using OTSSignsOrchestrator.Server.Clients;
using OTSSignsOrchestrator.Server.Data.Entities;
using Microsoft.Extensions.Configuration;

namespace OTSSignsOrchestrator.Server.Health.Checks;

/// <summary>
/// Compares the installed Xibo CMS version (from GET /about) against the latest known
/// release configured in <c>HealthChecks:LatestXiboVersion</c>. Reports Degraded if behind.
/// </summary>
public sealed class XiboVersionHealthCheck : IHealthCheck
{
    private readonly XiboClientFactory _clientFactory;
    private readonly IServiceProvider _services;
    private readonly IConfiguration _configuration;
    private readonly ILogger<XiboVersionHealthCheck> _logger;

    public string CheckName => "XiboVersion";
    public bool AutoRemediate => false;

    public XiboVersionHealthCheck(
        XiboClientFactory clientFactory,
        IServiceProvider services,
        IConfiguration configuration,
        ILogger<XiboVersionHealthCheck> logger)
    {
        _clientFactory = clientFactory;
        _services = services;
        _configuration = configuration;
        _logger = logger;
    }

    public async Task<HealthCheckResult> RunAsync(Instance instance, CancellationToken ct)
    {
        var latestVersion = _configuration["HealthChecks:LatestXiboVersion"];
        if (string.IsNullOrEmpty(latestVersion))
            return new HealthCheckResult(HealthStatus.Healthy, "LatestXiboVersion not configured — skipping");

        var (client, _) = await ResolveAsync(instance);
        if (client is null)
            return new HealthCheckResult(HealthStatus.Critical, "No OAuth app — cannot check version");

        try
        {
            var response = await client.GetAboutAsync();
            if (!response.IsSuccessStatusCode || response.Content is null)
                return new HealthCheckResult(HealthStatus.Critical, "GET /about failed");

            string? installedVersion = null;
            if (response.Content is System.Text.Json.JsonElement je &&
                je.TryGetProperty("version", out var verProp))
            {
                installedVersion = verProp.GetString();
            }

            if (string.IsNullOrEmpty(installedVersion))
                return new HealthCheckResult(HealthStatus.Degraded, "Could not determine installed version");

            if (string.Equals(installedVersion, latestVersion, StringComparison.OrdinalIgnoreCase))
                return new HealthCheckResult(HealthStatus.Healthy,
                    $"Xibo version {installedVersion} is current");

            return new HealthCheckResult(HealthStatus.Degraded,
                $"Xibo version {installedVersion}, latest is {latestVersion}",
                "Consider scheduling an upgrade");
        }
        catch (Exception ex)
        {
            return new HealthCheckResult(HealthStatus.Critical,
                $"Version check failed: {ex.Message}");
        }
    }

    private async Task<(IXiboApiClient? Client, string Abbrev)> ResolveAsync(Instance instance)
    {
        var abbrev = instance.Customer.Abbreviation;
        var oauthApp = instance.OauthAppRegistries.FirstOrDefault();
        if (oauthApp is null) return (null, abbrev);

        var settings = _services.GetRequiredService<Core.Services.SettingsService>();
        var secret = await settings.GetAsync(Core.Services.SettingsService.InstanceOAuthSecretId(abbrev));
        if (string.IsNullOrEmpty(secret)) return (null, abbrev);

        var client = await _clientFactory.CreateAsync(instance.XiboUrl, oauthApp.ClientId, secret);
        return (client, abbrev);
    }
}