#!/usr/bin/env bash
# Deterministic verification of one run's end state:
#   1. diff vs pristine exercise  ->  diff.patch (the agent's final diff)
#   2. drop in the solution's test + approved file, run mvn test
#      PASS = deterministic end state matches the reference solution's behavior
#   3. structural check: does collectExpectedWeather exist and take the lambda?
# usage: bash verify_outcome.sh <run_dir>
set -uo pipefail
RUN_DIR="$1"
WS="$RUN_DIR/workspace"
REPO=/home/cardfanatic/qwan/exercises/learning-hour-maker
SOLUTION="$REPO/ideas/slice-with-lambda/exercise/solution"
PRISTINE=/tmp/rehearsal/pristine

echo "--- Run $(basename "$RUN_DIR") ---"

# 1. final diff vs pristine
diff -ru --exclude=target "$PRISTINE" "$WS" > "$RUN_DIR/diff.patch"
if [ -s "$RUN_DIR/diff.patch" ]; then
  echo "final diff vs pristine: $(grep -c '^[+-][^+-]' "$RUN_DIR/diff.patch") changed lines -> $RUN_DIR/diff.patch"
else
  echo "final diff vs pristine: EMPTY (agent made no changes)"
fi

# 2. deterministic test: replace test tree with the solution's test + approved file
if [ ! -d "$SOLUTION" ]; then
  echo "solution dir missing, skipping mvn verification"
  exit 0
fi
rm -rf "$WS/src/test"
mkdir -p "$WS/src/test/java/codingdojo"
cp -r "$SOLUTION/src/test/java/codingdojo/." "$WS/src/test/java/codingdojo/"

echo "mvn test with solution's test + approved file:"
if ( cd "$WS" && JAVA_HOME=/tmp/jdk21 PATH="/tmp/jdk21/bin:/tmp/apache-maven-3.9.9/bin:$PATH" \
       mvn -q test ) > "$RUN_DIR/mvn-verify.log" 2>&1; then
  echo "  RESULT: PASS (deterministic)"
else
  echo "  RESULT: FAIL (see $RUN_DIR/mvn-verify.log, last lines:)"
  tail -15 "$RUN_DIR/mvn-verify.log" | sed 's/^/    /'
fi

# 3. structural checks on the produced LongRangeForecasts.java
echo "structural checks:"
LR="$WS/src/main/java/codingdojo/LongRangeForecasts.java"
grep -q "collectExpectedWeather" "$LR" \
  && echo "  [x] method collectExpectedWeather exists" \
  || echo "  [ ] method collectExpectedWeather MISSING"
grep -q "LongFunction<Boolean>" "$LR" \
  && echo "  [x] takes LongFunction<Boolean> parameter" \
  || echo "  [ ] LongFunction<Boolean> parameter MISSING"
grep -q "scorer" "$LR" \
  && echo "  [i] note: 'scorer' still referenced in LongRangeForecasts.java" \
  || echo "  [x] no direct scorer reference left in LongRangeForecasts.java"
if grep -qF -- "->" "$LR"; then
  echo "  [x] lambda syntax present"
else
  echo "  [ ] lambda syntax MISSING (the classic drift: extracted method closes over scorer)"
fi

# comparison against reference solution shape
if diff -q "$SOLUTION/src/main/java/codingdojo/LongRangeForecasts.java" "$LR" > /dev/null; then
  echo "  [x] main class byte-identical to reference solution"
else
  echo "  [i] main class differs from reference solution (may still be a valid variant)"
fi