package nl.saxion.cos;

import org.antlr.v4.runtime.tree.ParseTreeProperty;

public class CodeGenerator extends MusicLangBaseVisitor<Void> {
    private JasminBytecode jasminCode;

    public JasminBytecode getJasminCode() {
        return jasminCode;
    }

    private ParseTreeProperty<DataType> types;
    private ParseTreeProperty<Symbol> symbols;

    private int unique = 0;

    private String nextLabel() {
        return "L" + ++unique;
    }

    private String ifLabel = "";
    private String doneLabel = "";
    private boolean isLast = false;


    public CodeGenerator(JasminBytecode jasminCode, ParseTreeProperty<DataType> types,
                         ParseTreeProperty<Symbol> symbols) {
        this.jasminCode = jasminCode;
        this.types = types;
        this.symbols = symbols;
    }

    private int localStorageCounter = 0;

    private int getNextIndex() {
        return ++localStorageCounter;
    }

    @Override
    public Void visitProgram(MusicLangParser.ProgramContext ctx) {

        for (MusicLangParser.FunctionContext f : ctx.function()) {
            visit(f);
        }
        jasminCode.add(".method public static main([Ljava/lang/String;)V");
        jasminCode.add(".limit stack 99");
        jasminCode.add(".limit locals 99");
        jasminCode.add("");

        visit(ctx.main_method);

        jasminCode.add("return");
        jasminCode.add(".end method");
        return null;
    }

    @Override
    public Void visitFunction(MusicLangParser.FunctionContext ctx) {
        String returnType = ";";
        if (ctx.type() != null) {
            returnType = "I";
        } else {
            returnType = "V";
        }
        String paramTypes = "";
//        for (MusicLangParser.ParametersContext param : ctx.parameters()) {
//            if (param.type().getText().equals("number")) {
//                paramTypes += "I";
//            }
//        }

        if (ctx.parameters() != null) {
            for (MusicLangParser.TypeContext t : ctx.parameters().type()) {
                if (t.getText().equals("number")) {
                    paramTypes += "I";
                }
            }
        }


        jasminCode.add(".method public static " + ctx.IDENTIFIER() + "(" + paramTypes + ")" + returnType);
        jasminCode.add(".limit stack 99");
        jasminCode.add(".limit locals 99");
        jasminCode.add("");


        if (!ctx.statement().isEmpty()) {
            for (MusicLangParser.StatementContext stat : ctx.statement()) {
                visit(stat);
            }
        }

        if (returnType.equals("I")) {
            returnType = "i";
        } else {
            returnType = "";
        }

        if (ctx.expression() != null) {
            visit(ctx.expression());
        }

        jasminCode.add(returnType + "return");
        jasminCode.add(".end method");

        return null;
    }


    @Override
    public Void visitDclNum(MusicLangParser.DclNumContext ctx) {

        visit(ctx.num_decl());

        return null;
    }

    @Override
    public Void visitDclSound(MusicLangParser.DclSoundContext ctx) {

        visit(ctx.sound_decl());

        return null;
    }

    @Override
    public Void visitSound_decl(MusicLangParser.Sound_declContext ctx) {


//        jasminCode.add("    ldc  \"" + ctx.SOUND_VALUE().getText() + "\"");
//        jasminCode.add("    astore " + getNextIndex());
        String soundAsString = ctx.SOUND_VALUE().getText();
        int soundAsNum = soundToNumber(soundAsString);
        jasminCode.add("    ldc  " + soundAsNum);
        jasminCode.add("    istore " + getNextIndex());
        return null;
    }

    @Override
    public Void visitNum_decl(MusicLangParser.Num_declContext ctx) {

        if (ctx.INT_VALUE() != null) {
            jasminCode.add("    ldc " + ctx.INT_VALUE().getText());
        } else if (ctx.scan_num() != null) {
            visit(ctx.scan_num());
        }

        jasminCode.add("    istore " + getNextIndex());
        return null;
    }

    @Override
    public Void visitDclNote(MusicLangParser.DclNoteContext ctx) {
        visit(ctx.note_decl());
        return null;
    }

    @Override
    public Void visitNote_decl(MusicLangParser.Note_declContext ctx) {
        jasminCode.add("    new nl/saxion/cos/Note");
        jasminCode.add("    dup");


        jasminCode.add("    ldc  \"" + ctx.SOUND_VALUE().getText() + "\"");

        jasminCode.add("    ldc " + ctx.INT_VALUE().getText());


        jasminCode.add("   invokenonvirtual nl/saxion/cos/Note/<init>(Ljava/lang/String;I)V");

        jasminCode.add("    astore " + getNextIndex());

        return null;
    }

    @Override
    public Void visitPlay(MusicLangParser.PlayContext ctx) {
        jasminCode.add("getstatic java/lang/System/out Ljava/io/PrintStream;");
        MusicLangParser.ExpressionContext expression = ctx.expression();
        visit(expression);
        System.out.println("type of expresiion " + types.get(expression));

        if (types.get(expression) == DataType.NUM) {
            jasminCode.add("invokevirtual java/io/PrintStream/println(I)V");
        } else if (types.get(expression) == DataType.SOUND) {
            jasminCode.add("invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V");
        }

        return null;
    }

    @Override
    public Void visitScan_num(MusicLangParser.Scan_numContext ctx) {

        jasminCode.add("    new java/util/Scanner");
        jasminCode.add("    dup");
        jasminCode.add("    getstatic java/lang/System/in Ljava/io/InputStream;");
        jasminCode.add("    invokenonvirtual  java/util/Scanner/<init>(Ljava/io/InputStream;)V");
        int index = getNextIndex();
        jasminCode.add("    astore " + index);
        jasminCode.add("    aload " + index);
        jasminCode.add("    invokevirtual java/util/Scanner/nextInt()I");

        return null;
    }

    @Override
    public Void visitRepeat(MusicLangParser.RepeatContext ctx) {
        if (ctx.INT_VALUE() != null) {
            jasminCode.add("    ldc 0");
            int index = getNextIndex();
            jasminCode.add("    istore " + index);
            jasminCode.add("    iload " + index);
            jasminCode.add("    ldc " + ctx.INT_VALUE().getText());
            String loopLabel = nextLabel();
            jasminCode.add(loopLabel + ":");
            String outLabel = nextLabel();
            jasminCode.add("    if_icmpge " + outLabel);
            visit(ctx.repeat_body);
            jasminCode.add("    iinc " + index + " " + 1);
            jasminCode.add("    goto " + loopLabel);
            jasminCode.add(outLabel + ":");
        }

        return null;
    }

    @Override
    public Void visitExNegate(MusicLangParser.ExNegateContext ctx) {
        visit(ctx.expression());
        jasminCode.add("ineg");
        return null;
    }

    @Override
    public Void visitExIdentifier(MusicLangParser.ExIdentifierContext ctx) {
        Symbol symbol = symbols.get(ctx);
//        String instruction = symbol.getType() != DataType.NUM ? "iload" : "aload";
        String instruction = "  iload";
        jasminCode.add(instruction + " " + symbol.getLocalSlot());
        return null;
    }


    @Override
    public Void visitExMulOp(MusicLangParser.ExMulOpContext ctx) {
        visit(ctx.left);
        visit(ctx.right);
        jasminCode.add("    imul");
        return null;
    }

    @Override
    public Void visitExSoundLiteral(MusicLangParser.ExSoundLiteralContext ctx) {

        //jasminCode.add("    ldc  \"" + ctx.SOUND_VALUE().getText() + "\"");
        String soundAsString = ctx.SOUND_VALUE().getText();
        int soundAsNum = soundToNumber(soundAsString);
        jasminCode.add("    ldc  " + soundAsNum);
        return null;
    }

    @Override
    public Void visitExAddOp(MusicLangParser.ExAddOpContext ctx) {
        visit(ctx.left);
        visit(ctx.right);
        if (ctx.op.getText().equals(ctx.PLUS_SIGN().getText())) {
            jasminCode.add("    iadd");
        } else {
            jasminCode.add("    isub");
        }
        return null;
    }

    @Override
    public Void visitExIntLiteral(MusicLangParser.ExIntLiteralContext ctx) {
        jasminCode.add("    ldc  " + ctx.INT_VALUE().getText());
        return null;
    }

    @Override
    public Void visitExParentheses(MusicLangParser.ExParenthesesContext ctx) {
        visit(ctx.expression());
        return null;
    }


    @Override
    public Void visitIf_statement(MusicLangParser.If_statementContext ctx) {
        System.out.println("par - " + ctx.parent.getText());

        if (ctx.else_statement() != null) {
            isLast = false;
            visit(ctx.if_else_body());
            if (doneLabel.equals("")) {
                doneLabel = nextLabel();
            }
            jasminCode.add("    goto " + doneLabel);
            jasminCode.add("    " + ifLabel + ":");
            System.out.println("done1 - " + doneLabel);


            if (ctx.else_statement().if_statement() == null) {
                System.out.println("this is else statement");

                visit(ctx.else_statement());
                jasminCode.add("    " + doneLabel + ":");
                System.out.println("done2 - " + doneLabel);
                ifLabel = "";
                doneLabel = "";

            } else {
                System.out.println("this is else if statement");

                visit(ctx.else_statement());


            }
        } else {
            isLast = true;
            if (doneLabel.equals("")) {
                doneLabel = nextLabel();
            }
            visit(ctx.if_else_body());
            System.out.println(ctx.parent);
            System.out.println(ctx.children);
            if (!jasminCode.getLines().contains(doneLabel)) {
                jasminCode.add("    " + doneLabel + ":");

                System.out.println("done3 - " + doneLabel);

                ifLabel = "";
                doneLabel = "";
            }

        }


        return null;
    }

    @Override
    public Void visitIf_else_body(MusicLangParser.If_else_bodyContext ctx) {
        visit(ctx.my_boolean());
        for (MusicLangParser.StatementContext s : ctx.statement()) {
            visit(s);
        }

        return null;
    }

    @Override
    public Void visitElse_statement(MusicLangParser.Else_statementContext ctx) {
        return super.visitElse_statement(ctx);
    }

    @Override
    public Void visitMy_boolean(MusicLangParser.My_booleanContext ctx) {
        MusicLangParser.ExpressionContext left = ctx.left;
        MusicLangParser.ExpressionContext right = ctx.right;
        visit(left);
        visit(right);
        String operator = reverseComparison(ctx.BOOLEAN_OPERATOR().getText());

        if (isLast) {
            jasminCode.add("    if_icmp" + operator + " " + doneLabel);

        } else {
            System.out.println(ctx.left.getText());

            ifLabel = nextLabel();
            jasminCode.add("    if_icmp" + operator + " " + ifLabel);
        }

        return null;
    }

    private String reverseComparison(String text) {
        switch (text) {
            case "<":
                return "ge";
            case "<=":
                return "gt";
            case ">":
                return "le";
            case ">=":
                return "lt";
            case "==":
                return "ne";
            case "!=":
                return "eq";
            default:
                return null;
        }
    }

    private int soundToNumber(String sound) {
        switch (sound) {
            case "C":
            case "B#":
                return 0;
            case "C#":
            case "Db":
                return 1;
            case "Cb":
            case "B":
                return 11;
            case "D":
                return 2;
            case "D#":
            case "Eb":
                return 3;
            case "E":
            case "Fb":
                return 4;
            case "E#":
            case "F":
                return 5;
            case "F#":
            case "Gb":
                return 6;
            case "G":
                return 7;
            case "G#":
            case "Ab":
                return 8;
            case "A":
                return 9;
            case "A#":
            case "Bb":
                return 10;

            default:
                return -1;
        }
    }
}