#!/bin/sh
# vendor-check -- how far behind upstream the vendored libghostty-vt is.
#
#   contrib/vendor-check            # summary + the commits that matter
#   contrib/vendor-check -q         # one line, for scripts and reminders
#
# Vendoring is pinned by commit on purpose (D12): upstream has no stable
# release channel for the lib, so the pin moves when we move it. This is the
# tool that makes "keeping an eye on upstream" one command instead of a
# browser tab: it reads the pin from vendor/libghostty-vt.vendor.json, asks
# the GitHub API what has happened since, and shows the commits touching the
# parts we actually ship -- the terminal core, not ghostty's app shell.
#
# Read-only, no working-tree changes. Re-vendoring itself stays the
# documented manual process (vendor/patches/README.md): drop in the new
# tree, re-apply the patches, run make test.
set -eu

UPSTREAM="${SLOSH_VT_UPSTREAM:-ghostty-org/ghostty}"
# What the vendored build actually compiles: the VT core and the lib entry
# points. Churn in ghostty's app, GUI and packaging is noise to us.
PATHS="${SLOSH_VT_PATHS:-src/terminal src/lib include}"
VJ="$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)/vendor/libghostty-vt.vendor.json"

fail() { printf 'vendor-check: %s\n' "$*" >&2; exit 1; }

quiet=0
[ "${1:-}" = "-q" ] && quiet=1

[ -f "$VJ" ] || fail "no $VJ"
command -v gh >/dev/null 2>&1 || fail "needs gh (for the GitHub API)"

pin="$(sed -n 's/.*"source_commit": "\([a-f0-9]*\)".*/\1/p' "$VJ")"
date="$(sed -n 's/.*"source_date": "\([^"]*\)".*/\1/p' "$VJ")"
npatch="$(grep -c 'patches/' "$VJ" || true)"
[ -n "$pin" ] || fail "no source_commit in $VJ"

total="$(gh api "repos/$UPSTREAM/compare/$pin...HEAD" --jq .total_commits)" \
    || fail "compare failed -- is the pin still reachable upstream?"

# Per relevant path: commits since the snapshot date. Date rather than commit
# because a path-filtered listing may never contain the pin itself; the hour
# of slack this costs is nothing to a watch tool. The + in a timezone must
# not reach the URL as a space.
since="$(printf '%s' "$date" | sed 's/+/%2B/')"
tmp="$(mktemp)"
trap 'rm -f "$tmp"' EXIT INT TERM
for p in $PATHS; do
    gh api "repos/$UPSTREAM/commits?sha=HEAD&path=$p&since=$since&per_page=100" \
        --jq '.[] | .sha[0:9] + " " + (.commit.message | split("\n")[0])' \
        2>/dev/null || true
done | sort -u > "$tmp"
relevant="$(wc -l < "$tmp" | tr -d ' ')"

if [ "$quiet" = 1 ]; then
    printf 'libghostty-vt: %s commits behind %s, %s touching the VT core (pinned %.7s, %s)\n' \
        "$total" "$UPSTREAM" "$relevant" "$pin" "${date%%T*}"
    exit 0
fi

printf 'vendored   %.7s (%s), %s local patch(es)\n' "$pin" "${date%%T*}" "$npatch"
printf 'upstream   %s is %s commits ahead\n' "$UPSTREAM" "$total"
printf 'relevant   %s commits touch %s:\n\n' "$relevant" "$(echo $PATHS | tr ' ' ',')"
head -25 "$tmp" | sed 's/^/  /'
[ "$relevant" -gt 25 ] && printf '  ... and %s more\n' "$((relevant - 25))"
printf '\nre-vendoring is documented in vendor/patches/README.md\n'