#!/usr/bin/env bash
set -u

# init-kpf.sh
# Portable-ish (macOS, Ubuntu, Raspberry Pi OS, Alpine) bash init-style script
# Manages kubectl port-forward daemons defined in an XML file.

PROG="init-port-forwards"
PROLE_HOME="/Users/chrisfu/dev/prole"
VERBOSE=0
CONFIG_FILE="$PROLE_HOME/conf/port-mappings.properties"

usage() {
  cat <<EOF
Usage:
  $PROG [-v|--verbose] [-c|--config-file=FILE] <start|stop|restart|status>

Options:
  -c, --config-file=FILE   Path to local-ports.properties (XML)
  -v, --verbose            Verbose output

Examples:
  $PROG -c ./port-mappings.properties start
  $PROG --verbose status
EOF
}

log()  { printf '%s\n' "$*"; }
vlog() { [ "$VERBOSE" -eq 1 ] && printf '[verbose] %s\n' "$*" || true; }
err()  { printf '[error] %s\n' "$*" >&2; }

have() { command -v "$1" >/dev/null 2>&1; }

# Choose a writable state dir for pid/log files:
# - Prefer XDG_RUNTIME_DIR if set and writable
# - Else /var/run if writable (rare without root)
# - Else ~/.local/state
# - Else /tmp
state_dir() {
  if [ -n "${XDG_RUNTIME_DIR:-}" ] && [ -w "${XDG_RUNTIME_DIR:-}" ]; then
    printf '%s/%s' "$XDG_RUNTIME_DIR" "$PROG"
    return
  fi
  if [ -d "/var/run" ] && [ -w "/var/run" ]; then
    printf '/var/run/%s' "$PROG"
    return
  fi
  if [ -n "${HOME:-}" ]; then
    mkdir -p "$HOME/.local/state" >/dev/null 2>&1 || true
    if [ -d "$HOME/.local/state" ] && [ -w "$HOME/.local/state" ]; then
      printf '%s/.local/state/%s' "$HOME" "$PROG"
      return
    fi
  fi
  printf '/tmp/%s' "$PROG"
}

STATE_DIR="$(state_dir)"
PID_DIR="$STATE_DIR/pids"
LOG_DIR="$STATE_DIR/logs"

ensure_dirs() {
  mkdir -p "$PID_DIR" "$LOG_DIR" 2>/dev/null || true
  if [ ! -d "$PID_DIR" ] || [ ! -d "$LOG_DIR" ]; then
    err "Unable to create state directories under: $STATE_DIR"
    exit 1
  fi
}

# Use kubectl for actions; kubecolor is used only for prettier status output.
KUBECTL="kubectl"
detect_kubectl() {
  if have kubectl; then
    KUBECTL="kubectl"
  else
    err "kubectl not found in PATH"
    exit 1
  fi
}

# Basic environment validation
validate_env() {
  detect_kubectl
  ensure_dirs

  if ! "$KUBECTL" version --client >/dev/null 2>&1; then
    err "kubectl seems broken or not executable"
    exit 1
  fi

  # Can we reach the cluster?
  if ! "$KUBECTL" cluster-info >/dev/null 2>&1; then
    err "kubectl cannot reach a cluster (check KUBECONFIG/context)"
    err "Try: kubectl config get-contexts && kubectl config use-context <ctx>"
    exit 1
  fi
}

pid_file_for() { printf '%s/%s.pid' "$PID_DIR" "$1"; }
log_file_for() { printf '%s/%s.log' "$LOG_DIR" "$1"; }

is_pid_running() {
  # Return 0 if pid exists and running, else 1
  # kill -0 is portable.
  local pid="$1"
  [ -n "$pid" ] && kill -0 "$pid" >/dev/null 2>&1
}

read_pid() {
  local pf="$1"
  [ -f "$pf" ] || return 1
  # shellcheck disable=SC2162
  read pid <"$pf" || return 1
  printf '%s' "$pid"
}

write_pid() {
  local pf="$1" pid="$2"
  printf '%s\n' "$pid" >"$pf"
}

remove_pidfile() {
  local pf="$1"
  rm -f "$pf" >/dev/null 2>&1 || true
}

# ---- XML parsing (simple attribute extraction) ----
# We parse lines containing: <mapping ... />
# Attributes must use double quotes in the XML (as in the sample).
get_attr() {
  # $1 = line, $2 = attribute name
  # outputs value or empty
  printf '%s\n' "$1" | sed -n "s/.*$2=\"\([^\"]*\)\".*/\1/p"
}

foreach_mapping() {
  # Calls a provided function with mapping fields:
  # callback id ns target address hostPort servicePort protocol description
  local callback="$1"
  [ -f "$CONFIG_FILE" ] || { err "Config file not found: $CONFIG_FILE"; exit 1; }

  # Support both single-line and multi-line self-closing mapping tags, e.g.:
  # <mapping id="x" ... /> OR lines spanning multiple lines until "/>".
  local in_mapping=0 in_comment=0 buffer="" line
  while IFS= read -r line; do
    # Handle XML comments: skip anything between <!-- and -->
    if [ $in_comment -eq 1 ]; then
      case "$line" in
        *"-->"*) in_comment=0; continue ;;
        *) continue ;;
      esac
    fi
    case "$line" in
      *"<!--"*)
        case "$line" in
          *"-->"*)
            # single-line comment; skip line
            continue
            ;;
          *)
            in_comment=1
            continue
            ;;
        esac
        ;;
    esac
    if [ $in_mapping -eq 0 ]; then
      case "$line" in
        *"<mapping"*)
          in_mapping=1
          buffer="$line"
          ;;
        *)
          continue
          ;;
      esac
    else
      # Accumulate lines until we see the closing '/>'
      buffer="$buffer $line"
    fi

    if [ $in_mapping -eq 1 ] && printf '%s' "$line" | grep -q "/>"; then
      # Normalize whitespace to make attribute extraction robust
      local merged
      merged=$(printf '%s\n' "$buffer" | tr '\n' ' ' | sed 's/[[:space:]]\+/ /g')

      local id ns target address hostPort servicePort protocol description
      id="$(get_attr "$merged" "id")"
      ns="$(get_attr "$merged" "namespace")"
      target="$(get_attr "$merged" "target")"
      address="$(get_attr "$merged" "address")"
      hostPort="$(get_attr "$merged" "hostPort")"
      servicePort="$(get_attr "$merged" "servicePort")"
      protocol="$(get_attr "$merged" "protocol")"
      description="$(get_attr "$merged" "description")"

      # Basic validation
      if [ -z "$id" ] || [ -z "$ns" ] || [ -z "$target" ] || [ -z "$hostPort" ] || [ -z "$servicePort" ]; then
        err "Invalid mapping (missing required attributes): $merged"
        exit 1
      fi
      if [ -z "$address" ]; then address="127.0.0.1"; fi
      if [ -z "$protocol" ]; then protocol="TCP"; fi

      vlog "mapping: id=$id ns=$ns target=$target address=$address hostPort=$hostPort servicePort=$servicePort protocol=$protocol"
      "$callback" "$id" "$ns" "$target" "$address" "$hostPort" "$servicePort" "$protocol" "$description"

      # Reset accumulator
      in_mapping=0
      buffer=""
    fi
  done <"$CONFIG_FILE"
}

build_port_forward_cmd() {
  # echo a command string
  local ns="$1" target="$2" address="$3" hostPort="$4" servicePort="$5"
  # kubectl port-forward -n <ns> --address <addr> <target> <local>:<remote>
  printf '%s port-forward -n %s --address %s %s %s:%s' \
    "$KUBECTL" "$ns" "$address" "$target" "$hostPort" "$servicePort"
}

start_port_forward() {
  echo "start_port_forward()"
  local id="$1" ns="$2" target="$3" address="$4" hostPort="$5" servicePort="$6" protocol="$7" description="$8"
  local pf pidfile logfile cmd pid

  pidfile="$(pid_file_for "$id")"
  logfile="$(log_file_for "$id")"
  cmd="$(build_port_forward_cmd "$ns" "$target" "$address" "$hostPort" "$servicePort")"
  echo $cmd
  # If pidfile exists and process is alive, skip
  if [ -f "$pidfile" ]; then
    pid="$(read_pid "$pidfile" || true)"
    if [ -n "${pid:-}" ] && is_pid_running "$pid"; then
      vlog "$id already running (pid=$pid)"
      return 0
    else
      # stale pidfile
      remove_pidfile "$pidfile"
    fi
  fi

  log "Starting: $id  $address:$hostPort -> $target:$servicePort  ($ns)  ${description:-}"
  vlog "Command: $cmd"

  # Start in background, keep output in log.
  # nohup is available on macOS/Linux; redirect stdin from /dev/null to detach.
  nohup sh -c "$cmd" >>"$logfile" 2>&1 </dev/null &
  pid="$!"
  write_pid "$pidfile" "$pid"

  # Quick verification
  sleep 0.2
  if is_pid_running "$pid"; then
    vlog "$id started (pid=$pid, log=$logfile)"
    return 0
  else
    err "$id failed to start (see log: $logfile)"
    remove_pidfile "$pidfile"
    return 1
  fi
}

stop_port_forward() {
  local id="$1" ns="$2" target="$3" address="$4" hostPort="$5" servicePort="$6" protocol="$7" description="$8"
  local pidfile pid

  pidfile="$(pid_file_for "$id")"
  if [ ! -f "$pidfile" ]; then
    vlog "$id not running (no pidfile)"
    return 0
  fi

  pid="$(read_pid "$pidfile" || true)"
  if [ -z "${pid:-}" ]; then
    remove_pidfile "$pidfile"
    return 0
  fi

  if is_pid_running "$pid"; then
    log "Stopping: $id (pid=$pid)"
    kill "$pid" >/dev/null 2>&1 || true

    # wait a moment, then SIGKILL if needed
    local i
    for i in 1 2 3 4 5; do
      if ! is_pid_running "$pid"; then break; fi
      sleep 0.2
    done
    if is_pid_running "$pid"; then
      err "$id did not stop gracefully; sending SIGKILL"
      kill -9 "$pid" >/dev/null 2>&1 || true
    fi
  else
    vlog "$id stale pidfile (pid=$pid not running)"
  fi

  remove_pidfile "$pidfile"
}

status_one() {
  local id="$1" ns="$2" target="$3" address="$4" hostPort="$5" servicePort="$6" protocol="$7" description="$8"
  local pidfile pid

  pidfile="$(pid_file_for "$id")"
  pid=""
  if [ -f "$pidfile" ]; then
    pid="$(read_pid "$pidfile" || true)"
  fi

  if [ -n "${pid:-}" ] && is_pid_running "$pid"; then
    printf 'RUNNING  %-12s pid=%-7s %s:%s -> %s:%s  ns=%s  %s\n' \
      "$id" "$pid" "$address" "$hostPort" "$target" "$servicePort" "$ns" "${description:-}"
    # ps details (portable flags vary; use a conservative format)
    ps -p "$pid" -o pid=,ppid=,etime=,command= 2>/dev/null | sed 's/^/         /' || true
  else
    printf 'STOPPED  %-12s (no live pid) %s:%s -> %s:%s  ns=%s  %s\n' \
      "$id" "$address" "$hostPort" "$target" "$servicePort" "$ns" "${description:-}"
  fi
}

do_start() {
  validate_env
  foreach_mapping start_port_forward
}

do_stop() {
  # stop doesn't require cluster access, but it does need state dirs
  ensure_dirs
  foreach_mapping stop_port_forward
}

do_restart() {
  validate_env
  foreach_mapping stop_port_forward
  foreach_mapping start_port_forward
}

do_status() {
  validate_env

  log "== Context / Cluster =="
  "$KUBECTL" config current-context 2>/dev/null | sed 's/^/  context: /' || true
  "$KUBECTL" cluster-info 2>/dev/null | sed 's/^/  /' || true
  log ""

  log "== Port-forward processes =="
  foreach_mapping status_one
  log ""

  log "== Quick k3d awareness checks (best-effort) =="
  # If user is on k3d, current-context often includes k3d-... but not guaranteed.
  # Show nodes + a few namespaces/services related to mappings (best effort).
  "$KUBECTL" get nodes -o wide 2>/dev/null | sed 's/^/  /' || true
  log ""
  "$KUBECTL" get ns 2>/dev/null | sed 's/^/  /' || true
  log ""

  # For each mapping, try to show target existence
  log "== Target existence (best-effort) =="
  _target_check() {
    local id="$1" ns="$2" target="$3" address="$4" hostPort="$5" servicePort="$6" protocol="$7" description="$8"
    # kubectl get <target> -n <ns>
    # If target is like "svc/name", "deploy/name", etc.
    if "$KUBECTL" get -n "$ns" "$target" >/dev/null 2>&1; then
      printf 'OK      %-12s %s (ns=%s)\n' "$id" "$target" "$ns"
    else
      printf 'MISSING %-12s %s (ns=%s)\n' "$id" "$target" "$ns"
    fi
  }
  foreach_mapping _target_check
}

# ---- arg parsing ----
ACTION=""

while [ $# -gt 0 ]; do
  case "$1" in
    start|stop|restart|status)
      ACTION="$1"
      shift
      ;;
    -v|--verbose)
      VERBOSE=1
      shift
      ;;
    -c)
      shift
      [ $# -gt 0 ] || { err "-c requires a file path"; usage; exit 2; }
      CONFIG_FILE="$1"
      shift
      ;;
    --config-file=*)
      CONFIG_FILE="${1#*=}"
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      err "Unknown arg: $1"
      usage
      exit 2
      ;;
  esac
done

[ -n "$ACTION" ] || { usage; exit 2; }

case "$ACTION" in
  start)   do_start ;;
  stop)    do_stop ;;
  restart) do_restart ;;
  status)  do_status ;;
esac