var zrUtil = require("zrender/lib/core/util");

var VisualMapping = require("./VisualMapping");

/**
 * @file Visual solution, for consistent option specification.
 */
var each = zrUtil.each;

function hasKeys(obj) {
  if (obj) {
    for (var name in obj) {
      if (obj.hasOwnProperty(name)) {
        return true;
      }
    }
  }
}
/**
 * @param {Object} option
 * @param {Array.<string>} stateList
 * @param {Function} [supplementVisualOption]
 * @return {Object} visualMappings <state, <visualType, module:echarts/visual/VisualMapping>>
 */


function createVisualMappings(option, stateList, supplementVisualOption) {
  var visualMappings = {};
  each(stateList, function (state) {
    var mappings = visualMappings[state] = createMappings();
    each(option[state], function (visualData, visualType) {
      if (!VisualMapping.isValidType(visualType)) {
        return;
      }

      var mappingOption = {
        type: visualType,
        visual: visualData
      };
      supplementVisualOption && supplementVisualOption(mappingOption, state);
      mappings[visualType] = new VisualMapping(mappingOption); // Prepare a alpha for opacity, for some case that opacity
      // is not supported, such as rendering using gradient color.

      if (visualType === 'opacity') {
        mappingOption = zrUtil.clone(mappingOption);
        mappingOption.type = 'colorAlpha';
        mappings.__hidden.__alphaForOpacity = new VisualMapping(mappingOption);
      }
    });
  });
  return visualMappings;

  function createMappings() {
    var Creater = function () {}; // Make sure hidden fields will not be visited by
    // object iteration (with hasOwnProperty checking).


    Creater.prototype.__hidden = Creater.prototype;
    var obj = new Creater();
    return obj;
  }
}
/**
 * @param {Object} thisOption
 * @param {Object} newOption
 * @param {Array.<string>} keys
 */


function replaceVisualOption(thisOption, newOption, keys) {
  // Visual attributes merge is not supported, otherwise it
  // brings overcomplicated merge logic. See #2853. So if
  // newOption has anyone of these keys, all of these keys
  // will be reset. Otherwise, all keys remain.
  var has;
  zrUtil.each(keys, function (key) {
    if (newOption.hasOwnProperty(key) && hasKeys(newOption[key])) {
      has = true;
    }
  });
  has && zrUtil.each(keys, function (key) {
    if (newOption.hasOwnProperty(key) && hasKeys(newOption[key])) {
      thisOption[key] = zrUtil.clone(newOption[key]);
    } else {
      delete thisOption[key];
    }
  });
}
/**
 * @param {Array.<string>} stateList
 * @param {Object} visualMappings <state, Object.<visualType, module:echarts/visual/VisualMapping>>
 * @param {module:echarts/data/List} list
 * @param {Function} getValueState param: valueOrIndex, return: state.
 * @param {object} [scope] Scope for getValueState
 * @param {string} [dimension] Concrete dimension, if used.
 */


function applyVisual(stateList, visualMappings, data, getValueState, scope, dimension) {
  var visualTypesMap = {};
  zrUtil.each(stateList, function (state) {
    var visualTypes = VisualMapping.prepareVisualTypes(visualMappings[state]);
    visualTypesMap[state] = visualTypes;
  });
  var dataIndex;

  function getVisual(key) {
    return data.getItemVisual(dataIndex, key);
  }

  function setVisual(key, value) {
    data.setItemVisual(dataIndex, key, value);
  }

  if (dimension == null) {
    data.each(eachItem, true);
  } else {
    data.each([dimension], eachItem, true);
  }

  function eachItem(valueOrIndex, index) {
    dataIndex = dimension == null ? valueOrIndex : index;
    var rawDataItem = data.getRawDataItem(dataIndex); // Consider performance

    if (rawDataItem && rawDataItem.visualMap === false) {
      return;
    }

    var valueState = getValueState.call(scope, valueOrIndex);
    var mappings = visualMappings[valueState];
    var visualTypes = visualTypesMap[valueState];

    for (var i = 0, len = visualTypes.length; i < len; i++) {
      var type = visualTypes[i];
      mappings[type] && mappings[type].applyVisual(valueOrIndex, getVisual, setVisual);
    }
  }
}

exports.createVisualMappings = createVisualMappings;
exports.replaceVisualOption = replaceVisualOption;
exports.applyVisual = applyVisual;