#!/bin/bash
# VAMR Algorithm Service Script
# Usage: ./algorithm-service.sh {start|stop|restart|status}

# Get the script directory
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# Navigate to the root directory (2 levels up from the script directory)
ROOT_DIR="$(cd "$SCRIPT_DIR/../.." && pwd)"

# Define paths
PYTHON_PATH="$ROOT_DIR/venv/bin/python"
ALGORITHM_PATH="$ROOT_DIR/VAMR/VAMR/algorithm.py"
LOG_DIR="$ROOT_DIR/VAMR/logs"
LOG_ARCHIVE_DIR="$LOG_DIR/archive"
DATA_DIR="$ROOT_DIR/VAMR/data"
PID_FILE="$DATA_DIR/algorithm.pid"
STDOUT_LOG="$LOG_DIR/stdout.log"
ERROR_LOG="$LOG_DIR/error.log"
INFO_LOG="$LOG_DIR/info.log"

# Ensure directories exist
mkdir -p "$LOG_DIR"
mkdir -p "$LOG_ARCHIVE_DIR"
mkdir -p "$DATA_DIR"

# Function to start the algorithm
start_algorithm() {
    echo "Starting VAMR trading algorithm..."
    if [ -f "$PID_FILE" ]; then
        PID=$(cat "$PID_FILE")
        if ps -p $PID > /dev/null; then
            echo "Algorithm is already running with PID: $PID"
            return 1
        else
            echo "Removing stale PID file"
            rm "$PID_FILE"
        fi
    fi

    # Rotate log files: Move existing logs to archive with timestamp
    if [ -f "$INFO_LOG" ]; then
        TIMESTAMP=$(date +"%Y%m%d_%H%M%S")
        echo "Archiving existing info.log to archive folder with timestamp $TIMESTAMP"
        mv "$INFO_LOG" "$LOG_ARCHIVE_DIR/info_$TIMESTAMP.log"
    fi

    # Create empty logs
    touch "$INFO_LOG"
    
    # Change to root directory and activate virtual environment
    cd "$ROOT_DIR"
    source venv/bin/activate

    # Start algorithm in the background
    cd VAMR/VAMR
    nohup python algorithm.py > "$STDOUT_LOG" 2> "$ERROR_LOG" & disown
    
    # Save PID for later use
    echo $! > "$PID_FILE"
    echo "Algorithm started with PID: $(cat "$PID_FILE")"
    return 0
}

# Function to stop the algorithm
stop_algorithm() {
    echo "Stopping VAMR trading algorithm..."
    if [ -f "$PID_FILE" ]; then
        PID=$(cat "$PID_FILE")
        if ps -p $PID > /dev/null; then
            echo "Stopping algorithm with PID: $PID"
            kill $PID
            sleep 2
            
            # Check if process is still running
            if ps -p $PID > /dev/null; then
                echo "Algorithm still running, forcing termination..."
                kill -9 $PID
                sleep 1
            fi
            
            # Verify process is stopped
            if ps -p $PID > /dev/null; then
                echo "ERROR: Failed to stop algorithm!"
                return 1
            else
                echo "Algorithm stopped successfully."
                rm "$PID_FILE"
                return 0
            fi
        else
            echo "No algorithm running with PID: $PID (stale PID file)"
            rm "$PID_FILE"
            return 0
        fi
    else
        echo "No PID file found. Algorithm may not be running."
        return 0
    fi
}

# Function to check algorithm status
status_algorithm() {
    echo "===== VAMR Trading Algorithm Status ====="

    # Check if algorithm is running
    if [ -f "$PID_FILE" ]; then
        PID=$(cat "$PID_FILE")
        if ps -p $PID > /dev/null; then
            echo "Status: RUNNING"
            echo "PID: $PID"
            
            # Get runtime information
            PROC_START=$(ps -p $PID -o lstart=)
            echo "Running since: $PROC_START"
            
            # Get memory usage
            MEM_USAGE=$(ps -p $PID -o %mem=)
            echo "Memory usage: $MEM_USAGE%"
            
            # Check state file
            STATE_FILE="$DATA_DIR/state.json"
            if [ -f "$STATE_FILE" ]; then
                STATE_SIZE=$(du -h "$STATE_FILE" | cut -f1)
                STATE_TIME=$(date -r "$STATE_FILE" "+%Y-%m-%d %H:%M:%S")
                echo "State file: $STATE_SIZE, last updated: $STATE_TIME"
            else
                echo "State file: NOT FOUND"
            fi
            
            # Show recent log entries
            echo ""
            echo "Recent log entries:"
            echo "--- Last 5 lines of algorithm log ---"
            tail -n 5 "$INFO_LOG"
            return 0
        else
            echo "Status: NOT RUNNING (stale PID file)"
            rm "$PID_FILE"
            return 1
        fi
    else
        echo "Status: NOT RUNNING (no PID file)"
        return 1
    fi
}

# Main logic
case "$1" in
    start)
        start_algorithm
        ;;
    stop)
        stop_algorithm
        ;;
    restart)
        stop_algorithm
        sleep 2
        start_algorithm
        ;;
    status)
        status_algorithm
        ;;
    *)
        echo "Usage: $0 {start|stop|restart|status}"
        exit 1
        ;;
esac

exit $?