using System.Data;
using Dapper;
using Npgsql;

namespace KArtSell.Modules.IdentityAccess.ManageIdentityAndRoles.Features.RegisterIdentity;

public interface IRegisterIdentitySql
{
    Task<bool> EmailExistsAsync(string email, CancellationToken ct);
    Task<Guid> CreateIdentityAsync(NpgsqlConnection conn, NpgsqlTransaction transaction, Guid id, string email, string displayName, string correlationId, CancellationToken ct);
    Task<(Guid Id, string Email, string DisplayName, string State)> GetIdentityAsync(Guid id, CancellationToken ct);
}

public sealed class RegisterIdentitySql : IRegisterIdentitySql
{
    private readonly Func<Task<NpgsqlConnection>> _connectionFactory;

    public RegisterIdentitySql(Func<Task<NpgsqlConnection>> connectionFactory)
    {
        _connectionFactory = connectionFactory;
    }

    public async Task<bool> EmailExistsAsync(string email, CancellationToken ct)
    {
        using var conn = await _connectionFactory();
        const string sql = """
            SELECT EXISTS(SELECT 1 FROM public.identity WHERE email = @email)
            """;
        return await conn.QuerySingleAsync<bool>(sql, new { email }, commandTimeout: 5);
    }

    public async Task<Guid> CreateIdentityAsync(NpgsqlConnection conn, NpgsqlTransaction transaction, Guid id, string email, string displayName, string correlationId, CancellationToken ct)
    {
        const string sql = """
            INSERT INTO public.identity (identity_id, email, display_name, state, created_at, updated_at, published_at, revision_version, correlation_id, username)
            VALUES (@id, @email, @displayName, @state, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP, 1, @correlationId, @email)
            ON CONFLICT (email) DO NOTHING
            RETURNING identity_id;
            """;

        var result = await conn.QuerySingleOrDefaultAsync<Guid?>(
            new CommandDefinition(
                sql,
                new
                {
                    id,
                    email,
                    displayName,
                    state = Domain.IdentityState.Active,
                    correlationId
                },
                transaction,
                commandTimeout: 5,
                cancellationToken: ct));

        return result ?? Guid.Empty;
    }

    public async Task<(Guid Id, string Email, string DisplayName, string State)> GetIdentityAsync(Guid id, CancellationToken ct)
    {
        using var conn = await _connectionFactory();
        const string sql = """
            SELECT identity_id, email, display_name, state
            FROM public.identity
            WHERE identity_id = @id
            """;

        var row = await conn.QuerySingleOrDefaultAsync<dynamic>(sql, new { id }, commandTimeout: 5);
        if (row is null)
            throw new InvalidOperationException($"Identity {id} not found");

        return ((Guid)row.identity_id, (string)row.email, (string)row.display_name, (string)row.state);
    }
}