using System;
using System.Collections.Generic;
using System.Text;
using Upsilon;
using Upsilon.Evaluator;
using Upsilon.StandardLibraries;

namespace Ycicle
{
    internal static class Program
    {
        private static void Main()
        {
            Console.WriteLine("Upsilon REPL");
            Script script = null;
            var options = new ScriptOptions()
            {
                ThrowExceptionOnError = false
            };

            while (true)
            {
                Console.Write("» ");
                var input = Console.ReadLine();
                if (input == "exit") return;
                script = script == null
                    ? Executor.ParseInput(input, options)
                    : Executor.ContinueWith(script, input);

                if (script.Diagnostics.Errors.Count > 0)
                {
                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.WriteLine("Errors were found during parsing");
                    foreach (var diagnosticsMessage in script.Diagnostics.Errors)
                    {
                        LogMessage(DiagnosticLevel.Error, diagnosticsMessage);
                    }
                    Console.ResetColor();
                    continue;
                }
                script.Bind();
                if (script.Diagnostics.Errors.Count > 0)
                {
                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.WriteLine("Errors were found during parsing");
                    foreach (var diagnosticsMessage in script.Diagnostics.Errors)
                    {
                        LogMessage(DiagnosticLevel.Error, diagnosticsMessage);
                    }
                    Console.ResetColor();
                    continue;
                }

                //Console.WriteLine(script.PrettyPrintSyntaxTree());
                var evaluate = script.Evaluate();

                if (script.Diagnostics.Errors.Count > 0)
                {
                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.WriteLine("Errors were found during evaluating");
                    foreach (var diagnosticsMessage in script.Diagnostics.Errors)
                    {
                        LogMessage(DiagnosticLevel.Error, diagnosticsMessage);
                    }
                    Console.ResetColor();
                }
                else
                {
                    foreach (var diagnosticsMessage in script.Diagnostics.Warnings)
                    {
                        LogMessage(DiagnosticLevel.Warning, diagnosticsMessage);
                    }
                    Console.ResetColor();

                    if (evaluate == null)
                        continue;
                    Console.ForegroundColor = ConsoleColor.Cyan;

                    Console.WriteLine(ParseEvaluated(evaluate));
                    Console.ResetColor();
                }
            }
        }

        private static void LogMessage(DiagnosticLevel level, DiagnosticsMessage message)
        {
            if (level == DiagnosticLevel.Error)
                Console.ForegroundColor = ConsoleColor.Red;
            else if (level == DiagnosticLevel.Warning)
                Console.ForegroundColor = ConsoleColor.DarkYellow;

            Console.WriteLine(message.Message);

            Console.ForegroundColor = ConsoleColor.Gray;
            Console.Write(message.GetDiagnosticPosition() + " ");
            Console.Write(message.LineBeforeError());

            if (level == DiagnosticLevel.Error)
                Console.ForegroundColor = ConsoleColor.Red;
            else if (level == DiagnosticLevel.Warning)
                Console.ForegroundColor = ConsoleColor.DarkYellow;

            Console.Write(message.AtError());

            Console.ForegroundColor = ConsoleColor.Gray;
            Console.Write(message.LineAfterError());
            Console.WriteLine();
        }

        private static string ParseEvaluated(object o, int jumps = 0)
        {
            var sb = new StringBuilder();
            if (o is Dictionary<string, object> dic)
            {
                for (var i = 0; i < jumps; i++) sb.Append("  ");
                sb.Append("{\n");
                foreach (var (key, value) in dic)
                {
                    for (var i = 0; i < jumps; i++) sb.Append("  ");
                    sb.Append("  {");
                    sb.Append("\"");
                    sb.Append(key);
                    sb.Append("\": ");
                    sb.Append(ParseEvaluated(value, jumps + 1));
                    sb.Append(" }");
                    sb.Append(",\n");
                }
                for (var i = 0; i < jumps; i++) sb.Append("  ");
                sb.Append("}\n");
            }
            else
            {
                sb.Append(o);
            }

            return sb.ToString();
        }
    }
}