using System.Collections.Generic;
using Npgsql;
using pgLabII.Model;
using pgLabII.PgUtils.ConnectionStrings;
using pgLabII.Services;
using Xunit;

namespace pgLabII.Tests.Services;

public class ServerConfigurationMappingTests
{
    [Fact]
    public void ToDescriptor_Basic_MapsExpectedFields()
    {
        ServerConfigurationEntity cfg = new() 
        {
            Name = "Prod",
            Host = "db.example.com",
            Port = 5433,
            InitialDatabase = "appdb",
            SslMode = SslMode.Require,
            UserName = "alice", 
            Password = "secret"
        };

        var extra = new Dictionary<string,string>{{"search_path","public"}};
        var d = ServerConfigurationMapping.ToDescriptor(cfg, applicationName: "pgLabII", timeoutSeconds: 15, extraProperties: extra);

        Assert.Single(d.Hosts);
        Assert.Equal("db.example.com", d.Hosts[0].Host);
        Assert.Equal((ushort)5433, d.Hosts[0].Port);
        Assert.Equal("appdb", d.Database);
        Assert.Equal("alice", d.Username);
        Assert.Equal("secret", d.Password);
        Assert.Equal(SslMode.Require, d.SslMode);
        Assert.Equal("pgLabII", d.ApplicationName);
        Assert.Equal(15, d.TimeoutSeconds);
        Assert.True(d.Properties.ContainsKey("search_path"));
        Assert.Equal("public", d.Properties["search_path"]);
    }

    [Fact]
    public void ToDescriptor_OmitsEmptyFields()
    {
        ServerConfigurationEntity cfg = new ()
        {
            Name = "Empty",
            Host = "",
            InitialDatabase = "",
            UserName = "", 
            Password = "",
        };

        var d = ServerConfigurationMapping.ToDescriptor(cfg);

        Assert.Empty(d.Hosts);
        Assert.Null(d.Database);
        Assert.Null(d.Username);
        Assert.Null(d.Password);
    }

    [Fact]
    public void FromDescriptor_CreatesNew_UsesFirstHost()
    {
        var desc = new ConnectionDescriptor
        {
            Hosts = new []
            {
                new HostEndpoint{ Host = "host1", Port = 5432 },
                new HostEndpoint{ Host = "host2", Port = 5434 }
            },
            Database = "stagedb",
            Username = "bob",
            Password = "pwd",
            SslMode = SslMode.VerifyFull
        };

        ServerConfigurationEntity cfg = ServerConfigurationMapping.FromDescriptor(desc);

        Assert.Equal("host1", cfg.Host);
        Assert.Equal((ushort)5432, cfg.Port);
        Assert.Equal("stagedb", cfg.InitialDatabase);
        Assert.Equal(SslMode.VerifyFull, cfg.SslMode);
        Assert.Equal("bob", cfg.UserName);
        Assert.Equal("pwd", cfg.Password);
    }

    [Fact]
    public void FromDescriptor_UpdatesExisting_PreservesMissing()
    {
        ServerConfigurationEntity existing = new()
        {
            Name = "Existing",
            Host = "keep-host",
            Port = 5432,
            InitialDatabase = "keepdb",
            SslMode = SslMode.Prefer,
            UserName = "keepuser",
            Password = "keeppwd",
        };

        // Descriptor missing db and user/pass and sslmode
        var desc = new ConnectionDescriptor
        {
            Hosts = new [] { new HostEndpoint{ Host = "new-host" } }
        };

        var cfg = ServerConfigurationMapping.FromDescriptor(desc, existing);

        Assert.Equal("new-host", cfg.Host);
        Assert.Equal((ushort)5432, cfg.Port); // unchanged
        Assert.Equal("keepdb", cfg.InitialDatabase); // preserved
        Assert.Equal(SslMode.Prefer, cfg.SslMode); // preserved
        Assert.Equal("keepuser", cfg.UserName); // preserved
        Assert.Equal("keeppwd", cfg.Password); // preserved
    }

    [Fact]
    public void Roundtrip_Basic()
    {
        ServerConfigurationEntity cfg = new()
        {
            Name = "Round",
            Host = "localhost",
            Port = 5432,
            InitialDatabase = "postgres",
            SslMode = SslMode.Allow,
            UserName = "me",
            Password = "pw",
        };

        var d = ServerConfigurationMapping.ToDescriptor(cfg);
        var cfg2 = ServerConfigurationMapping.FromDescriptor(d);

        Assert.Equal(cfg.Host, cfg2.Host);
        Assert.Equal(cfg.Port, cfg2.Port);
        Assert.Equal(cfg.InitialDatabase, cfg2.InitialDatabase);
        Assert.Equal(cfg.SslMode, cfg2.SslMode);
        Assert.Equal(cfg.UserName, cfg2.UserName);
        Assert.Equal(cfg.Password, cfg2.Password);
    }
}