#!/bin/sh

# Globals

URL="https://forecast.weather.gov/zipcity.php"
ZIPCODE=46556
FORECAST=0
CELSIUS=0

# Functions

usage() {
    cat 1>&2 <<EOF
Usage: $(basename $0) [zipcode]

-c    Use Celsius degrees instead of Fahrenheit for temperature
-f    Display forecast text after the temperature

If zipcode is not provided, then it defaults to $ZIPCODE.
EOF
    exit $1
}

weather_information() {
    # Fetch weather information from URL based on ZIPCODE
    curl -sL "$URL?inputstring=$ZIPCODE"
}

temperature() {
    # Extract temperature information from weather source
    if [ $CELSIUS -eq 0 ]; then
    	weather_information | grep -Eo '\-?[0-9]{1,3}&deg;F<' | sed 's/&deg;F<//'
    else
	weather_information | grep -Eo '\-?[0-9]{1,3}&deg;C<' | sed 's/&deg;C<//'
    fi
}

forecast() {
    # Extract forecast information from weather source
    weather_information | grep -Eo '"myforecast-current">.*?<' | sed 's/"myforecast-current">//g; s/<//g; s/^[[:space:]]*//; s/[[:space:]]*$//'
}

# Parse Command Line Options

while [ $# -gt 0 ]; do
    case $1 in
    	-c) CELSIUS=1;;
	-f) FORECAST=1;;
        -h) usage 0;;
	*) ZIPCODE=$1;
    esac
    shift
done

# Display Information

echo "Temperature: $(temperature) degrees"
if [ $FORECAST -eq 1 ]; then
   echo "Forecast:    $(forecast)"
fi