using System;
using Umbraco.Core;
using Umbraco.Core.Models;
using Umbraco.Web.PublishedCache;

public static class UmbracoGuidExtensions {

    /// <summary>
    /// Gets an instance of <code>IPublishedContent</code> based on the specified <code>guid</code>. GUIDs are not
    /// available in the content cache, so a lookup will be made in the database (or the runtime cache if the GUID
    /// has been requested before).
    /// </summary>
    /// <param name="cache">A reference to the content cache.</param>
    /// <param name="guid">The GUID of the content.</param>
    /// <returns>Returns an instance of <code>IPublishedContent</code> if found, otherwise <code>null</code>.</returns>
    public static IPublishedContent GetByGuid(this ContextualPublishedContentCache cache, string guid) {
        return GetByGuid(cache, Guid.Parse(guid));
    }

    /// <summary>
    /// Gets an instance of <code>IPublishedContent</code> based on the specified <code>guid</code>. GUIDs are not
    /// available in the content cache, so a lookup will be made in the database (or the runtime cache if the GUID
    /// has been requested before).
    /// </summary>
    /// <param name="cache">A reference to the content cache.</param>
    /// <param name="guid">The GUID of the content.</param>
    /// <returns>Returns an instance of <code>IPublishedContent</code> if found, otherwise <code>null</code>.</returns>
    public static IPublishedContent GetByGuid(this ContextualPublishedContentCache cache, Guid guid) {

        // Get the ID from the database (or runtime cache)
        Attempt<int> attempt = ApplicationContext.Current.Services.EntityService.GetIdForKey(guid, UmbracoObjectTypes.Media);

        // Find the media in the media cache
        return attempt.Success ? cache.GetById(attempt.Result) : null;

    }

    /// <summary>
    /// Gets an instance of <code>T</code> based on the <code>IPublishedContent</code> with the specified <code>guid</code>. GUIDs are not
    /// available in the content cache, so a lookup will be made in the database (or the runtime cache if the GUID
    /// has been requested before).
    /// </summary>
    /// <typeparam name="T">The type returned by the specified <code>callback</code>.</typeparam>
    /// <param name="cache">A reference to the content cache.</param>
    /// <param name="guid">The GUID of the content.</param>
    /// <param name="callback">The callback function used for parsing the found instance of <code>IPublishedContent</code>.</param>
    /// <returns>Returns an instance of <code>T</code> based on the specified <code>callback</code>.</returns>
    public static T GetByGuid<T>(this ContextualPublishedContentCache cache, string guid, Func<IPublishedContent, T> callback) {
        return callback(GetByGuid(cache, guid));
    }

    /// <summary>
    /// Gets an instance of <code>T</code> based on the <code>IPublishedContent</code> with the specified <code>guid</code>. GUIDs are not
    /// available in the content cache, so a lookup will be made in the database (or the runtime cache if the GUID
    /// has been requested before).
    /// </summary>
    /// <typeparam name="T">The type returned by the specified <code>callback</code>.</typeparam>
    /// <param name="cache">A reference to the content cache.</param>
    /// <param name="guid">The GUID of the content.</param>
    /// <param name="callback">The callback function used for parsing the found instance of <code>IPublishedContent</code>.</param>
    /// <returns>Returns an instance of <code>T</code> based on the specified <code>callback</code>.</returns>
    public static T GetByGuid<T>(this ContextualPublishedContentCache cache, Guid guid, Func<IPublishedContent, T> callback) {
        return callback(GetByGuid(cache, guid));
    }

    /// <summary>
    /// Gets an instance of <code>IPublishedContent</code> based on the specified <code>guid</code>. GUIDs are not
    /// available in the media cache, so a lookup will be made in the database (or the runtime cache if the GUID
    /// has been requested before).
    /// </summary>
    /// <param name="cache">A reference to the media cache.</param>
    /// <param name="guid">The GUID of the media.</param>
    /// <returns>Returns an instance of <code>IPublishedContent</code> if found, otherwise <code>null</code>.</returns>
    public static IPublishedContent GetByGuid(this ContextualPublishedMediaCache cache, string guid) {
        return GetByGuid(cache, Guid.Parse(guid));
    }

    /// <summary>
    /// Gets an instance of <code>IPublishedContent</code> based on the specified <code>guid</code>. GUIDs are not
    /// available in the media cache, so a lookup will be made in the database (or the runtime cache if the GUID
    /// has been requested before).
    /// </summary>
    /// <param name="cache">A reference to the media cache.</param>
    /// <param name="guid">The GUID of the media.</param>
    /// <returns>Returns an instance of <code>IPublishedContent</code> if found, otherwise <code>null</code>.</returns>
    public static IPublishedContent GetByGuid(this ContextualPublishedMediaCache cache, Guid guid) {

        // Get the ID from the database (or runtime cache)
        Attempt<int> attempt = ApplicationContext.Current.Services.EntityService.GetIdForKey(guid, UmbracoObjectTypes.Media);

        // Find the media in the media cache
        return attempt.Success ? cache.GetById(attempt.Result) : null;

    }

    /// <summary>
    /// Gets an instance of <code>T</code> based on the <code>IPublishedContent</code> with the specified <code>guid</code>. GUIDs are not
    /// available in the media cache, so a lookup will be made in the database (or the runtime cache if the GUID
    /// has been requested before).
    /// </summary>
    /// <typeparam name="T">The type returned by the specified <code>callback</code>.</typeparam>
    /// <param name="cache">A reference to the media cache.</param>
    /// <param name="guid">The GUID of the media.</param>
    /// <param name="callback">The callback function used for parsing the found instance of <code>IPublishedContent</code>.</param>
    /// <returns>Returns an instance of <code>T</code> based on the specified <code>callback</code>.</returns>
    public static T GetByGuid<T>(this ContextualPublishedMediaCache cache, string guid, Func<IPublishedContent, T> callback) {
        return callback(GetByGuid(cache, guid));
    }

    /// <summary>
    /// Gets an instance of <code>T</code> based on the <code>IPublishedContent</code> with the specified <code>guid</code>. GUIDs are not
    /// available in the media cache, so a lookup will be made in the database (or the runtime cache if the GUID
    /// has been requested before).
    /// </summary>
    /// <typeparam name="T">The type returned by the specified <code>callback</code>.</typeparam>
    /// <param name="cache">A reference to the media cache.</param>
    /// <param name="guid">The GUID of the media.</param>
    /// <param name="callback">The callback function used for parsing the found instance of <code>IPublishedContent</code>.</param>
    /// <returns>Returns an instance of <code>T</code> based on the specified <code>callback</code>.</returns>
    public static T GetByGuid<T>(this ContextualPublishedMediaCache cache, Guid guid, Func<IPublishedContent, T> callback) {
        return callback(GetByGuid(cache, guid));
    }

}