using System.Text.Json;
using System.Text.Json.Serialization;

namespace WxAgent.Core;

public sealed record RemoteConfigurationAuditEntry
{
    [JsonPropertyName("at")]
    public DateTimeOffset At { get; init; }

    [JsonPropertyName("action")]
    public string Action { get; init; } = "";

    [JsonPropertyName("configVersion")]
    public long ConfigVersion { get; init; }
}

public sealed record RemoteNodeConfiguration
{
    [JsonPropertyName("remote")]
    public RemoteAgentOptions Remote { get; init; } = new();

    [JsonPropertyName("reporting")]
    public ReportingConfig Reporting { get; init; } = new();

    [JsonPropertyName("audit")]
    public IReadOnlyList<RemoteConfigurationAuditEntry> Audit { get; init; } = [];

    public RemoteNodeConfiguration NormalizeAndValidate()
    {
        var reporting = (Reporting ?? new ReportingConfig()).NormalizeAndValidate();
        if (Remote is { IsConfigured: true }) Remote.Validate();
        return this with
        {
            Remote = Remote ?? new RemoteAgentOptions(),
            Reporting = reporting,
            Audit = (Audit ?? []).TakeLast(1000).ToArray()
        };
    }
}

public static class RemoteNodeConfigurationStore
{
    public static async Task<RemoteNodeConfiguration> LoadAsync(string path, CancellationToken cancellationToken = default)
    {
        try
        {
            await using var stream = File.OpenRead(path);
            var configuration = await JsonSerializer.DeserializeAsync<RemoteNodeConfiguration>(stream, RemoteJson.Options, cancellationToken);
            return (configuration ?? new RemoteNodeConfiguration()).NormalizeAndValidate();
        }
        catch (FileNotFoundException)
        {
            return new RemoteNodeConfiguration();
        }
        catch (DirectoryNotFoundException)
        {
            return new RemoteNodeConfiguration();
        }
        catch (JsonException exception)
        {
            throw new WxAgentException(WxAgentErrorCode.InvalidArgument, "Remote node configuration is invalid JSON.", exception);
        }
        catch (WxAgentException)
        {
            throw;
        }
    }
}