// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.Json;
 
namespace Microsoft.ML.AutoML.SourceGenerator
{
    internal sealed class Utils
    {
        public static EstimatorsContract GetEstimatorsFromJson(string json)
        {
            return JsonSerializer.Deserialize<EstimatorsContract>(json);
        }
 
        public static string CreateEstimatorName(string functionName, string estimatorType)
        {
            if (estimatorType == "BinaryClassification")
            {
                return functionName + "Binary";
            }
            if (estimatorType == "MultiClassification")
            {
                return functionName + "Multi";
            }
            if (estimatorType == "Regression")
            {
                return functionName + "Regression";
            }
            if (estimatorType == "Ranking")
            {
                return functionName + "Ranking";
            }
            if (estimatorType == "OneVersusAll")
            {
                return functionName + "Ova";
            }
 
            return functionName;
        }
 
        public static string CapitalFirstLetter(string str)
        {
            if (str == null)
                return null;
 
            if (str.Length > 1)
                return char.ToUpper(str[0]) + str.Substring(1);
 
            return str.ToUpper();
        }
 
        public static string PrettyPrintListOfString(IEnumerable<string> strs)
        {
            // ["str1", "str2", "str3"] => "\"str1\", \"str2\", \"str3\""
            var sb = new StringBuilder();
            foreach (var str in strs)
            {
                sb.Append($"\"{str}\"");
                sb.Append(", ");
            }
 
            return sb.ToString();
        }
 
        public static string ToTitleCase(string str)
        {
            return string.Join(string.Empty, str.Split('_', ' ', '-').Select(x => CapitalFirstLetter(x)));
        }
 
        public static string GetPrefix(string estimatorType)
        {
            if (estimatorType == "BinaryClassification")
            {
                return "BinaryClassification.Trainers";
            }
            if (estimatorType == "MultiClassification")
            {
                return "MulticlassClassification.Trainers";
            }
            if (estimatorType == "Regression")
            {
                return "Regression.Trainers";
            }
            if (estimatorType == "Ranking")
            {
                return "Ranking.Trainers";
            }
            if (estimatorType == "OneVersusAll")
            {
                return "BinaryClassification.Trainers";
            }
            if (estimatorType == "Recommendation")
            {
                return "Recommendation().Trainers";
            }
            if (estimatorType == "Transforms")
            {
                return "Transforms";
            }
            if (estimatorType == "Categorical")
            {
                return "Transforms.Categorical";
            }
            if (estimatorType == "Conversion")
            {
                return "Transforms.Conversion";
            }
            if (estimatorType == "Text")
            {
                return "Transforms.Text";
            }
            if (estimatorType == "Calibrators")
            {
                return "BinaryClassification.Calibrators";
            }
            if (estimatorType == "Forecasting")
            {
                return "Forecasting";
            }
 
            throw new NotImplementedException();
        }
    }
}