using SurrealDb.Net;
using TarninaHub.Application.Abstractions;
using TarninaHub.Application.Dtos;

namespace TarninaHub.Infrastructure.Persistence;

public sealed class ConsentService : IConsentService
{
    private const string SelectConsentFields =
        "type::string(id) AS id, type::string(user) AS user, scope, granted_at, expires_at, revoked_at";

    private readonly ISurrealDbClient _client;

    public ConsentService(ISurrealDbClient client)
    {
        _client = client;
    }

    public async Task<ConsentResponse> GrantAsync(
        string userId,
        GrantConsentRequest request,
        CancellationToken cancellationToken)
    {
        var (userTable, userIdPart) = SurrealRecordId.Split(userId);
        var consentId = Guid.NewGuid().ToString("N");
        var expiresClause = request.ExpiresAt.HasValue ? ", expires_at = $expiresAt" : string.Empty;

        var parameters = new Dictionary<string, object?>
        {
            ["consentId"] = consentId,
            ["userTable"] = userTable,
            ["userId"] = userIdPart,
            ["scope"] = request.Scope,
        };

        if (request.ExpiresAt.HasValue)
        {
            parameters["expiresAt"] = request.ExpiresAt;
        }

        var response = await _client.RawQuery(
            "CREATE type::record('consent', $consentId) SET " +
            "user = type::record($userTable, $userId), scope = $scope, " +
            "granted_at = time::now()" + expiresClause + "; " +
            $"SELECT {SelectConsentFields} FROM type::record('consent', $consentId) LIMIT 1;",
            parameters,
            cancellationToken);

        response.EnsureAllOks();

        var rows = response.GetValue<List<ConsentRow>>(1) ?? [];

        return Map(rows[0]);
    }

    public async Task<IReadOnlyList<ConsentResponse>> ListForUserAsync(
        string userId,
        CancellationToken cancellationToken)
    {
        var (userTable, userIdPart) = SurrealRecordId.Split(userId);

        var response = await _client.RawQuery(
            $"SELECT {SelectConsentFields} FROM consent " +
            "WHERE user = type::record($userTable, $userId) ORDER BY granted_at DESC;",
            new Dictionary<string, object?>
            {
                ["userTable"] = userTable,
                ["userId"] = userIdPart,
            },
            cancellationToken);

        response.EnsureAllOks();

        var rows = response.GetValue<List<ConsentRow>>(0) ?? [];

        return rows.Select(Map).ToList();
    }

    public async Task<bool> RevokeAsync(
        string consentId,
        string userId,
        CancellationToken cancellationToken)
    {
        var (userTable, userIdPart) = SurrealRecordId.Split(userId);
        var (consentTable, consentIdPart) = SurrealRecordId.Split(consentId);

        var response = await _client.RawQuery(
            "UPDATE type::record($consentTable, $consentIdPart) SET revoked_at = time::now() " +
            "WHERE user = type::record($userTable, $userId) AND revoked_at = NONE; " +
            $"SELECT {SelectConsentFields} FROM type::record($consentTable, $consentIdPart) LIMIT 1;",
            new Dictionary<string, object?>
            {
                ["consentTable"] = consentTable,
                ["consentIdPart"] = consentIdPart,
                ["userTable"] = userTable,
                ["userId"] = userIdPart,
            },
            cancellationToken);

        response.EnsureAllOks();

        var rows = response.GetValue<List<ConsentRow>>(1) ?? [];

        return rows.Count > 0 && rows[0].RevokedAt is not null;
    }

    private static ConsentResponse Map(ConsentRow row) => new(
        row.Id,
        row.User,
        row.Scope,
        row.GrantedAt,
        row.ExpiresAt,
        row.RevokedAt);
}