package midend.llvm;

import java.util.HashMap;
import java.util.Stack;

import midend.llvm.value.IrFuncValue;
import midend.llvm.value.IrBasicBlock;
import midend.llvm.value.IrLoop;
import midend.llvm.type.IrType;
import midend.llvm.constant.IrConstant;
import midend.llvm.value.IrGlobalValue;
import midend.llvm.constant.IrConstantStr;
import midend.llvm.instr.IrInstr;

public class IrBuilder {
    private static final String prebb = "b_";
    private static final String prestr = "@s_";
    private static final String prefunc = "@f_";
    private static final String preglobal = "@g_";
    private static final String prelocal = "%v_";

    private static IrModule module = null;
    private static IrFuncValue currentFunc = null;
    private static IrBasicBlock currentBB = null;
    private static int strId = 0;
    private static int globalId = 0;
    private static int bblockId = 0;
    private static HashMap<IrFuncValue, Integer> funcIdMap = new HashMap<>(); // func, localId
    private static Stack<IrLoop> loopStack = new Stack<>();
    
    public static void setCurrentModule(IrModule module) {
        IrBuilder.module = module;
    }

    public static void addNewFunc(String name, IrType retType) {
        IrFuncValue func = new IrFuncValue(geFuncName(name), retType);
        module.addFunc(func);
        funcIdMap.put(func, 0);
        currentFunc = func;
        IrBasicBlock entryBB = new IrBasicBlock(getBlockName(), func);
        func.addBBlock(entryBB);
        currentBB = entryBB;
    }

    public static void addNewFunc(IrFuncValue func) {
        module.addFunc(func);
        funcIdMap.put(func, 0);
        currentFunc = func;
        IrBasicBlock entryBB = new IrBasicBlock(getBlockName(), func);
        func.addBBlock(entryBB);
        currentBB = entryBB;
    }

    public static void addNewBB() {
        IrBasicBlock bb = new IrBasicBlock(getBlockName(), currentFunc);
        currentFunc.addBBlock(bb);
    }

    public static void addNewBB(IrBasicBlock bb) {
        currentFunc.addBBlock(bb);
    }

    public static void setCurrentBBlock(IrBasicBlock bb) {
        currentBB = bb;
    }

    public static void addNewGlobal(IrType type, boolean isConstant, IrConstant initVal) {
        IrGlobalValue global = new IrGlobalValue(type, getGlobalName(), isConstant, initVal);
        module.addGlobalVar(global);
    }

    public static void addNewGlobal(IrGlobalValue global) {
        module.addGlobalVar(global);
    }

    public static void addNewStr(String str) {
        if (module.containStr(str)) {
            return;
        }
        module.addStr(new IrConstantStr(str, getStrName()));
    }

    public static void addNewStr(IrConstantStr str) {
        module.addStr(str);
    }

    public static void addInstr(IrInstr instr) {
        currentBB.addInstr(instr);
        instr.setBBlock(currentBB);
    }

    public static String geFuncName(String name) {
        return name.equals("main") ? "@main" : prefunc + name;
    }

    public static String getBlockName() {
        return prebb + bblockId++;
    }

    public static String getStrName() {
        return prestr + strId++;
    }

    public static String getGlobalName() {
        return preglobal + globalId++;
    }

    public static String getLocalName() {
        int id = funcIdMap.get(currentFunc);
        funcIdMap.put(currentFunc, id + 1);
        return prelocal + id;
    }

    public static String getLocalName(IrFuncValue func) {
        int id = funcIdMap.get(func);
        funcIdMap.put(func, id + 1);
        return prelocal + id;
    }

    public static IrModule getCurrentModule() {
        return module;
    }

    public static IrFuncValue getCurrentFunc() {
        return currentFunc;
    }

    public static IrBasicBlock getCurrentBB() {
        return currentBB;
    }

    public static void pushLoop(IrLoop loop) {
        loopStack.push(loop);
    }

    public static IrLoop popLoop() {
        return loopStack.pop();
    }

    public static IrLoop getCurrentLoop() {
        return loopStack.peek();
    }
}