#!/usr/bin/env sh
# test-abstraction-ssp-roundtrip.sh
#
# Reads each reference .ssp back into the abstraction and emits it again,
# and requires the result to be byte identical to the file it read.
#
# What that proves: the reader (sisudoc.ocda.abstraction.ssp_in) restores
# every field the writer emits. The check is made against the writer itself,
# since both go through template sspObjectRecord, so there is no second
# description of the format that could drift from the first.
#
# It needs no sample documents and no output directory: the committed
# reference set is the input. Run test-abstraction-ssp.sh first if you want
# to know that the reference set is itself current.
#
# Usage:
#   ./test/test-abstraction-ssp-roundtrip.sh                  # uses result/bin/spine
#   ./test/test-abstraction-ssp-roundtrip.sh ./bin/spine-ldc  # specify binary
#
# Exit codes:
#   0  every reference .ssp round trips byte identically
#   1  one or more do not (the first differences are printed)
#   2  set-up problem (no binary, no reference set)

set -e

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
SPINE_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
REF_DIR="$SCRIPT_DIR/reference/abstraction"

SPINE_BIN="${1:-}"
if [ -z "$SPINE_BIN" ]; then
  if   [ -x "$SPINE_DIR/result/bin/spine" ]; then SPINE_BIN="$SPINE_DIR/result/bin/spine"
  elif [ -x "$SPINE_DIR/bin/spine-ldc" ];    then SPINE_BIN="$SPINE_DIR/bin/spine-ldc"
  elif [ -x "$SPINE_DIR/bin/spine" ];        then SPINE_BIN="$SPINE_DIR/bin/spine"
  else
    echo "ERROR: spine binary not found. Specify path as argument." >&2
    exit 2
  fi
fi

if [ ! -d "$REF_DIR" ] || [ -z "$(ls "$REF_DIR"/*.ssp 2>/dev/null)" ]; then
  echo "ERROR: no reference files found at $REF_DIR" >&2
  echo "Run ./test/test-abstraction-ssp.sh --generate first." >&2
  exit 2
fi

TMP="$SCRIPT_DIR/current-roundtrip"
rm -rf "$TMP"
mkdir -p "$TMP"

echo "spine binary: $SPINE_BIN"
echo "reference: $REF_DIR"
echo "Reading each .ssp back and emitting it again ..."

COUNT=0
FAILURES=0
for ref in "$REF_DIR"/*.ssp; do
  base=$(basename "$ref")
  COUNT=$((COUNT + 1))
  if ! $SPINE_BIN --ssp-round-trip="$ref" > "$TMP/$base" 2> "$TMP/$base.err"; then
    echo "ERROR: $base (spine exited non-zero)"
    head -3 "$TMP/$base.err"
    FAILURES=$((FAILURES + 1))
    continue
  fi
  if ! cmp -s "$ref" "$TMP/$base"; then
    echo "DIFFERS: $base ($(diff "$ref" "$TMP/$base" | grep -c '^[<>]') lines)"
    diff --unified=1 "$ref" "$TMP/$base" | head -12
    echo "  ..."
    FAILURES=$((FAILURES + 1))
  fi
done

rm -rf "$TMP"

if [ "$FAILURES" -eq 0 ]; then
  echo "PASS: all $COUNT .ssp files read back and re-emit byte identically"
  exit 0
else
  echo "FAIL: $FAILURES of $COUNT do not round trip"
  exit 1
fi