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

namespace Asentrafin.Api.Services.Plaid;

public class PlaidClient(HttpClient httpClient, IOptions<PlaidOptions> options) : IPlaidClient
{
    private static readonly JsonSerializerOptions JsonOptions = new(JsonSerializerDefaults.Web);
    private readonly PlaidOptions _options = options.Value;

    public Task<JsonDocument> AccountsGetAsync(string accessToken, CancellationToken cancellationToken)
    {
        return PostAsync("/accounts/get", BuildAuthedRequest(accessToken), cancellationToken);
    }

    public Task<JsonDocument> TransactionsSyncAsync(string accessToken, string? cursor, CancellationToken cancellationToken)
    {
        var body = BuildAuthedRequest(accessToken);
        body["cursor"] = cursor;
        body["count"] = 500;
        body["options"] = new Dictionary<string, object?>
        {
            ["include_original_description"] = true,
            ["personal_finance_category_version"] = "v2"
        };

        return PostAsync("/transactions/sync", body, cancellationToken);
    }

    public Task<JsonDocument> InvestmentsHoldingsGetAsync(string accessToken, CancellationToken cancellationToken)
    {
        return PostAsync("/investments/holdings/get", BuildAuthedRequest(accessToken), cancellationToken);
    }

    public Task<JsonDocument> InvestmentsTransactionsGetAsync(
        string accessToken,
        DateOnly startDate,
        DateOnly endDate,
        int count,
        int offset,
        CancellationToken cancellationToken)
    {
        var body = BuildAuthedRequest(accessToken);
        body["start_date"] = startDate.ToString("yyyy-MM-dd");
        body["end_date"] = endDate.ToString("yyyy-MM-dd");
        body["options"] = new Dictionary<string, object?>
        {
            ["count"] = count,
            ["offset"] = offset
        };

        return PostAsync("/investments/transactions/get", body, cancellationToken);
    }

    private async Task<JsonDocument> PostAsync(
        string path,
        Dictionary<string, object?> body,
        CancellationToken cancellationToken)
    {
        EnsureConfigured();

        using var response = await httpClient.PostAsJsonAsync(path, body, JsonOptions, cancellationToken);
        var responseBody = await response.Content.ReadAsStringAsync(cancellationToken);

        if (!response.IsSuccessStatusCode)
        {
            throw new HttpRequestException(
                $"Plaid request to {path} failed with {(int)response.StatusCode}: {responseBody}",
                null,
                response.StatusCode);
        }

        return JsonDocument.Parse(responseBody);
    }

    private Dictionary<string, object?> BuildAuthedRequest(string accessToken)
    {
        return new Dictionary<string, object?>
        {
            ["client_id"] = _options.ClientId,
            ["secret"] = _options.Secret,
            ["access_token"] = accessToken
        };
    }

    private void EnsureConfigured()
    {
        if (string.IsNullOrWhiteSpace(_options.ClientId) || string.IsNullOrWhiteSpace(_options.Secret))
        {
            throw new InvalidOperationException("Plaid ClientId and Secret must be configured.");
        }
    }
}