#!/bin/bash
# Stale Process Monitor
# Manages and cleans up stale background processes from Claude Code sessions

set -e

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Process patterns to monitor
STALE_PATTERNS=(
    "kubectl port-forward"
    "npm run dev"
    "npx tsx"
    "node dist/index.js"
    "docker push"
    "kubectl exec"
)

# Maximum age in minutes before a process is considered stale
MAX_AGE_MINUTES=${MAX_AGE_MINUTES:-60}

print_header() {
    echo -e "${BLUE}========================================${NC}"
    echo -e "${BLUE}  Stale Process Monitor${NC}"
    echo -e "${BLUE}========================================${NC}"
    echo ""
}

list_processes() {
    local pattern="$1"
    local count=0

    while IFS= read -r line; do
        if [[ -n "$line" ]]; then
            ((count++))
            local pid=$(echo "$line" | awk '{print $1}')
            local start_time=$(ps -o lstart= -p "$pid" 2>/dev/null || echo "unknown")
            local elapsed=$(ps -o etime= -p "$pid" 2>/dev/null | tr -d ' ' || echo "unknown")
            local cmd=$(echo "$line" | awk '{$1=""; $2=""; print $0}' | sed 's/^ *//')

            echo -e "  ${YELLOW}PID:${NC} $pid  ${YELLOW}Elapsed:${NC} $elapsed"
            echo -e "  ${YELLOW}Cmd:${NC} ${cmd:0:80}..."
            echo ""
        fi
    done < <(ps aux | grep -E "$pattern" | grep -v grep | grep -v "stale-process-monitor")

    return $count
}

show_status() {
    print_header
    echo -e "${GREEN}Scanning for potentially stale processes...${NC}"
    echo ""

    local total=0

    for pattern in "${STALE_PATTERNS[@]}"; do
        local matches=$(ps aux | grep -E "$pattern" | grep -v grep | grep -v "stale-process-monitor" | wc -l)
        if [[ $matches -gt 0 ]]; then
            echo -e "${YELLOW}[$pattern]${NC} - $matches process(es) found:"
            echo ""
            list_processes "$pattern"
            ((total += matches))
        fi
    done

    echo -e "${BLUE}----------------------------------------${NC}"
    echo -e "${GREEN}Total potentially stale processes: $total${NC}"
    echo ""

    if [[ $total -eq 0 ]]; then
        echo -e "${GREEN}No stale processes detected.${NC}"
    fi
}

kill_pattern() {
    local pattern="$1"
    local dry_run="$2"

    # Get PIDs from the second column (proper PID column in ps aux)
    local pids=$(ps aux | grep -E "$pattern" | grep -v grep | grep -v "stale-process-monitor" | awk '{print $2}')

    if [[ -z "$pids" ]]; then
        echo -e "${YELLOW}No processes matching '$pattern'${NC}"
        return 0
    fi

    for pid in $pids; do
        # Validate that it's actually a number
        if [[ "$pid" =~ ^[0-9]+$ ]]; then
            if [[ "$dry_run" == "true" ]]; then
                echo -e "${YELLOW}[DRY-RUN] Would kill PID $pid${NC}"
            else
                echo -e "${RED}Killing PID $pid...${NC}"
                kill -9 "$pid" 2>/dev/null || echo -e "${YELLOW}  (already dead)${NC}"
            fi
        fi
    done
}

clean_all() {
    local dry_run="$1"

    print_header

    if [[ "$dry_run" == "true" ]]; then
        echo -e "${YELLOW}DRY RUN MODE - No processes will be killed${NC}"
    else
        echo -e "${RED}CLEANING ALL STALE PROCESSES${NC}"
    fi
    echo ""

    for pattern in "${STALE_PATTERNS[@]}"; do
        echo -e "${BLUE}Processing: $pattern${NC}"
        kill_pattern "$pattern" "$dry_run"
        echo ""
    done

    echo -e "${GREEN}Cleanup complete.${NC}"
}

clean_port_forwards() {
    local dry_run="$1"

    print_header
    echo -e "${BLUE}Cleaning kubectl port-forward processes...${NC}"
    echo ""

    kill_pattern "kubectl port-forward" "$dry_run"

    echo ""
    echo -e "${GREEN}Port-forward cleanup complete.${NC}"
}

clean_dev_servers() {
    local dry_run="$1"

    print_header
    echo -e "${BLUE}Cleaning npm run dev processes...${NC}"
    echo ""

    kill_pattern "npm run dev" "$dry_run"
    kill_pattern "vite" "$dry_run"
    kill_pattern "node.*dist/index.js" "$dry_run"

    echo ""
    echo -e "${GREEN}Dev server cleanup complete.${NC}"
}

interactive_menu() {
    while true; do
        print_header
        echo "Options:"
        echo "  1) Show status (list all stale processes)"
        echo "  2) Clean all stale processes"
        echo "  3) Clean all (dry-run)"
        echo "  4) Clean port-forwards only"
        echo "  5) Clean dev servers only"
        echo "  6) Clean specific pattern"
        echo "  q) Quit"
        echo ""
        read -p "Select option: " choice

        case $choice in
            1) show_status ;;
            2) clean_all "false" ;;
            3) clean_all "true" ;;
            4) clean_port_forwards "false" ;;
            5) clean_dev_servers "false" ;;
            6)
                read -p "Enter pattern to clean: " pattern
                kill_pattern "$pattern" "false"
                ;;
            q|Q) exit 0 ;;
            *) echo -e "${RED}Invalid option${NC}" ;;
        esac

        echo ""
        read -p "Press Enter to continue..."
    done
}

usage() {
    echo "Usage: $0 [command]"
    echo ""
    echo "Commands:"
    echo "  status      Show all potentially stale processes"
    echo "  clean       Clean all stale processes"
    echo "  clean-dry   Dry-run cleanup (show what would be killed)"
    echo "  ports       Clean kubectl port-forward processes only"
    echo "  devs        Clean dev server processes only"
    echo "  kill <pat>  Kill processes matching pattern"
    echo "  interactive Interactive menu mode"
    echo ""
    echo "Environment variables:"
    echo "  MAX_AGE_MINUTES  Maximum process age before considered stale (default: 60)"
    echo ""
    echo "Examples:"
    echo "  $0 status"
    echo "  $0 clean"
    echo "  $0 kill 'kubectl port-forward'"
}

# Main
case "${1:-}" in
    status)
        show_status
        ;;
    clean)
        clean_all "false"
        ;;
    clean-dry)
        clean_all "true"
        ;;
    ports)
        clean_port_forwards "false"
        ;;
    devs)
        clean_dev_servers "false"
        ;;
    kill)
        if [[ -z "${2:-}" ]]; then
            echo "Error: Pattern required"
            usage
            exit 1
        fi
        kill_pattern "$2" "false"
        ;;
    interactive|i)
        interactive_menu
        ;;
    help|-h|--help)
        usage
        ;;
    "")
        show_status
        ;;
    *)
        echo "Unknown command: $1"
        usage
        exit 1
        ;;
esac