/**
  * Aquarium Lab Series
  * Copyright (C) 2000  Alyce Brady
  *
  * Implementation file for AquaFish class -- see aquafish.h for details.
  *
  * Acknowledgements:
  *    This class is part of the Aquarium Lab Series, which was inspired
  *    by the AP Marine Biology Case Study found at
  *       http://www.collegeboard.org/ap/computer-science/marine_biology/
  *    This AquaFish class is NOT the same as the AquaFish class in Part I
  *    of the Case Study, but is loosely based on that class and the
  *    Fish class in Part II.
  *
  * License:
  *    This program is free software; you can redistribute it and/or modify
  *    it under the terms of the GNU General Public License as published by
  *    the Free Software Foundation.
  *
  *    This program is distributed in the hope that it will be useful,
  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *    GNU General Public License for more details.
  */

#include "aquafish.h"
#include "randgen.h"
#include "utils.h"

// initialization of class variables

int AquaFish::nextAvailableID = 0;

// constructors

AquaFish::AquaFish()
  : myId(nextAvailableID++), myColor("black"), myEnviron(0, 0), myX(0), myY(0)
// postcondition: InAquarium() == false, Color() == "black"
//                fish is facing right
{
}

AquaFish::AquaFish(Aquarium a)
  : myId(nextAvailableID++), myColor("black"), myEnviron (a)
// postcondition: Color() == "black", 
//                InAquarium() implies the location of fish is a valid
//                location in a, fish is facing right
{
        // Initialize location and direction
        InitLocDir();
}

AquaFish::AquaFish(Aquarium a, apstring initColor)
  : myId(nextAvailableID++), myColor(initColor), myEnviron (a)
// postcondition: Color() == initColor, 
//                InAquarium() implies the location of fish is a valid
//                location in a, fish is facing right
{
        // Initialize location and direction
        InitLocDir();
}

AquaFish::AquaFish(Aquarium a, int x_coord, int y_coord)
  : myId(nextAvailableID++), myColor("black"),
    myX(x_coord), myY(y_coord), myDir(1), myEnviron (a)
// precondition:  (x_coord, y_coord) is a valid location in a
// postcondition: InAquarium() == true, Color() == initColor,
//     location of fish is (x_coord, y_coord), fish is facing right
{
        if ( ! a.ValidLoc (myX, myY) )
            InitLocDir();
}

AquaFish::AquaFish(Aquarium a, apstring initColor, int x_coord, int y_coord)
  : myId(nextAvailableID++), myColor(initColor),
    myX(x_coord), myY(y_coord), myDir(1), myEnviron (a)
// precondition:  (x_coord, y_coord) is a valid location in a
// postcondition: InAquarium() == true, Color() == initColor,
//     location of fish is (x_coord, y_coord), fish is facing right
{
        if ( ! a.ValidLoc (myX, myY) )
            InitLocDir();
}

// public observer functions

int AquaFish::Id() const
// postcondition: returns unique id number of fish    
{
    return myId;
}

apstring AquaFish::Color() const
// postcondition: returns fish color
{
        return myColor;
}

bool AquaFish::InAquarium() const
// postcondition: returns true iff fish was constructed in, or has been placed 
//                in, an aquarium with width and height > 0
{
        return myEnviron.Width() > 0 && myEnviron.Height() > 0;
}

bool AquaFish::AtWall() const
// precondition:  InAquarium() is true
// postcondition: returns true iff fish is against a side wall
{
        return AtLeftWall() or AtRightWall();
}

bool AquaFish::AtLeftWall() const
// precondition:  InAquarium() is true
// postcondition: returns true iff fish is against the left side wall
{
        return (myX == myEnviron.LeftWallLoc() + 1);
}

bool AquaFish::AtRightWall() const
// precondition:  InAquarium() is true
// postcondition: returns true iff fish is against the right side wall
{
        return (myX == myEnviron.RightWallLoc() - 1);
}

bool AquaFish::AtSurface() const
// precondition:  InAquarium() is true
// postcondition: returns true iff fish is at the water's surface
{
        return (myY == 0);
}

bool AquaFish::AtBottom() const
// precondition:  InAquarium() is true
// postcondition: returns true iff fish is at the bottom of the aquarium
{
        return (myY == myEnviron.Height() - 1);
}

bool AquaFish::FacingRight() const
// postcondition: returns true if the fish is facing right
{
        return myDir == 1;
}

bool AquaFish::FacingLeft() const
// postcondition: returns true if the fish is facing left
{
        return ! FacingRight();
}

bool AquaFish::FacingWall() const
// postcondition: returns true if the fish is against a wall and facing it
{
        return ( AtLeftWall() and FacingLeft() ) or
               ( AtRightWall() and FacingRight() );
}

int AquaFish::XCoord() const
// precondition:  InAquarium() is true
// postcondition: returns x-coordinate of current fish position
{
        return myX;
}

int AquaFish::YCoord() const
// precondition:  InAquarium() is true
// postcondition: returns y-coordinate of current fish position
{
        return myY;
}

apstring AquaFish::ToString() const
// postcondition: returns a stringized form of AquaFish
{
    apstring fishDesc=IntToString(myId) + "(" + myColor + ",";
    if ( InAquarium() )
        fishDesc += IntToString(myX) + "," + IntToString(myY) + ",";
    if ( FacingRight() )
        fishDesc+="R)";
    else
        fishDesc+="L)";
    return fishDesc;
}

// public modifier functions

void AquaFish::MoveForward()
// precondition:  InAquarium() is true
// postcondition: fish has moved forward one space in the current direction
{
        if ( InAquarium() )
            myX += myDir;
}

void AquaFish::ChangeDir()
// precondition:  InAquarium() is true
// postcondition: fish is now facing in the opposite direction
{
        if ( InAquarium() )
            myDir *= -1;
}

// private helper functions

void AquaFish::InitLocDir()
// precondition:  InAquarium() is true
// determines initial location and direction for constructors
{
    if ( InAquarium() )
    {
        RandGen r;
        myX = r.RandInt(myEnviron.Width());
        myY = r.RandInt(myEnviron.Height());
        myDir = 1;       // For now, all fish are constructed facing right
    }
}