#!/bin/bash

set -e

DIR="$( cd "$( dirname "$(realpath "${BASH_SOURCE[0]}")" )" &> /dev/null && pwd )"
PROGNAME="$0"

BOLD=$(tput bold)
RST=$(tput sgr0)
RED=$(tput setaf 1)
GREEN=$(tput setaf 2)
YELLOW=$(tput setaf 3)
CYAN=$(tput setaf 6)

input=
output=
command=
motion_threshold=1
ffmpeg_args="-nostats -loglevel error"
dvr_scan_args="-q"
verbose=
config_dir=$HOME/.config/video-util
config_dir_set=
write_data_prefix=
write_data_time=

_time_started=

time_start() {
	_time_started=$(date +%s)
}

time_elapsed() {
	local _time_finished=$(date +%s)
	echo $(( _time_finished - _time_started ))
}

debug() {
	if [ -n "$verbose" ]; then
		>&2 echo "$@"
	fi
}

echoinfo() {
	>&2 echo "${CYAN}$@${RST}"
}

echoerr() {
	>&2 echo "${RED}${BOLD}error:${RST}${RED} $@${RST}"
}

echowarn() {
	>&2 echo "${YELLOW}${BOLD}warning:${RST}${YELLOW} $@${RST}"
}

die() {
    echoerr "$@"
    exit 1
}

file_in_use() {
	[ -n "$(lsof "$1")" ]
}

get_mtime() {
	stat -c %Y "$1"
}

# converts date in format yyyy-mm-dd-hh.ii.ss to unixtime
date_to_unixtime() {
	local date="$1"
	date=${date//./-}
	date=${date//-/ }

	local nums=($date)
	
	local y=${nums[0]}
	local m=${nums[1]}
	local d=${nums[2]}
	local h=${nums[3]}
	local i=${nums[4]}
	local s=${nums[5]}

	date --date="$y-$m-$d $h:$i:$s" +"%s"
}

filename_as_unixtime() {
	local name="$1"
	name="$(basename "$name")"
	name="${name/record_/}"
	name="${name/.mp4/}"
	date_to_unixtime "$name"
}

config_get_prev_mtime() {
	local prefix="$1"
	[ -z "$prefix" ] && die "config_get_prev_mtime: no prefix"

	local file="$config_dir/${prefix}_mtime"
	if [ -f "$file" ]; then
		debug "config_get_prev_mtime: $(cat "$file")"
		cat "$file"
	else
		debug "config_get_prev_mtime: 0"
		echo "0"
	fi
}

config_set_prev_mtime() {
	local prefix="$1"
	[ -z "$prefix" ] && die "config_set_prev_mtime: no prefix"

	local mtime="$2"
	[ -z "$mtime" ] && die "config_set_prev_mtime: no mtime"

	local file="$config_dir/${prefix}_mtime"
	
	debug "config_set_prev_mtime: writing '$mtime' to '$file'"
	echo "$mtime" > "$file"
}

usage() {
	cat <<EOF
usage: $PROGNAME OPTIONS command

Options:
	-i|--input  FILE  input file/directory
	-o|--output FILE  output file/directory
	--name NAME       camera name, affects config directory.
	                  default is $config_dir, specifying --name will make it 
	                  ${config_dir}-\$name
	-mt VALUE         motion threshold, default is $motion_threshold
	--write-data PREFIX FILENAME|UNIXTIME
	                  use with write-mtime-config command.
	                  second value may be filename (starting with record_)
	                  or number (unix timestamp).
	-v, -vv, vx       be verbose.
	                  -v enables debug logs.
	                  -vv also enables verbose output of ffmpeg and dvr-scan.
	                  -vx does \`set -x\`, may be used to debug the script.

Commands:
	fix             fix video timestamps
	mass-fix        fix timestamps of all videos in directory
	mass-fix-mtime  fix mtimes of recordings
	motion          detect motion
	mass-motion     detect motion
	snapshot        take video snapshot
	write-mtime-config

EOF
	exit 1
}

check_input_file() {
	[ -z "$input" ] && die "input file not specified"
	[ -f "$input" ] || die "input file '$input' doesn't exist"
}

check_input_dir() {
	[ -z "$input" ] && die "input directory not specified"
	[ -d "$input" ] || die "input directory '$input' doesn't exist"
}

fix_video_timestamps() {
	local input="$1"
	local dir=$(dirname "$input")
	local temp="$dir/.temporary_fixing.mp4"

	local mtime=$(get_mtime "$input")

	# debug "fix_video_timestamps: ffmpeg $ffmpeg_args -i \"$input\" -y -c copy \"$temp\""
	ffmpeg $ffmpeg_args -i "$input" -y -c copy "$temp" </dev/null
	rm "$input"
	mv "$temp" "$input"

	local unixtime=$(filename_as_unixtime "$input")
	touch --date=@$unixtime "$input"
}

do_mass_fix() {
	local mtime=$(config_get_prev_mtime "fix")
	local tmpfile=$(mktemp)
	debug "do_mass_fix: created temporary file $tmpfile"
	
	touch --date=@$mtime "$tmpfile"
	debug "do_mass_fix: mtime of temp file: $(get_mtime $tmpfile)"
	
	[ -f "$input/.temporary_fixing.mp4" ] && {
		echowarn "do_mass_fix: '$input/.temporary_fixing.mp4' exists, deleting"
		rm "$input/.temporary_fixing.mp4"
	}

	# find all files in $input directory, newer than $tmpfile's time,
	# sort them in ascending order, and finally remove timestamps
	# leaving only file names. Then loop through each line
	find "$input" -type f -newer "$tmpfile" -printf "%T+ %p\n" | sort | awk '{print $2}' | while read file; do
		if ! file_in_use "$file"; then
			debug "do_mass_fix: calling fix_video_timestamps($file)"
			
			fix_video_timestamps "$file"
			echoinfo "fixed $file"
		
			config_set_prev_mtime "fix" "$(filename_as_unixtime "$file")"
		else
			echowarn "file '$file' is in use"
		fi
	done

	rm "$tmpfile"
}

do_mass_fix_mtime() {
	local time
	find "$input" -type f -name "*.mp4" | while read file; do
		if [[ "$(basename "$file")" =~ ^record_.* ]]; then
			time="$(filename_as_unixtime "$file")"
			debug "$file: $time"
			touch --date=@$time "$file"
		else
			echowarn "unrecognized file: $file"
		fi
	done
}

do_motion() {
	local input="$1"
	local timecodes=()
	local roi_file="$config_dir/roi.txt"
	if ! [ -f "$roi_file" ]; then
		timecodes+=($(dvr_scan "$input"))
	else
		echoinfo "using roi sets from file: ${BOLD}$roi_file"
		while read line; do
			if ! [[ "$line" =~ ^#.*  ]]; then
				timecodes+=("$(dvr_scan "$input" "$line")")
			fi
		done < <(cat "$roi_file")
	fi

	timecodes="${timecodes[@]}"
	timecodes=${timecodes// /,}

	if [ -z "$timecodes" ]; then
		debug "do_motion: no motion detected"
	else
		debug "do_motion: detected timecodes: $timecodes"

		local output_dir="$(dirname "$input")/motion"
		if ! [ -d "$output_dir" ]; then
			mkdir "$output_dir" || die "do_motion: mkdir($output_dir) failed"
			debug "do_motion: created $output_dir directory"
		fi

		local fragment
		while read line; do
			fragment=($line)
			debug "do_motion: writing fragment start=${fragment[0]} duration=${fragment[1]} filename=$output_dir/${fragment[2]}"
			ffmpeg $ffmpeg_args -i "$input" -ss ${fragment[0]} -t ${fragment[1]} -c copy -y "$output_dir/${fragment[2]}" </dev/null
		done < <($DIR/process-motion-timecodes.py --source-filename "$input" --timecodes "$timecodes")
	fi
}

do_mass_motion() {
	local input="$1"
	local saved_time=$(config_get_prev_mtime motion)
	debug "do_mass_motion: saved_time=$saved_time"

	local file_time
	local file

	while read file; do
		file_time="$(filename_as_unixtime "$(basename "$file")")"
		#debug "do_mass_motion: time of ${BOLD}${file}${RST} is ${BOLD}${file_time}${RST}"
		(( file_time <= saved_time )) && continue

		debug "do_mass_motion: processing $file"
		do_motion "$file"

		config_set_prev_mtime motion $file_time
	done < <(find "$input" -type f -name "record_*.mp4" | sort)
}

#dvr_scan_fake() {
#	echo "00:05:06.930,00:05:24.063"
#}

dvr_scan() {
	local input="$1"
	local args=
	if [ ! -z "$2" ]; then
		args="-roi $2"
		echoinfo "dvr_scan(${BOLD}${input}${RST}${CYAN}): roi=($2), mt=$motion_threshold"
	else
		echoinfo "dvr_scan(${BOLD}${input}${RST}${CYAN}): no roi, mt=$motion_threshold"
	fi
	time_start
	dvr-scan $dvr_scan_args -i "$input" -so --min-event-length 3s -df 3 --frame-skip 2 -t $motion_threshold $args | tail -1
	debug "dvr_scan: finished in $(time_elapsed)s"
}

[[ $# -lt 1 ]] && usage

while [[ $# -gt 0 ]]; do
	case $1 in
		fix|mass-fix|motion|snapshot|mass-fix-mtime|mass-motion|write-mtime-config)
			command="$1"
			shift
			;;

		-i|--input)
			input="$2"
			shift; shift
			;;

		-o|--output)
			output="$2"
			shift; shift
			;;

		-mt)
			motion_threshold="$2"
			shift; shift
			;;

		--write-data)
			write_data_prefix="$2"
			write_data_time="$3"
			shift; shift; shift
			;;

		-v)
			verbose=1
			shift
			;;

		-vx)
			verbose=1
			set -x
			shift
			;;

		-vv)
			verbose=1
			ffmpeg_args="-loglevel info"
			dvr_scan_args=""
			shift
			;;

		--name)
			config_dir="$config_dir-$2"
			config_dir_set=1
			shift; shift
			;;

		*)
			die "unrecognized option $1"
			exit 1
			;;
	esac
done

if [ -z "$config_dir_set" ]; then
	echowarn "no --name specified, using default ($config_dir)"
else
	if [ ! -d "$config_dir" ]; then
		mkdir "$config_dir" || die "failed to create config directory ($config_dir)"
	fi
	>&2 echo "using ${BOLD}$config_dir${RST} as config directory"
fi

[ -z "$command" ] && die "command not specified"
case "$command" in
	fix)
		check_input_file
		fix_video_timestamps "$input"
		echo "done"
		;;

	mass-fix)
		check_input_dir
		do_mass_fix
		;;

	mass-fix-mtime)
		check_input_dir
		do_mass_fix_mtime
		;;

	motion)
		check_input_file
		do_motion "$input"
		;;

	mass-motion)
		check_input_dir
		do_mass_motion "$input"
		;;

	snapshot)
		check_input_file
		[ -z "$output" ] && {
			echowarn "--output not specified, using snapshot.jpg as default"
			output="snapshot.jpg"
		}
		ffmpeg $ffmpeg_args -i "$input" -frames:v 1 -q:v 2 "$output" </dev/null
		echoinfo "saved to $output"
		;;

	write-mtime-config)
		if [ -z "$write_data_prefix" ] || [ -z "$write_data_time" ]; then
			die "--write-data is required, see usage"
		fi

		if [[ $write_data_time == record_* ]]; then
			write_data_time=$(filename_as_unixtime "$write_data_time")
			[ -z "$write_data_time" ] && die "invalid filename"
		elif ! [[ $write_data_time =~ '^[0-9]+$' ]] ; then
			die "invalid timestamp or filename"
		fi

		config_set_prev_mtime "$write_data_prefix" "$write_data_time"
		;;

	*)
		echo "error: invalid command '$command'"
		;;
esac