using System.Text.Json;

namespace BoardApp.Config;

public sealed class BoardConfigLoader
{
    private readonly JsonSerializerOptions _jsonOpts = new()
    {
        PropertyNameCaseInsensitive = true
    };

    public string ConfigDir
    {
        get
        {
            var env = Environment.GetEnvironmentVariable("BOARD_CONFIG_DIR");
            if (!string.IsNullOrWhiteSpace(env))
            {
                return Path.GetFullPath(env);
            }
            return Path.Combine(Directory.GetCurrentDirectory(), "config");
        }
    }

    private T ReadJson<T>(string file)
    {
        var full = Path.Combine(ConfigDir, file);
        var raw = File.ReadAllText(full);
        var obj = JsonSerializer.Deserialize<T>(raw, _jsonOpts);
        if (obj is null) throw new InvalidOperationException($"无法解析配置文件: {full}");
        return obj;
    }

    private void WriteJson<T>(string file, T data)
    {
        var full = Path.Combine(ConfigDir, file);
        var text = JsonSerializer.Serialize(data, new JsonSerializerOptions(_jsonOpts)
        {
            WriteIndented = true
        }) + "\n";
        File.WriteAllText(full, text);
    }

    public AppConfig LoadAppConfig() => ReadJson<AppConfig>("app.config.json");
    public LdapConfig LoadLdapConfig() => ReadJson<LdapConfig>("ldap.config.json");
    public PagesConfig LoadPagesConfig() => ReadJson<PagesConfig>("pages.config.json");
    public SystemScenariosConfig LoadSystemScenariosConfig() => ReadJson<SystemScenariosConfig>("scenarios.system.json");
    public UserScenariosConfig LoadUserScenariosConfig() => ReadJson<UserScenariosConfig>("scenarios.users.json");
    public SqlServerConfig LoadSqlServerConfig() => ReadJson<SqlServerConfig>("sqlserver.config.json");
    public DataSrcConfig LoadDataSrcConfig() => ReadJson<DataSrcConfig>("datasrc.json");

    public void WriteUserScenariosConfig(UserScenariosConfig cfg) => WriteJson("scenarios.users.json", cfg);
}