using System.Net.Http.Headers;
using System.Net.Http.Json;

public class VigilCareApiClient
{
    private readonly HttpClient _http;

    public VigilCareApiClient(HttpClient http)
    {
        _http = http;
    }

    public async Task LoginAsync(string username, string password)
    {
        var response = await _http.PostAsJsonAsync("/api/v1/auth/login",
            new SimLoginRequest(username, password));

        if (!response.IsSuccessStatusCode)
        {
            var body = await response.Content.ReadAsStringAsync();
            throw new HttpRequestException(
                $"Login failed ({(int)response.StatusCode} {response.StatusCode}): {body}");
        }

        var envelope = await response.Content.ReadFromJsonAsync<ApiResponse<SimLoginResponse>>();
        var token = envelope!.Data!.AccessToken;
        _http.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
    }

    public async Task<PatientResponse> RegisterPatientAsync(RegisterPatientRequest req)
    {
        var response = await _http.PostAsJsonAsync("/api/v1/patients", req);
        response.EnsureSuccessStatusCode();
        var envelope = await response.Content.ReadFromJsonAsync<ApiResponse<PatientResponse>>();
        return envelope!.Data;
    }

    public async Task<EncounterResponse> OpenEncounterAsync(Guid patientId, OpenEncounterRequest req)
    {
        var response = await _http.PostAsJsonAsync($"/api/v1/patients/{patientId}/encounters", req);
        response.EnsureSuccessStatusCode();
        var envelope = await response.Content.ReadFromJsonAsync<ApiResponse<EncounterResponse>>();
        return envelope!.Data;
    }

    public async Task SendObservationBatchAsync(
        Guid encounterId, List<IngestObservationRequest> observations)
    {
        foreach (var chunk in observations.Chunk(10))
        {
            var batch = new BatchIngestRequest(chunk.ToList());
            var response = await _http.PostAsJsonAsync(
                $"/api/v1/encounters/{encounterId}/observations", batch);
            if (!response.IsSuccessStatusCode)
            {
                var body = await response.Content.ReadAsStringAsync();
                throw new HttpRequestException(
                    $"Observation batch failed ({(int)response.StatusCode} {response.StatusCode}): {body}");
            }
        }
    }

    public async Task<bool> TrySendMedicationAsync(
        Guid encounterId, CreateMedicationAdministrationRequest req)
    {
        var response = await _http.PostAsJsonAsync(
            $"/api/v1/encounters/{encounterId}/medications", req);
        if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
            return false;
        response.EnsureSuccessStatusCode();
        return true;
    }

    public async Task<bool> TryCreateOrderAsync(
        Guid encounterId, CreateOrderRequest req)
    {
        var response = await _http.PostAsJsonAsync(
            $"/api/v1/encounters/{encounterId}/orders", req);
        return response.IsSuccessStatusCode;
    }

    public async Task<bool> TryResultOrderAsync(
        Guid encounterId, string orderDescription, string? resultSummary)
    {
        var ordersResponse = await _http.GetAsync(
            $"/api/v1/encounters/{encounterId}/orders?status=PENDING");
        if (!ordersResponse.IsSuccessStatusCode)
            return false;

        var envelope = await ordersResponse.Content
            .ReadFromJsonAsync<ApiResponse<PagedResponse<OrderResponse>>>();
        var order = FindPendingOrder(envelope?.Data.Items ?? [], orderDescription);
        if (order is null)
            return false;

        var resultResponse = await _http.PatchAsJsonAsync(
            $"/api/v1/orders/{order.Id}/result",
            new RecordOrderResultRequest(resultSummary));
        return resultResponse.IsSuccessStatusCode;
    }

    private static OrderResponse? FindPendingOrder(
        List<OrderResponse> items, string description)
    {
        return items.FirstOrDefault(o => o.Description == description)
            ?? items.FirstOrDefault(o =>
                description.StartsWith(o.Description, StringComparison.OrdinalIgnoreCase))
            ?? items.FirstOrDefault(o =>
                o.Description.StartsWith(description, StringComparison.OrdinalIgnoreCase));
    }

    // --- Polling endpoints ---

    public async Task<List<AlertResponse>> GetAlertsAsync(Guid encounterId)
    {
        var response = await _http.GetAsync($"/api/v1/encounters/{encounterId}/alerts");
        if (!response.IsSuccessStatusCode) return new();
        var envelope = await response.Content
            .ReadFromJsonAsync<ApiResponse<PagedResponse<AlertResponse>>>();
        return envelope?.Data.Items.ToList() ?? new();
    }

    public async Task<News2Response?> GetCurrentNews2Async(Guid encounterId)
    {
        var response = await _http.GetAsync($"/api/v1/encounters/{encounterId}/news2/current");
        if (!response.IsSuccessStatusCode) return null;
        var envelope = await response.Content.ReadFromJsonAsync<ApiResponse<News2Response>>();
        return envelope?.Data;
    }

    public async Task<SepsisBundleResponse?> GetSepsisBundleAsync(Guid encounterId)
    {
        var response = await _http.GetAsync(
            $"/api/v1/encounters/{encounterId}/sepsis-bundle/current");
        if (!response.IsSuccessStatusCode) return null;
        var envelope = await response.Content
            .ReadFromJsonAsync<ApiResponse<SepsisBundleResponse>>();
        return envelope?.Data;
    }

    public async Task<GcsResponse?> GetCurrentGcsAsync(Guid encounterId)
    {
        var response = await _http.GetAsync($"/api/v1/encounters/{encounterId}/gcs");
        if (!response.IsSuccessStatusCode) return null;
        var envelope = await response.Content.ReadFromJsonAsync<ApiResponse<GcsResponse>>();
        return envelope?.Data;
    }

    public async Task<SofaResponse?> GetCurrentSofaAsync(Guid encounterId)
    {
        var response = await _http.GetAsync($"/api/v1/encounters/{encounterId}/sofa");
        if (!response.IsSuccessStatusCode) return null;
        var envelope = await response.Content.ReadFromJsonAsync<ApiResponse<SofaResponse>>();
        return envelope?.Data;
    }

    public async Task<QsofaResponse?> GetCurrentQsofaAsync(Guid encounterId)
    {
        var response = await _http.GetAsync($"/api/v1/encounters/{encounterId}/qsofa/current");
        if (!response.IsSuccessStatusCode) return null;
        var envelope = await response.Content.ReadFromJsonAsync<ApiResponse<QsofaResponse>>();
        return envelope?.Data;
    }
}