#!/bin/sh
set -e

CVSROOT=:pserver:anoncvs@cairographics.org:/cvs/cairo
GITMASTER=git://git.cairographics.org/cairo

if [ ! -e cairo-cvs ]; then
    echo -n "Performing CVS checkout to cairo-cvs..."
    cvs -d $CVSROOT co -d cairo-cvs cairo > /dev/null
    echo "done."
fi

if [ ! -e cairo-git ]; then
    echo -n "Cloning git repository to cairo-git..."
    git clone $GITMASTER cairo-git
    echo "done."
fi

# This is what you probably want to check all tags
#for tag in $(ls cairo-git/.git/refs/tags); do

# Instead, for cairo we whitelist the tags to check since there are
# some bogus partial-tree tags that just aren't interesting.
for tag in SNAPSHOT_0_1_16 SNAPSHOT_0_1_20 SNAPSHOT_0_1_21 SNAPSHOT_0_1_22 SNAPSHOT_0_1_23 LGPL_CHANGE_BEFORE LGPL_CHANGE_AFTER SNAPSHOT_0_2_0 SNAPSHOT_0_3_0 SNAPSHOT_0_4_0 SNAPSHOT_0_5_0 SNAPSHOT_0_5_1 SNAPSHOT_0_5_2 SNAPSHOT_0_6_0 RELEASE_0_9_0 RELEASE_0_9_2 RELEASE_1_0_0 RELEASE_1_0_2; do

    echo -n "Performing cvs update to $tag..."
    (cd cairo-cvs; cvs -Q update -r $tag > /dev/null)
    echo "done."

    echo -n "Performing git checkout of $tag..."

    # Linus says this is the most efficient way to do this, but it
    # seems to leave some empty directories around that shouldn't be
    # there.
    # (cd cairo-git; git checkout -b cvs-compare >& /dev/null || true; git checkout cvs-compare; git reset --hard $tag)

    # This might be slower, but it's plenty fast still and it does the right thing
    (cd cairo-git; git checkout master; git branch -D cvs-compare >& /dev/null || true; git checkout -b cvs-compare $tag)

    echo "done."

    echo -n "Comparing cvs and git trees for $tag..."
    if diff -r -x CVS -x .git cairo-cvs cairo-git >& cairo.diff; then
	echo "perfect."
	rm cairo.diff
    else
	echo "different. :("
	echo "	Saving trees to cairo-git-$tag & cairo-cvs-$tag and diff to cairo-$tag.diff"
	cp -a cairo-git cairo-git-$tag
	cp -a cairo-cvs cairo-cvs-$tag
	mv cairo.diff cairo-$tag.diff
    fi

done