#!/bin/bash

# Author: Steven Baltakatei Sandoval

#== Variable Initialization ==

#== Global constants ==
PATH="/usr/local/bin/:$PATH"    # Add default OpenTimestamps path to PATH (necessary if cron used to call this script)
PATH="/opt/bktei:$PATH"         # Add default baltakatei script install directory to PATH (necessary for other bk scripts)
SCRIPT_HOSTNAME=$(hostname)     # Save hostname of system running this script.
SCRIPT_VERSION="bkgpslog 0.0.1" # Define version of script.
SCRIPT_TIME_SHORT="$(date +%Y%m%dT%H%M%S%z)" # Save current date & time in ISO-8601 format.
SCRIPT_DATE_SHORT="$(date +%Y%m%d)"          # Save current date in ISO-8601 format.
#DIROUT1="/home/pi/Sync/Evanescent_Location"  # Define output directory.

#== Script Function Definitions ==
# Yell, Die, Try Three-Fingered Claw technique
# Ref/Attrib: https://stackoverflow.com/a/25515370
yell() { echo "$0: $*" >&2; }
die() { yell "$*"; exit 111; }
try() { "$@" || die "cannot $*"; }

echoerr() {
    echo "$@" 1>&2; # Define stderr echo function.
} # Define stderr message function.
showUsage() {
    echoerr "USAGE:"
    echoerr "    bkgpslog.sh [ options ]"
    echoerr
    echoerr "OPTIONS:"
    echoerr "    -h, --help"
    echoerr "            Display help information."
    echoerr
    echoerr "    --version"
    echoerr "            Display script version."
    echoerr
    echoerr "    -v, --verbose"
    echoerr "            Display debugging info."
    echoerr
    echoerr "    -o, --output [ directory ]"
    echoerr "            Specify output directory to save logs."
} # Display information on how to use this script.
showVersion() {
    echoerr "$SCRIPT_VERSION"
} # Display script version.
vbm() {
    if [ $OPTION_VERBOSE -eq "true" ]; then
	echoerr "$@"
    fi
} # Verbose message display function.
processArguments() {
    while [ ! $# -eq 0 ]; do   # While number of arguments ($#) is not (!) equal to (-eq) zero (0).
	echoerr "DEBUG:Starting processArguments while loop."
	echoerr "DEBUG:Provided arguments are:""$@"
	case "$1" in
	    --h | --help) showUsage; exit 1;; # Display usage.
	    --version) showVersion; exit 1;; # Show version
	    --v | --verbose) OPTION_VERBOSE="true"; vbm "DEBUG:Verbose mode enabled.";; # Enable verbose mode.
	    --o | --output) if [ -d "$2" ]; then DIROUT1="$2"; fi ;; # Define output directory.
	    *) echoerr "ERROR: Unrecognized argument."; exit 1;; # Handle unrecognized options.
	esac
	shift
    done
} # Argument Processing
checkExecutables() {
    
} # Check that certain executables exist.

main() {
    processArguments # Process arguments.
    checkExecutables "gpspipe" # Confirm that executables necessary to run are available.
} # Main function.






if [[ -d "$DIROUT1" ]] && command -v "gpspipe" 1>/dev/null 2>/dev/null ; then
    while true; do
	#echoerr "DEBUG:Starting while loop."
	# Update time constants
	TIME_CURRENT="$(date --iso-8601=seconds)" ;
	#echoerr "DEBUG:TIME_CURRENT is:""$TIME_CURRENT" ;
	TIME_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%dT%H%M%S%z)"
	#echoerr "DEBUG:TIME_CURRENT_SHORT is""$TIME_CURRENT_SHORT"
	DATE_CURRENT="$(date -d "$TIME_CURRENT" --iso-8601=date)" ;
	#echoerr "DEBUG:DATE_CURRENT is:""$DATE_CURRENT" ;
	DATE_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%d)" ;
	#echoerr "DEBUG:DATE_CURRENT is:""$DATE_CURRENT_SHORT" ;
	DATE_TOMORROW="$(date -d "$TIME_CURRENT next day" --iso-8601=date)" ;
	#echoerr "DEBUG:DATE_TOMORROW is:""$DATE_TOMORROW" ;
	TIME_NEXT_MIDNIGHT="$(date -d "$DATE_TOMORROW" --iso-8601=seconds)" ;
	#echoerr "DEBUG:TIME_NEXT_MIDNIGHT is:""$TIME_NEXT_MIDNIGHT" ;
	SECONDS_UNTIL_NEXT_MIDNIGHT="$((  $(date +%s -d "$TIME_NEXT_MIDNIGHT") - $(date +%s -d "$TIME_CURRENT")  ))" ;
	#echoerr "DEBUG:SECONDS_UNTIL_NEXT_MIDNIGHT is:""$SECONDS_UNTIL_NEXT_MIDNIGHT" ;
	if [ "$SECONDS_UNTIL_NEXT_MIDNIGHT" -eq 0 ]; then echoerr "WARNING:Is it exactly midnight?" ; continue; fi ; # Exit loop early if equal to 0 because "timeout 0s" never ends.
	if [ "$SECONDS_UNTIL_NEXT_MIDNIGHT" -lt 0 ]; then echoerr "ERROR:Time until midnight error." ; exit 1; fi ; # Exit script if equal to 0 because "timeout 0s" never ends.
	
	# Update output file names.
	DIROUTN="$DIROUT1" ;
	FILEOUTN="$DATE_CURRENT_SHORT""..""$(hostname)""_location.nmea" ;

	# Append location log until midnight.
	timeout "$SECONDS_UNTIL_NEXT_MIDNIGHT""s" gpspipe -r 1>> "$DIROUTN"/"$FILEOUTN" 2>>/dev/null ; # log raw nmea data
    done
    
    #gpspipe -r -d -l -o "$DIROUT1"/"$FILEOUT1" ;
    
else
    echo "$SCRIPT_TIME_SHORT"">gpspipe or $DIROUT1 not found." >> ~/"$SCRIPT_DATE_SHORT"..error.log ;
fi