using F4SD.DocuEngine.DocuEngineParser.Exceptions;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;

namespace F4SD.DocuEngine.DocuEngineParser.ContentBlock
{
    internal partial class ContentBlock
    {
        private void ParseSwitchCommand(ref int index)
        {
            string tempString = "";
            bool foundTrueCase = false;
            bool foundAllCases = false;
            int tempIndex = 0;
            (string VariableType, string VariableName) switchVariable = ParseSwitchBlock(ref index);
            while (!foundAllCases)
            {
                tempIndex = index;
                SkipWhiteSpace(ref index);
                if (DocuTemplate.Substring(index, 4).Equals("case"))
                {
                    index += 4;
                    tempString += ParseCaseBlock(ref index, switchVariable, out var isCaseTrue);
                    if (isCaseTrue && !foundTrueCase)
                    {
                        foundTrueCase = true;
                        parsingContext.Append(tempString);
                    }
                    tempString = "";
                }
                else
                {
                    foundAllCases = true;
                    index = tempIndex;
                }
            }
            tempIndex = index;
            SkipWhiteSpace(ref index);
            if (DocuTemplate.Substring(index, 7).Equals("default"))
            {
                index += 7;
                tempString += ParseDefaultBlock(ref index);
                if (!foundTrueCase)
                {
                    foundTrueCase = true;
                    parsingContext.Append(tempString);
                    tempString = "";
                }
            }
            else
            {
                index = tempIndex;
            }
        }

        private (string VariableType, string VariableName) ParseSwitchBlock(ref int index)
        {
            string variableName = "";
            string variableType = "";
            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);
            if (!DocuTemplate.Substring(index, 2).Equals("{{"))
            {
                throw new SyntaxErrorException("{{", DocuTemplate.Substring(index, 2));
            }
            index += 2;
            return (variableType, variableName);
        }

        private string ParseCaseBlock(ref int index, (string VariableType, string VariableName) switchVariable, out bool isCaseTrue)
        {
            string returnString = "";
            isCaseTrue = false;
            string value = "";
            SkipWhiteSpace(ref index);
            if (!(DocuTemplate.ElementAtOrDefault(index).Equals('(')))
            {
                throw new SyntaxErrorException("(", DocuTemplate.ElementAtOrDefault(index).ToString());
            }
            index++;
            SkipWhiteSpace(ref index);
            value = ParseValue(ref index);
            isCaseTrue = CheckCondition(switchVariable.VariableType, switchVariable.VariableName, '=', 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 ParseDefaultBlock(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;
        }
    }
}