// SzfFieldWriter.cs

using System.Text;

namespace SessionZero.Data;

/// <summary>
/// Helper class to write fields to a StringBuilder following SZF format,
/// respecting generator options like indentation.
/// </summary>
public class SzfFieldWriter
{
    public readonly StringBuilder Builder;
    public readonly SzfGeneratorOptions Options;

    public SzfFieldWriter(StringBuilder builder, SzfGeneratorOptions options)
    {
        Builder = builder;
        Options = options;
    }

    /// <summary>
    /// Writes a generic field with a string type.
    /// </summary>
    public void WriteField(string name, string type, object? value)
    {
        if (!Options.IncludeEmptyFields && (value == null || string.IsNullOrEmpty(value.ToString())))
        {
            return; // Skip empty fields if option is set
        }

        var formattedValue = FormatFieldValue(value, type);

        if (Options.IndentFields)
        {
            Builder.AppendLine($"{Options.Indent}{name} ({type}) = {formattedValue}");
        }
        else
        {
            Builder.AppendLine($"{name} ({type}) = {formattedValue}");
        }
    }

    /// <summary>
    /// Writes a field with a DatasetFieldType.
    /// </summary>
    public void WriteField(string name, DatasetFieldType type, object? value)
    {
        var typeString = type switch
        {
            DatasetFieldType.Text => "text",
            DatasetFieldType.TextField => "text-field",
            DatasetFieldType.Number => "number",
            DatasetFieldType.Boolean => "bool",
            DatasetFieldType.Group => "group",
            DatasetFieldType.Calculated => "calculated",
            DatasetFieldType.System => "system",
            DatasetFieldType.DatasetReference => "dataset-reference",
            DatasetFieldType.DatasetType => "dataset-type",
            DatasetFieldType.DatasetReferenceMultiple => "dataset-reference-multiple",
            DatasetFieldType.DatasetTypeMultiple => "dataset-type-multiple",
            _ => "text" // Default or unknown types
        };
        WriteField(name, typeString, value);
    }

    /// <summary>
    /// Formats field values based on their declared type for SZF output.
    /// </summary>
    private string FormatFieldValue(object? value, string fieldType)
    {
        if (value == null)
            return string.Empty;

        return fieldType.ToLower() switch
        {
            "bool" => (bool)value ? "true" : "false",
            "number" => value.ToString() ?? "0",
            _ => value.ToString() ?? string.Empty
        };
    }

    /// <summary>
    /// Appends a new line to the string builder.
    /// </summary>
    public void AppendLine()
    {
        Builder.AppendLine();
    }

    /// <summary>
    /// Appends a section header to the string builder.
    /// </summary>
    public void AppendSectionHeader(string header)
    {
        Builder.AppendLine($"[{header}]");
    }
}