#!/usr/bin/env bash
# scripts/run-unit-shard.sh
#
# Runs the unit suite for a single shard. Excludes test/e2e/* (those are run
# by scripts/run-e2e.sh in the E2E phase). When SHARD=N/M is set, keeps every
# M-th file starting at index N (1-indexed); otherwise runs the full unit set.
#
# Used by scripts/ci-local.sh to fan 4 unit-shard workers in parallel inside
# the runner container, each pinned to its own postgres shard for the
# downstream E2E phase.
#
# Sequential bun processes within a shard (one bun test invocation with the
# shard's file list); parallel across shards (4 of these run concurrently).

set -euo pipefail

cd "$(dirname "$0")/.."

# --max-concurrency=N is forwarded to `bun test`. v0.26.4: invoked by
# run-unit-parallel.sh; safe to call without (defaults to bun's default cap).
MAX_CONC=""
DRY_RUN=0
while [ $# -gt 0 ]; do
  case "$1" in
    --max-concurrency) MAX_CONC="$2"; shift 2 ;;
    --max-concurrency=*) MAX_CONC="${1#*=}"; shift ;;
    --dry-run-list) DRY_RUN=1; shift ;;
    *) echo "ERROR: unknown arg: $1" >&2; exit 2 ;;
  esac
done

# All non-E2E test files, sorted for deterministic shard splits.
# Tier 4: *.slow.test.ts is "always-slow" (cold-path correctness checks);
# *.serial.test.ts is "concurrency-unsafe" (file-wide shared state). Both
# are excluded from the fast loop. Slow runs via `bun run test:slow`; serial
# runs via scripts/run-serial-tests.sh after the parallel pass.
# Use while-read to stay portable to macOS bash 3.2 (no mapfile).
all_files=()
while IFS= read -r f; do
  all_files+=("$f")
done < <(find test -name '*.test.ts' -not -path 'test/e2e/*' -not -name '*.slow.test.ts' -not -name '*.serial.test.ts' | sort)

files=()
if [ -n "${SHARD:-}" ]; then
  shard_n=${SHARD%/*}
  shard_m=${SHARD#*/}
  if ! printf '%s' "$shard_n" | grep -qE '^[0-9]+$' || \
     ! printf '%s' "$shard_m" | grep -qE '^[0-9]+$' || \
     [ "$shard_n" -lt 1 ] || [ "$shard_m" -lt 1 ] || [ "$shard_n" -gt "$shard_m" ]; then
    echo "ERROR: invalid SHARD=$SHARD (expected N/M with 1<=N<=M, both integers)" >&2
    exit 1
  fi
  i=0
  for f in "${all_files[@]}"; do
    if [ $((i % shard_m + 1)) -eq "$shard_n" ]; then
      files+=("$f")
    fi
    i=$((i + 1))
  done
else
  files=("${all_files[@]}")
fi

if [ "${#files[@]}" -eq 0 ]; then
  echo "[unit-shard ${SHARD:-(unsharded)}] no files; exiting clean."
  exit 0
fi

if [ "$DRY_RUN" = "1" ]; then
  printf '%s\n' "${files[@]}"
  exit 0
fi

echo "[unit-shard ${SHARD:-(unsharded)}] running ${#files[@]} files"
if [ -n "$MAX_CONC" ]; then
  exec bun test --max-concurrency="$MAX_CONC" --timeout=60000 "${files[@]}"
fi
exec bun test --timeout=60000 "${files[@]}"