// Copyright (c) Microsoft Corporation
// The Microsoft Corporation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using Microsoft.PowerToys.Run.Plugin.Registry.Helper;
using Microsoft.Win32;

namespace Microsoft.PowerToys.Run.Plugin.Registry.Classes
{
    /// <summary>
    /// A entry of the registry.
    /// </summary>
    internal class RegistryEntry
    {
        /// <summary>
        /// Gets the full path to a registry key.
        /// </summary>
        internal string KeyPath { get; }

        /// <summary>
        /// Gets the registry key for this entry.
        /// </summary>
        internal RegistryKey? Key { get; }

        /// <summary>
        /// Gets a possible exception that was occurred when try to open this registry key (e.g. <see cref="UnauthorizedAccessException"/>).
        /// </summary>
        internal Exception? Exception { get; }

        /// <summary>
        /// Gets the name of the current selected registry value.
        /// </summary>
        internal string? ValueName { get; }

        /// <summary>
        /// Gets the value of the current selected registry value.
        /// </summary>
        internal object? ValueData { get; }

        /// <summary>
        /// Initializes a new instance of the <see cref="RegistryEntry"/> class.
        /// </summary>
        /// <param name="keyPath">The full path to the registry key for this entry.</param>
        /// <param name="exception">A exception that was occurred when try to access this registry key.</param>
        internal RegistryEntry(string keyPath, Exception exception)
        {
            KeyPath = keyPath;
            Exception = exception;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="RegistryEntry"/> class.
        /// </summary>
        /// <param name="key">The <see cref="RegistryKey"/> for this entry.</param>
        internal RegistryEntry(RegistryKey key)
        {
            KeyPath = key.Name;
            Key = key;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="RegistryEntry"/> class.
        /// </summary>
        /// <param name="key">The <see cref="RegistryKey"/> for this entry.</param>
        /// <param name="valueName">The value name of the current selected registry value.</param>
        /// <param name="value">The value of the current selected registry value.</param>
        internal RegistryEntry(RegistryKey key, string valueName, object value)
        {
            KeyPath = key.Name;
            Key = key;
            ValueName = valueName;
            ValueData = value;
        }

        /// <summary>
        /// Return the registry key.
        /// </summary>
        /// <returns>A registry key.</returns>
        internal string GetRegistryKey()
        {
            return $"{Key?.Name ?? KeyPath}";
        }

        /// <summary>
        /// Return the value name with the complete registry key.
        /// </summary>
        /// <returns>A value name with the complete registry key.</returns>
        internal string GetValueNameWithKey()
        {
            return $"{Key?.Name ?? KeyPath}\\\\{ValueName?.ToString() ?? string.Empty}";
        }

        /// <summary>
        /// Return the value data of a value name inside a registry key.
        /// </summary>
        /// <returns>A value data.</returns>
        internal string GetValueData()
        {
            if (Key is null)
            {
                return KeyPath;
            }

            if (string.IsNullOrEmpty(ValueName))
            {
                return Key.Name;
            }

            return ValueHelper.GetValue(Key, ValueName);
        }
    }
}
