#!/bin/bash
# 
# Mirror git repository with submodules - recursively
#
# Usage:
#  mirror-recursive <main repo url> [<depth=1000>]

# strict mode
set -euo pipefail
IFS=$'\n\t'

# Scratch - temp
tmpdir=$(mktemp -d -t mirror-recursive-XXXXXXX)
function finish {
	rm -rf "$tmpdir"
}
trap finish EXIT

source $(dirname $(realpath $0))/config
source $(dirname $(realpath $0))/gen-mirror-path


function progress(){
	local progress=${1:-100}
	echo -n "..$progress%"
	if [ $progress -eq 100 ] 
	then
		echo
	fi
}

function submoduleDiscovery(){
	# main parameters
	local repo=$1
	local gitdir=$(getRepoPath $repo)
	# depth (empty or prefixed from main script)
	local depth=${2:-}
	# temporary path
	local tmpname=$(getRepoUniq $repo)
	tmpname=$tmpdir/$tmpname
	local tmpCommitList=$tmpname.commits
	local tmpSubmoduleList=$tmpname.submodules
	# cache paths
	local cachePath=$(getRepoCache $repo)
	local cacheCommits=$cachePath/commits-checked
	local cacheSubmodules=$cachePath/submodules-checked

	# check, if cache exists
	[ -d $cachePath ] || mkdir -p $cachePath
	[ -f $cacheCommits ] || touch $cacheCommits
	[ -f $cacheSubmodules ] || touch $cacheSubmodules

	# avoid recursion - if commit list exists
	# there was activity with this run recently
	if [ ! -f $tmpCommitList ] 
	then

		# cache submodules reuse
		cat $cacheSubmodules > $tmpSubmoduleList

		echo -n "Discovering submodules of $repo.. "
		git --git-dir $gitdir  log --all $depth --format="%H" | sort > $tmpCommitList

		# check against cache
		echo -n "cache check.."
		comm -13 $cacheCommits $tmpCommitList > $tmpname
		mv $tmpname $tmpCommitList

		local commits=$(wc -l $tmpCommitList | cut -d' ' -f1)
		echo -n "$commits commits"
		# this can take long time...
		local processed=0
		local nextStamp=$(($(date +"%s") + 3))
		while read -r line || [[ -n "$line" ]]
		do
			submodule-describe $gitdir $line | cut -f 3 >> $tmpSubmoduleList
			# progress indication
			processed=$(($processed + 1))
			if [ $(date +"%s") -gt $nextStamp ]
			then
				progress $((100*$processed/$commits))
				nextStamp=$(($nextStamp + 3))
			fi
		done < $tmpCommitList
		# finish the bar
		progress

		# archive to cache
		cat $tmpCommitList $cacheCommits > $tmpname
		sort $tmpname > $cacheCommits
		sort $tmpSubmoduleList | uniq > $tmpname
		cat $tmpname > $cacheSubmodules

		# Recursion++
		while read -r submodule || [[ -n "$submodule" ]] 
		do
			mirror-main-repo $submodule
			submoduleDiscovery $submodule $depth
		done < $cacheSubmodules
	fi

}

# main repo
mainrepo=$1
depth=${2:-}

[ -n "$depth" ] && depth="-$depth"

# Make first mirror
mirror-main-repo $mainrepo
submoduleDiscovery $mainrepo $depth