#!/usr/bin/env bash
# Shared bounded-batch concurrent job runner. Sourced by
# scripts/sync-plugin-content.sh, tests/run-tests.sh, and tests/run-bats.sh so
# their concurrency-cap and per-item log/status handling can't silently
# diverge -- previously the same batching logic (core-count cap, per-item
# log/status files, batched `wait`) was hand-implemented independently in all
# three places.
#
# Batches (not a rolling pool) because a bounded rolling pool needs `wait -n`,
# which is bash 4.3+ -- all three callers are explicitly bash-3.2-safe.
# `getconf` over `nproc` for the same reason: `nproc` doesn't exist on macOS.
#
# Not meant to be executed directly -- source it.

# batch_jobs_limit
#   Prints the concurrency cap to use for batching.
batch_jobs_limit() {
  getconf _NPROCESSORS_ONLN 2>/dev/null || echo 4
}

# batch_run <scratch_dir> <key1> <cmd1> [<key2> <cmd2> ...]
#
# For each key/cmd pair, backgrounds `eval "$cmd"` with its combined
# stdout+stderr redirected to "<scratch_dir>/<key>.log", bounded to at most
# batch_jobs_limit concurrent jobs (waiting out the current batch before
# starting the next).
#
# Each <cmd> owns writing its own result to "<scratch_dir>/<key>.status" --
# this helper only owns dispatch/throttling and log capture, not status
# semantics. Callers differ on how they do that (capturing $? of an external
# command with `|| rc=$?`, or a sync function writing its own status flag
# directly) -- both patterns are preserved as-is by callers, not standardized
# here, so existing error-handling behavior (including how each pattern
# interacts with `set -e` in the caller) is unchanged by this extraction.
batch_run() {
  local scratch_dir="$1"
  shift
  local jobs_limit running key cmd
  jobs_limit="$(batch_jobs_limit)"
  running=0

  while [[ $# -gt 0 ]]; do
    key="$1" cmd="$2"
    shift 2
    (eval "$cmd") >"$scratch_dir/$key.log" 2>&1 &
    running=$((running + 1))
    if [[ $running -ge $jobs_limit ]]; then
      wait
      running=0
    fi
  done
  wait
}