#!/bin/bash
if [ $# -lt 1 ]; then
    echo "syntax: $0 <commit count> [<make args>]"
    echo "will attempt to run 'make' on each commit starting with the commit <commit count> commits ago all the way up to the current HEAD"
    echo "e.g. compile-commits 10 -j10"
    exit 1
fi

if [ ! -d ".git" ]; then
    echo ".git not found or not a dir"
    exit 2
fi

commit_count=$1
shift

# determine current branch
head=$(cat .git/HEAD)
branch=${head:16}
if [ "$branch" = "" ]; then
    echo "could not determine branch from $head (.git/HEAD)"
    exit 3
fi

# iterate commits - this iteration is in the opposite order (newest to oldest) of what we want
ordered_commits=""
for i in $(git log -$commit_count|grep "^commit [a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9][a-z0-9]$"); do
    if [ "$i" = "commit" ]; then continue; fi
    commit=$i
    ordered_commits="$commit $ordered_commits"
done

report=""
rebase_head=$commit_count
let rebase_head++ # if we rebase the first commit, we need to do HEAD~(arg + 1)
left=""
done=""
for i in $(seq 1 $commit_count); do
    left="$left "
    clr="$clr "
done
clr="$clr  \r"

clean_up=1
function trap_ctrlc()
{
    if [ $clean_up ]; then
	echo -n -e "\r$clr""Aborting..."
	git checkout $branch &>/dev/null
	echo ""
	exit 2
    fi
}

trap "trap_ctrlc" INT

for i in $ordered_commits; do
    git checkout $i &> .gco-output
    if [ $? -ne 0 ]; then echo "git checkout $i failed:"; echo "====="; cat .gco-output; rm .gco-output; git checkout $branch; exit 10; fi
    rm .gco-output
    echo -n -e "$i"
    git show HEAD | head -n5 | tail -n1
    echo -n -e "[$done$left]\r"
    make "$@" &> .make-output
    makeres=$?
    echo -n -e "$clr"
    if [ $makeres -ne 0 ]; then
	prevreport=$report
	report="$report$i: make failure\n"
	echo "make FAILURE"
	echo "====="
	cat .make-output
	rm .make-output
	while [ 1 ]; do
	    echo -n -e "rebase (r), ignore (i), or return to $branch (b): "
	    read x
	    if [ "$x" = "r" ]; then
		git checkout $branch
		git rebase -i HEAD~$rebase_head
		exit 12
	    elif [ "$x" = "i" ]; then
		break
	    elif [ "$x" = "b" ]; then
		git checkout $branch
		if [ "$prevreport" != "" ]; then
		    echo -n -e "Results:\n$report"
		fi
		exit 11
	    fi
	done
    fi
    rm .make-output
    left=${left:1}
    done="#$done"
done

git checkout $branch &> .gco-output
if [ $? -ne 0 ]; then echo "git checkout $i failed:"; echo "====="; cat .gco-output; rm .gco-output; exit 10; fi
rm .gco-output

if [ "$report" = "" ]; then
    echo "All OK"
else
    echo -n -e "Results:\n$report"
fi