#!/usr/bin/env bash
# Behaviour gate for the Space Taxi simulation.
#
# Runs every hook level through stsim and compares the per-tick trace
# against a golden capture. A refactor that changes nothing observable
# leaves all seventeen traces byte-identical; anything else is a regression.
#
# H, W, T and X ride the C64's own attract recordings (the ones checked
# against VICE traces). The other thirteen ride synthesised fixtures from
# gateStreams.h -- a regression gate only, not evidence of C64 fidelity.
#
#   gate.sh capture [dir]   record goldens from the CURRENT tree
#   gate.sh check   [dir]   compare the current tree against them
#   gate.sh hashes          print one md5 per level (compact reference)
#
# Capture from a tree you trust, refactor, then check.
set -u

here=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
repo=$(cd "$here/../.." && pwd)
levels=$repo/examples/spacetaxi/generated/iigs/levels
mode=${1:-check}
dir=${2:-$here/golden}
ticks=4000

# level letter -> level file number
pairs="H:08 T:20 W:23 X:24 G:07 I:09 K:11 O:15 Q:17 R:18 U:21 V:22 E:05 J:10 L:12 P:16 S:19"

make -C "$here" >/dev/null || { echo "gate: build failed" >&2; exit 2; }

case "$mode" in
capture)
    mkdir -p "$dir"
    for p in $pairs; do
        l=${p%%:*}; n=${p##*:}
        "$here/stsim" "$levels/level$n.dat" "$l" "$ticks" > "$dir/demo$l.jsonl" 2>/dev/null
        printf '  %s: %s ticks\n' "$l" "$(wc -l < "$dir/demo$l.jsonl")"
    done
    echo "gate: captured to $dir"
    ;;
check)
    fail=0
    for p in $pairs; do
        l=${p%%:*}; n=${p##*:}
        got=$(mktemp)
        "$here/stsim" "$levels/level$n.dat" "$l" "$ticks" > "$got" 2>/dev/null
        if [ ! -f "$dir/demo$l.jsonl" ]; then
            echo "  $l: no golden (run: gate.sh capture)"
        elif cmp -s "$dir/demo$l.jsonl" "$got"; then
            printf '  %s: IDENTICAL (%s ticks)\n' "$l" "$(wc -l < "$got")"
        else
            echo "  $l: *** DIFFERS ***"
            diff "$dir/demo$l.jsonl" "$got" | head -3
            fail=1
        fi
        rm -f "$got"
    done
    [ $fail -eq 0 ] && echo "gate: PASS" || echo "gate: FAIL"
    # The cel census rides the same recordings: a cel a ride displays that
    # its manifest does not bake is a mid-ride interpreted sprite.
    "$here/celGate.sh" || fail=1
    exit $fail
    ;;
hashes)
    for p in $pairs; do
        l=${p%%:*}; n=${p##*:}
        h=$("$here/stsim" "$levels/level$n.dat" "$l" "$ticks" 2>/dev/null | md5sum | cut -d' ' -f1)
        printf '%s  %s\n' "$l" "$h"
    done
    ;;
*)
    sed -n '2,20p' "$0"
    exit 2
    ;;
esac