package me.hammerle.code;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Stack;
import me.hammerle.exceptions.CodeTooLongException;
import me.hammerle.exceptions.GotoLabelNotFoundException;
import me.hammerle.exceptions.HoldCodeException;
import me.hammerle.exceptions.SnuviException;

public class Script 
{
    private final SnuviParser parser;
    protected final boolean receiveEventBroadcast;
    protected final ArrayList<String> eventVars;
    
    private final int id;
    private final String name;  

    private final HashMap<String, Object> variables;    
    private final HashMap<String, Integer> gotos;
    private final HashSet<String> events;
    private final Stack<Object> valueStack;
    private final Stack<Integer> returnStack;
    
    private Code[] code;
    private int position;

    private int loopCounter;
    
    private boolean halt;
    private boolean valid;
    
    private int tryJumpLine;
    
    public Script(SnuviParser parser, int id, String name, String code, boolean receiveEventBroadcast)
    {       
        this.eventVars = new ArrayList<>();
        this.receiveEventBroadcast = receiveEventBroadcast;
        this.parser = parser;
        this.id = id;
        this.name = name;
        
        variables = new HashMap<>();
        gotos = new HashMap<>();
        events = new HashSet<>();
        valueStack = new Stack<>();
        returnStack = new Stack<>();
        
        this.code = Code.generate(parser, name, code, gotos);
        /*for(Code c : this.code)
        {
            System.out.println(c);
        }*/
        
        position = 0;

        loopCounter = 0;
        
        halt = false;
        valid = true;
        
        tryJumpLine = -1;
    }
    
    public Script(SnuviParser parser, int id, String name, String code)
    {       
        this(parser, id, name, code, true);
    }
    
    protected void initExpansion(Object... o)
    {
        
    }
    
    public void overload(String code)
    {       
        gotos.clear();
        valueStack.clear();
        returnStack.clear();
        this.code = Code.generate(parser, name, code, gotos);
        position = 0;
        halt = false;
        valid = true;
        tryJumpLine = -1;
    }
    
    public Code[] getCode(int line)
    {
        int start = 0;
        int end = code.length;
        int helper;

        while(end - start > 1)
        {
            helper = (start + end) >> 1;
            if(code[helper].line > line)
            {
                end = helper;
            }
            else if(code[helper].line <= line)
            {
                start = helper;
            }
        }
        int realEnd = start;
        start = 0;
        end = code.length;
        while(end - start > 1)
        {
            helper = (start + end) >> 1;
            if(code[helper].line >= line)
            {
                end = helper;
            }
            else if(code[helper].line < line)
            {
                start = helper;
            }
        }
        return Arrays.copyOfRange(code, end, realEnd + 1);
    }
    
    // -----------------------------------------------------------------------------------
    // Script-Daten
    // -----------------------------------------------------------------------------------
    
    public int getId() 
    {
        return id;
    }

    public String getName() 
    {
        return name;
    }
    
    public boolean isHalt() 
    {
        return halt;
    }
    
    public void setHalt(boolean b) 
    {
        halt = b;
    }
    
    public boolean isValid() 
    {
        return valid;
    }
    
    public void setInvalid() 
    {
        valid = false;
    }
    
    public int getActiveCodeLine()
    {
        return code[position].line;
    }
    
    // -----------------------------------------------------------------------------------
    // Event-Handling
    // -----------------------------------------------------------------------------------
    
    public void loadEvent(String s)
    {
        events.add(s);
    }
    
    public boolean isLoadedEvent(String s)
    {
        return events.contains(s);
    }
    
    public void unloadEvent(String s)
    {
        events.remove(s);
    }
    
    // -----------------------------------------------------------------------------------
    // Script-Flow
    // -----------------------------------------------------------------------------------
    
    public void onTerm()
    {
    }
    
    public void runCode() 
    {
        if(this.isValid())
        {
            try
            {
                while(position < code.length)
                {
                    code[position].executeFunction(parser, this, valueStack);
                    position++;
                    if(isHalt())
                    {
                        return;
                    }
                }
                parser.termSafe(this);
            }
            catch(Exception ex)
            {
                if(ex.getClass() != HoldCodeException.class)
                {
                    parser.logger.printException(new SnuviException(ex, this));
                }
                position++;
            }
        }
    }
    
    // -----------------------------------------------------------------------------------
    // Variablen
    // -----------------------------------------------------------------------------------
    
    public void setEventVar(String var, Object value)
    {
        variables.put(var, value);   
        eventVars.add(var);
    }
    
    public void setVar(String var, Object value)
    {
        variables.put(var, value);   
    }
    
    public Object getVar(String var)
    {
        return variables.get(var);
    }
    
    public HashMap<String, Object> getVars()
    {
        return variables;
    }
    
    public boolean getBooleanVar(String var)
    {
        try
        {
            return (boolean) getVar(var);
        }
        catch(ClassCastException | NullPointerException ex)
        {
            return false;
        }
    }
    
    public void removeVar(String var)
    {
        variables.remove(var);
    }
    
    // -----------------------------------------------------------------------------------
    // Goto, Return
    // -----------------------------------------------------------------------------------
    
    public void incLoopCounter()
    {
        loopCounter++;
        if(loopCounter > 50)
        {
            resetLoopCounter();
            throw new CodeTooLongException(this);
        }
    }
    
    public void gotoLabel(String label)
    {
        try
        {
            int i = gotos.get(label);
            incLoopCounter();
            position = i - 1;
        }
        catch(NullPointerException ex)
        {
            throw new GotoLabelNotFoundException(this, label);
        }
    }  
    
    public void resetLoopCounter()
    {
        loopCounter = 0;
    }
    
    public void gotoLabelWithReturn(String label)
    {
        returnStack.push(position);
        gotoLabel(label);
    }
    
    public void doReturn()
    {
        position = returnStack.pop(); 
    }
    
    public void gotoSpecialJumpLine(int i)
    {
        position += code[position].getJumpLine() + i;
    }
    
    public void gotoSpecialJumpLine()
    {
        gotoSpecialJumpLine(-1);
    }
    
    public void jumpNextIfElse()
    {
        if(code.length <= position + 1)
        {
            return;
        }
        String s = code[position + 1].getFunction();
        if(s == null || !s.equals("else"))
        {
            return;
        }
        position++;
    }
    
    // -----------------------------------------------------------------------------------
    // try
    // -----------------------------------------------------------------------------------
    
    public void gotoTryJumpLine()
    {
        position = tryJumpLine; 
    }
    
    public void saveTryJumpLine()
    {
        tryJumpLine = position + code[position].getJumpLine();
    }
    
    public void resetTryJumpLine()
    {
        tryJumpLine = -1;
    }
    
    public int getTryJumpLine()
    {
        return tryJumpLine; 
    }
}