// <copyright file="WebElementFactory.cs" company="Selenium Committers">
// Licensed to the Software Freedom Conservancy (SFC) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The SFC licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.
// </copyright>

using System;
using System.Collections.Generic;

namespace OpenQA.Selenium
{
    /// <summary>
    /// Object used to create <see cref="WebElement"/> objects for a remote driver instance.
    /// </summary>
    public class WebElementFactory
    {
        private WebDriver driver;

        /// <summary>
        /// Initializes a new instance of the <see cref="WebElementFactory"/> class.
        /// </summary>
        /// <param name="parentDriver">The <see cref="WebDriver"/> object used to locate the elements.</param>
        public WebElementFactory(WebDriver parentDriver)
        {
            this.driver = parentDriver;
        }

        /// <summary>
        /// Gets the <see cref="WebDriver"/> instance used to locate elements.
        /// </summary>
        protected WebDriver ParentDriver
        {
            get { return this.driver; }
        }

        /// <summary>
        /// Creates a <see cref="WebElement"/> from a dictionary containing a reference to an element.
        /// </summary>
        /// <param name="elementDictionary">The dictionary containing the element reference.</param>
        /// <returns>A <see cref="WebElement"/> containing the information from the specified dictionary.</returns>
        public virtual WebElement CreateElement(Dictionary<string, object> elementDictionary)
        {
            string elementId = this.GetElementId(elementDictionary);
            return new WebElement(this.ParentDriver, elementId);
        }

        /// <summary>
        /// Gets a value indicating wether the specified dictionary represents a reference to a web element.
        /// </summary>
        /// <param name="elementDictionary">The dictionary to check.</param>
        /// <returns><see langword="true"/> if the dictionary contains an element reference; otherwise, <see langword="false"/>.</returns>
        public bool ContainsElementReference(Dictionary<string, object> elementDictionary)
        {
            string elementPropertyName;
            return this.TryGetElementPropertyName(elementDictionary, out elementPropertyName);
        }

        /// <summary>
        /// Gets the internal ID associated with the element.
        /// </summary>
        /// <param name="elementDictionary">A dictionary containing the element reference.</param>
        /// <returns>The internal ID associated with the element.</returns>
        public string GetElementId(Dictionary<string, object> elementDictionary)
        {
            string elementPropertyName;
            if (!this.TryGetElementPropertyName(elementDictionary, out elementPropertyName))
            {
                throw new ArgumentException("elementDictionary", "The specified dictionary does not contain an element reference");
            }

            string elementId = elementDictionary[elementPropertyName].ToString();
            if (string.IsNullOrEmpty(elementId))
            {
                throw new InvalidOperationException("The specified element ID is either null or the empty string.");
            }

            return elementId;
        }

        private bool TryGetElementPropertyName(Dictionary<string, object> elementDictionary, out string elementPropertyName)
        {
            if (elementDictionary == null)
            {
                throw new ArgumentNullException(nameof(elementDictionary), "The dictionary containing the element reference cannot be null");
            }

            if (elementDictionary.ContainsKey(WebElement.ElementReferencePropertyName))
            {
                elementPropertyName = WebElement.ElementReferencePropertyName;
                return true;
            }

            elementPropertyName = string.Empty;
            return false;
        }
    }
}
