using Cloud;
using DatabaseTest.Models;
using Microsoft.EntityFrameworkCore;
using System.Text.Json;
using Cloud.Models;

namespace DatabaseTest.Services;

public interface IDatabaseConfigService
{
    DatabaseProviderType ProviderType { get; }
    string ConnectionString { get; }
    string InMemoryDbName { get; }
    event Action? OnConfigurationChanged;

    void SetProvider(DatabaseProviderType providerType);
    void SetConnectionString(string connectionString);
    void SetInMemoryDbName(string name);
    AppDbContext CreateDbContext();
    string GetActiveProviderDescription();
}

public class DatabaseConfigService : IDatabaseConfigService
{
    private readonly IConfiguration _configuration;
    private DatabaseProviderType _providerType;
    private string _connectionString;
    private string _inMemoryDbName = "chrono_database_test";

    public event Action? OnConfigurationChanged;

    public DatabaseConfigService(IConfiguration configuration)
    {
        _configuration = configuration;
        
        var configuredConn = _configuration.GetConnectionString("DefaultConnection")
                             ?? _configuration.GetConnectionString("Postgres")
                             ?? Environment.GetEnvironmentVariable("POSTGRES_CONNECTION_STRING")
                             ?? "Host=localhost;Port=5432;Database=chrono;Username=postgres;Password=postgres";

        _connectionString = configuredConn;
        _providerType = DatabaseProviderType.PostgreSQL;
    }

    public DatabaseProviderType ProviderType => _providerType;
    public string ConnectionString => _connectionString;
    public string InMemoryDbName => _inMemoryDbName;

    public void SetProvider(DatabaseProviderType providerType)
    {
        if (_providerType != providerType)
        {
            _providerType = providerType;
            OnConfigurationChanged?.Invoke();
        }
    }

    public void SetConnectionString(string connectionString)
    {
        if (_connectionString != connectionString)
        {
            _connectionString = connectionString;
            OnConfigurationChanged?.Invoke();
        }
    }

    public void SetInMemoryDbName(string name)
    {
        if (_inMemoryDbName != name)
        {
            _inMemoryDbName = name;
            OnConfigurationChanged?.Invoke();
        }
    }

    public string GetActiveProviderDescription()
    {
        return _providerType switch
        {
            DatabaseProviderType.PostgreSQL => $"PostgreSQL ({GetMaskedConnectionString(_connectionString)})",
            DatabaseProviderType.InMemory => $"In-Memory Test Database ({_inMemoryDbName})",
            _ => _providerType.ToString()
        };
    }

    private static string GetMaskedConnectionString(string conn)
    {
        if (string.IsNullOrWhiteSpace(conn)) return "Not configured";
        // Hide password in display
        return System.Text.RegularExpressions.Regex.Replace(conn, @"(?i)Password=[^;]+", "Password=******");
    }

    public AppDbContext CreateDbContext()
    {
        var builder = new DbContextOptionsBuilder<AppDbContext>();

        if (_providerType == DatabaseProviderType.PostgreSQL)
        {
            builder.UseNpgsql(_connectionString, npgsqlOptions =>
            {
                npgsqlOptions.CommandTimeout(15);
            });
        }
        else
        {
            builder.UseInMemoryDatabase(_inMemoryDbName);
        }

        return new AppDbContext(builder.Options);
    }
}