using System.Collections.Generic;
using FluentResults;
using Npgsql;

namespace pgLabII.PgUtils.ConnectionStrings;

public enum ConnStringFormat
{
    Libpq,
    Npgsql,
    Url,
    Jdbc
}

public sealed class HostEndpoint
{
    public string Host { get; init; } = string.Empty;
    public ushort? Port { get; init; }
}

/// <summary>
/// Canonical, format-agnostic representation of a PostgreSQL connection.
/// Keep minimal fields for broad interoperability; store extras in Properties.
/// </summary>
public sealed class ConnectionDescriptor
{
    public string? Name { get; init; }

    // Primary hosts (support multi-host). If empty, implies localhost default.
    public IReadOnlyList<HostEndpoint> Hosts { get; init; } = new List<HostEndpoint>();

    public string? Database { get; init; }
    public string? Username { get; init; }
    public string? Password { get; init; }

    public SslMode? SslMode { get; init; }

    // Common optional fields
    public string? ApplicationName { get; init; }
    public int? TimeoutSeconds { get; init; } // connect_timeout

    // Additional parameters preserved across conversions
    public IReadOnlyDictionary<string, string> Properties { get; init; } =
        new Dictionary<string, string>();
}

/// <summary>
/// Codec for a specific connection string format (parse and format only for its own format).
/// Do not implement format specifics yet; provide interface only.
/// </summary>
public interface IConnectionStringCodec
{
    ConnStringFormat Format { get; }
    string FormatName { get; }

    // Parse input in this codec's format into a descriptor.
    Result<ConnectionDescriptor> TryParse(string input);

    // Format a descriptor into this codec's format.
    Result<string> TryFormat(ConnectionDescriptor descriptor);
}

/// <summary>
/// High-level service to detect, parse, format and convert between formats.
/// Implementations will compose specific codecs.
/// </summary>
public interface IConnectionStringService
{
    Result<ConnStringFormat> DetectFormat(string input);

    Result<ConnectionDescriptor> ParseToDescriptor(string input);

    Result<string> FormatFromDescriptor(ConnectionDescriptor descriptor, ConnStringFormat targetFormat);

    Result<string> Convert(string input, ConnStringFormat targetFormat);
}