#include <allegro.h>
#include <cstring>

#include "InputScrollingMenu.h"

#include "constant.h"

using namespace std;

extern FONT *joystix;

int InputScrollingMenu::getScrollPosition() {
    return scrollPosition;
}

void InputScrollingMenu::setCommand(int desiredLength,
  const char * const *desiredCommand) {
     length = desiredLength;
     command = desiredCommand;
     setValue(0);
}
void InputScrollingMenu::setScrollPosition(int desiredScrollPosition) {
     scrollPosition = desiredScrollPosition;
     if (scrollPosition >= length)
        scrollPosition = length - 1;
     if (scrollPosition < 0)
        scrollPosition = 0;
     
     if (onScroll)
        (*onScroll)();
}

void InputScrollingMenu::previous() {
     setValue((value + length - 1) % length);
}
void InputScrollingMenu::next() {
     setValue((value + 1) % length);
}

void InputScrollingMenu::scrollUp() {
     setScrollPosition(scrollPosition - 1);
}
void InputScrollingMenu::scrollDown() {
     setScrollPosition(scrollPosition + 1);
}

int InputScrollingMenu::getValue() {
    return value;
}
void InputScrollingMenu::setValue(int desiredValue) {
     value = desiredValue;
     if (value - scrollPosition < scrollDiff)
        setScrollPosition(scrollPosition - scrollStep);
     else if (displayLength - value + scrollPosition <= scrollDiff)
        setScrollPosition(scrollPosition + scrollStep);
     if (value < scrollPosition || value >= scrollPosition + displayLength)
        setScrollPosition(value - displayLength / 2);
}

bool InputScrollingMenu::acknowledgeKeyStroke(int keyStroke) {
     switch (keyStroke >> 8) {
            case KEY_1_PAD: case KEY_END:
                 setValue(length - 1);
                 return true;
            case KEY_2_PAD: case KEY_6_PAD: case KEY_RIGHT: case KEY_DOWN:
                 next();
                 return true;
            case KEY_3_PAD: case KEY_PGDN:
                 setValue((value + displayLength) % length);
                 return true;
            case KEY_4_PAD: case KEY_8_PAD: case KEY_LEFT: case KEY_UP:
                 previous();
                 return true;
            case KEY_7_PAD: case KEY_HOME:
                 setValue(0);
                 return true;
            case KEY_9_PAD: case KEY_PGUP:
                 setValue(((value - displayLength) % length + length) % length);
                 return true;
            case KEY_ESC:
                 if (blocking) {
                    commit(-1);
                    return true;
                 }
                 break;
            case KEY_ENTER: case KEY_ENTER_PAD:
                 if (blocking) {
                    commit(value);
                    return true;
                 }
     }
     return false;
}
bool InputScrollingMenu::acknowledgeMouse() {
     bool mouseIndicatesCommand = false;
     
     const int mousePosition = mouse_pos;
     const int mouseButtons = mouse_b;
     
     if ((mouseButtons & 0x1) && !(oldMouseB & 0x1))
        for (int i = scrollPosition;
             i < scrollPosition + displayLength && i < length;
             i++)
            if ((mousePosition >> 16) >= x &&
                (mousePosition >> 16) < x + commandMaxCharCount * charWidth &&
                (mousePosition & 0xffff) >= y + (i - scrollPosition) *
                  charHeight &&
                (mousePosition & 0xffff) < y + (i - scrollPosition) * charHeight
                  + charHeight) {
               setValue(i);
               mouseIndicatesCommand = true;
               break; // setValue has set the variables used in this loop!
            }
     
     if (blocking && mouseIndicatesCommand)
        commit(value);
     
     oldMouseB = mouseButtons;
     
     return mouseIndicatesCommand;
}

void InputScrollingMenu::shift(int xOffset, int yOffset) {
     x += xOffset;
     y += yOffset;
}
bool InputScrollingMenu::within(int xTarget, int yTarget) {
     return xTarget >= x && xTarget < x + commandMaxCharCount * charWidth &&
            yTarget >= y && yTarget < y + displayLength * charHeight;
}
void InputScrollingMenu::draw() {
     rectfill(canvas, x, y, x + commandMaxCharCount * charWidth - 1, y +
       displayLength * charHeight - 1, 16);
     for (int i = scrollPosition;
          i < scrollPosition + displayLength && i < length;
          i++) {
         char truncated[commandMaxCharCount + 1];
         rectfill(canvas, x, y + (i - scrollPosition) * charHeight, x +
           commandMaxCharCount * charWidth - 1, y + (i - scrollPosition) *
           charHeight + charHeight - 1, i == value ? interactivityColor : 16);
         textout_ex(canvas, joystix, strncpy(truncated, command[i],
           commandMaxCharCount), x, y + (i - scrollPosition) * charHeight, 15,
           -1);
     }
}
void InputScrollingMenu::erase() {
     rectfill(canvas, x, y, x + commandMaxCharCount * charWidth - 1, y +
       displayLength * charHeight - 1, 0);
}