Program.cs

using System;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using System.Collections.Generic;
using AngleSharp;
using AngleSharp.Dom;
using Microsoft.Data.Sqlite;
using System.Threading;
// <a href="../fotos1304/bu1304x002.jpg"><img src="../fotos1304/tn_bu1304x002.jpg" hspace="0" vspace="0" border="0" width="116" height="175"></a>
// <a href="bonus015/zbon15x001.jpg"><img src="bonus015/tn_zbon15x001.jpg" hspace="0" vspace="0" border="0" width="175" height="131"></a>

class Program
{
    static bool IsAlbumLink(string href)
    {
        //Console.WriteLine(href);
        if (href == null) return false;
        return href.Contains("pfoto") || href.Contains("bonus") ;
    }

    static bool IsFotoLink(string href)
    {
        //Console.WriteLine(href);
        if (href == null) return false;
        return href.Contains("jpg") && (href.Contains("bonus") || href.Contains("fotos"));
    }
    static async Task ProcessAlbumAsync(HttpClient client, string albumLink, Config appConfig, AlbumTracker tracker, SemaphoreSlim semaphore)
    {
        await semaphore.WaitAsync();
        try
        {
            var albumName = albumLink.Replace(".htm", "");

            if (tracker.IsProcessed(appConfig.ModelName, albumName))
            {
                Console.WriteLine($"Skipping already processed album: {albumName}");
                return;
            }

            Console.WriteLine("Process Album");

            var albumUrl = appConfig.MemberBaseUrl + albumLink;
            var albumResponse = await client.GetAsync(albumUrl);
            var albumHtml = await albumResponse.Content.ReadAsStringAsync();

            var config = Configuration.Default;
            var context = BrowsingContext.New(config);
            var album = await context.OpenAsync(req => req.Content(albumHtml));

            var imageLinks = album.QuerySelectorAll("a[href]");

            foreach (var link in imageLinks)
            {
                var href = link.GetAttribute("href");

                if (href == null)
                    continue;

                if (!IsFotoLink(href))
                    continue;

                await DownloadAndSaveFoto(client, href, albumName, appConfig);
            }

            tracker.MarkAsProcessed(appConfig.ModelName, albumName);
        }
        finally
        {
            semaphore.Release();
        }
    }

    static async Task DownloadAndSaveFoto(HttpClient client,  string href, string album, Config config)
    {
        var fotoUrl = config.MemberBaseUrl +href.Replace("../", "");

        //Console.WriteLine("Downloading: " + fotoUrl);

        var fotoResponse = await client.GetAsync(fotoUrl);
        var fotoBytes = await fotoResponse.Content.ReadAsByteArrayAsync();
        var fileName = href.Substring(href.LastIndexOf('/') + 1);
        // can the download path implemented as a "global" property of the main-class?

        var downloadPath = config.DownloadLocation + config.ModelName + "/" + album + "/";
        System.IO.Directory.CreateDirectory(downloadPath);
        fileName = downloadPath + fileName;
        await System.IO.File.WriteAllBytesAsync(fileName, fotoBytes);
        
        // Console.WriteLine("Saved: " + fileName);
    }

    static HttpClient CreateHttpClientWithCookies()
    {
        var handler = new HttpClientHandler
        {
            UseCookies = true,
            CookieContainer = new CookieContainer(),
            AllowAutoRedirect = true,
            
        };

        var client = new HttpClient(handler);
        client.DefaultRequestHeaders.UserAgent.ParseAdd(
            "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Safari/605.1.15");
        return client;
    }
    static List<string> albumLinks = new List<string>();
    static List<string> fotoLinks = new List<string>();
    static async Task Main()
    {

        var appConfig = new Config
        {
            //BaseUrl = "https://www.southern-charms3.com/",            
            //ModelName = "jessicajones",
            //BaseUrl = "https://www.southern-charms.com/",
            //ModelName = "kinkybootslut",
            //BaseUrl = "https://www.southern-charms3.com/",
            //ModelName = "alaya",

            BaseUrl = "https://www.southern-charms.com/",
            ModelName = "andrea",


            Username = "jomannx17",
            Password = "20postmannx17",
            Realm = "",
            RedirectUrl = "",
            //DownloadLocation = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) + "/Downloads/AngelScraper/"
            DownloadLocation = "/Volumes/4tbx/AngleScraper/",
            authRoot = "auth.form",
            //memberRoot = "previous.htm",
            //memberRoot = "previous2.htm",
            //memberRoot = "previous3.htm",
            memberRoot = "members.htm"
            //sidecarFile = "/Volumes/4tbx/AngleScraper/kinkybootslut/hidden_albums.txt"
            
        };
        
        appConfig.MemberBaseUrl = appConfig.BaseUrl + appConfig.ModelName + "/private/";
        appConfig.MemberMainUrl = appConfig.MemberBaseUrl + appConfig.memberRoot;
        appConfig.loginUrl = appConfig.BaseUrl + appConfig.authRoot;

        var dbPath = appConfig.DownloadLocation + appConfig.ModelName + "/albums.db";
        System.IO.Directory.CreateDirectory(System.IO.Path.GetDirectoryName(dbPath));


        //check if the sidear file exists. If so. read the album names (they are already fullqualified path) and add them to albumLinks. This way they will be processed like normal albums, but we can control them by just editing the textfile.
        if (System.IO.File.Exists(appConfig.sidecarFile))
        {                               
            var hiddenAlbums = System.IO.File.ReadAllLines(appConfig.sidecarFile);
            foreach (var album in hiddenAlbums)
            {
                if (!string.IsNullOrWhiteSpace(album))
                {
                    albumLinks.Add(album.Trim());
                }
            }
        }
        


        var tracker = new AlbumTracker(dbPath);

        using var client = CreateHttpClientWithCookies();        

        // get the main membership site that redirects to the login page if not authenticated. 
        // We need some form-data from the login page.
        var redirectResponse = await client.GetAsync(appConfig.MemberMainUrl);
        var redirectHtml = await redirectResponse.Content.ReadAsStringAsync();

        // Parse HTML with AngleSharp
        var config = Configuration.Default;
        var context = BrowsingContext.New(config);
        var loginForm = await context.OpenAsync(req => req.Content(redirectHtml));

        var inputs = loginForm.QuerySelectorAll("input");

        var formData = new Dictionary<string, string>();

        foreach (var input in inputs)
        {
            var name = input.GetAttribute("name");
            if (string.IsNullOrWhiteSpace(name))
                continue;

            var value = input.GetAttribute("value") ?? "";
            formData[name] = value;
        }
        formData["uid"] = appConfig.Username;
        formData["pwd"] = appConfig.Password;
        formData.Remove("rmb");
        formData.Remove("img");


        var loginContent = new FormUrlEncodedContent(formData);
        var loginResponse = await client.PostAsync(appConfig.loginUrl, loginContent);

        Console.WriteLine("Login status: " + loginResponse.StatusCode);

        // 3. Fetch main page (authenticated)
        var mainResponse = await client.GetAsync(appConfig.MemberMainUrl);
        var mainHtml = await mainResponse.Content.ReadAsStringAsync();

        // 4. Parse HTML with AngleSharp
        //var config = Configuration.Default;
        //var context = BrowsingContext.New(config);
        var document = await context.OpenAsync(req => req.Content(mainHtml));

        // Example: extract all links with a specific CSS selector
        //var links = document.QuerySelectorAll("a.some-class");
        var links = document.QuerySelectorAll("a[href]");

        foreach (var link in links)
        {
            var href = link.GetAttribute("href");

            if (href == null)
                continue;

            if (!IsAlbumLink(href))
                continue;
            
            albumLinks.Add(href);

        }

        var semaphore = new SemaphoreSlim(5);
        var tasks = new List<Task>();

        foreach (var albumLink in albumLinks)
        {
            tasks.Add(ProcessAlbumAsync(client, albumLink, appConfig, tracker, semaphore));
        }

        await Task.WhenAll(tasks);

        Console.WriteLine("Done.");
    }

}