using BlueLaminate.Scraper.Proxies;
using Microsoft.Extensions.Logging;
using OpenQA.Selenium;
using OpenQA.Selenium.Edge;

namespace BlueLaminate.Scraper.Browser;

/// <summary>
/// Builds a non-headless Edge (Chromium) WebDriver routed through a
/// <see cref="ProxyLease"/>. Two things make this non-trivial:
/// <list type="bullet">
/// <item>Proxy authentication. Chromium can't auto-fill the gateway's auth
/// dialog under automation, and the classic extension trick relies on
/// Manifest V2 which current Chromium disables. Instead we answer the proxy's
/// 407 challenge through the DevTools (CDP) auth handler, which works
/// non-headless and needs no extension.</item>
/// <item>Bandwidth. The residential plan is metered per GB, so images are
/// disabled at the content-settings level. Cloudflare gates on JS execution and
/// TLS/behaviour, not whether pictures render, so this stays realistic.</item>
/// </list>
/// Each driver gets a throwaway user-data dir so runs never share cookies and
/// never touch the user's real Edge profile.
/// </summary>
public sealed class BrowserDriverFactory
{
    private readonly ILogger<BrowserDriverFactory> _logger;

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

    public async Task<IWebDriver> CreateAsync(ProxyLease lease, bool blockImages = true)
    {
        var options = new EdgeOptions();

        // Route browser traffic through the gateway via the launch argument
        // rather than EdgeOptions.Proxy. Setting Proxy makes Selenium hand the
        // gateway to Selenium Manager for the driver *download* too, which fails
        // because that step can't authenticate. The arg scopes the proxy to the
        // browser only; credentials are answered below via CDP. No scheme = all
        // protocols use the gateway.
        options.AddArgument($"--proxy-server={lease.Endpoint}");

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

        // Isolated, disposable profile per launch.
        var profileDir = Path.Combine(Path.GetTempPath(), "bluelaminate-edge", Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(profileDir);
        options.AddArgument($"--user-data-dir={profileDir}");

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

        _logger.LogInformation(
            "Launching Edge via proxy {Endpoint} (provider {Provider}, session {Session}).",
            lease.Endpoint, lease.Provider, lease.SessionId ?? "rotating");

        var driver = new EdgeDriver(options);

        try
        {
            // Answer the gateway's proxy-auth (407) challenge with the lease
            // credentials. UriMatcher returns true so it applies to every
            // request, since the challenge originates from the proxy itself.
            var network = driver.Manage().Network;
            network.AddAuthenticationHandler(new NetworkAuthenticationHandler
            {
                UriMatcher = _ => true,
                Credentials = new PasswordCredentials(lease.Username, lease.Password),
            });
            await network.StartMonitoring();
        }
        catch
        {
            driver.Quit();
            throw;
        }

        return driver;
    }
}