        var existingPropPathAtIndex = arr2[ii]; // [(1), 1, 2, 1, 6]

        if (propIndex !== existingPropPathAtIndex) {
          return false;
        }
      }

      return true;
    }

    /**
     * Checks whether an array is a subset of any array in a collection
     *
     * @param {number[]} array             Array to check
     * @param {number[][]} arrayCollection Collection of arrays to check against
     * @return {boolean}                   Whether array is a subset of anything in collection
     */
    function checkArrayIsSubsetInCollection(array, arrayCollection) {
      for (var ii = 0, il = arrayCollection.length; ii < il; ii++) {
        var collectionArray = arrayCollection[ii];

        var isSubset = arrayIsSubsetOfArray(array, collectionArray);

        if (isSubset) {
          return true;
        }
      }

      return false;
    }

    var allPropPaths = [];
    var pruned = [];

    // Reverse-sort by property depth
    props.sort(function (a, b) {
      if (a.propertyDepth > b.propertyDepth) {
        return -1;
      } else if (a.propertyDepth < b.propertyDepth) {
        return 1;
      }

      return 0;
    });

    for (var ii = 0, il = props.length; ii < il; ii++) {
      var prop = props[ii];
      var propPath = getPropPath(prop);

      var pathExists = checkArrayIsSubsetInCollection(propPath, allPropPaths);

      if (!pathExists) {
        allPropPaths.push(propPath);
        pruned.push(prop);
      }
    }

    return pruned;
  }

  /**
   * Gets selected properties, else all comp layers
   *
   * @returns {(Property|PropertyGroup)[]} Items to freeze
   */
  function getTarget(comp) {
    var props = comp.selectedProperties;
    var pruned = pruneAncestorGroups(props);

    if (pruned.length > 0) {
      return pruned;
    }

    return comp.selectedLayers;
  }

  app.beginUndoGroup("Freeze Selected Properties");

  var comp = app.project.activeItem;

  if (!(comp && comp instanceof CompItem)) {
    alert("Open a comp!");
    return;
  }

  var props = getTarget(comp);

  try {
    for (var ii = 0, il = props.length; ii < il; ii++) {
      var prop = props[ii];
      freeze(prop);
    }
  } catch (e) {
    alert(e);
  }

  app.endUndoGroup();
})();