using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using TLang.Lexer;
namespace TLang.Parser
{
    public class Parse
    {
        private Parse(LexContext ctx)
        {
            Context = ctx;
        }
        private LexContext Context {get;set;}
        private Node Node {get;set;}
        private void ParseNodeRoot()
        {
            Node = ParseNode(true);
        }
        public static Node ParseFromLexContext(params LexContext[] ctx)
        {
            if(ctx.Length > 0)
            {
                var ctx2 = ctx[0];
                for(int i = 1;i<ctx.Length;i++)
                {
                    ctx2 += ctx[i];
                }
                Parse p=new Parse(ctx2);
                p.ParseNodeRoot();
                return p.Node;
            }
            return new Node();
        }
        public static Node ParseFromTextReader(TextReader reader,string filename="memory.tlang")
        {
            var lexed = Lex.GetTokens(reader,filename);
            return ParseFromLexContext(lexed);
        }
        
        public static Node ParseFromFiles(params string[] filenames)
        {
            return ParseFromLexContext(filenames.Select<string,LexContext>(e=>Lex.GetTokensFromFile(e)).ToArray());
        }
        public static Node ParseFromString(string str,string filename="memory.tlang")
        {
            var lexed=Lex.GetTokensFromString(str,filename);
            return ParseFromLexContext(lexed);
        }

        private Node ParseNode(bool isRoot=false,bool inCase=false)
        {   
            
            ScopeNode node = new ScopeNode();
            node.LineInfo = Context.CurrentLineInfo;
            

            while(Context.Offset < Context.Tokens.Count && (isRoot || !Context.NextEntries(true,"}").Success))
            {
                if(Context.NextEntries(true,"{").Success)
                {
                    node.Add(ParseNode());
                }
                node.Add(ParseAssigable());
            }

            return node;
        }

        private Node ParseAssigable()
        {
            Node expr = ParseLOr();
            while(Context.NextEntryIsAnyOf(true,out var token,"=","+=","-=","*=","/=","%=","|=","&=","^=","^^="))
            {
                if(token.Text == "=")
                {
                    var symbolNode = expr as SymbolNode;
                    if(symbolNode == null) throw new CompilerError("Assigning variable to something that is not a symbol",expr);
                    
                    expr = new SetVariableNode(symbolNode,ParseLOr()){LineInfo=token.Position};
                }
                if(token.Text == "+=")
                {
                    var symbolNode = expr as SymbolNode;
                    if(symbolNode == null) throw new CompilerError("Assigning variable to something that is not a symbol",expr);

                    expr = new SetVariableNode(symbolNode,new AddNode(new GetVariableNode(symbolNode.Name),ParseLOr())){LineInfo=token.Position};
                }
                if(token.Text == "-=")
                {
                    var symbolNode = expr as SymbolNode;
                    if(symbolNode == null) throw new CompilerError("Assigning variable to something that is not a symbol",expr);

                    expr = new SetVariableNode(symbolNode,new SubtractNode(new GetVariableNode(symbolNode.Name),ParseLOr())){LineInfo=token.Position};
                }
                if(token.Text == "*=")
                {
                    var symbolNode = expr as SymbolNode;
                    if(symbolNode == null) throw new CompilerError("Assigning variable to something that is not a symbol",expr);

                    expr = new SetVariableNode(symbolNode,new MultiplyNode(new GetVariableNode(symbolNode.Name),ParseLOr())){LineInfo=token.Position};
                }
                if(token.Text == "/=")
                {
                    var symbolNode = expr as SymbolNode;
                    if(symbolNode == null) throw new CompilerError("Assigning variable to something that is not a symbol",expr);

                    expr = new SetVariableNode(symbolNode,new DivideNode(new GetVariableNode(symbolNode.Name),ParseLOr())){LineInfo=token.Position};
                }
                if(token.Text == "%=")
                {
                    var symbolNode = expr as SymbolNode;
                    if(symbolNode == null) throw new CompilerError("Assigning variable to something that is not a symbol",expr);

                    expr = new SetVariableNode(symbolNode,new ModuloNode(new GetVariableNode(symbolNode.Name),ParseLOr())){LineInfo=token.Position};
                }
                if(token.Text == "|=")
                {
                    var symbolNode = expr as SymbolNode;
                    if(symbolNode == null) throw new CompilerError("Assigning variable to something that is not a symbol",expr);

                    expr = new SetVariableNode(symbolNode,new BOrNode(new GetVariableNode(symbolNode.Name),ParseLOr())){LineInfo=token.Position};
                }
                if(token.Text == "&=")
                {
                    var symbolNode = expr as SymbolNode;
                    if(symbolNode == null) throw new CompilerError("Assigning variable to something that is not a symbol",expr);

                    expr = new SetVariableNode(symbolNode,new BAndNode(new GetVariableNode(symbolNode.Name),ParseLOr())){LineInfo=token.Position};
                }
                if(token.Text == "^=")
                {
                    var symbolNode = expr as SymbolNode;
                    if(symbolNode == null) throw new CompilerError("Assigning variable to something that is not a symbol",expr);

                    expr = new SetVariableNode(symbolNode,new XOrNode(new GetVariableNode(symbolNode.Name),ParseLOr())){LineInfo=token.Position};
                }
                if(token.Text == "^^=")
                {
                    var symbolNode = expr as SymbolNode;
                    if(symbolNode == null) throw new CompilerError("Assigning variable to something that is not a symbol",expr);

                    expr = new SetVariableNode(symbolNode,new PowNode(new GetVariableNode(symbolNode.Name),ParseLOr())){LineInfo=token.Position};
                }
            }
            return expr;
        }

        private Node ParseLOr()
        {
            Node expr = ParseLAnd();
            while(Context.NextEntryIsAnyOf(true,out var token,"||"))
            {
                
                    
                    expr = new LOrNode(expr,ParseLAnd()){LineInfo=token.Position};
                
            }
            return expr;
        }

        private Node ParseLAnd()
        {
            Node expr = ParseBOr();
            while(Context.NextEntryIsAnyOf(true,out var token,"&&"))
            {
                
                    
                    expr = new LAndNode(expr,ParseBOr()){LineInfo=token.Position};
                
            }
            return expr;
        }

        private Node ParseBOr()
        {
            Node expr = ParseXOr();
            while(Context.NextEntryIsAnyOf(true,out var token,"|"))
            {
                
                    
                    expr = new BOrNode(expr,ParseXOr()){LineInfo=token.Position};
                
            }
            return expr;
        }

        private Node ParseXOr()
        {
            Node expr = ParseBAnd();
            while(Context.NextEntryIsAnyOf(true,out var token,"^"))
            {
                
                    
                    expr = new XOrNode(expr,ParseBAnd()){LineInfo=token.Position};
                
            }
            return expr;
        }

        private Node ParseBAnd()
        {
            Node expr = ParseEq();
            while(Context.NextEntryIsAnyOf(true,out var token,"&"))
            {
                
                    
                    expr = new BAndNode(expr,ParseEq()){LineInfo=token.Position};
                
            }
            return expr;        
        }

        private Node ParseEq()
        {
            Node expr = ParseRo();
            while(Context.NextEntryIsAnyOf(true,out var token,"==","!="))
            {
                
                if(token.Text == "==")
                {
                     expr = new EqualsNode(expr,ParseRo()){LineInfo=token.Position};
                }
                if(token.Text == "!=")
                {
                    expr = new NotEqualsNode(expr,ParseRo()){LineInfo=token.Position};
                }
                   
                
            }
            return expr;    
        }

        private Node ParseRo()
        {
            Node expr = ParseRo();
            while(Context.NextEntryIsAnyOf(true,out var token,"<","<=",">",">="))
            {
                
                if(token.Text == "<")
                {
                     expr = new LessThanNode(expr,ParseShift()){LineInfo=token.Position};
                }
                if(token.Text == "<=")
                {
                    expr = new LessThanEqualsNode(expr,ParseShift()){LineInfo=token.Position};
                }
                if(token.Text == ">")
                {
                     expr = new GreaterThanNode(expr,ParseShift()){LineInfo=token.Position};
                }
                if(token.Text == ">=")
                {
                    expr = new GreaterThanEqualsNode(expr,ParseShift()){LineInfo=token.Position};
                }
                
            }
            return expr;               
        }
        private Node ParseShift()
        {
            Node expr = ParseSum();
            while(Context.NextEntryIsAnyOf(true,out var token,"<<",">>"))
            {
                
                if(token.Text == "<<")
                {
                     expr = new LeftShiftNode(expr,ParseSum()){LineInfo=token.Position};
                }
                if(token.Text == ">>")
                {
                    expr = new RightShiftNode(expr,ParseSum()){LineInfo=token.Position};
                }
                   
                
            }
            return expr;    
        }

        private Node ParseSum()
        {
            Node expr = ParseFactor();
            while(Context.NextEntryIsAnyOf(true,out var token,"+","-"))
            {
                
                if(token.Text == "+")
                {
                     expr = new AddNode(expr,ParseFactor()){LineInfo=token.Position};
                }
                if(token.Text == "-")
                {
                    expr = new SubtractNode(expr,ParseFactor()){LineInfo=token.Position};
                }
                   
                
            }
            return expr; 
        }

        private Node ParseFactor()
        {
            Node expr = ParseExpo();
            while(Context.NextEntryIsAnyOf(true,out var token,"*","/","%"))
            {
                
                if(token.Text == "*")
                {
                     expr = new MultiplyNode(expr,ParseExpo()){LineInfo=token.Position};
                }
                if(token.Text == "/")
                {
                    expr = new DivideNode(expr,ParseExpo()){LineInfo=token.Position};
                }
                if(token.Text == "%")
                {
                    expr = new ModuloNode(expr,ParseExpo()){LineInfo=token.Position};
                }
                
            }
            return expr;
        }
        private Node ParseExpo()
        {
             Node expr = ParseValue();
            while(Context.NextEntryIsAnyOf(true,out var token,"^^"))
            {
                expr = new PowNode(expr,ParseValue());
            }
            return expr;
        }

        private Node ParseValue()
        {
            var doc = Context.PopDocumentation();
            var token = Context.NextEntry;
            if(token.IsString) return new StringNode(token.Text){LineInfo = token.Position};
            if(token.IsChar) return new CharNode(token.Text){LineInfo = token.Position};
            if(token.Text == "(")
            {
                var assignable = ParseAssigable();
                assignable.LineInfo = token.Position;
                if(!Context.NextEntries(true,")").Success) throw new CompilerError("symbol must be a ')'",assignable);
                return assignable;
            }
            if(token.Text == "class")
            {
                ClassNode classInstance = new ClassNode();
                classInstance.Name = Context.NextEntry.Text;
                classInstance.Documentation = doc;

               
                if(Context.NextEntries(true,":").Success)
                {
                    
                    classInstance.InheritsFrom = Context.NextEntry.Text;

                }
                Context.NextEntries(true,"{");
                while(Context.MoreTokens && !Context.NextEntries(true,"}").Success)
                {
                    var doc2 = Context.PopDocumentation();
                    var token2 = Context.NextEntry;
                    var modifier = token2.Text;
                    if(Context.NextEntryIsAnyOf(true,out var token3,"func","abst"))
                    {
                        var name = Context.NextEntry.Text;
                        if(Context.NextEntries(true,"(").Success)
                        {
                            var pos = Context.PeekEntry.Position;
                            List<string> args=new List<string>();
                            while(!Context.NextEntries(true,")").Success)
                            {
                                if(Context.NextEntries(true,",").Success) continue;

                                if(Context.Offset < Context.Tokens.Count)
                                {
                                    var n0 = ParseNode();
                                    var n= n0 as GetVariableNode;
                                    if(n != null)
                                    {
                                        args.Add(n.Name);
                                    }
                                    else
                                    {
                                        throw new CompilerError("Argument must be a GetVariableNode",n0);
                                    }
                                }
                            }
                            ClassEntryNode nod=new ClassEntryNode(){LineInfo = token2.Position};
                            nod.Abstract = token3.Text == "abst";
                            nod.Documentation = doc2;
                            nod.Modifier = modifier;
                            nod.Name = name;
                            nod.InitialValue = new ClosureNode(args,ParseNode()){LineInfo = pos};
                            classInstance.Entries.Add(nod);
                        }
                    }
                    else
                    {
                        ClassEntryNode nod = new ClassEntryNode(){LineInfo = token2.Position};
                        nod.Documentation = doc2;
                        nod.Name = Context.NextEntry.Text;
                        if(!Context.NextEntries(true,"=").Success) throw new CompilerError("Invalid member",classInstance);

                        nod.Modifier = modifier;
                        nod.InitialValue = ParseNode();
                        classInstance.Entries.Add(nod);
                    }
                   
                }
                return classInstance;
            }
            if(token.Text == "brk" || token.Text == "break")
            {
                return new BreakNode(){LineInfo = token.Position};
            }
            if(token.Text == "cont" || token.Text == "continue")
            {
                return new ContinueNode(){LineInfo = token.Position};
            }
            if(token.Text == "ret" || token.Text == "return") 
            {
                return new ReturnNode(ParseNode()){LineInfo = token.Position};
            }
            if(token.Text == "case")
            {
                var expr = ParseNode();
                if(!Context.NextEntries(true,":").Success) throw new CompilerError("Missing :",expr);
                return new CaseNode(expr,ParseNode(true,true)){LineInfo = token.Position};
            }
            if(token.Text == "default")
            {
                var cur = Context.CurrentLineInfo;
                var r=Context.NextEntries(true,":");
                if(!r.Success) throw new CompilerError("Missing :",new Node(){LineInfo = cur});
                return new DefaultNode(ParseNode(true,true)){LineInfo = token.Position};
            }
            if(token.Text == "-")
            {
                return new NegativeNode(ParseNode());
            }
            if(token.Text == "~")
            {
                return new BitwiseNotNode(ParseNode());
            }
            if(token.Text == "!")
            {
                return new NotNode(ParseNode());
            }
            if(long.TryParse(token.Text,out var number))
            {
                if(Context.NextEntries(true,".").Success)
                {
                    var entry=Context.NextEntry;
                    if(!entry.IsChar && !entry.IsDocumentation && !entry.IsEmpty && !entry.IsString && double.TryParse($"{number}.{entry.Text}",out var number2))
                    {
                        return new ConstNumberNode(number2);
                    }
                }
                
                //just a long
                return new ConstNumberNode(number);
                
            }
            else 
            {
                if(Context.NextEntries(true,"(").Success)
                {
                    if(token.Text == "func")
                    {
                        List<string> args=new List<string>();
                        while(!Context.NextEntries(true,")").Success)
                        {
                            if(Context.NextEntries(true,",").Success) continue;

                            if(Context.Offset < Context.Tokens.Count)
                            {
                                var n0 = ParseNode();
                                var n= n0 as GetVariableNode;
                                if(n != null)
                                {
                                    args.Add(n.Name);
                                }
                                else
                                {
                                    throw new CompilerError("Argument must be a GetVariableNode",n0);
                                }
                            }
                        }
                        return new ClosureNode(args,ParseNode());
                    }
                    else if(token.Text == "for")
                    {
                        Node init=new Node();
                        Node condition = new Node();
                        Node inc = new Node();
                        Node body = new Node();
                        if(Context.MoreTokens && (Context.PeekEntry.Text != ")" || Context.PeekEntry.Text != ";"))
                        {
                            init = ParseNode();
                        }
                        Context.NextEntries(true,";");
                        if(Context.MoreTokens && (Context.PeekEntry.Text != ")" || Context.PeekEntry.Text != ";"))
                        {
                            condition = ParseNode();
                        }
                        Context.NextEntries(true,";");
                        if(Context.MoreTokens && (Context.PeekEntry.Text != ")" || Context.PeekEntry.Text != ";"))
                        {
                            inc = ParseNode();
                        }
                        Context.NextEntries(true,")");
                        if(Context.MoreTokens)
                            body = ParseNode();
                        
                        return new ForLoopNode(init,condition,inc,body);
                    }
                    else if(token.Text == "each")
                    {
                        SymbolNode varNode = new GetVariableNode("item"){LineInfo = token.Position};
                        Node expr = ParseNode();
                        
                        if(Context.NextEntries(true,":").Success)
                        {
                            var vNode = expr as SymbolNode;
                            if(vNode != null)
                            {
                                varNode = vNode;
                            }
                            expr = ParseNode();

                        }
                        Context.NextEntries(true,")");
                        if(Context.MoreTokens)
                        {
                            return new EachLoopNode(varNode,expr,ParseNode()){LineInfo = token.Position};
                        }
                    }
                    else if(token.Text == "switch")
                    {
                        Node cond = ParseNode();
                        Context.NextEntries(true,")");
                        Node body = new Node();
                        if(!Context.NextEntries(true,";").Success)
                        {
                            body = ParseNode();
                        }
                        var scopeBody = body as ScopeNode;
                        if(scopeBody != null)
                        {
                            scopeBody.IsSwitchScope=true;
                            scopeBody.SwitchCondition = cond;
                        }
                        return body;
                    }
                    else if(token.Text == "while" || token.Text == "do")
                    {
                        Node cond = ParseNode();
                        Context.NextEntries(true,")");
                        Node body = new Node();
                        if(!Context.NextEntries(true,";").Success)
                        {
                            body = ParseNode();
                        }
                        return new WhileLoop(cond,body,token.Text == "do");
                    }
                    else if(token.Text == "if")
                    {
                        Node cond = ParseNode();
                        Context.NextEntries(true,")");
                        Node yes = new Node();
                        Node no = new Node();
                        if(Context.MoreTokens && !Context.NextEntries(false,"else").Success)
                        {
                            yes = ParseNode();
                        }
                        if(Context.MoreTokens && Context.NextEntries(true,"else").Success)
                        {
                            no = ParseNode();
                        }
                        return new IfNode(cond,yes,no);
                    }
                    else
                    {
                        var fcall = new FunctionCallNode(token.Text){LineInfo = token.Position};
                        SymbolNode ret = fcall;
                        while(Context.MoreTokens && !Context.NextEntries(true,")").Success)
                        {
                            if(Context.NextEntries(true,",").Success) continue;
                            fcall.Arguments.Add(ParseNode());
                        }   
                        while(Context.MoreTokens && Context.NextEntries(true,"[").Success)
                        {
                            var p = ParseNode();
                            ret = new GetArrayNode(ret,p){LineInfo = p.LineInfo};
                            Context.NextEntries(true,"]");
                        }
                        while(Context.MoreTokens && Context.NextEntries(true,".").Success)
                        {
                            var token2 = Context.NextEntry;

                            if(Context.MoreTokens && Context.NextEntries(true,"(").Success)
                            {
                                var mCall = new MethodCallNode(ret,token2.Text){LineInfo=token2.Position};
                                ret = mCall;
                                while(Context.MoreTokens &&  !Context.NextEntries(true,")").Success)
                                {
                                    if(Context.NextEntries(true,",").Success) continue;
                                    mCall.Arguments.Add(ParseNode());
                                }
                            }
                            else if(Context.MoreTokens && Context.NextEntries(false,"[").Success)
                            {
                                while(Context.MoreTokens && Context.NextEntries(true,"[").Success)
                                {
                                    var p = ParseNode();
                                    ret = new GetArrayNode(ret,p){LineInfo = p.LineInfo};
                                    Context.NextEntries(true,"]");
                                }
                            }
                            else
                            {
                                ret = new GetMemberNode(ret,token2.Text){LineInfo = token2.Position};
                            }
                            
                        }
                        if(Context.MoreTokens && Context.NextEntries(true,"++").Success)
                        {
                            var r = new PostFixIncrementNode(ret){LineInfo = ret.LineInfo};
                            ret = r;
                        }
                        if(Context.MoreTokens && Context.NextEntries(true,"--").Success)
                        {
                            var r = new PostFixDecrementNode(ret){LineInfo = ret.LineInfo};
                            ret = r;
                        }
                        return ret;
                    }
                }
                else{
                    SymbolNode ret = new NullNode();
                    if(token.Text == "func")
                    {
                        var res = new GetVariableNode(Context.NextEntry.Text);
                        if(Context.MoreTokens && Context.NextEntries(true,"(").Success)
                        {
                            List<string> args=new List<string>();
                            while(!Context.NextEntries(true,")").Success)
                            {
                                if(Context.NextEntries(true,",").Success) continue;

                                if(Context.Offset < Context.Tokens.Count)
                                {
                                    var n0 = ParseNode();
                                    var n= n0 as GetVariableNode;
                                    if(n != null)
                                    {
                                        args.Add(n.Name);
                                    }
                                    else
                                    {
                                        throw new CompilerError("Argument must be a GetVariableNode",n0);
                                    }
                                }
                            }
                            return new SetVariableNode( res,new ClosureNode(args,ParseNode()));
                        }
                    }
                    if(token.Text == "null")
                    {
                        ret=new NullNode(){LineInfo=token.Position};
                    }
                    else if(token.Text == "undefined")
                    {
                        ret = new UndefinedNode(){LineInfo=token.Position};
                    }
                    else if(token.Text == "true")
                    {
                        ret = new TrueNode(){LineInfo=token.Position};
                    }
                    else if(token.Text == "false")
                    {
                        ret = new FalseNode(){LineInfo=token.Position};
                    }
                    else
                    {
                        ret = new GetVariableNode(token.Text){LineInfo = token.Position};
                    }

                    while(Context.MoreTokens && Context.NextEntries(true,"[").Success)
                        {
                            var p = ParseNode();
                            ret = new GetArrayNode(ret,p){LineInfo = p.LineInfo};
                            Context.NextEntries(true,"]");
                        }
                        while(Context.MoreTokens && Context.NextEntries(true,".").Success)
                        {
                            var token2 = Context.NextEntry;

                            if(Context.MoreTokens && Context.NextEntries(true,"(").Success)
                            {
                                var mCall = new MethodCallNode(ret,token2.Text){LineInfo=token2.Position};
                                ret = mCall;
                                while(Context.MoreTokens &&  !Context.NextEntries(true,")").Success)
                                {
                                    if(Context.NextEntries(true,",").Success) continue;
                                    mCall.Arguments.Add(ParseNode());
                                }
                            }
                            else if(Context.MoreTokens && Context.NextEntries(false,"[").Success)
                            {
                                while(Context.MoreTokens && Context.NextEntries(true,"[").Success)
                                {
                                    var p = ParseNode();
                                    ret = new GetArrayNode(ret,p){LineInfo = p.LineInfo};
                                    Context.NextEntries(true,"]");
                                }
                            }
                            else
                            {
                                ret = new GetMemberNode(ret,token2.Text){LineInfo = token2.Position};
                            }
                            
                        }
                        if(Context.MoreTokens && Context.NextEntries(true,"++").Success)
                        {
                            var r = new PostFixIncrementNode(ret){LineInfo = ret.LineInfo};
                            ret = r;
                        }
                        if(Context.MoreTokens && Context.NextEntries(true,"--").Success)
                        {
                            var r = new PostFixDecrementNode(ret){LineInfo = ret.LineInfo};
                            ret = r;
                        }
                        return ret;

                }
            }
        
            throw new CompilerError("End of ParseValue func",new Node(){LineInfo = token.Position});
        }

    }
}