#!/bin/bash
set -euo pipefail

# ==============================================================================
# I2P (Invisible Internet Project) Installation
# ==============================================================================
# Anonymous overlay network using "garlic routing"
# - Internal network of hidden services (eepsites)
# - Anonymous torrenting
# - More resistant to traffic analysis than Tor for internal traffic
# - Every user is both client and relay
# ==============================================================================

# Colors
readonly GREEN='\033[0;32m'
readonly YELLOW='\033[1;33m'
readonly BLUE='\033[0;34m'
readonly RED='\033[0;31m'
readonly NC='\033[0m'

log() { echo -e "${GREEN}[INFO]${NC} $*"; }
warn() { echo -e "${YELLOW}[WARN]${NC} $*"; }
error() { echo -e "${RED}[ERROR]${NC} $*"; }
section() { echo -e "${BLUE}=== $* ===${NC}"; }

section "I2P Installation"
echo ""

# Check if already installed
if command -v i2prouter &>/dev/null || [ -d /usr/share/i2p ]; then
    log "I2P appears to be already installed"
    read -p "Reinstall/upgrade? [y/N] " -n 1 -r
    echo
    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
        log "Skipping installation"
        exit 0
    fi
fi

# Detect distro
if [ -f /etc/os-release ]; then
    . /etc/os-release
    DISTRO="${ID:-unknown}"
else
    error "Cannot detect distribution"
    exit 1
fi

log "Detected: $DISTRO"

case "$DISTRO" in
    debian|ubuntu|linuxmint|pop)
        # Try i2pd from repos first (C++ implementation - lighter, faster)
        if apt-cache show i2pd &>/dev/null; then
            section "Installing i2pd (C++ implementation) from Debian repos"
            log "i2pd is a lighter, faster C++ implementation of I2P"

            sudo apt update
            sudo apt install -y i2pd

            log "i2pd installed from Debian repositories"
        else
            section "Installing I2P via Official Repository"
            warn "i2pd not in repos, trying official I2P repository..."

            # Install dependencies
            log "Installing dependencies..."
            sudo apt update
            sudo apt install -y apt-transport-https curl gnupg

            # Add I2P repo signing key
            log "Adding I2P repository key..."
            curl -fsSL https://geti2p.net/_static/i2p-archive-keyring.gpg | sudo gpg --dearmor -o /usr/share/keyrings/i2p-archive-keyring.gpg
            sudo chmod 644 /usr/share/keyrings/i2p-archive-keyring.gpg

            # Add I2P repository
            log "Adding I2P repository..."
            echo "deb [signed-by=/usr/share/keyrings/i2p-archive-keyring.gpg] https://deb.i2p2.de/ $(lsb_release -sc) main" | \
                sudo tee /etc/apt/sources.list.d/i2p.list > /dev/null

            # Install I2P
            log "Installing I2P..."
            sudo apt update
            sudo apt install -y i2p i2p-keyring
        fi
        ;;

    fedora|rhel|centos)
        section "Installing I2P via Copr"

        log "Adding I2P Copr repository..."
        sudo dnf copr enable -y i2p/i2p

        log "Installing I2P..."
        sudo dnf install -y i2p
        ;;

    arch|manjaro|endeavouros)
        section "Installing I2P via AUR"

        if command -v yay &>/dev/null; then
            log "Installing via yay..."
            yay -S --noconfirm i2pd
        elif command -v paru &>/dev/null; then
            log "Installing via paru..."
            paru -S --noconfirm i2pd
        else
            warn "No AUR helper found, installing i2pd manually..."
            cd /tmp
            git clone https://aur.archlinux.org/i2pd.git
            cd i2pd
            makepkg -si --noconfirm
            cd ..
            rm -rf i2pd
        fi
        ;;

    *)
        error "Unsupported distribution: $DISTRO"
        log "Please install manually from: https://geti2p.net/en/download"
        exit 1
        ;;
esac

echo ""
section "Installation Complete!"
echo ""

cat << 'EOF'
I2P has been installed. Here's how to use it:

=== IF YOU INSTALLED i2pd (C++ version) ===

START i2pd:
  sudo systemctl start i2pd
  sudo systemctl enable i2pd  # Auto-start on boot

WEB CONSOLE:
  Open in browser: http://127.0.0.1:7070

PROXY PORTS:
  HTTP Proxy:   127.0.0.1:4444  (for .i2p sites)
  SOCKS Proxy:  127.0.0.1:4447

CONFIG FILE:
  /etc/i2pd/i2pd.conf

=== IF YOU INSTALLED i2p (Java version) ===

START I2P:
  sudo systemctl start i2p
  # Or: i2prouter start

WEB CONSOLE:
  Open in browser: http://127.0.0.1:7657

PROXY PORT:
  HTTP Proxy: 127.0.0.1:4444

=== GENERAL USAGE ===

CONFIGURE YOUR BROWSER:
  Set HTTP proxy to: 127.0.0.1:4444
  (This lets you access .i2p eepsites)

FIRST-TIME SETUP:
  1. Start I2P and wait ~5 minutes for network integration
  2. Access the web console
  3. Configure bandwidth limits based on your connection

POPULAR EEPSITES TO TEST:
  - http://i2p-projekt.i2p  (I2P Project homepage)
  - http://stats.i2p        (Network statistics)

SECURITY NOTES:
  - I2P is for accessing I2P internal services (eepsites)
  - Don't use I2P for regular web browsing (use Tor for that)
  - Takes time to build up "tunnels" - be patient on first run
  - More peers = better anonymity and speed

EOF

# Check if service is available
if systemctl list-unit-files | grep -q i2p.service; then
    echo ""
    log "To start I2P now: sudo systemctl start i2p"
    log "To enable auto-start: sudo systemctl enable i2p"
fi

echo ""