#!/bin/sh
# DPI Flow Collector - Aggregates netifyd flow statistics
# Part of secubox-dpi-dual package

. /lib/functions.sh

config_load dpi-dual

FLOW_DIR=""
STATS_DIR=""
RETENTION=""

load_config() {
    config_get FLOW_DIR settings flow_dir "/tmp/dpi-flows"
    config_get STATS_DIR settings stats_dir "/tmp/secubox"
    config_get RETENTION tap flow_retention "300"
}

init_dirs() {
    mkdir -p "$FLOW_DIR"
    mkdir -p "$STATS_DIR"
}

collect_flows() {
    local stats_file="$STATS_DIR/dpi-flows.json"
    local netifyd_socket="/var/run/netifyd/netifyd.sock"

    # Count recent flow files
    local total_flows=0
    if [ -d "$FLOW_DIR" ]; then
        total_flows=$(find "$FLOW_DIR" -name "*.json" -mmin -1 2>/dev/null | wc -l)
    fi

    # Get protocol distribution from netifyd status
    local protocols="{}"
    if [ -S "$netifyd_socket" ]; then
        # Try to get stats from netifyd socket
        local proto_data
        proto_data=$(echo '{"type":"get_stats"}' | nc -U "$netifyd_socket" 2>/dev/null | head -1)
        if [ -n "$proto_data" ]; then
            protocols=$(echo "$proto_data" | jsonfilter -e '@.protocols' 2>/dev/null || echo '{}')
        fi
    fi

    # Get interface stats from /proc
    local tap_if
    config_get tap_if tap interface "tap0"

    local rx_bytes=0 tx_bytes=0 rx_packets=0 tx_packets=0
    if [ -d "/sys/class/net/$tap_if/statistics" ]; then
        rx_bytes=$(cat "/sys/class/net/$tap_if/statistics/rx_bytes" 2>/dev/null || echo 0)
        tx_bytes=$(cat "/sys/class/net/$tap_if/statistics/tx_bytes" 2>/dev/null || echo 0)
        rx_packets=$(cat "/sys/class/net/$tap_if/statistics/rx_packets" 2>/dev/null || echo 0)
        tx_packets=$(cat "/sys/class/net/$tap_if/statistics/tx_packets" 2>/dev/null || echo 0)
    fi

    # Write stats JSON
    cat > "$stats_file" << EOF
{
    "timestamp": "$(date -Iseconds)",
    "flows_1min": $total_flows,
    "tap_interface": "$tap_if",
    "rx_bytes": $rx_bytes,
    "tx_bytes": $tx_bytes,
    "rx_packets": $rx_packets,
    "tx_packets": $tx_packets,
    "protocols": $protocols,
    "mode": "passive_tap"
}
EOF
}

cleanup_old_flows() {
    # Remove flow files older than retention period
    local retention_min=$((RETENTION / 60))
    [ "$retention_min" -lt 1 ] && retention_min=1

    find "$FLOW_DIR" -name "*.json" -mmin +"$retention_min" -delete 2>/dev/null
}

run_collector() {
    load_config
    init_dirs

    echo "DPI Flow Collector started"
    echo "  Flow dir: $FLOW_DIR"
    echo "  Stats dir: $STATS_DIR"
    echo "  Retention: ${RETENTION}s"

    while true; do
        collect_flows
        cleanup_old_flows
        sleep 10
    done
}

case "$1" in
    start)
        run_collector
        ;;
    once)
        load_config
        init_dirs
        collect_flows
        cleanup_old_flows
        ;;
    *)
        echo "Usage: $0 {start|once}"
        exit 1
        ;;
esac