using System;
using System.Collections.Generic;
using System.Reflection;

namespace Chernobyl.Reflection
{
    /// <summary>
    /// Thrown when an error involving method(s) occurs.
    /// </summary>
    public class MethodException : Exception
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="MethodException"/> class
        /// whose <see cref="Exception.InnerException"/> is set to null.
        /// </summary>
        /// <param name="message">The error message that explains the reason for 
        /// the exception.</param>
        /// <param name="methods">The methods that are involved in the error.</param>
        public MethodException(string message, IEnumerable<MethodBase> methods)
            : this(message, methods, null)
        {}

        /// <summary>
        /// Initializes a new instance of the <see cref="MethodException"/> class.
        /// </summary>
        /// <param name="message">The error message that explains the reason for 
        /// the exception.</param>
        /// <param name="methods">The methods that are involved in the error.</param>
        /// <param name="innerException">The exception that is the cause of the 
        /// current exception, or a null reference (Nothing in Visual Basic) if 
        /// no inner exception is specified.</param>
        public MethodException(string message, IEnumerable<MethodBase> methods, Exception innerException)
            : base(message, innerException)
        {
            Methods = methods;
        }

        /// <summary>
        /// The methods that are involved in the error. 
        /// </summary>
        public IEnumerable<MethodBase> Methods { get; private set; }
    }

    /// <summary>
    /// Extension and utility methods for <see cref="MethodException"/> and
    /// related types.
    /// </summary>
    public static class MethodExceptionExtensions
    {
        /// <summary>
        /// Throws an <see cref="MethodException" /> when the provided
        /// <paramref name="method" /> instance's <see cref="MethodBase.IsStatic" />
        /// equals <paramref name="value" />.
        /// </summary>
        /// <param name="method">The method whose <see cref="MethodBase.IsStatic" />
        /// is to be checked.</param>
        /// <param name="value">True to throw exception when
        /// <see cref="MethodBase.IsStatic" /> is true, false to throw exception
        /// when <see cref="MethodBase.IsStatic" /> is false.</param>
        /// <exception cref="MethodException">Thrown when the provided
        /// <paramref name="method" /> instance's <see cref="MethodBase.IsStatic" />
        /// equals <paramref name="value" />.</exception>
        public static void ThrowWhenStaticIs(this MethodBase method, bool value)
        {
            if (method.IsStatic == value)
            {
                string message = string.Format(
                    value ? "The method '{0}' must not be static." : 
                            "The method '{0}' must be static.", method);

                throw new MethodException(message, method.ToEnumerable());
            }
        }
    }
}