using C4IT.F4SD.DisplayFormatting;
using F4SD.DocuEngine.DocuEngineParser.Exceptions;
using System.ComponentModel;
using System.Linq;
using System.Text.RegularExpressions;

namespace F4SD.DocuEngine.DocuEngineParser.ContentBlock
{
    internal partial class ContentBlock
    {
        private string ParseVariableType(ref int index)
        {
            bool foundTypeEnd = false;
            string variableType = "";
            while (!foundTypeEnd)
            {
                char c = DocuTemplate.ElementAt(index);
                if (char.IsLetter(c))
                {
                    variableType += c;
                    index++;
                }
                else
                {
                    foundTypeEnd = true;
                }
            }
            return variableType;
        }

        private string ParseVariableName(ref int index)
        {
            bool foundVariableEnd = false;
            string variableName = "";
            while (!foundVariableEnd)
            {
                char c = DocuTemplate.ElementAt(index);
                if (char.IsLetterOrDigit(c) || c == '.')
                {
                    variableName += c;
                    index++;
                }
                else
                {
                    foundVariableEnd = true;
                }
            }
            return variableName;
        }

        private void SkipWhiteSpace(ref int index)
        {
            bool foundNonWhiteSpace = false;
            while (!foundNonWhiteSpace)
            {
                char c = DocuTemplate.ElementAt(index);
                if (char.IsWhiteSpace(c))
                {
                    index++;
                }
                else
                {
                    foundNonWhiteSpace = true;
                }
            }
        }

        private string ParseDisplayType(ref int index)
        {
            bool foundDisplayTypeEnd = false;
            string displayType = "";
            while (!foundDisplayTypeEnd)
            {
                char c = DocuTemplate.ElementAt(index);
                if (char.IsLetterOrDigit(c))
                {
                    displayType += c;
                    index++;
                }
                else
                {
                    foundDisplayTypeEnd = true;
                }
            }
            return displayType;
        }

        private string SubstituteVariable(string variableName, RawValueType? displayType)
        {
            IRawValueFormatter rawValueFormatter = new RawValueFormatter();

            var property = Container.GetPropertyByName(variableName);
            if (property == null)
            {
                //Syntax Error
            }
            if (displayType != null)
            {
                return rawValueFormatter.GetDisplayValue(property.Value, (RawValueType)displayType, null);
            }
            else if (property.ValueType != null)
            {
                return rawValueFormatter.GetDisplayValue(property.Value, (RawValueType)property.ValueType, null);
            }
            else
            {
                return property.Value.ToString();
            }
        }

        private char ParseComparator(ref int index)
        {
            char comparator = DocuTemplate.ElementAtOrDefault(index);
            if (!(comparator == '<' || comparator == '>' || comparator == '=' || comparator == '!'))
            {
                throw new SyntaxErrorException("<\" / \">\" / \"=\" / \"!", comparator.ToString());
            }
            index++;
            return comparator;
        }

        private string ParseValue(ref int index)
        {
            string value = "";
            string pattern = @"("")(.*?)(""\s*\))";
            Regex regex = new Regex(pattern);
            Match match = regex.Match(DocuTemplate, index);
            if (match.Success)
            {
                value = match.Groups[2].Value;
                string wholeMatch = match.Value.ToString();
                index += wholeMatch.Length;
            }
            else
            {
                throw new SyntaxErrorException("\"VariableName\")", "");
            }
            return value;
        }

        private bool CheckCondition(string variableType, string variableName, char comparator, string value)
        {
            string stringVariable = "";
            var property = Container.GetPropertyByName(variableName);
            if (property == null)
            {
                //Syntax Error
            }
            stringVariable = property.Value.ToString();
            switch (variableType)
            {
                case "string":
                    if (!(comparator == '=' || comparator == '!'))
                    {
                        throw new SyntaxErrorException("=\" / \"!", comparator.ToString());
                    }
                    return CompareStrings(stringVariable, comparator, value);
                case "int":
                    if (!(comparator == '<' || comparator == '>' || comparator == '=' || comparator == '!'))
                    {
                        throw new SyntaxErrorException("<\" / \">\" / \"=\" / \"!", comparator.ToString());
                    }
                    if (!(int.TryParse(value, out var intValue)))
                    {
                        throw new VariableErrorException(value, "int");
                    }
                    stringVariable = stringVariable.Replace("\"", "");
                    if (!(int.TryParse(stringVariable, out var intVariable)))
                    {
                        throw new VariableErrorException(stringVariable, "int");
                    }
                    return CompareIntegers(intVariable, comparator, intValue);
                case "bool":
                    if (!(comparator == '=' || comparator == '!'))
                    {
                        throw new SyntaxErrorException("=\" / \"!", comparator.ToString());
                    }
                    if (!(bool.TryParse(value, out var boolValue)))
                    {
                        throw new VariableErrorException(value, "bool");
                    }
                    if (!(bool.TryParse(stringVariable, out var boolVariable)))
                    {
                        throw new VariableErrorException(stringVariable, "bool");
                    }
                    return CompareBooleans(boolVariable, comparator, boolValue);
                default:
                    throw new SyntaxErrorException("string\" / \"int\" / \"bool", variableType);
            }
        }

        private bool CompareStrings(string variable, char comparator, string value)
        {
            switch (comparator)
            {
                case '=':
                    if (variable == value)
                    {
                        return true;
                    }
                    else
                    {
                        return false;
                    }
                case '!':
                    if (variable != value)
                    {
                        return true;
                    }
                    else
                    {
                        return false;
                    }
                default:
                    return false;
            }
        }

        private bool CompareIntegers(int variable, char comparator, int value)
        {
            switch (comparator)
            {
                case '=':
                    if (variable == value)
                    {
                        return true;
                    }
                    else
                    {
                        return false;
                    }
                case '!':
                    if (variable != value)
                    {
                        return true;
                    }
                    else
                    {
                        return false;
                    }
                case '>':
                    if (variable > value)
                    {
                        return true;
                    }
                    else
                    {
                        return false;
                    }
                case '<':
                    if (variable < value)
                    {
                        return true;
                    }
                    else
                    {
                        return false;
                    }
                default:
                    return false;
            }
        }

        private bool CompareBooleans(bool variable, char comparator, bool value)
        {
            switch (comparator)
            {
                case '=':
                    if (variable == value)
                    {
                        return true;
                    }
                    else
                    {
                        return false;
                    }
                case '!':
                    if (variable != value)
                    {
                        return true;
                    }
                    else
                    {
                        return false;
                    }
                default:
                    return false;
            }
        }
    }
}