#!/usr/bin/env bash
set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
VENV_DIR="${FGAI_VENV_DIR:-$ROOT_DIR/.venv}"
PORT="${FGAI_SYSLOG_PORT:-5514}"
HOST="${FGAI_SYSLOG_HOST:-0.0.0.0}"
LOG_FILE="${FGAI_SYSLOG_FILE:-$ROOT_DIR/logs/fg_syslog.jsonl}"
LISTENER_LOG="${FGAI_LISTENER_LOG:-$ROOT_DIR/logs/fgai-listener.log}"
PID_FILE="${FGAI_PID_FILE:-$ROOT_DIR/run/fgai-listener.pid}"

usage() {
    printf 'Usage: %s [start|stop|restart|status|tail|analyze|install]\n' "$0"
    printf '\nDefault action: start\n'
    printf '\nEnvironment overrides:\n'
    printf '  FGAI_SYSLOG_PORT=%s\n' "$PORT"
    printf '  FGAI_SYSLOG_HOST=%s\n' "$HOST"
    printf '  FGAI_SYSLOG_FILE=%s\n' "$LOG_FILE"
    printf '  FGAI_LISTENER_LOG=%s\n' "$LISTENER_LOG"
}

activate_venv_for_script() {
    # Activation here affects this script process. It cannot modify the parent shell prompt.
    # Use "source .venv/bin/activate" manually if you want your interactive prompt to show it.
    # shellcheck disable=SC1091
    source "$VENV_DIR/bin/activate"
}

install_deps() {
    if [ ! -x "$VENV_DIR/bin/python" ]; then
        printf 'Creating venv: %s\n' "$VENV_DIR"
        python3 -m venv "$VENV_DIR"
    fi

    activate_venv_for_script
    printf 'Installing/updating fgAI dependencies...\n'
    python -m pip install --upgrade pip
    python -m pip install -e "$ROOT_DIR"
}

is_running() {
    [ -f "$PID_FILE" ] && ps -p "$(cat "$PID_FILE")" >/dev/null 2>&1
}

needs_privileged_port() {
    [ "$PORT" -lt 1024 ] && [ "${EUID:-$(id -u)}" -ne 0 ]
}

listener_command() {
    "$VENV_DIR/bin/fgai" listen-syslog \
        --host "$HOST" \
        --port "$PORT" \
        --output "$LOG_FILE" \
        --quiet
}

start_listener() {
    install_deps
    mkdir -p "$(dirname "$LOG_FILE")" "$(dirname "$LISTENER_LOG")" "$(dirname "$PID_FILE")"
    touch "$LOG_FILE"

    if is_running; then
        printf 'fgAI syslog listener already running, pid %s\n' "$(cat "$PID_FILE")"
        return 0
    fi

    if needs_privileged_port; then
        printf 'Port %s needs elevated privileges; starting listener with sudo.\n' "$PORT"
        sudo nohup "$VENV_DIR/bin/fgai" listen-syslog \
            --host "$HOST" \
            --port "$PORT" \
            --output "$LOG_FILE" \
            --quiet > "$LISTENER_LOG" 2>&1 &
    else
        nohup "$VENV_DIR/bin/fgai" listen-syslog \
            --host "$HOST" \
            --port "$PORT" \
            --output "$LOG_FILE" \
            --quiet > "$LISTENER_LOG" 2>&1 &
    fi
    printf '%s\n' "$!" > "$PID_FILE"

    printf 'Started fgAI syslog listener, pid %s\n' "$(cat "$PID_FILE")"
    printf 'Input: udp://%s:%s\n' "$HOST" "$PORT"
    printf 'Syslog file: %s\n' "$LOG_FILE"
    printf 'Process log: %s\n' "$LISTENER_LOG"
}

stop_listener() {
    if ! is_running; then
        printf 'fgAI syslog listener is not running\n'
        rm -f "$PID_FILE"
        return 0
    fi

    if ! kill "$(cat "$PID_FILE")" 2>/dev/null; then
        sudo kill "$(cat "$PID_FILE")"
    fi
    rm -f "$PID_FILE"
    printf 'Stopped fgAI syslog listener\n'
}

status_listener() {
    if is_running; then
        printf 'fgAI syslog listener running, pid %s\n' "$(cat "$PID_FILE")"
        printf 'Input: udp://%s:%s\n' "$HOST" "$PORT"
        printf 'Syslog file: %s\n' "$LOG_FILE"
        if command -v ss >/dev/null 2>&1; then
            ss -lunp 2>/dev/null | awk -v port=":$PORT" '$0 ~ port {print}'
        fi
        return 0
    fi

    printf 'fgAI syslog listener is not running\n'
    return 1
}

command="${1:-start}"
case "$command" in
    start)
        start_listener
        ;;
    stop)
        stop_listener
        ;;
    restart)
        stop_listener
        start_listener
        ;;
    status)
        status_listener
        ;;
    tail)
        mkdir -p "$(dirname "$LOG_FILE")"
        touch "$LOG_FILE"
        tail -f "$LOG_FILE"
        ;;
    analyze)
        install_deps
        fgai analyze-logs --logs "$LOG_FILE"
        ;;
    install)
        install_deps
        ;;
    -h|--help|help)
        usage
        ;;
    *)
        usage
        exit 2
        ;;
esac