// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

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

namespace PowerShellEditorServices.Test.E2E;

/// <summary>
/// A <see cref="ServerManager"/> is responsible for launching or attaching to a language server, providing access to its input and output streams, and tracking its lifetime.
/// </summary>
internal class PsesStdioLanguageServerProcessHost(bool isDebugAdapter)
: StdioLanguageServerProcessHost(PwshExe, GeneratePsesArguments(isDebugAdapter))
{
    protected static readonly string s_binDir =
        Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);

    private static readonly string s_bundledModulePath = new FileInfo(Path.Combine(
        s_binDir, "..", "..", "..", "..", "..", "module")).FullName;

    private static readonly string s_sessionDetailsPath = Path.Combine(
        s_binDir, $"pses_test_sessiondetails_{Path.GetRandomFileName()}");

    private static readonly string s_logPath = Path.Combine(
        s_binDir, $"pses_test_logs_{Path.GetRandomFileName()}");

    private const string s_logLevel = "Diagnostic";
    private static readonly string[] s_featureFlags = { "PSReadLine" };
    private const string s_hostName = "TestHost";
    private const string s_hostProfileId = "TestHost";
    private const string s_hostVersion = "1.0.0";

    // Adjust the environment variable if wanting to test with 5.1 or a specific pwsh path
    public static string PwshExe { get; } = Environment.GetEnvironmentVariable("PWSH_EXE_NAME") ?? "pwsh";
    public static bool IsWindowsPowerShell { get; } = PwshExe.EndsWith("powershell");
    public static bool RunningInConstrainedLanguageMode { get; } =
        Environment.GetEnvironmentVariable("__PSLockdownPolicy", EnvironmentVariableTarget.Machine) != null;

    private static string[] GeneratePsesArguments(bool isDebugAdapter)
    {
        List<string> args = new()
            {
                "&",
                SingleQuoteEscape(Path.Combine(s_bundledModulePath, "PowerShellEditorServices", "Start-EditorServices.ps1")),
                "-LogPath",
                SingleQuoteEscape(s_logPath),
                "-LogLevel",
                s_logLevel,
                "-SessionDetailsPath",
                SingleQuoteEscape(s_sessionDetailsPath),
                "-FeatureFlags",
                string.Join(',', s_featureFlags),
                "-HostName",
                s_hostName,
                "-HostProfileId",
                s_hostProfileId,
                "-HostVersion",
                s_hostVersion,
                "-BundledModulesPath",
                SingleQuoteEscape(s_bundledModulePath),
                "-Stdio"
            };

        if (isDebugAdapter)
        {
            args.Add("-DebugServiceOnly");
        }

        string base64Str = Convert.ToBase64String(
            System.Text.Encoding.Unicode.GetBytes(string.Join(' ', args)));

        return
        [
            "-NoLogo",
                "-NoProfile",
                "-EncodedCommand",
                base64Str
        ];
    }

    private static string SingleQuoteEscape(string str) => $"'{str.Replace("'", "''")}'";
}