using System.Net.Http;
using System.Text.Json;

namespace Recordingtest.EngineBridge.Client;

public sealed class HmEgHttpSnapshot : IEngineSnapshot, IDisposable
{
    public const string DefaultBaseUrl = "http://localhost:38080";
    private readonly HttpClient _http;
    private readonly bool _ownsClient;
    private readonly string _baseUrl;

    public HmEgHttpSnapshot(string baseUrl = DefaultBaseUrl, HttpClient? httpClient = null, TimeSpan? timeout = null)
    {
        _baseUrl = baseUrl.TrimEnd('/');
        if (httpClient is null)
        {
            _http = new HttpClient { Timeout = timeout ?? TimeSpan.FromSeconds(2) };
            _ownsClient = true;
        }
        else
        {
            _http = httpClient;
            if (timeout.HasValue) _http.Timeout = timeout.Value;
            _ownsClient = false;
        }
    }

    public IReadOnlyList<string> SelectedObjectIds
    {
        get
        {
            using var doc = Get("/selection");
            var arr = doc.RootElement.GetProperty("selected_ids");
            var list = new List<string>(arr.GetArrayLength());
            foreach (var e in arr.EnumerateArray()) list.Add(e.GetString() ?? string.Empty);
            return list;
        }
    }

    public CameraState Camera
    {
        get
        {
            using var doc = Get("/camera");
            var r = doc.RootElement;
            return new CameraState(
                ToArray(r.GetProperty("eye")),
                ToArray(r.GetProperty("target")),
                ToArray(r.GetProperty("up")),
                r.GetProperty("fov").GetDouble());
        }
    }

    public SceneSummary Scene
    {
        get
        {
            using var doc = Get("/scene");
            var r = doc.RootElement;
            string? path = r.TryGetProperty("document_path", out var dp) && dp.ValueKind == JsonValueKind.String ? dp.GetString() : null;
            return new SceneSummary(r.GetProperty("object_count").GetInt32(), path);
        }
    }

    public bool IsRenderComplete
    {
        get
        {
            using var doc = Get("/render");
            return doc.RootElement.GetProperty("complete").GetBoolean();
        }
    }

    public bool IsHealthy
    {
        get
        {
            try
            {
                using var doc = Get("/health");
                return doc.RootElement.TryGetProperty("status", out var s) && s.GetString() == "ok";
            }
            catch (EngineBridgeException) { return false; }
        }
    }

    private JsonDocument Get(string endpoint)
    {
        try
        {
            using var resp = _http.GetAsync(_baseUrl + endpoint).GetAwaiter().GetResult();
            if (!resp.IsSuccessStatusCode)
                throw new EngineBridgeException(endpoint, $"HTTP {(int)resp.StatusCode}");
            var body = resp.Content.ReadAsStringAsync().GetAwaiter().GetResult();
            return JsonDocument.Parse(body);
        }
        catch (EngineBridgeException) { throw; }
        catch (TaskCanceledException ex)
        {
            throw new EngineBridgeException(endpoint, "timeout", ex);
        }
        catch (Exception ex)
        {
            throw new EngineBridgeException(endpoint, ex.Message, ex);
        }
    }

    private static double[] ToArray(JsonElement e)
    {
        var arr = new double[e.GetArrayLength()];
        int i = 0;
        foreach (var item in e.EnumerateArray()) arr[i++] = item.GetDouble();
        return arr;
    }

    public void Dispose()
    {
        if (_ownsClient) _http.Dispose();
    }
}