#!/usr/bin/env bash
# max25-bcpr-ctl — BayCom/based PC-COM helper (preflight / start / stop).
# Lite policy: plain English operator messages (new Linux user level).
set -euo pipefail

INI="${MAX25_BCPR_INI:-${BCPR_INI:-/etc/max25/max25-bcpr.ini}}"
BCPRD="${MAX25_BCPRD:-${BCPRD:-max25-bcprd}}"
BCPRD_INIT="${MAX25_BCPRD_INIT:-max25-bcprd-init}"
PIDFILE="${MAX25_BCPR_PIDFILE:-/tmp/max25-bcpr/max25-bcprd.pid}"
STATE_DIR="/tmp/max25-bcpr"
SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
SMOKE_SH="$SCRIPT_DIR/max25-bcpr-rxtx-smoke.sh"

msg() { echo "max25-bcpr-ctl: $*"; }
ok()  { msg "OK — $*"; }
warn(){ msg "WARN — $*"; }
err() { msg "ERROR — $*" >&2; }

usage() {
  cat <<USAGE
max25-bcpr-ctl — BayCom/based PC-COM modem helper

Usage: max25-bcpr-ctl [-c ini] {preflight|start|status|stop|smoke|version}

  preflight   check config and serial port before start
  start       start the PC-COM background service
  status      show whether the service is running
  stop        stop the service
  smoke       offline/optional live test (see --help on smoke script)

Config file default: /etc/max25/max25-bcpr.ini
Create one with: max25-lite-setup  (BayCom/based path)

RX before TX — confirm receive before live transmit.
USAGE
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    -c) INI="$2"; shift 2 ;;
    -h|--help) usage; exit 0 ;;
    *) break ;;
  esac
done
CMD="${1:-}"
if [[ $# -gt 0 ]]; then
  shift
fi

resolve_max25_bcprd_init() {
  if [[ -n "${BCPRD_INIT:-}" && "$BCPRD_INIT" != "max25-bcprd-init" && -x "$BCPRD_INIT" ]]; then
    echo "$BCPRD_INIT"; return
  fi
  if command -v "$BCPRD_INIT" >/dev/null 2>&1; then
    command -v "$BCPRD_INIT"; return
  fi
  local root cand
  root="$(cd "$SCRIPT_DIR/../../.." && pwd)"
  for cand in \
    ${MAX25_BCPR_BUILD_DIR:-${BCPR_BUILD_DIR:-}}/bin/max25-bcprd-init \
    "$root/build-max25-bcpr/bin/max25-bcprd-init" \
    "$root/build-max25-bcpr-${USER:-user}/bin/max25-bcprd-init" \
    "/tmp/max25-build-max25-bcpr-${USER:-user}/bin/max25-bcprd-init" \
    "$root/build/bin/max25-bcprd-init" \
    /usr/local/bin/max25-bcprd-init /usr/bin/max25-bcprd-init; do
    [[ -n "$cand" && -x "$cand" ]] && { echo "$cand"; return; }
  done
  return 1
}

resolve_max25_bcprd() {
  if [[ -n "${BCPRD:-}" && "$BCPRD" != "max25-bcprd" && -x "$BCPRD" ]]; then
    echo "$BCPRD"; return
  fi
  if command -v "$BCPRD" >/dev/null 2>&1; then
    command -v "$BCPRD"; return
  fi
  local root cand
  root="$(cd "$SCRIPT_DIR/../../.." && pwd)"
  for cand in \
    ${MAX25_BCPR_BUILD_DIR:-${BCPR_BUILD_DIR:-}}/bin/max25-bcprd \
    "$root/build-max25-bcpr/bin/max25-bcprd" \
    "$root/build-max25-bcpr-${USER:-user}/bin/max25-bcprd" \
    "/tmp/max25-build-max25-bcpr-${USER:-user}/bin/max25-bcprd" \
    "$root/build/bin/max25-bcprd" \
    /usr/local/bin/max25-bcprd /usr/bin/max25-bcprd; do
    [[ -n "$cand" && -x "$cand" ]] && { echo "$cand"; return; }
  done
  return 1
}

ini_get() {
  local section="$1" key="$2"
  awk -F= -v s="[$section]" -v k="$key" '
    $0 ~ /^\[/ { cur=$0; gsub(/[[:space:]]/,"",cur) }
    cur==s && $1 ~ "^[[:space:]]*"k"[[:space:]]*$" {
      v=$2; gsub(/^[[:space:]]+|[[:space:]]+$/,"",v); print v; exit
    }' "$INI" 2>/dev/null || true
}

is_truthy() {
  case "${1,,}" in yes|true|on|1) return 0 ;; *) return 1 ;; esac
}

find_setserial() {
  local p
  for p in /usr/bin/setserial /bin/setserial /sbin/setserial /usr/sbin/setserial; do
    [[ -x "$p" ]] && { echo "$p"; return; }
  done
  command -v setserial 2>/dev/null || true
}

setserial_port_irq() {
  local bin="$1" dev="$2" out port irq
  out="$("$bin" -g "$dev" 2>/dev/null)" || return 1
  port="$(printf '%s\n' "$out" | sed -n 's/.*Port:[[:space:]]*\(0x[0-9a-fA-F]\+\).*/\1/p' | head -1)"
  irq="$(printf '%s\n' "$out" | sed -n 's/.*IRQ:[[:space:]]*\([0-9]\+\).*/\1/p' | head -1)"
  printf '%s %s\n' "${port:-}" "${irq:-}"
}

norm_hex() {
  local v="${1,,}"
  if [[ "$v" =~ ^0x ]]; then
    printf '0x%x' "$((v))"
  else
    printf '%s' "$v"
  fi
}

is_freebsd() {
  [[ "$(uname -s)" == "FreeBSD" ]]
}

port_busy() {
  local serial="$1"
  local out
  if command -v lsof >/dev/null 2>&1; then
    out="$(lsof "$serial" 2>/dev/null || true)"
    [[ -n "$out" ]] && return 0
    return 1
  fi
  if command -v fuser >/dev/null 2>&1; then
    out="$(fuser "$serial" 2>/dev/null || true)"
    [[ -n "$out" ]]
    return $?
  fi
  return 1
}

baycom_modules_loaded() {
  local m
  if ! command -v lsmod >/dev/null 2>&1; then
    return 1
  fi
  for m in baycom_ser_fdx baycom_ser_hdx baycom_par baycom_epp; do
    if lsmod 2>/dev/null | awk '{print $1}' | grep -qx "$m"; then
      echo "$m"
      return 0
    fi
  done
  return 1
}

cmd_preflight() {
  local fail=0 dry serial irq iobase name sysirq got ss ss_port ss_irq pair
  local -a seen_irq=() seen_serial=()
  if [[ ! -f "$INI" ]]; then
    err "config not found ($INI) — run max25-lite-setup or copy stacks/max25-bcpr/share/max25-bcpr.ini.example"
    return 1
  fi
  dry="$(ini_get max25-bcpr dry_run)"; [[ -z "$dry" ]] && dry="$(ini_get bcpr dry_run)"
  sd="$(ini_get max25-bcpr state_dir)"; [[ -z "$sd" ]] && sd="$(ini_get max25-bcpr state_dir)"
  [[ -n "$sd" ]] && STATE_DIR="$sd"
  msg "checking BayCom/based PC-COM setup (config: $INI)"

  if mod="$(baycom_modules_loaded)"; then
    err "Linux BayCom kernel driver is loaded ($mod) — unload it first: sudo modprobe -r $mod"
    fail=1
  else
    ok "no conflicting Linux BayCom kernel driver"
  fi

  ss="$(find_setserial)"
  if [[ -z "$ss" ]]; then
    warn "setserial not installed — limited port checks (optional: sudo apt install setserial)"
  else
    ok "setserial found"
  fi

  for sec in bc0 bc1; do
    serial="$(ini_get "$sec" serial)"
    [[ -z "$serial" ]] && continue
    enabled="$(ini_get "$sec" enabled)"
    if [[ -n "$enabled" ]] && ! is_truthy "$enabled"; then
      msg "section [$sec] disabled — skipped"
      continue
    fi
    irq="$(ini_get "$sec" irq)"
    iobase="$(ini_get "$sec" iobase)"
    msg "port [$sec]: serial=$serial irq=${irq:-?} iobase=${iobase:-?}"

    if is_truthy "$dry"; then
      msg "dry-run mode — skipping live port checks"
      continue
    fi

    if [[ ! -e "$serial" ]]; then
      if is_freebsd && [[ -n "$iobase" && "$iobase" != "0" ]]; then
        warn "$serial not present — using direct I/O address $iobase (FreeBSD)"
      else
        err "serial port missing ($serial) — check cable, enable UART in BIOS, or fix max25-bcpr.ini"
        fail=1; continue
      fi
    else
      ok "serial port exists ($serial)"
    fi

    if [[ -e "$serial" ]]; then
      if port_busy "$serial"; then
        err "serial port busy ($serial) — close minicom, other TNC tools, or second max25d"
        fail=1
      else
        ok "serial port free ($serial)"
      fi
    elif is_freebsd && [[ -n "$iobase" && "$iobase" != "0" ]]; then
      ok "no tty node — direct I/O path"
    fi

    if [[ -z "$irq" || "$irq" == "0" ]]; then
      err "IRQ missing in [$sec] — set irq= in max25-bcpr.ini (often 4 for COM1 / ttyS0)"
      fail=1
    fi

    name="${serial##*/}"
    sysirq="/sys/class/tty/${name}/irq"
    if [[ -r "$sysirq" ]]; then
      got="$(tr -d '[:space:]' <"$sysirq")"
      if [[ -n "$irq" && "$irq" != "0" && "$got" != "$irq" ]]; then
        err "IRQ mismatch — config says $irq but system says $got — fix max25-bcpr.ini"
        fail=1
      elif [[ -n "$irq" && "$irq" != "0" ]]; then
        ok "IRQ $irq matches system"
      fi
    else
      warn "cannot read IRQ from $sysirq — check config by hand"
    fi

    if [[ -n "$ss" && -n "$iobase" ]]; then
      pair="$(setserial_port_irq "$ss" "$serial" || true)"
      ss_port="$(printf '%s' "$pair" | awk '{print $1}')"
      ss_irq="$(printf '%s' "$pair" | awk '{print $2}')"
      if [[ -n "$ss_port" ]]; then
        if [[ "$(norm_hex "$iobase")" != "$(norm_hex "$ss_port")" ]]; then
          err "I/O address mismatch — config $iobase vs setserial $ss_port"
          fail=1
        else
          ok "I/O address matches setserial"
        fi
      else
        warn "setserial did not report port address for $serial"
      fi
      if [[ -n "$ss_irq" && -n "$irq" && "$irq" != "0" && "$ss_irq" != "$irq" ]]; then
        err "IRQ mismatch — config $irq vs setserial $ss_irq"
        fail=1
      elif [[ -n "$ss_irq" && -n "$irq" && "$irq" != "0" ]]; then
        ok "IRQ matches setserial"
      fi
    elif [[ -n "$iobase" && -z "$ss" ]]; then
      warn "cannot verify I/O address $iobase without setserial"
    fi

    for s in "${seen_serial[@]:-}"; do
      if [[ -n "$s" && "$s" == "$serial" ]]; then
        err "duplicate serial port $serial in config"
        fail=1
      fi
    done
    for i in "${seen_irq[@]:-}"; do
      if [[ -n "$i" && -n "$irq" && "$irq" != "0" && "$i" == "$irq" ]]; then
        err "duplicate IRQ $irq — use different IRQ per port"
        fail=1
      fi
    done
    seen_serial+=("$serial")
    [[ -n "$irq" && "$irq" != "0" ]] && seen_irq+=("$irq")
  done

  if [[ "$fail" -eq 0 ]]; then
    ok "checks passed — you can run: max25-bcpr-ctl start -c $INI"
  else
    err "checks failed — fix errors above, then run preflight again"
  fi
  return "$fail"
}

cmd_start() {
  local bin init dry
  cmd_preflight || return 1
  sd="$(ini_get max25-bcpr state_dir)"; [[ -z "$sd" ]] && sd="$(ini_get bcpr state_dir)"; [[ -n "$sd" ]] && STATE_DIR="$sd"
  mkdir -p "$STATE_DIR"
  PIDFILE="$STATE_DIR/max25-bcprd.pid"
  if [[ -f "$PIDFILE" ]] && kill -0 "$(cat "$PIDFILE")" 2>/dev/null; then
    ok "already running (pid $(cat "$PIDFILE"))"
    return 0
  fi
  dry="$(ini_get max25-bcpr dry_run)"; [[ -z "$dry" ]] && dry="$(ini_get bcpr dry_run)"
  if is_truthy "$dry"; then
    bin="$(resolve_max25_bcprd)" || {
      err "test program max25-bcprd not found — run: cmake -B build && cmake --build build"
      return 1
    }
    "$bin" -c "$INI" --dry-run </dev/null >/dev/null 2>&1 &
    echo $! >"$PIDFILE"
    ok "started test mode (dry-run) pid $(cat "$PIDFILE") — no radio TX"
    return 0
  fi
  init="$(resolve_max25_bcprd_init)" || {
    err "start helper max25-bcprd-init not found — run: sudo cmake --install build"
    return 1
  }
  if ! "$init" -c "$INI" </dev/null; then
    err "PC-COM service failed to start — run preflight again; use sudo if asked"
    return 1
  fi
  if [[ -f "$PIDFILE" ]] && kill -0 "$(cat "$PIDFILE")" 2>/dev/null; then
    ok "PC-COM service running (pid $(cat "$PIDFILE")) — next: run-max25d.sh"
  else
    err "service exited unexpectedly — check errors above"
    return 1
  fi
}

cmd_stop() {
  sd="$(ini_get max25-bcpr state_dir 2>/dev/null || true)"
  [[ -z "${sd:-}" ]] && sd="$(ini_get bcpr state_dir 2>/dev/null || true)"
  [[ -n "${sd:-}" ]] && STATE_DIR="$sd"
  PIDFILE="$STATE_DIR/max25-bcprd.pid"
  if [[ -f "$PIDFILE" ]]; then
    kill "$(cat "$PIDFILE")" 2>/dev/null || true
    rm -f "$PIDFILE"
  fi
  pkill -x max25-bcprd 2>/dev/null || true
  pkill -x max25-bcprd-init 2>/dev/null || true
  ok "PC-COM service stopped"
}

cmd_status() {
  sd="$(ini_get max25-bcpr state_dir 2>/dev/null || true)"
  [[ -z "${sd:-}" ]] && sd="$(ini_get bcpr state_dir 2>/dev/null || true)"
  [[ -n "${sd:-}" ]] && STATE_DIR="$sd"
  PIDFILE="$STATE_DIR/max25-bcprd.pid"
  if [[ -f "$PIDFILE" ]] && kill -0 "$(cat "$PIDFILE")" 2>/dev/null; then
    msg "PC-COM service: running (pid $(cat "$PIDFILE"))"
  else
    msg "PC-COM service: not running — start with: max25-bcpr-ctl start -c $INI"
  fi
  for link in "$STATE_DIR"/kiss-bc*; do
    [[ -e "$link" ]] || continue
    msg "  link $link → $(readlink -f "$link" 2>/dev/null || echo '?')"
  done
}

cmd_smoke() {
  [[ -x "$SMOKE_SH" ]] || {
    err "smoke test script missing ($SMOKE_SH) — rebuild the project"
    return 1
  }
  exec "$SMOKE_SH" -c "$INI" "$@"
}

case "$CMD" in
  preflight) cmd_preflight ;;
  start) cmd_start ;;
  stop) cmd_stop ;;
  status) cmd_status ;;
  smoke) cmd_smoke "$@" ;;
  version) msg "max25-bcpr-ctl 0.5.0-lite (BayCom/based PC-COM)" ;;
  *) usage; exit 1 ;;
esac