#!/usr/bin/env bash
# materializer_parity — run Bun + Go materializer against an identical
# synthetic root, diff the resulting data/evidence/ JSONL files.
#
# This validates the parity claim from the 2026-05-02 port: "on-wire
# JSON shape matches TS so Bun and Go runs are interchangeable." Any
# divergence here is a finding the architecture comparison should
# record (precedent: 2026-05-02 validator parity probe surfaced the
# Rust serde-tagged-enum vs Go flat-struct error envelope gap).
#
# Approach:
#   1. Set up a temp ROOT with a fixed source data/_kb/distilled_facts.jsonl
#      + observer_escalations.jsonl (small, every transform field exercised)
#   2. Run Bun materializer:
#        bun run /home/profit/lakehouse/scripts/distillation/build_evidence_index.ts
#      against TS-side ROOT (TS expects a real lakehouse repo layout)
#   3. Run Go materializer:
#        ./bin/materializer -root <ROOT>
#      against the same ROOT (after wiping evidence/ between runs)
#   4. Diff the output JSONL files, normalized for non-deterministic
#      fields (provenance.recorded_at, ordering).
#
# Outputs: reports/cutover/gauntlet_2026-05-02/parity/materializer_parity.md
#
# Exit 0 = byte-equal (modulo timestamps); exit non-zero = drift.
#
# Env overrides:
#   RUST_REPO=/home/profit/lakehouse           # Rust legacy repo
#   GO_BIN=./bin/materializer                  # Go binary (built per-call)

set -uo pipefail
cd "$(dirname "$0")/../../.."

RUST_REPO="${RUST_REPO:-/home/profit/lakehouse}"
GO_BIN="${GO_BIN:-./bin/materializer}"
OUT_DIR="reports/cutover/gauntlet_2026-05-02/parity"
mkdir -p "$OUT_DIR"
OUT="$OUT_DIR/materializer_parity.md"

# Build Go materializer fresh.
export PATH="$PATH:/usr/local/go/bin"
go build -o "$GO_BIN" ./cmd/materializer

# Locate Bun. Skip with an explicit message if it's missing (CI without bun).
if ! command -v bun >/dev/null 2>&1; then
  echo "[materializer-parity] SKIP: bun not on PATH"
  exit 0
fi

# Confirm Rust-side materializer is present.
TS_MAT="$RUST_REPO/scripts/distillation/build_evidence_index.ts"
if [ ! -f "$TS_MAT" ]; then
  echo "[materializer-parity] SKIP: $TS_MAT not found"
  exit 0
fi

ROOT="$(mktemp -d)"
trap 'rm -rf "$ROOT"' EXIT INT TERM

mkdir -p "$ROOT/data/_kb"
# Synthetic distilled_facts — exercises the simplest transform shape.
cat > "$ROOT/data/_kb/distilled_facts.jsonl" <<EOF
{"run_id":"r1","source_label":"lab-a","created_at":"2026-04-26T00:00:00Z","extractor":"qwen3.5:latest","text":"first fact"}
{"run_id":"r2","source_label":"lab-b","created_at":"2026-04-26T01:00:00Z","extractor":"qwen3.5:latest","text":"second fact"}
{"run_id":"r3","source_label":"lab-c","created_at":"2026-04-26T02:00:00Z","extractor":"qwen2.5:latest","text":"third — different extractor"}
EOF
# observer_escalations — exercises the prompt_tokens/completion_tokens
# fields we added to EvidenceRecord during the materializer port.
cat > "$ROOT/data/_kb/observer_escalations.jsonl" <<EOF
{"ts":"2026-04-26T12:00:00Z","sig_hash":"abc123","cluster_endpoint":"/v1/chat","prompt_tokens":150,"completion_tokens":75,"analysis":"escalation review notes"}
EOF

# Pin recorded_at across BOTH runs so provenance.recorded_at matches.
PINNED_TS="2026-05-02T00:00:00Z"

# ── Bun run ────────────────────────────────────────────────────────
# Bun side reads its own root. We have to copy the fixtures under the
# Bun side's expectation (it defaults to /home/profit/lakehouse), or
# override via LH_DISTILL_ROOT. But the Bun materializer's CLI reads
# `new Date().toISOString()` for recorded_at — we can't pin without
# editing the script. Workaround: capture the full output, then
# normalize provenance.recorded_at out of both sides for diff.
BUN_ROOT="$ROOT/bun_side"
mkdir -p "$BUN_ROOT/data/_kb"
cp "$ROOT/data/_kb/"* "$BUN_ROOT/data/_kb/"

echo "[materializer-parity] running Bun materializer..."
LH_DISTILL_ROOT="$BUN_ROOT" bun run "$TS_MAT" \
  > /tmp/bun_mat.log 2>&1 || {
    echo "[materializer-parity] bun run failed:"
    tail -30 /tmp/bun_mat.log
    exit 1
  }

# ── Go run ─────────────────────────────────────────────────────────
GO_ROOT="$ROOT/go_side"
mkdir -p "$GO_ROOT/data/_kb"
cp "$ROOT/data/_kb/"* "$GO_ROOT/data/_kb/"

echo "[materializer-parity] running Go materializer..."
"$GO_BIN" -root "$GO_ROOT" > /tmp/go_mat.log 2>&1 || {
  echo "[materializer-parity] go run failed:"
  tail -30 /tmp/go_mat.log
  exit 1
}

# ── Find output day-partition ──────────────────────────────────────
# Both runs use today's UTC date. Look up the partition.
TODAY="$(date -u +%Y/%m/%d)"
BUN_OUT="$BUN_ROOT/data/evidence/$TODAY"
GO_OUT="$GO_ROOT/data/evidence/$TODAY"

if [ ! -d "$BUN_OUT" ]; then
  echo "[materializer-parity] no Bun output dir: $BUN_OUT"
  ls -la "$BUN_ROOT/data/evidence" 2>/dev/null || true
  exit 1
fi
if [ ! -d "$GO_OUT" ]; then
  echo "[materializer-parity] no Go output dir: $GO_OUT"
  exit 1
fi

# ── Normalize + diff per source-stem ───────────────────────────────
# Stripped fields:
#   provenance.recorded_at    — different per-run wall clock
#
# Sorted by sig_hash so dedup ordering can't matter.
normalize() {
  jq -c -S 'del(.provenance.recorded_at)' "$1" 2>/dev/null \
    | sort
}

TOTAL=0; MATCH=0; DIFF=0
DIFF_DETAIL=""
for f in "$BUN_OUT"/*.jsonl; do
  stem=$(basename "$f" .jsonl)
  go_f="$GO_OUT/$stem.jsonl"
  TOTAL=$((TOTAL+1))
  if [ ! -f "$go_f" ]; then
    DIFF=$((DIFF+1))
    DIFF_DETAIL="$DIFF_DETAIL"$'\n'"- $stem: present in Bun, missing in Go"
    continue
  fi
  bun_norm=$(normalize "$f")
  go_norm=$(normalize "$go_f")
  if [ "$bun_norm" = "$go_norm" ]; then
    MATCH=$((MATCH+1))
  else
    DIFF=$((DIFF+1))
    # Capture a small diff for the report.
    diff_block="$(diff <(echo "$bun_norm") <(echo "$go_norm") | head -40)"
    DIFF_DETAIL="$DIFF_DETAIL"$'\n\n'"### $stem"$'\n''```diff'$'\n'"$diff_block"$'\n''```'
  fi
done

# ── Write report ───────────────────────────────────────────────────
{
  echo "# Materializer parity probe — Bun vs Go"
  echo
  echo "**Date:** $(date -u +%Y-%m-%dT%H:%M:%SZ)"
  echo "**Bun:** \`$TS_MAT\`"
  echo "**Go:**  \`$GO_BIN\`"
  echo
  echo "Identical \`data/_kb/\` source → both runtimes' materializer."
  echo "Match = JSONL byte-equal after normalizing \`provenance.recorded_at\`"
  echo "(per-run wall clock) + sorted line order (dedup ordering)."
  echo
  echo "**Tally:** $MATCH match · $DIFF diff (out of $TOTAL stems)"
  if [ -n "$DIFF_DETAIL" ]; then
    echo
    echo "## Divergences"
    echo "$DIFF_DETAIL"
  else
    echo
    echo "_No divergences — on-wire JSON parity holds._"
  fi
} > "$OUT"

echo "[parity] materializer: $MATCH match / $DIFF diff (out of $TOTAL) → $OUT"
[ "$DIFF" -eq 0 ]