using System.Net.Http.Json;
using System.Text.Json;
using Microsoft.Extensions.Options;
using QMax.Api.Configuration;

namespace QMax.Api.Infrastructure.Max;

public sealed class WorkerMaxBridgeClient(
    HttpClient httpClient,
    IOptions<QMaxOptions> options,
    ILogger<WorkerMaxBridgeClient> logger) : IMaxBridgeClient
{
    private static readonly JsonSerializerOptions JsonOptions = new(JsonSerializerDefaults.Web);
    private readonly QMaxOptions _options = options.Value;

    public async Task<MaxBridgeStatus> GetStatusAsync(CancellationToken cancellationToken)
    {
        return await SendAsync<MaxBridgeStatus>(HttpMethod.Get, "/status", null, cancellationToken)
            ?? ErrorStatus("Worker returned an empty status.");
    }

    public async Task<MaxBridgeStatus> BeginPhoneLoginAsync(string phoneNumber, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxBridgeStatus>(HttpMethod.Post, "/login/start", new { phoneNumber }, cancellationToken)
            ?? ErrorStatus("Worker returned an empty login status.");
    }

    public async Task<MaxBridgeStatus> SubmitLoginCodeAsync(string code, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxBridgeStatus>(HttpMethod.Post, "/login/code", new { code, waitMs = 60000 }, cancellationToken)
            ?? ErrorStatus("Worker returned an empty code status.");
    }

    public async Task<MaxBrowserSnapshot> GetSnapshotAsync(CancellationToken cancellationToken)
    {
        return await SendAsync<MaxBrowserSnapshot>(HttpMethod.Get, "/snapshot", null, cancellationToken)
            ?? new MaxBrowserSnapshot(null, "Worker unavailable", "", "", DateTimeOffset.UtcNow);
    }

    public async Task<IReadOnlyList<MaxChatUpdate>> FetchUpdatesAsync(CancellationToken cancellationToken)
    {
        return await SendAsync<IReadOnlyList<MaxChatUpdate>>(HttpMethod.Get, "/updates", null, cancellationToken)
            ?? throw new InvalidOperationException("MAX worker returned an empty updates response.");
    }

    public async Task<MaxChatUpdate?> FetchChatHistoryAsync(string externalChatId, string? chatUrl, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxChatUpdate>(HttpMethod.Post, "/chat/history", new { externalChatId, chatUrl }, cancellationToken);
    }

    public async Task<MaxChatPresence?> FetchChatPresenceAsync(string externalChatId, string? chatUrl, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxChatPresence>(HttpMethod.Post, "/chat/presence", new { externalChatId, chatUrl }, cancellationToken);
    }

    public async Task<MaxChatUrlResult> ResolveChatUrlAsync(string externalChatId, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxChatUrlResult>(HttpMethod.Post, "/chat/resolve-url", new { externalChatId }, cancellationToken)
            ?? new MaxChatUrlResult(false, null, "Worker returned an empty chat URL result.");
    }

    public async Task<MaxActionResult> ClearChatHistoryAsync(string externalChatId, string? chatUrl, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxActionResult>(
                HttpMethod.Post,
                "/chat/clear-history",
                new { externalChatId, chatUrl },
                cancellationToken)
            ?? new MaxActionResult(false, "Worker returned an empty clear history result.");
    }

    public Task<MaxActionResult> DeleteChatAsync(string externalChatId, string? chatUrl, CancellationToken cancellationToken)
    {
        return Task.FromResult(new MaxActionResult(
            false,
            "Chat deletion is disabled because MAX does not remove chats from the web client."));
    }

    public async Task<MaxSendResult> SendTextAsync(string externalChatId, string? chatUrl, string text, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxSendResult>(HttpMethod.Post, "/send/text", new { externalChatId, chatUrl, text }, cancellationToken)
            ?? new MaxSendResult(false, null, "Worker returned an empty send result.");
    }

    public async Task<MaxSendResult> SendAttachmentAsync(string externalChatId, string? chatUrl, string path, string caption, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxSendResult>(HttpMethod.Post, "/send/attachment", new { externalChatId, chatUrl, path = ToWorkerPath(path), caption }, cancellationToken)
            ?? new MaxSendResult(false, null, "Worker returned an empty attachment result.");
    }

    public async Task<MaxActionResult> EditMessageAsync(string externalChatId, string externalMessageId, string? currentText, string text, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxActionResult>(
                HttpMethod.Post,
                "/message/edit",
                new { externalChatId, externalMessageId, currentText, text },
                cancellationToken)
            ?? new MaxActionResult(false, "Worker returned an empty edit result.");
    }

    public async Task<MaxActionResult> DeleteMessageAsync(string externalChatId, string externalMessageId, string? currentText, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxActionResult>(
                HttpMethod.Post,
                "/message/delete",
                new { externalChatId, externalMessageId, currentText },
                cancellationToken)
            ?? new MaxActionResult(false, "Worker returned an empty delete result.");
    }

    public async Task<MaxActionResult> SetReactionAsync(string externalChatId, string externalMessageId, string? currentText, string emoji, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxActionResult>(
                HttpMethod.Post,
                "/message/reaction",
                new { externalChatId, externalMessageId, currentText, emoji },
                cancellationToken)
            ?? new MaxActionResult(false, "Worker returned an empty reaction result.");
    }

    public async Task<MaxActionResult> ClearReactionAsync(string externalChatId, string externalMessageId, string? currentText, string emoji, CancellationToken cancellationToken)
    {
        return await SendAsync<MaxActionResult>(
                HttpMethod.Delete,
                "/message/reaction",
                new { externalChatId, externalMessageId, currentText, emoji },
                cancellationToken)
            ?? new MaxActionResult(false, "Worker returned an empty reaction clear result.");
    }

    public async Task<MaxMediaDownload?> DownloadMediaAsync(string remoteUrl, CancellationToken cancellationToken)
    {
        if (string.IsNullOrWhiteSpace(remoteUrl))
        {
            return null;
        }

        try
        {
            httpClient.BaseAddress ??= new Uri(_options.MaxWorkerBaseUrl.TrimEnd('/') + "/");
            var path = $"media/fetch?url={Uri.EscapeDataString(remoteUrl)}";
            var response = await httpClient.GetAsync(path, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
            if (!response.IsSuccessStatusCode)
            {
                var content = await response.Content.ReadAsStringAsync(cancellationToken);
                logger.LogWarning("MAX worker media fetch failed with {Status}: {Content}", response.StatusCode, content);
                response.Dispose();
                return null;
            }

            var contentType = response.Content.Headers.ContentType?.MediaType ?? "application/octet-stream";
            var contentLength = response.Content.Headers.ContentLength;
            var stream = await response.Content.ReadAsStreamAsync(cancellationToken);
            return new MaxMediaDownload(new ResponseDisposingStream(stream, response), contentType, contentLength);
        }
        catch (Exception ex)
        {
            logger.LogWarning(ex, "MAX worker media fetch request failed.");
            return null;
        }
    }

    private async Task<T?> SendAsync<T>(HttpMethod method, string path, object? body, CancellationToken cancellationToken)
    {
        try
        {
            httpClient.BaseAddress ??= new Uri(_options.MaxWorkerBaseUrl.TrimEnd('/') + "/");
            using var request = new HttpRequestMessage(method, path.TrimStart('/'));
            if (body is not null)
            {
                request.Content = JsonContent.Create(body, options: JsonOptions);
            }

            using var response = await httpClient.SendAsync(request, cancellationToken);
            if (!response.IsSuccessStatusCode)
            {
                var content = await response.Content.ReadAsStringAsync(cancellationToken);
                logger.LogWarning("MAX worker {Path} failed with {Status}: {Content}", path, response.StatusCode, content);
                return default;
            }

            return await response.Content.ReadFromJsonAsync<T>(JsonOptions, cancellationToken);
        }
        catch (Exception ex)
        {
            logger.LogWarning(ex, "MAX worker {Path} request failed.", path);
            return default;
        }
    }

    private static MaxBridgeStatus ErrorStatus(string error)
    {
        return new MaxBridgeStatus("Worker", false, "Unavailable", "WorkerUnavailable", null, null, error, DateTimeOffset.UtcNow);
    }

    private static string ToWorkerPath(string path)
    {
        var normalized = path.Replace('\\', '/');
        return normalized.StartsWith("/data/", StringComparison.Ordinal)
            ? "/qmax-data/" + normalized["/data/".Length..]
            : normalized;
    }

    private sealed class ResponseDisposingStream(Stream inner, HttpResponseMessage response) : Stream
    {
        public override bool CanRead => inner.CanRead;
        public override bool CanSeek => inner.CanSeek;
        public override bool CanWrite => inner.CanWrite;
        public override long Length => inner.Length;
        public override long Position
        {
            get => inner.Position;
            set => inner.Position = value;
        }

        public override void Flush() => inner.Flush();
        public override int Read(byte[] buffer, int offset, int count) => inner.Read(buffer, offset, count);
        public override long Seek(long offset, SeekOrigin origin) => inner.Seek(offset, origin);
        public override void SetLength(long value) => inner.SetLength(value);
        public override void Write(byte[] buffer, int offset, int count) => inner.Write(buffer, offset, count);
        public override async ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken = default) =>
            await inner.ReadAsync(buffer, cancellationToken);

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                inner.Dispose();
                response.Dispose();
            }

            base.Dispose(disposing);
        }

        public override async ValueTask DisposeAsync()
        {
            await inner.DisposeAsync();
            response.Dispose();
            await base.DisposeAsync();
        }
    }
}