using LibGit2Sharp.Core;

namespace LibGit2Sharp
{
    /// <summary>
    ///   Provides helper overloads to a <see cref = "BranchCollection" />.
    /// </summary>
    public static class BranchCollectionExtensions
    {
        /// <summary>
        ///   Create a new local branch with the specified name
        /// </summary>
        /// <param name = "name">The name of the branch.</param>
        /// <param name = "committish">Revparse spec for the target commit.</param>
        /// <param name = "allowOverwrite">True to allow silent overwriting a potentially existing branch, false otherwise.</param>
        /// <param name = "branches">The <see cref="BranchCollection"/> being worked with.</param>
        /// <returns>A new <see cref="Branch"/>.</returns>
        public static Branch Add(this BranchCollection branches, string name, string committish, bool allowOverwrite = false)
        {
            Ensure.ArgumentNotNullOrEmptyString(name, "name");
            Ensure.ArgumentNotNullOrEmptyString(committish, "committish");

            Commit commit = branches.repo.LookupCommit(committish);

            return branches.Add(name, commit, allowOverwrite);
        }

        /// <summary>
        ///   Deletes the branch with the specified name.
        /// </summary>
        /// <param name = "name">The name of the branch to delete.</param>
        /// <param name = "isRemote">True if the provided <paramref name="name"/> is the name of a remote branch, false otherwise.</param>
        /// <param name = "branches">The <see cref="BranchCollection"/> being worked with.</param>
        public static void Remove(this BranchCollection branches, string name, bool isRemote = false)
        {
            Ensure.ArgumentNotNullOrEmptyString(name, "name");

            string branchName = isRemote ? Reference.RemoteTrackingBranchPrefix + name : name;

            Branch branch = branches[branchName];

            if (branch == null)
            {
                return;
            }

            branches.Remove(branch);
        }

        /// <summary>
        ///   Renames an existing local branch with a new name.
        /// </summary>
        /// <param name = "currentName">The current branch name.</param>
        /// <param name = "newName">The new name the existing branch should bear.</param>
        /// <param name = "allowOverwrite">True to allow silent overwriting a potentially existing branch, false otherwise.</param>
        /// <param name = "branches">The <see cref="BranchCollection"/> being worked with.</param>
        /// <returns>A new <see cref="Branch"/>.</returns>
        public static Branch Move(this BranchCollection branches, string currentName, string newName, bool allowOverwrite = false)
        {
            Ensure.ArgumentNotNullOrEmptyString(currentName, "currentName");
            Ensure.ArgumentNotNullOrEmptyString(newName, "newName");

            Branch branch = branches[currentName];

            if (branch == null)
            {
                throw new LibGit2SharpException("No branch named '{0}' exists in the repository.");
            }

            return branches.Move(branch, newName, allowOverwrite);
        }
    }
}