#!/bin/sh

[ -d "$1" ] || exit 1  # Exit with error if not pointing to a directory

# Misc
duration() { ffprobe -i "$1" -show_entries format=duration -v quiet -of csv="p=0" | tr -d . ; }
timebase="1/1000000"  # duration function gives microseconds

safename() { echo "$1" | tr -d '<>:"/\|?*' ; }

# Temp dirs
workdir="$(mktemp -d "${TMPDIR:-/tmp}/combinetapesworkdir.XXXXXX")"

cleanup() { rm -rf "$workdir" ; }
trap cleanup EXIT INT HUP QUIT TERM ALRM USR1

# Loop vars
current_date=0
duration_total=0
chapter_start=0
chapter_time=0
last_chapter_concurrent=0

# TODO this relys on the for loop looping in order

# Either can be ran on single dv containing directory, or many dv containing directories
for dir in "$1"/ "$1"/*/; do
	dir="${dir%/}"  # Remove trailing slash
	title=""

	if [ "$dir" != "$1" ]; then
		title="$(basename "$dir")"
	fi
	if echo "$dir" | grep '/\*' >/dev/null; then
		break
	fi

	for tape in "$dir"/*.dv; do
		date="$(echo "$(basename "$tape")" | grep -o '[0-9]*\.[0-9]*\.[0-9]*' | tr '.' '-')"
		time="$(echo "$(basename "$tape")" | grep -o '[0-9]*-[0-9]*-[0-9]*'   | tr '-' ':')"

		if [ "$title$date" != "$current_date" ]; then
			# Reset vars
			current_date="$title$date"
			duration_total=0
			chapter_start=0
			chapter_time=0
			last_chapter_concurrent=0

			# Create dirs
			date_dir="$workdir/$current_date"
			mkdir -p "$date_dir"

			files="$date_dir/files"
			chapters="$date_dir/chapters"

			# Init chapters file
			printf ";FFMETADATA1\n\n" > "$chapters"

			# title file
			if [ "$title" ]; then
				echo "$title" > "$date_dir/title"
			fi
		fi

		# Concat files
		echo "file '$(realpath "$tape" | sed "s/'/'\\\\''/g")'" >> "$files"

		# Chapter marker
		tape_duration=$(duration "$tape" | grep -o "[1-9][0-9]*")
		duration_total=$(( $duration_total + $tape_duration ))

		# Only insert chapter marker if recordings are not concurrent. dvgrab
		# splits files into 1gb chunks, or 291557933 microseconds of raw dv footage
		# (with digital 8)
		if [ $last_chapter_concurrent = 0 ]; then
			chapter_time=$time
		fi
		if [ $tape_duration = 291557933 ]; then
			last_chapter_concurrent=1
			continue
		else
			last_chapter_concurrent=0
		fi

		echo "[CHAPTER]"                             >> "$chapters"
		echo "TIMEBASE=$timebase"                    >> "$chapters"
		echo "START=$chapter_start"                  >> "$chapters"
		echo "END=$duration_total"                   >> "$chapters"
		echo "title=Section starts at $chapter_time" >> "$chapters"
		echo                                         >> "$chapters"

		chapter_start=$duration_total
	done
done


# ffmpeg combine
out_dir=export
default_title=Untitled
mkdir -p "$out_dir"

for date_dir in "$workdir"/*; do
	date="$(echo "$date_dir" | grep -o "[0-9][0-9][0-9][0-9]-[0-9]*-[0-9]*")"
	origin_tape="$(basename "$1")"

	# Files
	title="$date_dir/title"
	files="$date_dir/files"
	chapters="$date_dir/chapters"

	# Nicely title
	if [ -e "$title" ]; then
		# title file
		output_title="$(cat "$title")"
	#elif echo "$origin_tape" | grep "^[^0-9].*[0-9]*-[0-9]*-[0-9]*" >/dev/null; then
	#	# Beginning descriptor
	#	output_title="$(echo "$origin_tape" | sed 's/ [0-9#].*//')"
	#elif echo "$origin_tape" | grep "$date [A-Z]" >/dev/null; then
	#	# Date range or list of dates with titles (Title must be capitalized, 'to' must be made lowercase
	#	output_title="$(echo "$origin_tape" | sed "s/.*$date //; s/ to [0-9].*//; s/;.*//")"
	else
		# default
		output_title=$default_title
	fi

	output_title="$(echo "$output_title" | sed 's/\s*#[0-9]*$//')"  # Remove sequence numbers

	# File name
	if [ "$output_title" = "$default_title" ]; then
		output_name="$date"
	else
		output_name="$date $output_title"
	fi

	if [ -e "$out_dir/$output_name.mp4" ]; then
		output=$(ls "$out_dir" | grep "$output_name *[0-9]*.mp4" | while read -r file; do
			file_tape="$(mediainfo "$out_dir/$file" | sed -n 's/Comment.* - Origin tape: //p')"
			if [ "$origin_tape" = "$file_tape" ]; then
				echo 0
				break
			fi
		done)
		if [ "$output" = 0 ]; then
			continue
		fi
		output_name="$output_name $(ls "$out_dir" | grep "$output_name *[0-9]*.mp4" | wc -l)"
	fi

	# Convert
		#-c copy \
		#-metadata "title=$output_title" \  # Dont set title since it will be stuck if file is renamed
	ffmpeg -hide_banner -nostdin \
		-n \
		-f concat -safe 0 -i "$files" \
		-i "$chapters" -map_metadata 1 \
		-c:v libx264 -crf 22 -preset medium -tune grain \
		-vf yadif \
		-c:a aac -b:a 320k \
		-metadata "date=$date" \
		-metadata "comment=tapes.tjkeller.xyz - Origin tape: $origin_tape" \
		"$out_dir/$output_name.mp4"
		#"$out_dir/$output_name.mkv"
done