// Copyright (c) .NET Foundation and contributors. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

using System.IO;
using System.Reflection;

namespace System.CommandLine.Suggest
{
    internal static class SuggestionShellScriptHandler
    {
        public static void Handle(TextWriter output, ShellType shellType)
        {
            switch (shellType)
            {
                case ShellType.Bash:
                    PrintToConsoleFrom(output, "dotnet-suggest-shim.bash", useUnixLineEndings: true);
                    break;
                case ShellType.PowerShell:
                    PrintToConsoleFrom(output, "dotnet-suggest-shim.ps1", useUnixLineEndings: false);
                    break;
                case ShellType.Zsh:
                    PrintToConsoleFrom(output, "dotnet-suggest-shim.zsh", useUnixLineEndings: true);
                    break;
                default:
                    throw new SuggestionShellScriptException($"Shell '{shellType}' is not supported.");
            }
        }

        private static void PrintToConsoleFrom(TextWriter output, string scriptName, bool useUnixLineEndings)
        {
            var assemblyLocation = Assembly.GetAssembly(typeof(SuggestionShellScriptHandler)).Location;
            var directory = Path.GetDirectoryName(assemblyLocation);
            string scriptContent = File.ReadAllText(Path.Combine(directory, scriptName));
            bool hasUnixLineEndings = !scriptContent.Contains("\r\n");
            if (hasUnixLineEndings != useUnixLineEndings)
            {
                if (useUnixLineEndings)
                {
                    scriptContent = scriptContent.Replace("\r\n", "\n");
                }
                else
                {
                    scriptContent = scriptContent.Replace("\n", "\r\n");
                }
            }
            output.Write(scriptContent);
        }
    }
}