#!/bin/bash
#
# Copyright (c) 2013 Krytarik Raido
#
# Homepage: http://www.tuxgarage.com/
#
# This script queries the current weather conditions and forecast
# using the Yahoo Weather API and prints them.
#
########################################################################
#
# 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, either version 3 of the License, or
# (at your option) any later version.
#
# 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.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

usage () {
    printf "\nUsage:\n"
    printf "\t weather [options]\n\n"
    printf "Options:\n\n"
    printf "\t -m   only metric units; if combined with \"-b\", primary units\n"
    printf "\t -i   only imperial units; if combined with \"-b\", primary units\n"
    printf "\t -b   also include the respective other units\n"
    printf "\t -f   also include forecast\n"
    printf "\t -e   also include extended forecast\n"
    printf "\t -c   only current conditions\n"
    printf "\t -v   verbose current conditions\n"
    printf "\t -t   also include observation time\n"
    printf "\t -l   also include location\n"
    printf "\t -p   no coloring\n"
    printf "\t -h   print this help text\n\n"
}

### Defaults

WOEID="638242"   # get location ID by searching on <http://weather.yahoo.com/>

UNITS="c"	# "c" = metric units
		# "f" = imperial units

UNITSCONV="no"   # "yes" = also include the respective other units

FORECASTS="yes"   # "yes" = also include forecast

FCSTDAYS="2"   # number of forecast days to include (max. 5)

CONDVERB="no"   # "yes" = verbose current conditions

OBSTIME="yes"   # "yes" = also include observation time

LOCATION="no"   # "yes" = also include location

if [ -t 0 ]; then
    CLON="\e[1;34m"
    CLOFF="\e[0m"
else
    CLON="\x0312"
    CLOFF="\x03"
fi

### Options

while getopts ":imbcfevtlph" OPT; do
    case $OPT in
	i)
	    UNITS="f"
	    UNITSCONV="no"
	    ;;
	m)
	    UNITS="c"
	    UNITSCONV="no"
	    ;;
	b)
	    UNITSCONV="yes"
	    ;;
	c)
	    FORECASTS="no"
	    ;;
	f)
	    FORECASTS="yes"
	    if (( $FCSTDAYS < 2 )); then
	    	FCSTDAYS="2"
	    fi
	    ;;
	e)
	    FORECASTS="yes"
	    FCSTDAYS="5"
	    ;;
	v)
	    CONDVERB="yes"
	    ;;
	t)
	    OBSTIME="yes"
	    ;;
	l)
	    LOCATION="yes"
	    ;;
	p)
	    CLON=""
	    CLOFF=""
	    ;;
	h)
	    usage
	    exit 0
	    ;;
	\?)
	    echo "Invalid option \"-$OPTARG\"." >&2
	    exit 1
	    ;;
    esac
done

### Get data

getdata () {
    FULLDATA=$(wget -t 5 -T 10 -qO - "http://weather.yahooapis.com/forecastrss?w=$WOEID&u=$UNITS" | grep '<yweather:')
    if [ -z "$FULLDATA" ]; then
    	echo "Retrieval of weather data failed." >&2
    	exit 1
    fi

    UNITSTEMP="°"$(expr "$FULLDATA" : '.*<yweather:units[^>]* temperature="\([^"]*\)".*')
    UNITSSPEED=$(expr "$FULLDATA" : '.*<yweather:units[^>]* speed="\([^"]*\)".*')

    if [ "$FORECASTS" = "yes" ]; then
	FCSTDATA=$(awk -v fcstdays="$FCSTDAYS" '/<yweather:forecast/ {print; fcstday++} fcstday==fcstdays {exit}' <<< "$FULLDATA")
	ORIGIFS="$IFS"
	IFS=$'\n'
	FCSTWDAY=($(sed -n 's/.* day="\([^"]*\)".*/\1/p' <<< "$FCSTDATA"))
	FCSTLOW=($(sed -n 's/.* low="\([^"]*\)".*/\1/p' <<< "$FCSTDATA"))
	FCSTHIGH=($(sed -n 's/.* high="\([^"]*\)".*/\1/p' <<< "$FCSTDATA"))
	FCSTTEXT=($(sed -n 's/.* text="\([^"]*\)".*/\1/p' <<< "$FCSTDATA"))
    	IFS="$ORIGIFS"
    fi

    if [ "$1" != "convert" ]; then
	CONDTEXT=$(expr "$FULLDATA" : '.*<yweather:condition[^>]* text="\([^"]*\)".*')
	ATMOHUMID=$(expr "$FULLDATA" : '.*<yweather:atmosphere[^>]* humidity="\([^"]*\)".*')"%"

	if [ "$OBSTIME" = "yes" ]; then
	    OBSTMDATA=$(expr "$FULLDATA" : '.*<yweather:condition[^>]* date="\([^"]*\)".*')
	    OBSTMDAY=${OBSTMDATA%%,*}
	    OBSTMTIME=$(awk -F '[ ,:]+' '$7 == "pm" && $5 != "12" {conv = 12} {printf "%d:%d", $5 + conv, $6}' <<< $OBSTMDATA)
	fi

	if [ "$LOCATION" = "yes" ]; then
	    LOCATCITY=$(expr "$FULLDATA" : '.*<yweather:location[^>]* city="\([^"]*\)".*')
	    LOCATREGION=$(expr "$FULLDATA" : '.*<yweather:location[^>]* region="\([^"]*\)".*')
	    LOCATCOUNTRY=$(expr "$FULLDATA" : '.*<yweather:location[^>]* country="\([^"]*\)".*')
	fi

	CONDTEMP=$(expr "$FULLDATA" : '.*<yweather:condition[^>]* temp="\([^"]*\)".*')"$UNITSTEMP"
	WINDSPEED=$(expr "$FULLDATA" : '.*<yweather:wind[^>]* speed="\([^"]*\)".*')" $UNITSSPEED"

	if [ "$CONDVERB" = "yes" ]; then
	    UNITSDIST=$(expr "$FULLDATA" : '.*<yweather:units[^>]* distance="\([^"]*\)".*')
	    UNITSPRESS=$(expr "$FULLDATA" : '.*<yweather:units[^>]* pressure="\([^"]*\)".*')
	    ATMOVISIB=$(expr "$FULLDATA" : '.*<yweather:atmosphere[^>]* visibility="\([^"]*\)".*')" $UNITSDIST"
	    ATMOPRESS=$(expr "$FULLDATA" : '.*<yweather:atmosphere[^>]* pressure="\([^"]*\)".*')" $UNITSPRESS"
	    ATMOTRENDS=("→" "↑" "↓")
	    ATMOTREND=${ATMOTRENDS[$(expr "$FULLDATA" : '.*<yweather:atmosphere[^>]* rising="\([^"]*\)".*')]}
	    WINDDIRS=("N" "NNE" "NE" "ENE" "E" "ESE" "SE" "SSE" "S" "SSW" "SW" "WSW" "W" "WNW" "NW" "NNW")
	    WINDDIR=${WINDDIRS[($(expr "$FULLDATA" : '.*<yweather:wind[^>]* direction="\([^"]*\)".*') * 100 + 1125) / 2250 % 16]}
	    WINDCHILL=$(expr "$FULLDATA" : '.*<yweather:wind[^>]* chill="\([^"]*\)".*')"$UNITSTEMP"
	fi

	for FCSTDAY in "${!FCSTWDAY[@]}"; do
	    FCSTTEMPS[$FCSTDAY]="${FCSTLOW[$FCSTDAY]}/${FCSTHIGH[$FCSTDAY]}${UNITSTEMP}"
	done
    else
	CONDTEMP="$CONDTEMP ("$(expr "$FULLDATA" : '.*<yweather:condition[^>]* temp="\([^"]*\)".*')"$UNITSTEMP)"
	WINDSPEED="$WINDSPEED ("$(expr "$FULLDATA" : '.*<yweather:wind[^>]* speed="\([^"]*\)".*')" $UNITSSPEED)"

	if [ "$CONDVERB" = "yes" ]; then
	    UNITSDIST=$(expr "$FULLDATA" : '.*<yweather:units[^>]* distance="\([^"]*\)".*')
	    UNITSPRESS=$(expr "$FULLDATA" : '.*<yweather:units[^>]* pressure="\([^"]*\)".*')
	    ATMOVISIB="$ATMOVISIB ("$(expr "$FULLDATA" : '.*<yweather:atmosphere[^>]* visibility="\([^"]*\)".*')" $UNITSDIST)"
	    ATMOPRESS="$ATMOPRESS ("$(expr "$FULLDATA" : '.*<yweather:atmosphere[^>]* pressure="\([^"]*\)".*')" $UNITSPRESS)"
	    WINDCHILL="$WINDCHILL ("$(expr "$FULLDATA" : '.*<yweather:wind[^>]* chill="\([^"]*\)".*')"$UNITSTEMP)"
	fi

	for FCSTDAY in "${!FCSTWDAY[@]}"; do
	    FCSTTEMPS[$FCSTDAY]="${FCSTTEMPS[$FCSTDAY]} (${FCSTLOW[$FCSTDAY]}/${FCSTHIGH[$FCSTDAY]}${UNITSTEMP})"
	done
    fi
}

### Main

getdata

if [ "$UNITSCONV" = "yes" ]; then
    case $UNITS in
	c)
	    UNITS="f"
	    ;;
	f)
	    UNITS="c"
	    ;;
    esac
    getdata convert
fi

if [ "$LOCATION" = "yes" ]; then
    OUTPUT="${CLON}Location:$CLOFF $LOCATCITY, $LOCATREGION, $LOCATCOUNTRY $CLON~$CLOFF "
fi

if [ "$CONDVERB" = "yes" ]; then
    OUTPUT+="${CLON}Cond:$CLOFF $CONDTEMP, $CONDTEXT $CLON~ Atmo:$CLOFF $ATMOHUMID, $ATMOVISIB, $ATMOTREND $ATMOPRESS $CLON~ Wind:$CLOFF $WINDSPEED, $WINDDIR, $WINDCHILL"
else
    OUTPUT+="${CLON}Temp:$CLOFF $CONDTEMP $CLON~ Cond:$CLOFF $CONDTEXT $CLON~ Humid:$CLOFF $ATMOHUMID $CLON~ Wind:$CLOFF $WINDSPEED"
fi

for FCSTDAY in "${!FCSTWDAY[@]}"; do
    OUTPUT+=" $CLON~ ${FCSTWDAY[$FCSTDAY]}:$CLOFF ${FCSTTEMPS[$FCSTDAY]}, ${FCSTTEXT[$FCSTDAY]}"
done

if [ "$OBSTIME" = "yes" ]; then
    OUTPUT+=" $CLON~ Time:$CLOFF "
    if [ "$FORECASTS" = "yes" ]; then
	OUTPUT+="$OBSTMDAY, "
    fi
    OUTPUT+="$OBSTMTIME"
fi

printf "%b\n" "$OUTPUT"