using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text.Json.Serialization;
using Model;

namespace Web.Services;

public class CardNotesGraphQLService
{
    private readonly AuthService _authService;
    private readonly string _graphqlEndpoint;
    private readonly HttpClient _http;
    private readonly NetworkStatusService _networkStatus;

    public CardNotesGraphQLService(HttpClient http, NetworkStatusService networkStatus, AuthService authService)
    {
        _http = http;
        _networkStatus = networkStatus;
        _authService = authService;
        _graphqlEndpoint = http.BaseAddress != null && http.BaseAddress.Port == 5256
            ? "/graphql"
            : "http://localhost:5256/graphql";
    }

    public async Task<bool> IsApiOnlineAsync()
    {
        if (!_networkStatus.IsOnline) return false;

        try
        {
            var request = new GraphQLRequest
            {
                Query = "query { __typename }"
            };
            var response = await SendGraphQLAsync<object>(request);
            return response != null;
        }
        catch
        {
            return false;
        }
    }

    public async Task<string> GetNoteAsync(string cardName)
    {
        if (!_networkStatus.IsOnline || !_authService.IsLoggedIn) return string.Empty;

        try
        {
            var request = new GraphQLRequest
            {
                Query = @"query GetCardNote($cardName: String!) {
                    note(cardName: $cardName) {
                        username
                        cardName
                        note
                    }
                }",
                Variables = new Dictionary<string, object>
                {
                    ["cardName"] = cardName
                }
            };

            var response = await SendGraphQLAsync<GetNoteData>(request);
            return response?.Data?.Note?.Note ?? string.Empty;
        }
        catch (Exception ex)
        {
            Console.WriteLine($"[WARNING] Failed to fetch note for {cardName}: {ex.Message}");
            return string.Empty;
        }
    }

    public async Task<bool> SaveNoteAsync(string cardName, string note)
    {
        if (!_networkStatus.IsOnline || !_authService.IsLoggedIn) return false;

        try
        {
            var request = new GraphQLRequest
            {
                Query = @"mutation SaveCardNote($cardName: String!, $note: String!) {
                    saveNote(cardName: $cardName, note: $note) {
                        username
                        cardName
                        note
                    }
                }",
                Variables = new Dictionary<string, object>
                {
                    ["cardName"] = cardName,
                    ["note"] = note
                }
            };

            var response = await SendGraphQLAsync<SaveNoteData>(request);
            return response?.Data?.SaveNote != null;
        }
        catch (Exception ex)
        {
            Console.WriteLine($"[WARNING] Failed to save note for {cardName}: {ex.Message}");
            return false;
        }
    }

    private async Task<GraphQLResponse<T>?> SendGraphQLAsync<T>(GraphQLRequest request)
    {
        async Task<HttpResponseMessage> SendToUrlAsync(string url)
        {
            var httpRequest = new HttpRequestMessage(HttpMethod.Post, url)
            {
                Content = JsonContent.Create(request)
            };
            if (!string.IsNullOrEmpty(_authService.AuthToken))
                httpRequest.Headers.Authorization = new AuthenticationHeaderValue("Bearer", _authService.AuthToken);
            return await _http.SendAsync(httpRequest);
        }

        try
        {
            var httpResponse = await SendToUrlAsync(_graphqlEndpoint);
            if (httpResponse.IsSuccessStatusCode)
                return await httpResponse.Content.ReadFromJsonAsync<GraphQLResponse<T>>();

            if (_graphqlEndpoint == "/graphql")
            {
                var fallbackResponse = await SendToUrlAsync("http://localhost:5256/graphql");
                if (fallbackResponse.IsSuccessStatusCode)
                    return await fallbackResponse.Content.ReadFromJsonAsync<GraphQLResponse<T>>();
            }
        }
        catch
        {
            try
            {
                var fallbackResponse = await SendToUrlAsync("http://localhost:5256/graphql");
                if (fallbackResponse.IsSuccessStatusCode)
                    return await fallbackResponse.Content.ReadFromJsonAsync<GraphQLResponse<T>>();
            }
            catch
            {
            }
        }

        return null;
    }

    public class GraphQLRequest
    {
        [JsonPropertyName("query")] public string Query { get; set; } = string.Empty;

        [JsonPropertyName("variables")] public Dictionary<string, object>? Variables { get; set; }
    }

    public class GraphQLResponse<T>
    {
        [JsonPropertyName("data")] public T? Data { get; set; }

        [JsonPropertyName("errors")] public List<GraphQLError>? Errors { get; set; }
    }

    public class GraphQLError
    {
        [JsonPropertyName("message")] public string Message { get; set; } = string.Empty;
    }

    public class GetNoteData
    {
        [JsonPropertyName("note")] public CardNote? Note { get; set; }
    }

    public class SaveNoteData
    {
        [JsonPropertyName("saveNote")] public CardNote? SaveNote { get; set; }
    }
}