using MailKit.Search;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Http.Extensions;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Build.Framework;
using Microsoft.Extensions.Logging;
using Remotely.Server.Auth;
using Remotely.Server.Extensions;
using Remotely.Server.Services;
using Remotely.Shared;
using Remotely.Shared.Models;
using Remotely.Shared.Services;
using Remotely.Shared.Utilities;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;

namespace Remotely.Server.API;

[Route("api/[controller]")]
[ApiController]
public class ClientDownloadsController : ControllerBase
{
    private readonly IApplicationConfig _appConfig;
    private readonly IEmbeddedServerDataSearcher _embeddedDataSearcher;
    private readonly SemaphoreSlim _fileLock = new(1, 1);
    private readonly IWebHostEnvironment _hostEnv;
    private readonly ILogger<ClientDownloadsController> _logger;
    public ClientDownloadsController(
        IWebHostEnvironment hostEnv,
        IEmbeddedServerDataSearcher embeddedDataSearcher,
        IApplicationConfig appConfig,
        ILogger<ClientDownloadsController> logger)
    {
        _hostEnv = hostEnv;
        _embeddedDataSearcher = embeddedDataSearcher;
        _appConfig = appConfig;
        _logger = logger;
    }

    [HttpGet("desktop/{platformID}")]
    public async Task<IActionResult> GetDesktop(string platformID)
    {
        switch (platformID)
        {
            case "WindowsDesktop-x64":
                {
                    var filePath = Path.Combine(_hostEnv.WebRootPath, "Content", "Win-x64", "Remotely_Desktop.exe");
                    return await GetDesktopFile(filePath);
                }
            case "WindowsDesktop-x86":
                {
                    var filePath = Path.Combine(_hostEnv.WebRootPath, "Content", "Win-x86", "Remotely_Desktop.exe");
                    return await GetDesktopFile(filePath);
                }
            case "UbuntuDesktop":
                {
                    var filePath = Path.Combine(_hostEnv.WebRootPath, "Content", "Linux-x64", "Remotely_Desktop");
                    return await GetDesktopFile(filePath);
                }
            case "MacOS-x64":
                {
                    var filePath = Path.Combine(_hostEnv.WebRootPath, "Content", "MacOS-x64", "Remotely_Desktop");
                    return await GetDesktopFile(filePath);
                }
            case "MacOS-arm64":
                {
                    var filePath = Path.Combine(_hostEnv.WebRootPath, "Content", "MacOS-arm64", "Remotely_Desktop");
                    return await GetDesktopFile(filePath);
                }
            default:
                return NotFound();
        }
    }


    [HttpGet("desktop/{platformId}/{organizationId}")]
    public async Task<IActionResult> GetDesktop(string platformId, string organizationId)
    {
        switch (platformId)
        {
            case "WindowsDesktop-x64":
                {
                    var filePath = Path.Combine(_hostEnv.WebRootPath, "Content", "Win-x64", "Remotely_Desktop.exe");
                    return await GetDesktopFile(filePath, organizationId);
                }
            case "WindowsDesktop-x86":
                {
                    var filePath = Path.Combine(_hostEnv.WebRootPath, "Content", "Win-x86", "Remotely_Desktop.exe");
                    return await GetDesktopFile(filePath, organizationId);
                }
            case "UbuntuDesktop":
                {
                    var filePath = Path.Combine(_hostEnv.WebRootPath, "Content", "Linux-x64", "Remotely_Desktop");
                    return await GetDesktopFile(filePath, organizationId);
                }
            case "MacOS-x64":
                {
                    var filePath = Path.Combine(_hostEnv.WebRootPath, "Content", "MacOS-x64", "Remotely_Desktop");
                    return await GetDesktopFile(filePath);
                }
            case "MacOS-arm64":
                {
                    var filePath = Path.Combine(_hostEnv.WebRootPath, "Content", "MacOS-arm64", "Remotely_Desktop");
                    return await GetDesktopFile(filePath);
                }
            default:
                return NotFound();
        }
    }

    [ServiceFilter(typeof(ApiAuthorizationFilter))]
    [HttpGet("{platformID}")]
    public async Task<IActionResult> GetInstaller(string platformID)
    {
        if (!Request.Headers.TryGetOrganizationId(out var orgId))
        {
            return BadRequest("OrganizationID is required.");
        }
        return await GetInstallFile(orgId, platformID);
    }

    [HttpGet("{organizationID}/{platformID}")]
    public async Task<IActionResult> GetInstaller(string organizationID, string platformID)
    {
        return await GetInstallFile(organizationID, platformID);
    }

    private async Task<IActionResult> GetBashInstaller(string fileName, string organizationId)
    {
        var fileContents = new List<string>();
        fileContents.AddRange(await System.IO.File.ReadAllLinesAsync(Path.Combine(_hostEnv.WebRootPath, "Content", fileName)));

        var hostIndex = fileContents.IndexOf("HostName=");
        var orgIndex = fileContents.IndexOf("Organization=");

        var effectiveScheme = _appConfig.ForceClientHttps ? "https" : Request.Scheme;

        fileContents[hostIndex] = $"HostName=\"{effectiveScheme}://{Request.Host}\"";
        fileContents[orgIndex] = $"Organization=\"{organizationId}\"";
        var fileBytes = Encoding.UTF8.GetBytes(string.Join("\n", fileContents));
        return File(fileBytes, "application/octet-stream", fileName);
    }

    private async Task<IActionResult> GetDesktopFile(string filePath, string organizationId = null)
    {
        LogRequest(nameof(GetDesktopFile));

        var effectiveScheme = _appConfig.ForceClientHttps ? "https" : Request.Scheme;
        var serverUrl = $"{effectiveScheme}://{Request.Host}";
        var embeddedData = new EmbeddedServerData(new Uri(serverUrl), organizationId);
        var result = await _embeddedDataSearcher.GetRewrittenStream(filePath, embeddedData);

        if (!result.IsSuccess)
        {
            throw result.Exception;
        }

        return File(result.Value, "application/octet-stream", Path.GetFileName(filePath));
    }

    private async Task<IActionResult> GetInstallFile(string organizationId, string platformID)
    {
        LogRequest(nameof(GetInstallFile));

        if (!await _fileLock.WaitAsync(TimeSpan.FromSeconds(15)))
        {
            return StatusCode(StatusCodes.Status408RequestTimeout);
        }

        try
        {
            switch (platformID)
            {
                case "WindowsInstaller":
                    {
                        var effectiveScheme = _appConfig.ForceClientHttps ? "https" : Request.Scheme;
                        var serverUrl = $"{effectiveScheme}://{Request.Host}";
                        var filePath = Path.Combine(_hostEnv.WebRootPath, "Content", "Remotely_Installer.exe");
                        var embeddedData = new EmbeddedServerData(new Uri(serverUrl), organizationId);
                        var result = await _embeddedDataSearcher.GetRewrittenStream(filePath, embeddedData);

                        if (!result.IsSuccess)
                        {
                            throw result.Exception;
                        }

                        return File(result.Value, "application/octet-stream", "Remotely_Installer.exe");
                    }
                case "ManjaroInstaller-x64":
                    {
                        var fileName = "Install-Manjaro-x64.sh";

                        return await GetBashInstaller(fileName, organizationId);
                    }
                case "UbuntuInstaller-x64":
                    {
                        var fileName = "Install-Ubuntu-x64.sh";

                        return await GetBashInstaller(fileName, organizationId);
                    }
                case "MacOSInstaller-x64":
                    {
                        var fileName = "Install-MacOS-x64.sh";

                        return await GetBashInstaller(fileName, organizationId);
                    }
                case "MacOSInstaller-arm64":
                    {
                        var fileName = "Install-MacOS-arm64.sh";

                        return await GetBashInstaller(fileName, organizationId);
                    }
                default:
                    return BadRequest();
            }
        }
        finally
        {
            _fileLock.Release();
        }
    }

    private void LogRequest(string methodName)
    {
        if (_appConfig.UseHttpLogging)
        {
            var ip = Request.HttpContext.Connection.RemoteIpAddress;
            if (ip?.IsIPv4MappedToIPv6 == true)
            {
                ip = ip.MapToIPv4();
            }

            var effectiveScheme = _appConfig.ForceClientHttps ? "https" : Request.Scheme;

            _logger.LogInformation(
                "Started client download via {methodName}.  Effective Scheme: {scheme}.  Effective Host: {host}.  Remote IP: {ip}.",
                methodName,
                effectiveScheme,
                Request.Host,
                $"{ip}");
        }
    }
}