using System.Collections;

using System.Text.Json;

using System.Text.Json.Nodes;

using NpgsqlRest;

namespace NpgsqlRestClient;

public class Config

{

public IConfigurationRoot Cfg { get; private set; } = null!;

public IConfigurationSection NpgsqlRestCfg { get; private set; } = null!;

public IConfigurationSection ConnectionSettingsCfg { get; private set; } = null!;

public bool UseConnectionApplicationNameWithUsername { get; private set; }

public string CurrentDir => Directory.GetCurrentDirectory();

public Dictionary<string, string>? EnvDict { get; private set; } = null;

public void Build(string[] args, string[] skip)

{

if (args.Length >= 1 && skip.Contains(args[0], StringComparer.CurrentCultureIgnoreCase))

{

args = [];

}

var tempBuilder = new ConfigurationBuilder();

IConfigurationRoot tempCfg;

var arguments = new Out();

var (configFiles, commandLineArgs) = BuildFromArgs(args);

if (configFiles.Count > 0)

{

foreach (var (fileName, optional) in configFiles)

{

tempBuilder.AddJsonFile(Path.GetFullPath(fileName, CurrentDir), optional: optional);

}

tempCfg = tempBuilder.Build();

}

else

{

tempCfg = tempBuilder

.AddJsonFile(Path.GetFullPath("appsettings.json", CurrentDir), optional: true)

.AddJsonFile(Path.GetFullPath("appsettings.Development.json", CurrentDir), optional: true)

.Build();

}

var cfgCfg = tempCfg.GetSection("Config");

ConfigurationBuilder configBuilder = new();

var useEnv = cfgCfg != null && GetConfigBool("AddEnvironmentVariables", cfgCfg);

if (configFiles.Count > 0)

{

foreach (var (fileName, optional) in configFiles)

{

configBuilder.AddJsonFile(Path.GetFullPath(fileName, CurrentDir), optional: optional);

}

if (useEnv)

{

configBuilder.AddEnvironmentVariables();

}

configBuilder.AddCommandLine(commandLineArgs);

Cfg = configBuilder.Build();

}

else

{

if (useEnv)

{

Cfg = configBuilder

.AddJsonFile(Path.GetFullPath("appsettings.json", CurrentDir), optional: true)

.AddJsonFile(Path.GetFullPath("appsettings.Development.json", CurrentDir), optional: true)

.AddEnvironmentVariables()

.AddCommandLine(commandLineArgs)

.Build();

}

else

{

Cfg = configBuilder

.AddJsonFile(Path.GetFullPath("appsettings.json", CurrentDir), optional: true)

.AddJsonFile(Path.GetFullPath("appsettings.Development.json", CurrentDir), optional: true)

.AddCommandLine(commandLineArgs)

.Build();

}

}

NpgsqlRestCfg = Cfg.GetSection("NpgsqlRest");

ConnectionSettingsCfg = Cfg.GetSection("ConnectionSettings");

if (cfgCfg != null && GetConfigBool("ParseEnvironmentVariables", cfgCfg, true) is true)

{

EnvDict = new Dictionary<string, string>();

var envVars = Environment.GetEnvironmentVariables();

foreach (var key in envVars.Keys)

{

EnvDict.Add(key.ToString()!, envVars[key.ToString()!]?.ToString()!);

}

}

UseConnectionApplicationNameWithUsername = GetConfigBool("UseJsonApplicationName", ConnectionSettingsCfg);

}

public bool Exists(IConfigurationSection? section)

{

if (section is null)

{

return false;

}

if (section.GetChildren().Any() is false)

{

return false;

}

return true;

}

public bool GetConfigBool(string key, IConfiguration? subsection = null, bool defaultVal = false)

{

var section = subsection?.GetSection(key) ?? Cfg.GetSection(key);

if (string.IsNullOrEmpty(section.Value))

{

return defaultVal;

}

var value = EnvDict is not null ?

Formatter.FormatString(section.Value.AsSpan(), EnvDict).ToString() :

section.Value;

// Handle various boolean representations

return value.ToLowerInvariant() switch

{

"true" or "yes" or "1" => true,

"false" or "no" or "0" => false,

_ => throw new InvalidOperationException($"Invalid boolean value '{value}' for configuration key '{key}'. Valid values are: true, false, yes, no, 1, 0")

};

}

public string? GetConfigStr(string key, IConfiguration? subsection = null)

{

var section = subsection?.GetSection(key) ?? Cfg.GetSection(key);

if (string.IsNullOrEmpty(section.Value))

{

return null;

}

return EnvDict is not null ?

Formatter.FormatString(section.Value.AsSpan(), EnvDict).ToString() :

section.Value;

}

public int? GetConfigInt(string key, IConfiguration? subsection = null)

{

var section = subsection?.GetSection(key) ?? Cfg.GetSection(key);

if (string.IsNullOrEmpty(section.Value))

{

return null;

}

var configValue = EnvDict is not null ?

Formatter.FormatString(section.Value.AsSpan(), EnvDict).ToString() :

section.Value;

return int.TryParse(configValue, out var value) ? value :

throw new InvalidOperationException($"Invalid integer value '{configValue}' for configuration key '{key}'.");

}

public T? GetConfigEnum<T>(string key, IConfiguration? subsection = null)

{

var section = subsection?.GetSection(key) ?? Cfg.GetSection(key);

if (string.IsNullOrEmpty(section.Value))

{

return default;

}

var value = EnvDict is not null ?

Formatter.FormatString(section.Value.AsSpan(), EnvDict).ToString() :

section.Value;

return GetEnum<T>(section?.Value);

}

public T? GetEnum<T>(string? value)

{

if (value is null)

{

return default;

}

var type = typeof(T);

var nullable = Nullable.GetUnderlyingType(type);

var names = Enum.GetNames(nullable ?? type);

foreach (var name in names)

{

if (string.Equals(value, name, StringComparison.OrdinalIgnoreCase))

{

return (T)Enum.Parse(nullable ?? type, name);

}

}

return default;

}

public IEnumerable<string>? GetConfigEnumerable(string key, IConfiguration? subsection = null)

{

var section = subsection is not null ? subsection?.GetSection(key) : Cfg.GetSection(key);

if (section.Exists() is false)

{

return null;

}

var children = section?.GetChildren().ToArray();

if (children is null || (children.Length == 0 && section?.Value == ""))

{

return null;

}

if (EnvDict is not null)

{

return children

.Where(c => string.IsNullOrEmpty(c.Value) is false)

.Select(c => Formatter.FormatString(c.Value.AsSpan(), EnvDict).ToString());

}

return children

.Where(c => string.IsNullOrEmpty(c.Value) is false)

.Select(c => c.Value!);

}

public T? GetConfigFlag<T>(string key, IConfiguration? subsection = null)

{

var array = GetConfigEnumerable(key, subsection)?.ToArray();

if (array is null)

{

return default;

}

var type = typeof(T);

var nullable = Nullable.GetUnderlyingType(type);

var names = Enum.GetNames(nullable ?? type);

T? result = default;

foreach (var value in array)

{

foreach (var name in names)

{

if (string.Equals(value, name, StringComparison.OrdinalIgnoreCase))

{

var e = (T)Enum.Parse(nullable ?? type, name);

if (result is null)

{

result = e;

}

else

{

result = (T)Enum.ToObject(type, Convert.ToInt32(result) | Convert.ToInt32(e));

}

}

}

}

return result;

}

public Dictionary<string, string>? GetConfigDict(IConfiguration config)

{

var result = new Dictionary<string, string>();

foreach (var section in config.GetChildren())

{

if (section.Value is not null)

{

var value = EnvDict is not null ?

Formatter.FormatString(section.Value.AsSpan(), EnvDict).ToString() :

section.Value;

result.TryAdd(section.Key, value);

}

}

return result.Count == 0 ? null : result;

}

public string Serialize()

{

var json = SerializeConfig(Cfg);

return json?.ToJsonString(new JsonSerializerOptions() { WriteIndented = true }) ?? "{}";

}

private JsonNode? SerializeConfig(IConfiguration config)

{

JsonObject obj = [];

foreach (var child in config.GetChildren())

{

if (child.Path.EndsWith(":0"))

{

var arr = new JsonArray();

foreach (var arrayChild in config.GetChildren())

{

arr.Add(SerializeConfig(arrayChild));

}

return arr;

}

obj.Add(child.Key, SerializeConfig(child));

}

if (obj.Count == 0 && config is IConfigurationSection section)

{

var value = EnvDict is not null ?

Formatter.FormatString(section.Value.AsSpan(), EnvDict).ToString() :

section.Value;

if (bool.TryParse(value, out bool boolean))

{

return JsonValue.Create(boolean);

}

else if (decimal.TryParse(value, out decimal real))

{

return JsonValue.Create(real);

}

else if (long.TryParse(value, out long integer))

{

return JsonValue.Create(integer);

}

if (section.Path.StartsWith("ConnectionStrings:"))

{

return JsonValue.Create(string.Join(';',

value?.Split(';')?.Where(p => p.StartsWith("password", StringComparison.OrdinalIgnoreCase) is false) ?? []));

}

return JsonValue.Create(value);

}

return obj;

}

private (List<(string fileName, bool optional)> configFiles, string[] commanLineArgs) BuildFromArgs(string[] args)

{

var configFiles = new List<(string fileName, bool optional)>();

var commandLineArgs = new List<string>();

bool nextIsOptional = false;

foreach (var arg in args)

{

if (arg.StartsWith('-'))

{

var lower = arg.ToLowerInvariant();

if (lower is "-o" or "--optional")

{

nextIsOptional = true;

}

else if ((arg.StartsWith("--") && arg.Contains('=')) || string.Equals("--config", lower))

{

commandLineArgs.Add(arg);

}

else

{

throw new ArgumentException($"Unknown parameter {arg}");

}

}

else

{

configFiles.Add((arg, nextIsOptional));

nextIsOptional = false;

}

}

return (configFiles, commandLineArgs.ToArray());

}

}