#!/usr/bin/env bash
# BotLauncher entry point for DevControlBot.
#
# Thin wrapper: all build/run/cleanup logic lives in the `runBot` nimble task
# of DevControlBot.nimble. This script only locates itself, moves next to the
# .nimble so Nimble finds it, forwards caller arguments, calls the task and
# propagates the real exit code. Signals are forwarded to Nimble so the task's
# own EXIT/INT/TERM cleanup always runs.
#
# Usage: DevControlBot.sh [--debug] [<metadata.json>] [extra args for the bot]
#
#   (no args)   RELEASE build + run with the bundled DevControlBot.json
#   (no flag)   RELEASE build (nim c -d:release), quiet output
#   --debug     classic DEBUG build (plain nim c): compiler hints + diagnostics
#
# --debug is a build-mode flag for this wrapper only: it is stripped here and
# never reaches the bot binary or nimble's task arguments. It travels to the
# runBot task as $DEVCONTROLBOT_DEBUG (exported), because an env var cannot be
# confused with a bot argument, cannot collide with the status file mechanism
# and keeps the task's argument parsing untouched. Repeated --debug is harmless.
#
# Configuration (SERVER_URL, SERVER_SECRET, ...) is NOT handled here at all: the
# API's start() reads those from the environment, and the optional .env file is
# loaded by the runBot task, so it also works with a direct `nimble runBot`.
set -uo pipefail
set -m   # job control: the background job gets its own process group

SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
cd "$SCRIPT_DIR"

usage() {
  cat <<EOF
Usage: $(basename "$0") [--debug] [<metadata.json>] [extra args for the bot]

  --debug    classic debug build: shows compiler hints and diagnostics
              (default is a quiet RELEASE build, nim c -d:release)
  -h,--help   show this help

Examples:
  $(basename "$0")                       # release build + run, bundled DevControlBot.json
  $(basename "$0") my.json               # release build + run with custom metadata
  $(basename "$0") -h                    # this help
  $(basename "$0") --debug               # debug build
  $(basename "$0") --debug my.json       # debug build with custom metadata
EOF
}

# Split caller args: everything except --debug is forwarded verbatim.
BUILD_MODE=release
FORWARDED=()
for a in "$@"; do
  case "$a" in
    --debug) BUILD_MODE=debug ;;
    *) FORWARDED+=("$a") ;;
  esac
done
set -- ${FORWARDED+"${FORWARDED[@]}"}

# No arguments is the normal case: build and run with the bundled metadata.
# Usage is printed ONLY for an explicit -h/--help.
case "${1:-}" in
  -h|--help) usage; exit 0 ;;
esac

export DEVCONTROLBOT_DEBUG="$BUILD_MODE"

# The runBot task's shell always exits 0 (otherwise Nimble raises a NimScript
# exception with a stack trace and a dump of the whole script) and writes the
# bot's real exit code here instead. We read it back and exit with it, so
# BotLauncher still sees the faithful status: 1 = no game server on 7654,
# 2 = a dependency is missing, 3 = compile failure, anything else = the bot's
# own code, 0 = clean run.
STATUS_FILE="$(mktemp "${TMPDIR:-/tmp}/devcontrolbot.status.XXXXXX")"
export DEVCONTROLBOT_STATUS_FILE="$STATUS_FILE"
trap 'rm -f "$STATUS_FILE"' EXIT

# Forward to the whole job process group (nimble + the shell it spawned) so the
# task's own EXIT/INT/TERM cleanup runs. No cleanup logic here.
forward() { kill -s "$1" -- "-$NIMBLE_PID" 2>/dev/null; }
trap 'forward TERM' TERM
trap 'forward INT' INT

nimble runBot ${1+"$@"} &
NIMBLE_PID=$!
wait "$NIMBLE_PID"
rc=$?
trap - TERM INT
# Prefer the code the run actually produced; fall back to Nimble's own status if
# the task died before it could report (e.g. Nimble itself failed).
real_rc="$(head -n 1 "$STATUS_FILE" 2>/dev/null | tr -d '[:space:]')"
[ -n "$real_rc" ] || real_rc=$rc
exit "$real_rc"