using Microsoft.Extensions.Logging;
using OpenQA.Selenium;
using OpenQA.Selenium.Edge;

namespace BlueLaminate.Scraper.Browser;

/// <summary>
/// Builds a non-headless Edge (Chromium) WebDriver pointed at a local, auth-free
/// proxy endpoint (a <see cref="Proxies.LocalForwardingProxy"/> that chains to the
/// residential gateway). Deliberately uses <b>zero CDP</b>: enabling DevTools
/// domains — even just to answer proxy auth — is a Cloudflare automation tell, and
/// the local proxy already carries the upstream credentials, so there's no 407 to
/// answer in the browser. Combined with a warmed, persistent profile this is the
/// lowest-fingerprint configuration we can manage without an undetected-chromedriver
/// (which has no .NET equivalent).
/// <para>
/// Bandwidth: the residential plan is metered per GB, so images are disabled at the
/// content-settings level by default. Cloudflare gates on JS/TLS/behaviour, not
/// whether pictures render, so this stays realistic.
/// </para>
/// </summary>
public sealed class BrowserDriverFactory
{
    private readonly ILogger<BrowserDriverFactory> _logger;

    public BrowserDriverFactory(ILogger<BrowserDriverFactory> logger)
    {
        _logger = logger;
    }

    /// <summary>
    /// Launch Edge routed through <paramref name="proxyEndpoint"/> ("host:port", no
    /// auth). When <paramref name="profileDir"/> is set the profile persists across
    /// runs (so a once-cleared Cloudflare <c>cf_clearance</c> cookie and browsing
    /// history carry over — a warmed profile looks far less like a fresh bot); when
    /// null a throwaway profile is used.
    /// </summary>
    public IWebDriver Create(string? proxyEndpoint, bool blockImages = true, string? profileDir = null)
    {
        var options = new EdgeOptions();

        // Route browser traffic through the local proxy via the launch argument
        // rather than EdgeOptions.Proxy (which would also route Selenium Manager's
        // driver download). No scheme = all protocols use the proxy. When null/empty
        // the browser uses the machine's direct connection (diagnostic --no-proxy).
        if (!string.IsNullOrWhiteSpace(proxyEndpoint))
        {
            options.AddArgument($"--proxy-server={proxyEndpoint}");
        }

        // Reduce the most obvious automation tells; residential exit + a real
        // (non-headless) browser + a warmed profile do the rest.
        options.AddArgument("--disable-blink-features=AutomationControlled");
        options.AddExcludedArgument("enable-automation");
        options.AddAdditionalOption("useAutomationExtension", false);
        options.AddArgument("--no-first-run");
        options.AddArgument("--no-default-browser-check");
        options.AddArgument("--start-maximized");

        var persist = !string.IsNullOrWhiteSpace(profileDir);
        var dir = persist
            ? profileDir!
            : Path.Combine(Path.GetTempPath(), "bluelaminate-edge", Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(dir);
        options.AddArgument($"--user-data-dir={dir}");

        if (blockImages)
        {
            options.AddUserProfilePreference("profile.managed_default_content_settings.images", 2);
        }

        _logger.LogInformation(
            "Launching Edge via {Route} (profile: {Profile}).",
            string.IsNullOrWhiteSpace(proxyEndpoint) ? "DIRECT (no proxy)" : $"local proxy {proxyEndpoint}",
            persist ? dir : "throwaway");

        return new EdgeDriver(options);
    }
}