#!/usr/bin/env bash
# Cross-language parity harness (T07).
#
# Drives the SAME fixtures through the native Kotlin implementation and the Dart port,
# and diffs the output. This is the port's strongest correctness guarantee: it proved the
# elevation accumulator is bit-identical across both languages.
#
# Requires: kotlinc (brew install kotlin) and a JDK 17-21.
#
# NOTE: never redirect the build to /dev/null. A v2 sweep once returned four identical
# results because a quoting bug corrupted the source while the compile error hid behind
# a redirect. If every value looks suspiciously equal, suspect the harness first.
set -euo pipefail

HERE="$(cd "$(dirname "$0")" && pwd)"
NATIVE="${RIPPR_NATIVE:-$HOME/dojo/rippr}"
WORK="$(mktemp -d)"
trap 'rm -rf "$WORK"' EXIT

if [ ! -d "$NATIVE" ]; then
  echo "Native repo not found at $NATIVE. Set RIPPR_NATIVE." >&2
  exit 1
fi

# The files actually under test are copied verbatim from the native repo — never
# reimplemented. Only the Room-annotated holders and one Telemetry constant are stubbed,
# so the algorithm files compile without androidx or org.json on the classpath.
cp "$NATIVE/app/src/main/java/com/rippr/geo/Geo.kt"             "$WORK/"
cp "$NATIVE/app/src/main/java/com/rippr/stats/RideStatistics.kt" "$WORK/"
cp "$HERE/stubs.kt" "$HERE/telemetry_stub.kt" "$HERE/main.kt"    "$WORK/"

echo "== compiling Kotlin oracle =="
( cd "$WORK" && kotlinc Geo.kt RideStatistics.kt stubs.kt telemetry_stub.kt main.kt \
    -include-runtime -d parity.jar 2>&1 | grep -v '^warning:' || true )

JAVA_BIN="${JAVA_HOME:+$JAVA_HOME/bin/}java"
"$JAVA_BIN" -jar "$WORK/parity.jar" | grep '=' | sort > "$WORK/kotlin.txt"

echo "== running Dart side =="
( cd "$HERE/../.." && dart run tool/parity/probe.dart ) | grep '=' | sort > "$WORK/dart.txt"

echo "== diff =="
if diff -u "$WORK/kotlin.txt" "$WORK/dart.txt"; then
  echo "PARITY OK - byte-identical on every key"
else
  echo
  echo "Differences above. Expected and accepted: run_avg_speed and any other"
  echo "speed-derived value, where Kotlin's 32-bit Float widens to double with"
  echo "artefacts Dart's uniform binary64 does not reproduce. Anything else is a bug."
  exit 1
fi