chem

#!/bin/bash

# Print usage informations
function printUsage {
  echo "Usage"
  echo
  echo "chem -h, chem --help, chem ? - show this info"
  echo "chem - show statistics and known elements"
  echo "chem <el1> <el2>, chem <el1> + <el2> - combine elements"
}

# Craft new element
# Expecting two parameters (element1 and element2)
function craftElement {
  if [ $(isKnown $1) -ne 1 ]; then
    echo "I don't know element $1!"
    exit 1
  fi
  if [ $(isKnown $2) -ne 1 ]; then
    echo "I don't know element $2!"
    exit 1
  fi
  
  ELEMENT=$(cat db/combos|grep -e " $1+$2" -e " $2+$1"|head -1|cut -d"=" -f1)
  if [ "$ELEMENT" != "" ]; then
    if [ $(isKnown $ELEMENT) -ne 1 ]; then
      echo "Congratz! You just found $ELEMENT ;)"
      setKnown $ELEMENT
    else
      echo "You made $ELEMENT (already known)"
    fi
  else
    echo "Nothing happen ..."
  fi
} 

# Set element as known
# Expecting one parameter (element name)
function setKnown {
  echo $1 >> ~/.chem
}

# Check if element is known
# Expecting one parameter (element name)
function isKnown {
  if cat ~/.chem|grep -q $1; then
    echo 1
  else
    echo 0
  fi
}

# Print all known elements
function getKnown {
  echo "Already known elements: "
  cat ~/.chem|sort
}

# Initialize .chem db file, if not exists
function initGame {
  if [ ! -f ~/.chem ]; then
    echo -e "fire\nwater\nair\nearth" > ~/.chem
    echo "Initialized new game"
  fi
}

## Main game ##
initGame

case "$1" in
  -h|--help) printUsage; exit 0 ;;
esac 

if [ $# -eq 0 ]; then
 getKnown
 exit 0
fi

if [ $# -lt 2 ]; then
  printUsage
  exit 1
fi

ELEMENT1=$1
ELEMENT2=$2

if [ "$2" == "+" ]; then
  if [ $# -lt 3 ]; then
    printUsage
    exit 1
  fi
  
  ELEMENT2=$3
fi

echo $(craftElement $ELEMENT1 $ELEMENT2)