#!/bin/bash
# ==============================================================================================
# ============================= User Scripts Stop ==============================================
# ==============================================================================================
# Stops all running User Script processes spawned by the unRAID User Scripts plugin.
# Identifies processes by their /tmp/user.scripts path signature.
# Shows script names not just PIDs — you know what's being stopped.
#
# ── WHEN TO USE ───────────────────────────────────────────────────────────────────────────────
#   - Before a planned reboot when scripts are running mid-cycle
#   - When a script is stuck and won't respond to the Abort button in the UI
#   - Called automatically by server_reboot.sh as part of shutdown sequence
#   - Emergency stop of all background ecosystem scripts
#
# ── HOW IT IDENTIFIES PROCESSES ───────────────────────────────────────────────────────────────
# Scans /proc/*/cmdline for processes whose command line contains "/tmp/user.scripts".
# The unRAID User Scripts plugin stages all scripts in /tmp/user.scripts/ before execution.
# This is more reliable than process name matching which can vary.
#
# ── STOP SEQUENCE PER PROCESS ─────────────────────────────────────────────────────────────────
#   1. Send SIGTERM — allows script to trap and clean up gracefully
#   2. Wait 5 seconds
#   3. Check if still running → SIGKILL (force) if SIGTERM ignored
#   4. Verify dead after SIGKILL
#
# ── SELF-EXCLUSION ────────────────────────────────────────────────────────────────────────────
# If this script itself is run via the User Scripts plugin it would find its own PID.
# Self-exclusion prevents this script from killing itself mid-execution.
#
# ── SAFEGUARDS ────────────────────────────────────────────────────────────────────────────────
#   Root check           — kill requires root for other users' processes
#   acquire_lock         — prevents concurrent stop attempts
#   Self-exclusion       — never kills its own process tree
#   SIGTERM → SIGKILL    — graceful then forced
#   Verify after kill    — confirms processes are actually dead
#   validate_unraid_cmd  — notify validated before use
#   Silent when clean    — no processes running = log() only ✅
#
# ── USAGE ─────────────────────────────────────────────────────────────────────────────────────
#   user_scripts_stop.sh              — stop all user scripts
#   user_scripts_stop.sh --dry-run    — show what would be stopped
#   user_scripts_stop.sh --status     — show currently running user scripts
#   user_scripts_stop.sh --log        — verbose output
# ==============================================================================================

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

source "$SCRIPT_DIR/../load_config.sh"

parse_args "$@"

MY_PID=$$
MY_PPID=$PPID

# ==============================================================================================
# ━━━ Setup ━━━
# ==============================================================================================
if [[ "$EUID" -ne 0 ]]; then
    error "Must be run as root — kill requires root for other users' processes"
    exit 1
fi

validate_unraid_cmd \
    "/usr/local/emhttp/plugins/dynamix/scripts/notify" \
    "" "" \
    "unRAID notify script" || warn "unRAID notify script not found — native notifications disabled"

acquire_lock

detect_hosts

[[ "$DRY_RUN" == true ]] && warn "DRY RUN — no processes will be killed"

# ==============================================================================================
# ── HELPER FUNCTIONS ──────────────────────────────────────────────────────────────────────────
# ==============================================================================================

# Get script name from PID — extracts meaningful name from /tmp/user.scripts path
get_script_name() {
    local pid="$1"
    local cmdline
    cmdline=$(tr '\0' ' ' < /proc/"$pid"/cmdline 2>/dev/null || echo "")
    # Extract the script filename from the /tmp/user.scripts/... path
    echo "$cmdline" | grep -o '/tmp/user\.scripts[^ ]*' | \
        awk -F/ '{print $NF}' | head -1 || echo "pid-$pid"
}

# Get all user script PIDs — excludes self and own parent process tree
get_user_script_pids() {
    local -a pids=()
    while IFS= read -r pid; do
        [[ -z "$pid" ]] && continue
        # Self-exclusion — don't kill our own process or parent
        [[ "$pid" == "$MY_PID" ]] && continue
        [[ "$pid" == "$MY_PPID" ]] && continue
        pids+=("$pid")
    done < <(
        for dir in /proc/[0-9]*/cmdline; do
            pid="${dir%/cmdline}"
            pid="${pid#/proc/}"
            if grep -ql '/tmp/user\.scripts' "$dir" 2>/dev/null; then
                echo "$pid"
            fi
        done
    )
    printf '%s\n' "${pids[@]}"
}

# ==============================================================================================
# ━━━ Status ━━━
# ==============================================================================================
if [[ "$SHOW_STATUS" == true ]]; then
    echo ""
    echo "━━━━━ $ICON_SUMMARY USER SCRIPTS STATUS ━━━━━"
    echo "$ICON_HOST   Identity: $MY_ID ($LOCAL_SERVER_NAME)"
    echo ""

    mapfile -t PIDS < <(get_user_script_pids)

    if [[ ${#PIDS[@]} -eq 0 ]]; then
        log "No User Script processes running"
    else
        echo "  ${#PIDS[@]} User Script process(es) running:"
        for pid in "${PIDS[@]}"; do
            name=$(get_script_name "$pid")
            elapsed=$(ps -o etimes= -p "$pid" 2>/dev/null | tr -d ' ')
            runtime=$(format_duration "${elapsed:-0}")
            echo "  $ICON_RUNNING PID $pid — $name (${runtime})"
        done
    fi
    echo "━━━━━━━━━━━━━━━━━━━━━━━"
    exit 0
fi

# ==============================================================================================
# ━━━ User Scripts Stop ━━━
# ==============================================================================================
echo ""
echo "━━━ $ICON_PLUGIN User Scripts Stop — $MY_ID ━━━"

START=$(date +%s)

mapfile -t PIDS < <(get_user_script_pids)

KILLED=()
FAILED=()
SKIPPED=()

if [[ ${#PIDS[@]} -eq 0 ]]; then
    log "No User Script processes running — nothing to do"
else
    warn "${#PIDS[@]} User Script process(es) found"
    echo ""

    for pid in "${PIDS[@]}"; do
        name=$(get_script_name "$pid")

        if [[ "$DRY_RUN" == true ]]; then
            warn "DRY RUN — would stop: $name (PID $pid)"
            SKIPPED+=("$name")
            continue
        fi

        # Verify still running before trying to kill
        if ! kill -0 "$pid" 2>/dev/null; then
            log "$name (PID $pid) — already exited"
            continue
        fi

        # SIGTERM — graceful stop
        log "Sending SIGTERM to $name (PID $pid)..."
        kill -TERM "$pid" 2>/dev/null || true
        sleep 5

        # Check if stopped after SIGTERM
        if ! kill -0 "$pid" 2>/dev/null; then
            warn "Stopped: $name (PID $pid) ✅"
            KILLED+=("$name")
            continue
        fi

        # SIGKILL — forced stop
        warn "$name still running after SIGTERM — sending SIGKILL"
        kill -KILL "$pid" 2>/dev/null || true
        sleep 2

        # Final verify
        if ! kill -0 "$pid" 2>/dev/null; then
            warn "Force-stopped: $name (PID $pid) ✅"
            KILLED+=("$name")
        else
            error "Failed to kill: $name (PID $pid)"
            FAILED+=("$name")
        fi
    done
fi

END=$(date +%s)

# ==============================================================================================
# ━━━ Summary ━━━
# ==============================================================================================
echo ""
echo "━━━━━ $ICON_SUMMARY USER SCRIPTS STOP SUMMARY ━━━━━"
echo "$ICON_HOST   Identity: $MY_ID ($LOCAL_SERVER_NAME)"
echo "$ICON_TIME   Duration: $(format_duration $(( END - START )))"
echo ""

if [[ ${#PIDS[@]} -eq 0 ]]; then
    log "No processes were running"
elif [[ "$DRY_RUN" == true ]]; then
    warn "DRY RUN — would have stopped ${#SKIPPED[@]} process(es): ${SKIPPED[*]}"
else
    [[ ${#KILLED[@]} -gt 0 ]] && warn "Stopped (${#KILLED[@]}): ${KILLED[*]}"
    [[ ${#FAILED[@]} -gt 0 ]] && echo "$ICON_ERROR Failed (${#FAILED[@]}): ${FAILED[*]}"
fi

echo ""
if [[ "$DRY_RUN" == true ]]; then
    warn "DRY RUN — no changes made"
elif [[ ${#FAILED[@]} -gt 0 ]]; then
    echo "$ICON_ERROR Status: SOME PROCESSES COULD NOT BE KILLED"
    notify "User Scripts stop failed on $(hostname) ($MY_ID) — unkillable: ${FAILED[*]}" \
        "User Scripts Stop" "warning"
else
    log "$ICON_DONE Status: done ✅"
fi
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"

[[ ${#FAILED[@]} -gt 0 ]] && exit 1
exit 0