using System.Collections.Generic;
using Microsoft.CodeAnalysis;
using System.Linq;
using CliFx.Analyzers.Utils.Extensions;

namespace CliFx.Analyzers.ObjectModel
{
    internal partial class CommandOptionSymbol
    {
        public string? Name { get; }

        public char? ShortName { get; }

        public ITypeSymbol? ConverterType { get; }

        public IReadOnlyList<ITypeSymbol> ValidatorTypes { get; }

        public CommandOptionSymbol(
            string? name,
            char? shortName,
            ITypeSymbol? converterType,
            IReadOnlyList<ITypeSymbol> validatorTypes)
        {
            Name = name;
            ShortName = shortName;
            ConverterType = converterType;
            ValidatorTypes = validatorTypes;
        }
    }

    internal partial class CommandOptionSymbol
    {
        private static AttributeData? TryGetOptionAttribute(IPropertySymbol property) =>
            property
                .GetAttributes()
                .FirstOrDefault(a => a.AttributeClass.DisplayNameMatches(SymbolNames.CliFxCommandOptionAttribute));

        private static CommandOptionSymbol FromAttribute(AttributeData attribute)
        {
            var name = attribute
                .ConstructorArguments
                .Where(a => a.Type.DisplayNameMatches("string") || a.Type.DisplayNameMatches("System.String"))
                .Select(a => a.Value)
                .FirstOrDefault() as string;

            var shortName = attribute
                .ConstructorArguments
                .Where(a => a.Type.DisplayNameMatches("char") || a.Type.DisplayNameMatches("System.Char"))
                .Select(a => a.Value)
                .FirstOrDefault() as char?;

            var converter = attribute
                .NamedArguments
                .Where(a => a.Key == "Converter")
                .Select(a => a.Value.Value)
                .Cast<ITypeSymbol?>()
                .FirstOrDefault();

            var validators = attribute
                .NamedArguments
                .Where(a => a.Key == "Validators")
                .SelectMany(a => a.Value.Values)
                .Select(c => c.Value)
                .Cast<ITypeSymbol>()
                .ToArray();

            return new CommandOptionSymbol(name, shortName, converter, validators);
        }

        public static CommandOptionSymbol? TryResolve(IPropertySymbol property)
        {
            var attribute = TryGetOptionAttribute(property);

            if (attribute is null)
                return null;

            return FromAttribute(attribute);
        }

        public static bool IsOptionProperty(IPropertySymbol property) =>
            TryGetOptionAttribute(property) is not null;
    }
}