using System.Security.Claims;
using System.Text.Encodings.Web;
using Microsoft.AspNetCore.Authentication;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace Infrastructure.Services.Authentication;

public class ApiKeyAuthenticationHandler(
    IOptionsMonitor<AuthenticationSchemeOptions> options,
    ILoggerFactory logger,
    UrlEncoder encoder,
    ISystemClock clock,
    IConfiguration configuration)
    : AuthenticationHandler<AuthenticationSchemeOptions>(options, logger, encoder, clock)
{
    private const string ApiKeyHeaderName = "ApiKey";

    protected override Task<AuthenticateResult> HandleAuthenticateAsync()
    {
        if (!Request.Headers.TryGetValue(ApiKeyHeaderName, out var apiKeyHeaderValues))
            return Task.FromResult(AuthenticateResult.NoResult());

        var providedApiKey = apiKeyHeaderValues.FirstOrDefault();

        if (string.IsNullOrWhiteSpace(providedApiKey)) return Task.FromResult(AuthenticateResult.NoResult());

        var configuredApiKey = configuration.GetValue<string>("ApiKey");

        if (configuredApiKey.Equals(providedApiKey))
        {
            var claims = new[] { new Claim(ClaimTypes.Name, "ApiKeyUser") };
            var identity = new ClaimsIdentity(claims, Scheme.Name);
            var principal = new ClaimsPrincipal(identity);
            var ticket = new AuthenticationTicket(principal, Scheme.Name);

            return Task.FromResult(AuthenticateResult.Success(ticket));
        }

        return Task.FromResult(AuthenticateResult.Fail("Invalid API Key provided."));
    }
}