using SessionZero.SzfLib.Helpers;

namespace SessionZero.SzfLib.Parser;

public class SzfField(string name, SzfFieldType type)
{
    public string Name { get; set; } = name;
    public SzfFieldType SzfType { get; set; } = type;
    public string? Value { get; set; }

    /// <summary>
    /// Validates the field based on its type and value. Returns an SzfError object containing validation results, if any.
    /// </summary>
    /// <param name="canHaveEmptyValue"></param>
    /// <returns></returns>
    public SzfError Validate(bool canHaveEmptyValue = false)
    {
        SzfError result = new();
        
        if (string.IsNullOrEmpty(Name))
        {
            result.AddError("Field name cannot be null or empty.");
        }
        
        if (!canHaveEmptyValue && string.IsNullOrEmpty(Value))
        {
            result.AddError($"Field '{Name}' cannot be empty.");
        }
        else
        {
            var isValid = ValidateSzfType(this);
            if (!isValid)
            {
                result.AddError($"Field '{Name}' has an invalid value for type '{SzfType}'.");
            }
        }

        return result;
    }
    
    /// <summary>
    /// Validates the value of the field based on its SzfType.
    /// </summary>
    /// <param name="field"></param>
    /// <returns></returns>
    private bool ValidateSzfType(SzfField field)
    {
        var modifiedValue = field.Value?.Trim().ToLower();
        
        switch (field.SzfType)
        {
            case SzfFieldType.Text:
                return !string.IsNullOrEmpty(modifiedValue);
            case SzfFieldType.TextField:
                return !string.IsNullOrEmpty(modifiedValue);
            case SzfFieldType.Number:
                if (decimal.TryParse(modifiedValue, out _)) return true;
                break;
            case SzfFieldType.Bool:
                if (bool.TryParse(modifiedValue, out _)) return true;
                break;
            case SzfFieldType.Calculated:
                // TODO: Implement validation for calculated fields
                // For now, we assume they are valid if they are not empty
                return !string.IsNullOrEmpty(modifiedValue);
            case SzfFieldType.EntryReference:
                // Currently, we assume entry references are valid if they are not empty
                return !string.IsNullOrEmpty(modifiedValue);
            case SzfFieldType.EntryReferenceList:
                // Currently, we assume entry reference lists are valid if they are not empty
                return !string.IsNullOrEmpty(modifiedValue);
            case SzfFieldType.System:
                // System fields are typically predefined and may not require validation
                return true;
        }

        return false;
    }
}