using F4SD.DocuEngine.DocuEngineParser.Exceptions;
using System.ComponentModel;
using System.Linq;

namespace F4SD.DocuEngine.DocuEngineParser.ContentBlock
{
    internal partial class ContentBlock
    {
        private void ParseIfCommand(ref int index)
        {
            string tempString = "";
            bool foundTrueCondition = false;
            bool foundAllElseIf = false;
            int tempIndex = 0;

            tempString = ParseIfBlock(ref index, out var isIfConditionTrue);
            if (isIfConditionTrue)
            {
                foundTrueCondition = true;
                parsingContext.Append(tempString);
            }
            tempString = "";
            while (!foundAllElseIf)
            {
                tempIndex = index;
                SkipWhiteSpace(ref index);
                if (DocuTemplate.Substring(index, 7).Equals("else-if"))
                {
                    index += 7;
                    tempString += ParseElseIfBlock(ref index, out var isElseIfConditionTrue);
                    if (isElseIfConditionTrue && !foundTrueCondition)
                    {
                        foundTrueCondition = true;
                        parsingContext.Append(tempString);
                    }
                    tempString = "";
                }
                else
                {
                    foundAllElseIf = true;
                    index = tempIndex;
                }
            }
            tempIndex = index;
            SkipWhiteSpace(ref index);
            if (DocuTemplate.Substring(index, 4).Equals("else"))
            {
                index += 4;
                tempString += ParseElseBlock(ref index);
                if (!foundTrueCondition)
                {
                    foundTrueCondition = true;
                    parsingContext.Append(tempString);
                    tempString = "";
                }
            }
            else
            {
                index = tempIndex;
            }
        }

        private string ParseIfBlock(ref int index, out bool isConditionTrue)
        {
            string returnString = "";
            string variableType = "";
            string variableName = "";
            char comparator;
            string value = "";
            SkipWhiteSpace(ref index);
            variableType += ParseVariableType(ref index);
            SkipWhiteSpace(ref index);
            if (!(DocuTemplate.ElementAtOrDefault(index).Equals(';')))
            {
                throw new SyntaxErrorException(";", DocuTemplate.ElementAtOrDefault(index).ToString());
            }
            index++;
            SkipWhiteSpace(ref index);
            variableName += ParseVariableName(ref index);
            SkipWhiteSpace(ref index);
            if (!(DocuTemplate.ElementAtOrDefault(index).Equals(';')))
            {
                throw new SyntaxErrorException(";", DocuTemplate.ElementAtOrDefault(index).ToString());
            }
            index++;
            SkipWhiteSpace(ref index);
            comparator = ParseComparator(ref index);
            SkipWhiteSpace(ref index);
            if (!(DocuTemplate.ElementAtOrDefault(index).Equals(';')))
            {
                throw new SyntaxErrorException(";", DocuTemplate.ElementAtOrDefault(index).ToString());
            }
            index++;
            SkipWhiteSpace(ref index);
            value += ParseValue(ref index);
            SkipWhiteSpace(ref index);
            isConditionTrue = CheckCondition(variableType, variableName, comparator, value);
            SkipWhiteSpace(ref index);
            if (!DocuTemplate.Substring(index, 2).Equals("{{"))
            {
                throw new SyntaxErrorException("{{", DocuTemplate.Substring(index, 2));
            }
            index += 2;
            ContentBlock contentBlock = new ContentBlock(DocuTemplate, Container);
            returnString += contentBlock.ParseContentBlock(ref index);
            return returnString;
        }

        private string ParseElseIfBlock(ref int index, out bool isConditionTrue)
        {
            string returnString = "";
            string variableType = "";
            string variableName = "";
            char comparator;
            string value = "";
            SkipWhiteSpace(ref index);
            if (!(DocuTemplate.ElementAt(index).Equals('(')))
            {
                throw new SyntaxErrorException("(", DocuTemplate.ElementAtOrDefault(index).ToString());
            }
            index++;
            SkipWhiteSpace(ref index);
            variableType += ParseVariableType(ref index);
            SkipWhiteSpace(ref index);
            if (!(DocuTemplate.ElementAtOrDefault(index).Equals(';')))
            {
                throw new SyntaxErrorException(";", DocuTemplate.ElementAtOrDefault(index).ToString());
            }
            index++;
            SkipWhiteSpace(ref index);
            variableName += ParseVariableName(ref index);
            SkipWhiteSpace(ref index);
            if (!(DocuTemplate.ElementAtOrDefault(index).Equals(';')))
            {
                throw new SyntaxErrorException(";", DocuTemplate.ElementAtOrDefault(index).ToString());
            }
            index++;
            SkipWhiteSpace(ref index);
            comparator = ParseComparator(ref index);
            SkipWhiteSpace(ref index);
            if (!(DocuTemplate.ElementAtOrDefault(index).Equals(';')))
            {
                throw new SyntaxErrorException(";", DocuTemplate.ElementAtOrDefault(index).ToString());
            }
            index++;
            SkipWhiteSpace(ref index);
            value += ParseValue(ref index);
            SkipWhiteSpace(ref index);
            isConditionTrue = CheckCondition(variableType, variableName, comparator, value);
            SkipWhiteSpace(ref index);
            if (!DocuTemplate.Substring(index, 2).Equals("{{"))
            {
                throw new SyntaxErrorException("{{", DocuTemplate.Substring(index, 2));
            }
            index += 2;
            ContentBlock contentBlock = new ContentBlock(DocuTemplate, Container);
            returnString += contentBlock.ParseContentBlock(ref index);
            return returnString;
        }

        private string ParseElseBlock(ref int index)
        {
            string returnString = "";
            SkipWhiteSpace(ref index);
            if (!DocuTemplate.Substring(index, 2).Equals("{{"))
            {
                throw new SyntaxErrorException("{{", DocuTemplate.Substring(index, 2));
            }
            index += 2;
            ContentBlock contentBlock = new ContentBlock(DocuTemplate, Container);
            returnString += contentBlock.ParseContentBlock(ref index);
            return returnString;
        }
    }
}