#!/bin/sh

test_description='commit graph'
. ./test-lib.sh

test_expect_success 'setup full repo' '
        mkdir full &&
        cd "$TRASH_DIRECTORY/full" &&
        git init &&
        git config core.commitGraph true &&
        objdir=".git/objects" &&
        test_oid_init
'

test_expect_success 'verify graph with no graph file' '
        cd "$TRASH_DIRECTORY/full" &&
        git commit-graph verify
'

test_expect_success 'write graph with no packs' '
        cd "$TRASH_DIRECTORY/full" &&
        git commit-graph write --object-dir . &&
        test_path_is_file info/commit-graph
'

test_expect_success 'create commits and repack' '
        cd "$TRASH_DIRECTORY/full" &&
        for i in $(test_seq 3)
        do
                test_commit $i &&
                git branch commits/$i
        done &&
        git repack
'

graph_git_two_modes() {
        git -c core.commitGraph=true $1 >output
        git -c core.commitGraph=false $1 >expect
        test_cmp expect output
}

graph_git_behavior() {
        MSG=$1
        DIR=$2
        BRANCH=$3
        COMPARE=$4
        test_expect_success "check normal git operations: $MSG" '
                cd "$TRASH_DIRECTORY/$DIR" &&
                graph_git_two_modes "log --oneline $BRANCH" &&
                graph_git_two_modes "log --topo-order $BRANCH" &&
                graph_git_two_modes "log --graph $COMPARE..$BRANCH" &&
                graph_git_two_modes "branch -vv" &&
                graph_git_two_modes "merge-base -a $BRANCH $COMPARE"
        '
}

graph_git_behavior 'no graph' full commits/3 commits/1

graph_read_expect() {
        OPTIONAL=""
        NUM_CHUNKS=3
        if test ! -z $2
        then
                OPTIONAL=" $2"
                NUM_CHUNKS=$((3 + $(echo "$2" | wc -w)))
        fi
        cat >expect <<- EOF
        header: 43475048 1 1 $NUM_CHUNKS 0
        num_commits: $1
        chunks: oid_fanout oid_lookup commit_metadata$OPTIONAL
        EOF
        git commit-graph read >output &&
        test_cmp expect output
}

test_expect_success 'write graph' '
        cd "$TRASH_DIRECTORY/full" &&
        git commit-graph write &&
        test_path_is_file $objdir/info/commit-graph &&
        graph_read_expect "3"
'

graph_git_behavior 'graph exists' full commits/3 commits/1

test_expect_success 'Add more commits' '
        cd "$TRASH_DIRECTORY/full" &&
        git reset --hard commits/1 &&
        for i in $(test_seq 4 5)
        do
                test_commit $i &&
                git branch commits/$i
        done &&
        git reset --hard commits/2 &&
        for i in $(test_seq 6 7)
        do
                test_commit $i &&
                git branch commits/$i
        done &&
        git reset --hard commits/2 &&
        git merge commits/4 &&
        git branch merge/1 &&
        git reset --hard commits/4 &&
        git merge commits/6 &&
        git branch merge/2 &&
        git reset --hard commits/3 &&
        git merge commits/5 commits/7 &&
        git branch merge/3 &&
        git repack
'

# Current graph structure:
#
#   __M3___
#  /   |   \
# 3 M1 5 M2 7
# |/  \|/  \|
# 2    4    6
# |___/____/
# 1

test_expect_success 'write graph with merges' '
        cd "$TRASH_DIRECTORY/full" &&
        git commit-graph write &&
        test_path_is_file $objdir/info/commit-graph &&
        graph_read_expect "10" "extra_edges"
'

graph_git_behavior 'merge 1 vs 2' full merge/1 merge/2
graph_git_behavior 'merge 1 vs 3' full merge/1 merge/3
graph_git_behavior 'merge 2 vs 3' full merge/2 merge/3

test_expect_success 'Add one more commit' '
        cd "$TRASH_DIRECTORY/full" &&
        test_commit 8 &&
        git branch commits/8 &&
        ls $objdir/pack | grep idx >existing-idx &&
        git repack &&
        ls $objdir/pack| grep idx | grep -v -f existing-idx >new-idx
'

# Current graph structure:
#
#      8
#      |
#   __M3___
#  /   |   \
# 3 M1 5 M2 7
# |/  \|/  \|
# 2    4    6
# |___/____/
# 1

graph_git_behavior 'mixed mode, commit 8 vs merge 1' full commits/8 merge/1
graph_git_behavior 'mixed mode, commit 8 vs merge 2' full commits/8 merge/2

test_expect_success 'write graph with new commit' '
        cd "$TRASH_DIRECTORY/full" &&
        git commit-graph write &&
        test_path_is_file $objdir/info/commit-graph &&
        graph_read_expect "11" "extra_edges"
'

graph_git_behavior 'full graph, commit 8 vs merge 1' full commits/8 merge/1
graph_git_behavior 'full graph, commit 8 vs merge 2' full commits/8 merge/2

test_expect_success 'write graph with nothing new' '
        cd "$TRASH_DIRECTORY/full" &&
        git commit-graph write &&
        test_path_is_file $objdir/info/commit-graph &&
        graph_read_expect "11" "extra_edges"
'

graph_git_behavior 'cleared graph, commit 8 vs merge 1' full commits/8 merge/1
graph_git_behavior 'cleared graph, commit 8 vs merge 2' full commits/8 merge/2

test_expect_success 'build graph from latest pack with closure' '
        cd "$TRASH_DIRECTORY/full" &&
        cat new-idx | git commit-graph write --stdin-packs &&
        test_path_is_file $objdir/info/commit-graph &&
        graph_read_expect "9" "extra_edges"
'

graph_git_behavior 'graph from pack, commit 8 vs merge 1' full commits/8 merge/1
graph_git_behavior 'graph from pack, commit 8 vs merge 2' full commits/8 merge/2

test_expect_success 'build graph from commits with closure' '
        cd "$TRASH_DIRECTORY/full" &&
        git tag -a -m "merge" tag/merge merge/2 &&
        git rev-parse tag/merge >commits-in &&
        git rev-parse merge/1 >>commits-in &&
        cat commits-in | git commit-graph write --stdin-commits &&
        test_path_is_file $objdir/info/commit-graph &&
        graph_read_expect "6"
'

graph_git_behavior 'graph from commits, commit 8 vs merge 1' full commits/8 merge/1
graph_git_behavior 'graph from commits, commit 8 vs merge 2' full commits/8 merge/2

test_expect_success 'build graph from commits with append' '
        cd "$TRASH_DIRECTORY/full" &&
        git rev-parse merge/3 | git commit-graph write --stdin-commits --append &&
        test_path_is_file $objdir/info/commit-graph &&
        graph_read_expect "10" "extra_edges"
'

graph_git_behavior 'append graph, commit 8 vs merge 1' full commits/8 merge/1
graph_git_behavior 'append graph, commit 8 vs merge 2' full commits/8 merge/2

test_expect_success 'build graph using --reachable' '
        cd "$TRASH_DIRECTORY/full" &&
        git commit-graph write --reachable &&
        test_path_is_file $objdir/info/commit-graph &&
        graph_read_expect "11" "extra_edges"
'

graph_git_behavior 'append graph, commit 8 vs merge 1' full commits/8 merge/1
graph_git_behavior 'append graph, commit 8 vs merge 2' full commits/8 merge/2

test_expect_success 'setup bare repo' '
        cd "$TRASH_DIRECTORY" &&
        git clone --bare --no-local full bare &&
        cd bare &&
        git config core.commitGraph true &&
        baredir="./objects"
'

graph_git_behavior 'bare repo, commit 8 vs merge 1' bare commits/8 merge/1
graph_git_behavior 'bare repo, commit 8 vs merge 2' bare commits/8 merge/2

test_expect_success 'write graph in bare repo' '
        cd "$TRASH_DIRECTORY/bare" &&
        git commit-graph write &&
        test_path_is_file $baredir/info/commit-graph &&
        graph_read_expect "11" "extra_edges"
'

graph_git_behavior 'bare repo with graph, commit 8 vs merge 1' bare commits/8 merge/1
graph_git_behavior 'bare repo with graph, commit 8 vs merge 2' bare commits/8 merge/2

test_expect_success 'perform fast-forward merge in full repo' '
        cd "$TRASH_DIRECTORY/full" &&
        git checkout -b merge-5-to-8 commits/5 &&
        git merge commits/8 &&
        git show-ref -s merge-5-to-8 >output &&
        git show-ref -s commits/8 >expect &&
        test_cmp expect output
'

test_expect_success 'check that gc computes commit-graph' '
        cd "$TRASH_DIRECTORY/full" &&
        git commit --allow-empty -m "blank" &&
        git commit-graph write --reachable &&
        cp $objdir/info/commit-graph commit-graph-before-gc &&
        git reset --hard HEAD~1 &&
        git config gc.writeCommitGraph true &&
        git gc &&
        cp $objdir/info/commit-graph commit-graph-after-gc &&
        ! test_cmp_bin commit-graph-before-gc commit-graph-after-gc &&
        git commit-graph write --reachable &&
        test_cmp_bin commit-graph-after-gc $objdir/info/commit-graph
'

test_expect_success 'replace-objects invalidates commit-graph' '
        cd "$TRASH_DIRECTORY" &&
        test_when_finished rm -rf replace &&
        git clone full replace &&
        (
                cd replace &&
                git commit-graph write --reachable &&
                test_path_is_file .git/objects/info/commit-graph &&
                git replace HEAD~1 HEAD~2 &&
                git -c core.commitGraph=false log >expect &&
                git -c core.commitGraph=true log >actual &&
                test_cmp expect actual &&
                git commit-graph write --reachable &&
                git -c core.commitGraph=false --no-replace-objects log >expect &&
                git -c core.commitGraph=true --no-replace-objects log >actual &&
                test_cmp expect actual &&
                rm -rf .git/objects/info/commit-graph &&
                git commit-graph write --reachable &&
                test_path_is_file .git/objects/info/commit-graph
        )
'

test_expect_success 'commit grafts invalidate commit-graph' '
        cd "$TRASH_DIRECTORY" &&
        test_when_finished rm -rf graft &&
        git clone full graft &&
        (
                cd graft &&
                git commit-graph write --reachable &&
                test_path_is_file .git/objects/info/commit-graph &&
                H1=$(git rev-parse --verify HEAD~1) &&
                H3=$(git rev-parse --verify HEAD~3) &&
                echo "$H1 $H3" >.git/info/grafts &&
                git -c core.commitGraph=false log >expect &&
                git -c core.commitGraph=true log >actual &&
                test_cmp expect actual &&
                git commit-graph write --reachable &&
                git -c core.commitGraph=false --no-replace-objects log >expect &&
                git -c core.commitGraph=true --no-replace-objects log >actual &&
                test_cmp expect actual &&
                rm -rf .git/objects/info/commit-graph &&
                git commit-graph write --reachable &&
                test_path_is_missing .git/objects/info/commit-graph
        )
'

test_expect_success 'replace-objects invalidates commit-graph' '
        cd "$TRASH_DIRECTORY" &&
        test_when_finished rm -rf shallow &&
        git clone --depth 2 "file://$TRASH_DIRECTORY/full" shallow &&
        (
                cd shallow &&
                git commit-graph write --reachable &&
                test_path_is_missing .git/objects/info/commit-graph &&
                git fetch origin --unshallow &&
                git commit-graph write --reachable &&
                test_path_is_file .git/objects/info/commit-graph
        )
'

# the verify tests below expect the commit-graph to contain
# exactly the commits reachable from the commits/8 branch.
# If the file changes the set of commits in the list, then the
# offsets into the binary file will result in different edits
# and the tests will likely break.

test_expect_success 'git commit-graph verify' '
        cd "$TRASH_DIRECTORY/full" &&
        git rev-parse commits/8 | git commit-graph write --stdin-commits &&
        git commit-graph verify >output
'

NUM_COMMITS=9
NUM_OCTOPUS_EDGES=2
HASH_LEN="$(test_oid rawsz)"
GRAPH_BYTE_VERSION=4
GRAPH_BYTE_HASH=5
GRAPH_BYTE_CHUNK_COUNT=6
GRAPH_CHUNK_LOOKUP_OFFSET=8
GRAPH_CHUNK_LOOKUP_WIDTH=12
GRAPH_CHUNK_LOOKUP_ROWS=5
GRAPH_BYTE_OID_FANOUT_ID=$GRAPH_CHUNK_LOOKUP_OFFSET
GRAPH_BYTE_OID_LOOKUP_ID=$(($GRAPH_CHUNK_LOOKUP_OFFSET + \
                            1 * $GRAPH_CHUNK_LOOKUP_WIDTH))
GRAPH_BYTE_COMMIT_DATA_ID=$(($GRAPH_CHUNK_LOOKUP_OFFSET + \
                             2 * $GRAPH_CHUNK_LOOKUP_WIDTH))
GRAPH_FANOUT_OFFSET=$(($GRAPH_CHUNK_LOOKUP_OFFSET + \
                       $GRAPH_CHUNK_LOOKUP_WIDTH * $GRAPH_CHUNK_LOOKUP_ROWS))
GRAPH_BYTE_FANOUT1=$(($GRAPH_FANOUT_OFFSET + 4 * 4))
GRAPH_BYTE_FANOUT2=$(($GRAPH_FANOUT_OFFSET + 4 * 255))
GRAPH_OID_LOOKUP_OFFSET=$(($GRAPH_FANOUT_OFFSET + 4 * 256))
GRAPH_BYTE_OID_LOOKUP_ORDER=$(($GRAPH_OID_LOOKUP_OFFSET + $HASH_LEN * 8))
GRAPH_BYTE_OID_LOOKUP_MISSING=$(($GRAPH_OID_LOOKUP_OFFSET + $HASH_LEN * 4 + 10))
GRAPH_COMMIT_DATA_OFFSET=$(($GRAPH_OID_LOOKUP_OFFSET + $HASH_LEN * $NUM_COMMITS))
GRAPH_BYTE_COMMIT_TREE=$GRAPH_COMMIT_DATA_OFFSET
GRAPH_BYTE_COMMIT_PARENT=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN))
GRAPH_BYTE_COMMIT_EXTRA_PARENT=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 4))
GRAPH_BYTE_COMMIT_WRONG_PARENT=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 3))
GRAPH_BYTE_COMMIT_GENERATION=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 11))
GRAPH_BYTE_COMMIT_DATE=$(($GRAPH_COMMIT_DATA_OFFSET + $HASH_LEN + 12))
GRAPH_COMMIT_DATA_WIDTH=$(($HASH_LEN + 16))
GRAPH_OCTOPUS_DATA_OFFSET=$(($GRAPH_COMMIT_DATA_OFFSET + \
                             $GRAPH_COMMIT_DATA_WIDTH * $NUM_COMMITS))
GRAPH_BYTE_OCTOPUS=$(($GRAPH_OCTOPUS_DATA_OFFSET + 4))
GRAPH_BYTE_FOOTER=$(($GRAPH_OCTOPUS_DATA_OFFSET + 4 * $NUM_OCTOPUS_EDGES))

# usage: corrupt_graph_and_verify <position> <data> <string> [<zero_pos>]
# Manipulates the commit-graph file at the position
# by inserting the data, optionally zeroing the file
# starting at <zero_pos>, then runs 'git commit-graph verify'
# and places the output in the file 'err'. Test 'err' for
# the given string.
corrupt_graph_and_verify() {
        pos=$1
        data="${2:-\0}"
        grepstr=$3
        cd "$TRASH_DIRECTORY/full" &&
        orig_size=$(wc -c < $objdir/info/commit-graph) &&
        zero_pos=${4:-${orig_size}} &&
        test_when_finished mv commit-graph-backup $objdir/info/commit-graph &&
        cp $objdir/info/commit-graph commit-graph-backup &&
        printf "$data" | dd of="$objdir/info/commit-graph" bs=1 seek="$pos" conv=notrunc &&
        dd of="$objdir/info/commit-graph" bs=1 seek="$zero_pos" if=/dev/null &&
        generate_zero_bytes $(($orig_size - $zero_pos)) >>"$objdir/info/commit-graph" &&
        test_must_fail git commit-graph verify 2>test_err &&
        grep -v "^+" test_err >err &&
        test_i18ngrep "$grepstr" err
}

test_expect_success 'detect bad signature' '
        corrupt_graph_and_verify 0 "\0" \
                "graph signature"
'

test_expect_success 'detect bad version' '
        corrupt_graph_and_verify $GRAPH_BYTE_VERSION "\02" \
                "graph version"
'

test_expect_success 'detect bad hash version' '
        corrupt_graph_and_verify $GRAPH_BYTE_HASH "\02" \
                "hash version"
'

test_expect_success 'detect low chunk count' '
        corrupt_graph_and_verify $GRAPH_BYTE_CHUNK_COUNT "\02" \
                "missing the .* chunk"
'

test_expect_success 'detect missing OID fanout chunk' '
        corrupt_graph_and_verify $GRAPH_BYTE_OID_FANOUT_ID "\0" \
                "missing the OID Fanout chunk"
'

test_expect_success 'detect missing OID lookup chunk' '
        corrupt_graph_and_verify $GRAPH_BYTE_OID_LOOKUP_ID "\0" \
                "missing the OID Lookup chunk"
'

test_expect_success 'detect missing commit data chunk' '
        corrupt_graph_and_verify $GRAPH_BYTE_COMMIT_DATA_ID "\0" \
                "missing the Commit Data chunk"
'

test_expect_success 'detect incorrect fanout' '
        corrupt_graph_and_verify $GRAPH_BYTE_FANOUT1 "\01" \
                "fanout value"
'

test_expect_success 'detect incorrect fanout final value' '
        corrupt_graph_and_verify $GRAPH_BYTE_FANOUT2 "\01" \
                "fanout value"
'

test_expect_success 'detect incorrect OID order' '
        corrupt_graph_and_verify $GRAPH_BYTE_OID_LOOKUP_ORDER "\01" \
                "incorrect OID order"
'

test_expect_success 'detect OID not in object database' '
        corrupt_graph_and_verify $GRAPH_BYTE_OID_LOOKUP_MISSING "\01" \
                "from object database"
'

test_expect_success 'detect incorrect tree OID' '
        corrupt_graph_and_verify $GRAPH_BYTE_COMMIT_TREE "\01" \
                "root tree OID for commit"
'

test_expect_success 'detect incorrect parent int-id' '
        corrupt_graph_and_verify $GRAPH_BYTE_COMMIT_PARENT "\01" \
                "invalid parent"
'

test_expect_success 'detect extra parent int-id' '
        corrupt_graph_and_verify $GRAPH_BYTE_COMMIT_EXTRA_PARENT "\00" \
                "is too long"
'

test_expect_success 'detect wrong parent' '
        corrupt_graph_and_verify $GRAPH_BYTE_COMMIT_WRONG_PARENT "\01" \
                "commit-graph parent for"
'

test_expect_success 'detect incorrect generation number' '
        corrupt_graph_and_verify $GRAPH_BYTE_COMMIT_GENERATION "\070" \
                "generation for commit"
'

test_expect_success 'detect incorrect generation number' '
        corrupt_graph_and_verify $GRAPH_BYTE_COMMIT_GENERATION "\01" \
                "non-zero generation number"
'

test_expect_success 'detect incorrect commit date' '
        corrupt_graph_and_verify $GRAPH_BYTE_COMMIT_DATE "\01" \
                "commit date"
'

test_expect_success 'detect incorrect parent for octopus merge' '
        corrupt_graph_and_verify $GRAPH_BYTE_OCTOPUS "\01" \
                "invalid parent"
'

test_expect_success 'detect invalid checksum hash' '
        corrupt_graph_and_verify $GRAPH_BYTE_FOOTER "\00" \
                "incorrect checksum"
'

test_expect_success 'detect incorrect chunk count' '
        corrupt_graph_and_verify $GRAPH_BYTE_CHUNK_COUNT "\377" \
                "chunk lookup table entry missing" $GRAPH_CHUNK_LOOKUP_OFFSET
'

test_expect_success 'git fsck (checks commit-graph)' '
        cd "$TRASH_DIRECTORY/full" &&
        git fsck &&
        corrupt_graph_and_verify $GRAPH_BYTE_FOOTER "\00" \
                "incorrect checksum" &&
        test_must_fail git fsck
'

test_expect_success 'setup non-the_repository tests' '
        rm -rf repo &&
        git init repo &&
        test_commit -C repo one &&
        test_commit -C repo two &&
        git -C repo config core.commitGraph true &&
        git -C repo rev-parse two | \
                git -C repo commit-graph write --stdin-commits
'

test_expect_success 'parse_commit_in_graph works for non-the_repository' '
        test-tool repository parse_commit_in_graph \
                repo/.git repo "$(git -C repo rev-parse two)" >actual &&
        {
                git -C repo log --pretty=format:"%ct " -1 &&
                git -C repo rev-parse one
        } >expect &&
        test_cmp expect actual &&

        test-tool repository parse_commit_in_graph \
                repo/.git repo "$(git -C repo rev-parse one)" >actual &&
        git -C repo log --pretty="%ct" -1 one >expect &&
        test_cmp expect actual
'

test_expect_success 'get_commit_tree_in_graph works for non-the_repository' '
        test-tool repository get_commit_tree_in_graph \
                repo/.git repo "$(git -C repo rev-parse two)" >actual &&
        git -C repo rev-parse two^{tree} >expect &&
        test_cmp expect actual &&

        test-tool repository get_commit_tree_in_graph \
                repo/.git repo "$(git -C repo rev-parse one)" >actual &&
        git -C repo rev-parse one^{tree} >expect &&
        test_cmp expect actual
'

test_done