#!/usr/bin/env bash

# Configure Chinese mirrors if USE_CHINA_MIRRORS is set
configure_china_mirrors() {
    if [[ "$USE_CHINA_MIRRORS" == "1" || "${USE_CHINA_MIRRORS,,}" == "true" ]]; then
        echo "Configuring Chinese mirrors for apt and pip..."
        
        # Replace Ubuntu sources
        if [[ -f /etc/apt/sources.list.d/ubuntu.sources ]]; then
            sudo sed -i 's|http://archive.ubuntu.com/ubuntu/|https://mirrors.tuna.tsinghua.edu.cn/ubuntu/|g' /etc/apt/sources.list.d/ubuntu.sources
            sudo sed -i 's|http://security.ubuntu.com/ubuntu/|https://mirrors.tuna.tsinghua.edu.cn/ubuntu/|g' /etc/apt/sources.list.d/ubuntu.sources
            echo "Updated Ubuntu apt sources to use Chinese mirrors"
        fi
        
        # Configure npm registry to use Chinese mirror (npmmirror.com is the recommended mirror)
        if command -v npm &> /dev/null; then
            npm config set registry https://registry.npmmirror.com/
            echo "Configured npm registry to use Chinese mirror (registry.npmmirror.com)"
        fi
        # Also set system-wide npm config for all users
        sudo mkdir -p /etc/npm
        echo "registry=https://registry.npmmirror.com/" | sudo tee /etc/npm/npmrc > /dev/null
        # Set for root user as well (for when npm is installed later)
        sudo mkdir -p /root/.npm
        echo "registry=https://registry.npmmirror.com/" | sudo tee /root/.npmrc > /dev/null
        echo "Configured npm registry to use Chinese mirror (registry.npmmirror.com)"
        
        # Configure pip to use Chinese mirrors
        sudo mkdir -p /etc/pip
        echo "[global]
index-url = https://pypi.tuna.tsinghua.edu.cn/simple
trusted-host = pypi.tuna.tsinghua.edu.cn" | sudo tee /etc/pip/pip.conf > /dev/null
        echo "Configured pip to use Chinese mirrors"
        
        echo "Chinese mirrors configuration completed"
    fi
}

# Run mirror configuration early, before any apt/pip operations
configure_china_mirrors

if [[ "$UPDATE_APT" == "1" || "${UPDATE_APT,,}" == "true" ]]; then
    # Gracefully update package lists if network is available
    echo "Checking network connectivity..."
    if ping -c 1 -W 5 8.8.8.8 >/dev/null 2>&1 || ping -c 1 -W 5 1.1.1.1 >/dev/null 2>&1; then
        echo "Network detected, refreshing package lists..."
        if sudo apt update; then
            echo "Package lists updated successfully"
        else
            echo "Warning: apt update failed despite network connectivity"
            echo "Falling back to cached package lists"
        fi
    else
        echo "No network connectivity detected, using cached package lists"
    fi
fi

# Global variables to track background processes
TAIL_PID=""
INIT_PID=""

term_handler() {
    echo "Received termination signal (PID: $$), cleaning up..."
    
    # First run user-defined exit commands (may gracefully shut down processes)
    if [[ -n "$COMMAND_EXIT" ]]; then
        echo "Running legacy COMMAND_EXIT..."
        eval "$COMMAND_EXIT"
    fi
    
    # Then run numbered COMMAND_EXIT variables in order
    for i in {01..99}; do
        var_name="COMMAND_EXIT$i"
        var_value="${!var_name}"
        if [[ -n "$var_value" ]]; then
            echo "Running $var_name..."
            eval "$var_value"
        fi
    done
    
    # Kill any still-running background processes if they didn't shut down gracefully
    if [[ -n "$INIT_PID" ]]; then
        if kill -0 "$INIT_PID" 2>/dev/null; then
            echo "Init process still running, force killing: $INIT_PID"
            kill "$INIT_PID" 2>/dev/null
        else
            echo "Init process already terminated gracefully"
        fi
    fi
    
    # Kill the tail process if it's running
    if [[ -n "$TAIL_PID" ]]; then
        echo "Killing tail process: $TAIL_PID"
        kill "$TAIL_PID" 2>/dev/null
    fi
    
    # Stop SSH service
    echo "Stopping SSH service..."
    sudo service ssh stop 2>/dev/null || true
    
    echo "Cleanup completed, exiting..."
    exit 0
}

# Debug: Show our PID and signal handling setup
echo "Entrypoint script starting with PID: $$"
echo "Setting up signal handlers..."

# Setup signal handlers for graceful shutdown
trap 'term_handler' SIGTERM SIGINT SIGQUIT

# Test signal handling is working
echo "Signal handlers registered. Testing with kill -0..."

# setup home directory for the current user. It is useful for attaching vscode with container.
user_name=$(whoami)
user_home="/home/$user_name"
sudo mkdir -p "$user_home"
sudo chown -R "$(id -u):$(id -g)" "$user_home"
cp -r /etc/skel/. "$user_home" 2>/dev/null || true

if [[ $LOG_FILE != "/dev/null" ]]; then
    sudo touch "$LOG_FILE"
    sudo chown -R "$(id -u):$(id -g)" "$LOG_FILE"
fi

echo "Starting SSH service..."
sudo service ssh start

# Run initialization commands (last one in background to allow signal handling)
# First collect all defined COMMAND_INIT variables
init_commands=()
if [[ -n "$COMMAND_INIT" ]]; then
    init_commands+=("COMMAND_INIT")
fi
for i in {01..99}; do
    var_name="COMMAND_INIT$i"
    if [[ -n "${!var_name}" ]]; then
        init_commands+=("$var_name")
    fi
done

# Execute them: all synchronously except the last one
for ((i=0; i<${#init_commands[@]}; i++)); do
    var_name="${init_commands[i]}"
    var_value="${!var_name}"
    
    if [[ $i -eq $((${#init_commands[@]} - 1)) ]]; then
        # Last command - run in background to avoid blocking signals
        echo "Running $var_name (final command) in background..."
        eval "$var_value" &
        INIT_PID=$!
        echo "Background process started with PID: $INIT_PID"
    else
        # Not last - run synchronously to preserve expected behavior
        echo "Running $var_name..."
        eval "$var_value"
    fi
done

# Start the main process loop
if [[ $LOG_FILE == "/dev/null" ]]; then
    # If no log file, just wait for signals
    echo "Container ready, waiting for signals..."
    while true; do
        sleep 1 &
        wait $! || break
    done
else
    # If log file specified, tail it
    echo "Container ready, tailing log file: $LOG_FILE"
    tail -f "$LOG_FILE" &
    TAIL_PID=$!
    
    # Wait for the tail process or signals, but make it interruptible
    while kill -0 $TAIL_PID 2>/dev/null; do
        sleep 1 &
        wait $! || break
    done
fi
# This should never be reached, but if it is, exit gracefully
echo "Main loop exited unexpectedly"
exit 0