using System.Collections.ObjectModel;
using System.Reflection;
using CommunityToolkit.Mvvm.ComponentModel;
using Newtonsoft.Json;
using OF_DL.Models.Config;

namespace OF_DL.Gui.ViewModels;

public partial class ConfigFieldViewModel : ViewModelBase
{
    public ConfigFieldViewModel(PropertyInfo propertyInfo, object? initialValue)
    {
        PropertyInfo = propertyInfo;
        PropertyName = propertyInfo.Name;
        DisplayName = ToDisplayName(propertyInfo.Name);
        PropertyType = propertyInfo.PropertyType;

        IsBoolean = PropertyType == typeof(bool);
        IsEnum = PropertyType.IsEnum;
        IsDate = PropertyType == typeof(DateTime?);
        IsNumeric = PropertyType == typeof(int) || PropertyType == typeof(int?);
        IsMultiline = PropertyType == typeof(Dictionary<string, CreatorConfig>);
        IsTextInput = !IsBoolean && !IsEnum && !IsDate && !IsNumeric;

        if (IsEnum)
        {
            foreach (string enumName in Enum.GetNames(PropertyType))
            {
                EnumOptions.Add(enumName);
            }
        }

        LoadInitialValue(initialValue);
    }

    public PropertyInfo PropertyInfo { get; }

    public string PropertyName { get; }

    public string DisplayName { get; }

    public Type PropertyType { get; }

    public bool IsBoolean { get; }

    public bool IsEnum { get; }

    public bool IsDate { get; }

    public bool IsNumeric { get; }

    public bool IsTextInput { get; }

    public bool IsMultiline { get; }

    public double TextBoxMinHeight => IsMultiline ? 150 : 36;

    public ObservableCollection<string> EnumOptions { get; } = [];

    [ObservableProperty] private bool _boolValue;

    [ObservableProperty] private string? _enumValue;

    [ObservableProperty] private DateTimeOffset? _dateValue;

    [ObservableProperty] private decimal? _numericValue;

    [ObservableProperty] private string _textValue = string.Empty;

    [ObservableProperty]
    [NotifyPropertyChangedFor(nameof(HasError))]
    private string _errorMessage = string.Empty;

    public bool HasError => !string.IsNullOrWhiteSpace(ErrorMessage);

    public bool TryGetTypedValue(out object? value, out string? error)
    {
        value = null;
        error = null;

        if (IsBoolean)
        {
            value = BoolValue;
            return true;
        }

        if (IsEnum)
        {
            if (string.IsNullOrWhiteSpace(EnumValue))
            {
                error = $"{DisplayName} is required.";
                return false;
            }

            if (!Enum.TryParse(PropertyType, EnumValue, true, out object? enumResult))
            {
                error = $"{DisplayName} must be one of: {string.Join(", ", EnumOptions)}.";
                return false;
            }

            value = enumResult;
            return true;
        }

        if (PropertyType == typeof(string))
        {
            value = TextValue.Trim();
            return true;
        }

        if (PropertyType == typeof(int))
        {
            if (!NumericValue.HasValue)
            {
                error = $"{DisplayName} must be a whole number.";
                return false;
            }

            if (decimal.Truncate(NumericValue.Value) != NumericValue.Value)
            {
                error = $"{DisplayName} must be a whole number.";
                return false;
            }

            value = (int)NumericValue.Value;
            return true;
        }

        if (PropertyType == typeof(int?))
        {
            if (!NumericValue.HasValue)
            {
                value = null;
                return true;
            }

            if (decimal.Truncate(NumericValue.Value) != NumericValue.Value)
            {
                error = $"{DisplayName} must be a whole number.";
                return false;
            }

            value = (int)NumericValue.Value;
            return true;
        }

        if (PropertyType == typeof(DateTime?))
        {
            if (!DateValue.HasValue)
            {
                value = null;
                return true;
            }

            value = DateValue.Value.DateTime;
            return true;
        }

        if (PropertyType == typeof(Dictionary<string, CreatorConfig>))
        {
            if (string.IsNullOrWhiteSpace(TextValue))
            {
                value = new Dictionary<string, CreatorConfig>();
                return true;
            }

            try
            {
                Dictionary<string, CreatorConfig>? parsed =
                    JsonConvert.DeserializeObject<Dictionary<string, CreatorConfig>>(TextValue);
                value = parsed ?? new Dictionary<string, CreatorConfig>();
                return true;
            }
            catch (JsonException)
            {
                error = $"{DisplayName} must be valid JSON.";
                return false;
            }
        }

        error = $"{DisplayName} has an unsupported field type.";
        return false;
    }

    public void ClearError()
    {
        ErrorMessage = string.Empty;
    }

    public void SetError(string message)
    {
        ErrorMessage = message;
    }

    private void LoadInitialValue(object? initialValue)
    {
        if (IsBoolean)
        {
            BoolValue = initialValue is bool boolValue && boolValue;
            return;
        }

        if (IsEnum)
        {
            EnumValue = initialValue?.ToString() ?? EnumOptions.FirstOrDefault();
            return;
        }

        if (PropertyType == typeof(Dictionary<string, CreatorConfig>))
        {
            Dictionary<string, CreatorConfig> creatorConfigs =
                initialValue as Dictionary<string, CreatorConfig> ?? new Dictionary<string, CreatorConfig>();
            TextValue = JsonConvert.SerializeObject(creatorConfigs, Formatting.Indented);
            return;
        }

        if (PropertyType == typeof(DateTime?))
        {
            DateTime? date = initialValue is DateTime dt ? dt : null;
            DateValue = date.HasValue ? new DateTimeOffset(date.Value) : null;
            return;
        }

        if (PropertyType == typeof(int))
        {
            NumericValue = initialValue is int intValue ? intValue : 0;
            return;
        }

        if (PropertyType == typeof(int?))
        {
            NumericValue = initialValue is int nullableIntValue ? nullableIntValue : null;
            return;
        }

        TextValue = initialValue?.ToString() ?? string.Empty;
    }

    private static string ToDisplayName(string propertyName)
    {
        if (string.IsNullOrWhiteSpace(propertyName))
        {
            return propertyName;
        }

        return string.Concat(propertyName.Select((character, index) =>
            index > 0 && char.IsUpper(character) && !char.IsUpper(propertyName[index - 1])
                ? $" {character}"
                : character.ToString()));
    }
}