#!/bin/bash
# WireGuard Secure Installer
# Copyright (c) 2025 Muhammad Fadhila Abiyyu Faris
# GitHub: [github.com/fadhila36/wireguard-secure-installer](https://github.com/fadhila36/wireguard-secure-installer)

new_client() {
    echo -e "${BLUE}=== Add New Client ===${NC}"
    echo -n "Enter Client Name (no spaces): "
    read -r CLIENT_NAME

    if [[ -z "$CLIENT_NAME" ]]; then
        log_error "Client name cannot be empty."
        return
    fi

    # Check if client already exists
    if grep -q "### Client: $CLIENT_NAME" "$WG_CONFIG"; then
        log_error "Client '$CLIENT_NAME' already exists."
        return
    fi

    # Find next available IP octet
    # We scan for 10.66.66.X and find the first missing number starting from 2
    for i in {2..254}; do
        if ! grep -q "10.66.66.$i" "$WG_CONFIG"; then
            NEXT_IP="$i"
            break
        fi
    done

    if [[ -z "$NEXT_IP" ]]; then
        fatal_error "No available IPs in the subnet."
    fi

    # Re-detect public IP in case it changed
    detect_public_ip

    # Use existing function from wg_core.sh
    create_client_config "$CLIENT_NAME" "$NEXT_IP"
    
    echo -e "${GREEN}Client $CLIENT_NAME added with IP 10.66.66.$NEXT_IP${NC}"
}

remove_client() {
    echo -e "${BLUE}=== Remove Client ===${NC}"
    
    # List clients
    echo "Existing Clients:"
    grep "### Client:" "$WG_CONFIG" | cut -d ' ' -f 3 | nl -s ') '

    echo -n "Enter Client Name to remove: "
    read -r CLIENT_TO_REMOVE

    if [[ -z "$CLIENT_TO_REMOVE" ]]; then
        log_error "Client name cannot be empty."
        return
    fi

    if ! grep -q "### Client: $CLIENT_TO_REMOVE" "$WG_CONFIG"; then
        log_error "Client '$CLIENT_TO_REMOVE' not found."
        return
    fi

    # Backup config
    cp "$WG_CONFIG" "${WG_CONFIG}.bak"

    # Remove the block from config
    # We use a more robust sed command that handles the block structure
    # It deletes from the line containing "### Client: NAME" up to the next blank line
    sed -i "/### Client: $CLIENT_TO_REMOVE/,/^$/d" "$WG_CONFIG"
    
    # Also clean up any potential double empty lines left behind
    sed -i '/^$/N;/^\n$/D' "$WG_CONFIG"

    # Reload WireGuard
    wg syncconf "$SERVER_WG_NIC" <(wg-quick strip "$SERVER_WG_NIC")

    # Remove config file
    rm -f "$INSTALL_DIR/clients/$CLIENT_TO_REMOVE.conf"

    echo -e "${GREEN}Client $CLIENT_TO_REMOVE removed.${NC}"
}

view_usage_logs() {
    echo -e "${BLUE}=== Bandwidth Usage ===${NC}"
    
    # Header
    printf "%-20s | %-15s | %-15s | %-20s\n" "Client Name" "Data Received" "Data Sent" "Last Handshake"
    echo "--------------------------------------------------------------------------------"

    # Get dump
    DUMP=$(wg show "$SERVER_WG_NIC" dump)
    
    # Iterate over clients in config to map names to keys
    # Grep Client Names
    CLIENT_NAMES=$(grep "### Client:" "$WG_CONFIG" | cut -d ' ' -f 3)

    for NAME in $CLIENT_NAMES; do
        # Get Public Key for this client from config
        # We need to read the config file more smartly.
        # Let's assume the structure:
        # ### Client: NAME
        # [Peer]
        # PublicKey = KEY
        
        # Extract Public Key for the specific client
        PUB_KEY=$(sed -n "/### Client: $NAME/,/PublicKey/p" "$WG_CONFIG" | grep "PublicKey" | cut -d ' ' -f 3)
        
        if [[ -n "$PUB_KEY" ]]; then
            # Find stats in dump
            # Dump format: public-key preshared-key endpoint allowed-ips latest-handshake transfer-rx transfer-tx persistent-keepalive
            STATS=$(echo "$DUMP" | grep "$PUB_KEY")
            
            if [[ -n "$STATS" ]]; then
                RX_BYTES=$(echo "$STATS" | awk '{print $6}')
                TX_BYTES=$(echo "$STATS" | awk '{print $7}')
                LAST_HANDSHAKE=$(echo "$STATS" | awk '{print $5}')
                
                # Convert Bytes
                RX_HUMAN=$(numfmt --to=iec-i --suffix=B "$RX_BYTES")
                TX_HUMAN=$(numfmt --to=iec-i --suffix=B "$TX_BYTES")
                
                # Convert Handshake Time
                if [[ "$LAST_HANDSHAKE" -eq 0 ]]; then
                    TIME_HUMAN="Never"
                else
                    TIME_HUMAN=$(date -d @"$LAST_HANDSHAKE" '+%Y-%m-%d %H:%M')
                fi
                
                printf "%-20s | %-15s | %-15s | %-20s\n" "$NAME" "$RX_HUMAN" "$TX_HUMAN" "$TIME_HUMAN"
            fi
        fi
    done
    echo ""
    echo -n "Press Enter to continue..."
    read -r
}