package midend.visit;

import java.util.ArrayList;

import frontend.ast.block.Block;
import frontend.ast.block.ForStmt;
import frontend.ast.block.Stmt;
import frontend.ast.exp.Cond;
import frontend.ast.exp.Exp;
import frontend.ast.exp.LVal;
import frontend.ast.token.TokenNode;
import frontend.lexer.Token;
import midend.symbol.SymbolManager;
import midend.llvm.IrBuilder;
import midend.llvm.constant.IrConstantStr;
import midend.llvm.instr.GetIntInstr;
import midend.llvm.instr.JumpInstr;
import midend.llvm.instr.PutIntInstr;
import midend.llvm.instr.PutStrInstr;
import midend.llvm.instr.ReturnInstr;
import midend.llvm.instr.StoreInstr;
import midend.llvm.type.IrInterType;
import midend.llvm.type.IrType;
import midend.llvm.value.IrBasicBlock;
import midend.llvm.value.IrValue;
import midend.llvm.value.IrLoop;

public class VisitorStmt {
    public static void visitStmt(Stmt stmt) {
        if (stmt.getChild(0) instanceof LVal) {
            visitAssign(stmt);
        } else if (stmt.getChild(0) instanceof Exp
                || (stmt.getChild(0) instanceof TokenNode
                        && ((TokenNode) stmt.getChild(0)).getValue().equals(";"))) {
            visitExp(stmt);
        } else if (stmt.getChild(0) instanceof Block) {
            visitBlock(stmt);
        } else if (((TokenNode) stmt.getChild(0)).getValue().equals("if")) {
            visitIf(stmt);
        } else if (((TokenNode) stmt.getChild(0)).getValue().equals("for")) {
            visitFor(stmt);
        } else if (((TokenNode) stmt.getChild(0)).getValue().equals("break")) {
            visitBreak(stmt);
        } else if (((TokenNode) stmt.getChild(0)).getValue().equals("continue")) {
            visitContinue(stmt);
        } else if (((TokenNode) stmt.getChild(0)).getValue().equals("return")) {
            visitReturn(stmt);
        } else {
            visitPrintf(stmt);
        }
    }

    public static void visitBlock(Stmt stmt) {
        Block block = (Block) stmt.getChild(0);
        VisitorBlock.visitBlock(block);
    }

    public static void visitExp(Stmt stmt) {
        if (stmt.getChild(0) instanceof Exp) {
            VisitorExp.visitExp((Exp) stmt.getChild(0));
        }
    }

    public static void visitAssign(Stmt stmt) {
        if (!stmt.isGetint()) {
            LVal lval = (LVal) stmt.getChild(0);
            Exp exp = (Exp) stmt.getChild(2);
            IrValue lvalIr = VisitorExp.visitLVal(lval, true);
            IrValue expIr = VisitorExp.visitExp(exp);
            expIr = IrType.convertType(expIr, IrInterType.INT32);
            StoreInstr storeInstr = new StoreInstr(expIr, lvalIr);
            IrBuilder.addInstr(storeInstr);
        } else {
            LVal lval = (LVal) stmt.getChild(0);
            IrValue lvalIr = VisitorExp.visitLVal(lval, true);
            GetIntInstr getIntInstr = new GetIntInstr(IrBuilder.getLocalName());
            IrBuilder.addInstr(getIntInstr);
            StoreInstr storeInstr = new StoreInstr(getIntInstr, lvalIr);
            IrBuilder.addInstr(storeInstr);
        }
    }

    public static void visitPrintf(Stmt stmt) {
        // System.out.println(((TokenNode)stmt.getChild(0)).getValue());//TODO:debug
        String strconst = ((TokenNode) stmt.getChild(2)).getValue();
        ArrayList<Exp> expList = stmt.getExpList();
        ArrayList<IrValue> expIrList = new ArrayList<>();
        for (Exp exp : expList) {
            expIrList.add(VisitorExp.visitExp(exp));
        }
        StringBuilder sb = new StringBuilder();
        int expnum = 0;
        ArrayList<IrValue> printValue = new ArrayList<>();
        for (int i = 0; i < strconst.length(); i++) {
            if (strconst.charAt(i) == '%') {
                if (!sb.isEmpty() && !sb.toString().equals("\"")) {
                    IrConstantStr str = IrBuilder.getCurrentModule().getStr(sb.toString());
                    // System.out.println(sb.toString());//TODO:debug
                    if (str == null) {
                        str = new IrConstantStr(sb.toString(), IrBuilder.getStrName());
                        IrBuilder.addNewStr(str);
                    }
                    printValue.add(str); // 修改为到最后统一输出，而不是立即输出
                    // PutStrInstr putStrInstr = new PutStrInstr(IrBuilder.getLocalName(), str);
                    // IrBuilder.addInstr(putStrInstr);
                    sb.setLength(0);
                } else if (sb.toString().equals("\"")) {
                    sb.setLength(0);
                }
                IrValue expIr = expIrList.get(expnum++);
                expIr = IrType.convertType(expIr, IrInterType.INT32);
                printValue.add(expIr); // 修改为到最后统一输出，而不是立即输出
                // PutIntInstr putIntInstr = new PutIntInstr(IrBuilder.getLocalName(), expIr);
                // IrBuilder.addInstr(putIntInstr);
                i++;
            } else {
                sb.append(strconst.charAt(i));
            }
        }
        if (!sb.isEmpty() && !sb.toString().equals("\"")) {
            IrConstantStr str = IrBuilder.getCurrentModule().getStr(sb.toString());
            // System.out.println(sb.toString());//TODO:debug
            if (str == null) {
                str = new IrConstantStr(sb.toString(), IrBuilder.getStrName());
                IrBuilder.addNewStr(str);
            }
            printValue.add(str); // 修改为到最后统一输出，而不是立即输出
            // PutStrInstr putStrInstr = new PutStrInstr(IrBuilder.getLocalName(), str);
            // IrBuilder.addInstr(putStrInstr);
            sb.setLength(0);
        }
        for (IrValue irValue : printValue) {
            if (irValue instanceof IrConstantStr) {
                PutStrInstr putStrInstr = new PutStrInstr(
                        IrBuilder.getLocalName(), (IrConstantStr) irValue);
                IrBuilder.addInstr(putStrInstr);
            } else {
                PutIntInstr putIntInstr = new PutIntInstr(IrBuilder.getLocalName(), irValue);
                IrBuilder.addInstr(putIntInstr);
            }
        }
    }

    public static void visitReturn(Stmt stmt) {
        IrValue retValue = null;
        if (stmt.getChild(1) instanceof Exp) {
            retValue = VisitorExp.visitExp((Exp) stmt.getChild(1));
            retValue = IrType.convertType(retValue, IrInterType.INT32);
        }
        ReturnInstr returnInstr = new ReturnInstr(retValue);
        IrBuilder.addInstr(returnInstr);
    } 

    public static void visitIf(Stmt stmt) {
        Cond cond = (Cond) stmt.getChild(2);
        Stmt ifStmt = (Stmt) stmt.getChild(4);
        if (stmt.getChildren().size() == 7) {
            IrBasicBlock ifBlock = new IrBasicBlock(
                    IrBuilder.getBlockName(), IrBuilder.getCurrentFunc());
            IrBuilder.addNewBB(ifBlock);
            IrBasicBlock elseBlock = new IrBasicBlock(
                    IrBuilder.getBlockName(), IrBuilder.getCurrentFunc());
            IrBuilder.addNewBB(elseBlock);
            VisitorExp.visitCond(cond, ifBlock, elseBlock);
            // ifblock解析
            IrBuilder.setCurrentBBlock(ifBlock);
            VisitorStmt.visitStmt(ifStmt);
            IrBasicBlock followBlock = new IrBasicBlock(
                    IrBuilder.getBlockName(), IrBuilder.getCurrentFunc());
            IrBuilder.addNewBB(followBlock);
            JumpInstr jumpInstr = new JumpInstr(followBlock);
            IrBuilder.addInstr(jumpInstr);
            //elseblock解析
            IrBuilder.setCurrentBBlock(elseBlock);
            Stmt elseStmt = (Stmt) stmt.getChild(6);
            VisitorStmt.visitStmt(elseStmt);
            jumpInstr = new JumpInstr(followBlock);
            IrBuilder.addInstr(jumpInstr);
            //跳转至followblock
            IrBuilder.setCurrentBBlock(followBlock);
        } else {
            IrBasicBlock ifBlock = new IrBasicBlock(
                    IrBuilder.getBlockName(), IrBuilder.getCurrentFunc());
            IrBuilder.addNewBB(ifBlock);
            IrBasicBlock followBlock = new IrBasicBlock(
                    IrBuilder.getBlockName(), IrBuilder.getCurrentFunc());
            IrBuilder.addNewBB(followBlock);
            VisitorExp.visitCond(cond, ifBlock, followBlock);
            IrBuilder.setCurrentBBlock(ifBlock);
            VisitorStmt.visitStmt(ifStmt);
            JumpInstr jumpInstr = new JumpInstr(followBlock);
            IrBuilder.addInstr(jumpInstr);
            //跳转至followblock
            IrBuilder.setCurrentBBlock(followBlock);
        }
    }

    public static void visitFor(Stmt stmt) {
        IrBasicBlock condBB = new IrBasicBlock(IrBuilder.getBlockName(), 
            IrBuilder.getCurrentFunc());
        IrBuilder.addNewBB(condBB);
        IrBasicBlock bodyBB = new IrBasicBlock(IrBuilder.getBlockName(), 
            IrBuilder.getCurrentFunc());
        IrBuilder.addNewBB(bodyBB);
        IrBasicBlock stepBB = new IrBasicBlock(IrBuilder.getBlockName(), 
            IrBuilder.getCurrentFunc());
        IrBuilder.addNewBB(stepBB);
        IrBasicBlock followBB = new IrBasicBlock(IrBuilder.getBlockName(), 
            IrBuilder.getCurrentFunc());
        IrBuilder.addNewBB(followBB);
        IrLoop loop = new IrLoop(condBB, bodyBB, stepBB, followBB);
        IrBuilder.pushLoop(loop);
        ForStmt initStmt = stmt.getinitStmt();
        if (initStmt != null) {
            VisitorStmt.visitForStmt(initStmt);
        }
        JumpInstr jumpInstr = new JumpInstr(condBB);
        IrBuilder.addInstr(jumpInstr);
        IrBuilder.setCurrentBBlock(condBB);
        Cond cond = stmt.getCond();
        if (cond != null) {
            VisitorExp.visitCond(cond, bodyBB, followBB);
        } else {
            JumpInstr jumpBody = new JumpInstr(bodyBB);
            IrBuilder.addInstr(jumpBody);
        }
        IrBuilder.setCurrentBBlock(bodyBB);
        Stmt bodyStmt = stmt.getBodyStmt();
        VisitorStmt.visitStmt(bodyStmt);
        jumpInstr = new JumpInstr(stepBB);
        IrBuilder.addInstr(jumpInstr);
        IrBuilder.setCurrentBBlock(stepBB);
        ForStmt stepStmt = stmt.getStepStmt();
        if (stepStmt != null) {
            VisitorStmt.visitForStmt(stepStmt);
        }
        JumpInstr jumpCond = new JumpInstr(condBB);
        IrBuilder.addInstr(jumpCond);
        IrBuilder.popLoop();
        IrBuilder.setCurrentBBlock(followBB);
    } /*TODO:此处可能还有问题，循环体和条件、步长表达式等可能不在一个符号表，应该修改，应该比较好改，判断一下stmt是否为block再决定是否last
    细想应该不用，如果body是一个block，那visit的时候符号表next，visit完之后符号表还会next，相当于再解析step的时候还是原来的符号表*/

    public static void visitForStmt(ForStmt stmt) {
        ArrayList<LVal> lvalList = stmt.getLValList();
        ArrayList<Exp> expList = stmt.getExpList();
        for (int i = 0; i < lvalList.size(); i++) {
            LVal lval = lvalList.get(i);
            Exp exp = expList.get(i);
            IrValue lvalIr = VisitorExp.visitLVal(lval, true);
            IrValue expIr = VisitorExp.visitExp(exp);
            expIr = IrType.convertType(expIr, IrInterType.INT32);
            StoreInstr storeInstr = new StoreInstr(expIr, lvalIr);
            IrBuilder.addInstr(storeInstr);
        }
    }

    public static void visitBreak(Stmt stmt) {
        IrLoop loop = IrBuilder.getCurrentLoop();
        IrBasicBlock followBB = loop.getFollowBB();
        JumpInstr jumpInstr = new JumpInstr(followBB);
        IrBuilder.addInstr(jumpInstr);
    }

    public static void visitContinue(Stmt stmt) {
        IrLoop loop = IrBuilder.getCurrentLoop();
        IrBasicBlock stepBB = loop.getStepBB();
        JumpInstr jumpInstr = new JumpInstr(stepBB);
        IrBuilder.addInstr(jumpInstr);
    }
}