#!/usr/bin/env bash

url2murl() {
	local x
	x=$1
	x=${x//'^'/'^5E'}
	x=${x//':'/'^3A'}
	x=${x//'%'/'^25'}
	printf '%s' "$x"
}

main() {
	set -euE -o pipefail
	shopt -s nullglob

	echo '# Pass 1'
	while read -r snap name date time size; do
		dirpart="${name%/*}"
		filepart="${name##*/}"
		filedir=dat/pools/files/"${date//-/}${time//:/}-${name//\//_}"
		snapdir=dat/pools/snaps/"${snap}-${dirpart//\//_}"
		mkdir -p -- "$filedir" "$snapdir"
		ln -sr "$filedir/$filepart" "$snapdir"
	done < "$1"

	echo '# Pass 1.5'
	# Looking at the data, there are 3 revisions that we DON'T
	# have directory listings for.  So we need to synthesize
	# those.
	#
	# I created the list of listings to synthesize by not
	# synthesizing anything, then looking for files ending in
	# ".1".  They are created during pass 2 if we have a file with
	# no matching listing.
	while read -r datetime dirpart newfiles; do
		# We need to figure out which files to put in the
		# directory listing.  We're going to do that by
		# mimicking the previous listing with that dirpart.
		prevsnap=''
		for isnap in dat/pools/snaps/*-"${dirpart//\//_}"; do
			isnap=${isnap##*/}
			if [[ "${isnap%%-*}" -lt "${datetime}00" ]]; then
				prevsnap=$isnap
			fi
		done
		if [[ -z "$prevsnap" ]]; then
			>& printf 'Could not find listing of %s before %s\n' "$dirpart" "$datetime"
			false
		fi
		# Ok, now copy that snapshot
		snapdir=dat/pools/snaps/"${datetime}00-${dirpart//\//_}"
		cp -aT dat/pools/snaps/"$prevsnap" "$snapdir"
		# And touch file files we need to change
		for filepart in $newfiles; do
			name="$dirpart/$filepart"
			filedir=dat/pools/files/"${datetime}-${name//\//_}"
			mkdir -p -- "$filedir"
			rm -- "$snapdir/$filepart"
			ln -sr "$filedir/$filepart" "$snapdir"
		done
	done < <(printf '%s\n' \
			'200303310700 PROGRAMS/CVTUTF     ConvertUTF.c ConvertUTF.h harness.c' \
			'200307291500 ALPHA/CVTUTF-1-1    ExpectedOutput.txt readme.txt' \
			'200412210100 PROGRAMS/CVTUTF.OLD CVTUTF7.C CVTUTF7.H' \
		)

	echo '# Pass 2'
	while read -r time url; do
		name="${url##*/Public/}"
		dirpart="${name%/*}"
		filepart="${name##*/}"

		if [[ -z "$filepart" ]]; then
			continue
		fi

		pools=(dat/pools/files/*-"${name//\//_}")
		pools=("${pools[@]##*/}")

		mypool=''
		for pool in "${pools[@]}"; do
			pooltime="${pool%%-*}"
			if [[ "${pooltime}00" -le "$time" ]]; then
				mypool=$pool
			fi
		done
		if [[ -z "$mypool" ]]; then
			>&2 printf 'Could not find pool for %s %s\n' "$time" "$url"
			false
		fi

		file="dat/content-file/$time/$(url2murl $url)"

		declare -i i=0
		while true; do
			link="dat/pools/files/$mypool/$filepart.$i"
			link="${link%.0}"
			a="$(readlink -f "$link")" || true
			b="$(readlink -f "$file")"
			if cmp -s -- "$a" "$b"; then
				break
			fi
			if ln -sr "$b" "$link"; then
				break
			fi
			i+=1
		done
	done < "$2"

	echo '# Pass 3'
	while read -r missing; do
		if [[ -f "${missing/.OLD}/${missing##*_}" ]]; then
			ln -sr "${missing/.OLD}/${missing##*_}" "$missing"
		fi
	done < <(find dat/pools/files/*-PROGRAMS_CVTUTF.OLD_* -type d -empty)
}

main "$@"