using RobotNet10.CustomConfiguration.Models;
using System.Globalization;

namespace RobotNet10.CustomConfiguration.Validators;

/// <summary>
/// Validator cho config files và variables
/// </summary>
public static class ConfigValidator
{
    /// <summary>
    /// Validate một config file
    /// </summary>
    public static ValidationResult ValidateConfig(ConfigFile config)
    {
        var errors = new List<string>();

        // Validate ConfigType
        if (string.IsNullOrWhiteSpace(config.ConfigType))
        {
            errors.Add("ConfigType cannot be empty");
        }

        // Validate Variables
        if (config.Variables != null && config.Variables.Count > 0)
        {
            foreach (var variable in config.Variables)
            {
                var variableErrors = ValidateVariable(variable);
                errors.AddRange(variableErrors);
            }
        }

        return new ValidationResult
        {
            IsValid = errors.Count == 0,
            Errors = errors
        };
    }

    /// <summary>
    /// Validate một variable
    /// </summary>
    public static List<string> ValidateVariable(ConfigVariable variable)
    {
        var errors = new List<string>();

        // Validate Name
        if (string.IsNullOrWhiteSpace(variable.Name))
        {
            errors.Add("Variable name cannot be empty");
        }

        // Validate Type
        if (!Enum.IsDefined(variable.Type))
        {
            errors.Add($"Invalid variable type: {variable.Type}");
        }

        // Validate Value theo Type
        if (variable.Value == null)
        {
            errors.Add($"Variable '{variable.Name}' value cannot be null");
        }
        else
        {
            var valueErrors = ValidateValueByType(variable.Name, variable.Type, variable.Value, variable.Min, variable.Max, variable);
            errors.AddRange(valueErrors);
        }

        return errors;
    }

    /// <summary>
    /// Validate value theo type và Min/Max constraints
    /// </summary>
    private static List<string> ValidateValueByType(string variableName, ConfigVariableType type, object value, double? min, double? max, ConfigVariable? variable = null)
    {
        var errors = new List<string>();

        switch (type)
        {
            case ConfigVariableType.Int:
                // Try parse
                if (int.TryParse(value.ToString(), NumberStyles.Integer, CultureInfo.InvariantCulture, out var parsedInt))
                {
                    if (min.HasValue && parsedInt < min.Value)
                        errors.Add($"Variable '{variableName}' value {parsedInt} is less than Min {min.Value}");
                    if (max.HasValue && parsedInt > max.Value)
                        errors.Add($"Variable '{variableName}' value {parsedInt} is greater than Max {max.Value}");
                }
                else
                {
                    errors.Add($"Variable '{variableName}' must be an integer");
                }
                break;

            case ConfigVariableType.Double:
                // Try parse
                if (double.TryParse(value.ToString(), NumberStyles.Float | NumberStyles.AllowThousands, CultureInfo.InvariantCulture, out var parsedDouble))
                {
                    if (min.HasValue && parsedDouble < min.Value)
                        errors.Add($"Variable '{variableName}' value {parsedDouble} is less than Min {min.Value}");
                    if (max.HasValue && parsedDouble > max.Value)
                        errors.Add($"Variable '{variableName}' value {parsedDouble} is greater than Max {max.Value}");
                }
                else
                {
                    errors.Add($"Variable '{variableName}' must be a double");
                }
                break;

            case ConfigVariableType.Bool:
                if (!bool.TryParse(value.ToString(), out _))
                {
                    errors.Add($"Variable '{variableName}' must be a boolean");
                }
                break;

            case ConfigVariableType.Object:
                // Object có thể là Dictionary<string, object> hoặc JsonElement
                if (value is not Dictionary<string, object> &&
                    value is not System.Text.Json.JsonElement)
                {
                    // Try parse as JSON object
                    try
                    {
                        var jsonString = value.ToString();
                        if (jsonString != null)
                        {
                            using var doc = System.Text.Json.JsonDocument.Parse(jsonString);
                            if (doc.RootElement.ValueKind != System.Text.Json.JsonValueKind.Object)
                            {
                                errors.Add($"Variable '{variableName}' must be a JSON object");
                            }
                        }
                    }
                    catch (System.Text.Json.JsonException)
                    {
                        errors.Add($"Variable '{variableName}' must be a valid JSON object");
                    }
                }
                break;

            case ConfigVariableType.Array:
                // Array có thể là List<object> hoặc JsonElement
                if (value is not List<object> &&
                    value is not System.Text.Json.JsonElement)
                {
                    // Try parse as JSON array
                    try
                    {
                        var jsonString = value.ToString();
                        if (jsonString != null)
                        {
                            using var doc = System.Text.Json.JsonDocument.Parse(jsonString);
                            if (doc.RootElement.ValueKind != System.Text.Json.JsonValueKind.Array)
                            {
                                errors.Add($"Variable '{variableName}' must be a JSON array");
                            }
                        }
                    }
                    catch (System.Text.Json.JsonException)
                    {
                        errors.Add($"Variable '{variableName}' must be a valid JSON array");
                    }
                }
                break;

            case ConfigVariableType.Enum:
                if (variable == null || variable.EnumValues == null || variable.EnumValues.Count == 0)
                {
                    errors.Add($"Variable '{variableName}' of type Enum must have EnumValues defined");
                }
                else
                {
                    var valueStr = value?.ToString();
                    if (string.IsNullOrEmpty(valueStr) || !variable.EnumValues.Contains(valueStr))
                    {
                        errors.Add($"Variable '{variableName}' value '{valueStr}' is not in allowed enum values: {string.Join(", ", variable.EnumValues)}");
                    }
                }
                break;
        }

        return errors;
    }
}

/// <summary>
/// Kết quả validation
/// </summary>
public class ValidationResult
{
    public bool IsValid { get; set; }
    public List<string> Errors { get; set; } = [];
}