#!/bin/sh
# Run a command over a sequence of commits.
# Example:
#  git test-sequence origin/master.. 'make clean && make test'

. "$(git --exec-path)/git-sh-setup"
require_work_tree

t=
force=
run_once=
ref_name=pass

# The tree must be really really clean.
if ! git update-index --ignore-submodules --refresh > /dev/null; then
    echo >&2 "cannot rebase: you have unstaged changes"
    git diff-files --name-status -r --ignore-submodules -- >&2
    exit 1
fi
diff=$(git diff-index --cached --name-status -r --ignore-submodules HEAD --)
case "$diff" in
    ?*) echo >&2 "cannot rebase: your index contains uncommitted changes"
        echo >&2 "$diff"
        exit 1
        ;;
esac

start_branch=`git rev-parse --symbolic-full-name HEAD | sed s,refs/heads/,,`
git checkout `git rev-parse HEAD` > /dev/null 2>/dev/null

cleanup() {
    git checkout $start_branch > /dev/null 2>/dev/null
}

already_passed() {
    obdata=${ref_name}-$t-$1
    obhash=`echo $obdata | git hash-object --stdin`
    git cat-file blob $obhash > /dev/null 2>/dev/null \
        && echo "Already ${ref_name} $1"
}

passed_on() {
    obdata=${ref_name}-$t-$1
    echo $obdata | git hash-object -w --stdin > /dev/null
    echo "Passed: $1."
}

broke_on() {
    git log --pretty="format:Broke on %H (%s)%n" -n 1 $1
    cleanup
    exit 1
}

new_test() {
    echo "Testing $2"
    git reset --hard $v && eval "$2" && passed_on $1 || broke_on $v
    status=$?
    if test -n "$run_once"; then
        cleanup
        exit $status
    fi
}


while test $# != 0
do
    case "$1" in
        --force)
            force=yes
            ;;
        --once)
            run_once=yes
            ;;
        --ref-name)
            ref_name=$2
            shift
            ;;
        *)
            break;
            ;;
    esac
    shift
done

t=`echo "$2" | git hash-object --stdin`

for v in `git rev-list --reverse $1`
do
    tree_ver=`git rev-parse "$v^{tree}"`
    test -z "$force" && already_passed $tree_ver || new_test $tree_ver "$2"
done
cleanup

if test -n "$run_once"; then
    echo "All commits already passed for --once argument. Quiting."
    exit 127
fi

echo "All's well."