// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Diagnostics;
using Microsoft.DotNet.HotReload;
using Microsoft.Extensions.Logging;

namespace Microsoft.DotNet.Watch;

[Flags]
internal enum TestFlags
{
    None = 0,
    RunningAsTest = 1 << 0,
    MockBrowser = 1 << 1,

    /// <summary>
    /// Instead of using <see cref="Console.ReadKey()"/> to watch for Ctrl+C, Ctlr+R, and other keys, read from standard input.
    /// This allows tests to trigger key based events.
    /// </summary>
    ReadKeyFromStdin = 1 << 2,

    /// <summary>
    /// Redirects the output of the launched browser process to watch output.
    /// </summary>
    RedirectBrowserOutput = 1 << 3,
}

internal sealed record EnvironmentOptions(
    string WorkingDirectory,
    string? SdkDirectory,
    string LogMessagePrefix,
    TimeSpan? ProcessCleanupTimeout = null,
    bool IsPollingEnabled = false,
    bool SuppressHandlingStaticWebAssets = false,
    bool SuppressMSBuildIncrementalism = false,
    bool SuppressLaunchBrowser = false,
    bool SuppressBrowserRefresh = false,
    bool SuppressEmojis = false,
    bool RestartOnRudeEdit = false,
    LogLevel? CliLogLevel = null,
    string? BrowserPath = null,
    WebSocketConfig BrowserWebSocketConfig = default,
    WebSocketConfig AgentWebSocketConfig = default,
    TestFlags TestFlags = TestFlags.None,
    string TestOutput = "")
{
    public static EnvironmentOptions FromEnvironment(string? sdkDirectory, string logMessagePrefix) => new
    (
        WorkingDirectory: Directory.GetCurrentDirectory(),
        SdkDirectory: sdkDirectory,
        LogMessagePrefix: logMessagePrefix,
        ProcessCleanupTimeout: EnvironmentVariables.ProcessCleanupTimeout,
        IsPollingEnabled: EnvironmentVariables.IsPollingEnabled,
        SuppressHandlingStaticWebAssets: EnvironmentVariables.SuppressHandlingStaticWebAssets,
        SuppressMSBuildIncrementalism: EnvironmentVariables.SuppressMSBuildIncrementalism,
        SuppressLaunchBrowser: EnvironmentVariables.SuppressLaunchBrowser,
        SuppressBrowserRefresh: EnvironmentVariables.SuppressBrowserRefresh,
        SuppressEmojis: EnvironmentVariables.SuppressEmojis,
        RestartOnRudeEdit: EnvironmentVariables.RestartOnRudeEdit,
        CliLogLevel: EnvironmentVariables.CliLogLevel,
        BrowserPath: EnvironmentVariables.BrowserPath,
        BrowserWebSocketConfig: new(EnvironmentVariables.BrowserWebSocketPort, EnvironmentVariables.BrowserWebSocketSecurePort, EnvironmentVariables.BrowserWebSocketHostName),
        AgentWebSocketConfig: new(EnvironmentVariables.AgentWebSocketPort, EnvironmentVariables.AgentWebSocketSecurePort, hostName: null),
        TestFlags: EnvironmentVariables.TestFlags,
        TestOutput: EnvironmentVariables.TestOutputDir
    );

    public TimeSpan GetProcessCleanupTimeout()
        // Allow sufficient time for the process to exit gracefully and release resources (e.g., network ports).
        => ProcessCleanupTimeout ?? TimeSpan.FromSeconds(5);

    private readonly string? _muxerPath = SdkDirectory != null
        ? Path.GetFullPath(Path.Combine(SdkDirectory, "..", "..", "dotnet" + PathUtilities.ExecutableExtension))
        : null;

    public string GetMuxerPath()
        => _muxerPath ?? throw new InvalidOperationException("SDK directory is required to determine muxer path.");

    private int _uniqueLogId;

    public bool RunningAsTest { get => (TestFlags & TestFlags.RunningAsTest) != TestFlags.None; }

    private static string ValidateMuxerPath(string path)
    {
        Debug.Assert(Path.GetFileName(path) == $"dotnet{PathUtilities.ExecutableExtension}");
        return path;
    }

    public string? GetBinLogPath(string projectPath, string operationName, GlobalOptions options)
        => options.BinaryLogPath != null
           ? $"{Path.Combine(WorkingDirectory, options.BinaryLogPath)[..^".binlog".Length]}-dotnet-watch.{operationName}.{Path.GetFileName(projectPath)}.{Interlocked.Increment(ref _uniqueLogId)}.binlog"
           : null;
}