#!/bin/bash
#
# Tyto System Monitor - Installation Script
#
# Usage:
#   curl -fsSL https://somegit.dev/vikingowl/tyto/raw/branch/main/scripts/install.sh | bash
#   or
#   wget -qO- https://somegit.dev/vikingowl/tyto/raw/branch/main/scripts/install.sh | bash
#
# Environment Variables:
#   TYTO_MODE       - Installation mode: standalone (default), server, agent
#   TYTO_VERSION    - Version to install (default: latest)
#   TYTO_INSTALL_DIR - Installation directory (default: /opt/tyto)
#   TYTO_DATA_DIR   - Data directory (default: /var/lib/tyto)
#   TYTO_USER       - System user for tyto (default: tyto)
#

set -euo pipefail

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Default values
TYTO_MODE="${TYTO_MODE:-standalone}"
TYTO_VERSION="${TYTO_VERSION:-latest}"
TYTO_INSTALL_DIR="${TYTO_INSTALL_DIR:-/opt/tyto}"
TYTO_DATA_DIR="${TYTO_DATA_DIR:-/var/lib/tyto}"
TYTO_USER="${TYTO_USER:-tyto}"
TYTO_REPO="somegit.dev/vikingowl/tyto"

# Logging functions
log_info() { echo -e "${BLUE}[INFO]${NC} $*"; }
log_success() { echo -e "${GREEN}[OK]${NC} $*"; }
log_warn() { echo -e "${YELLOW}[WARN]${NC} $*"; }
log_error() { echo -e "${RED}[ERROR]${NC} $*" >&2; }

# Check if running as root
check_root() {
    if [[ $EUID -ne 0 ]]; then
        log_error "This script must be run as root (use sudo)"
        exit 1
    fi
}

# Detect OS and architecture
detect_platform() {
    OS=$(uname -s | tr '[:upper:]' '[:lower:]')
    ARCH=$(uname -m)

    case "$ARCH" in
        x86_64|amd64) ARCH="amd64" ;;
        aarch64|arm64) ARCH="arm64" ;;
        armv7l|armhf) ARCH="arm" ;;
        *) log_error "Unsupported architecture: $ARCH"; exit 1 ;;
    esac

    case "$OS" in
        linux) OS="linux" ;;
        darwin) OS="darwin" ;;
        *) log_error "Unsupported operating system: $OS"; exit 1 ;;
    esac

    log_info "Detected platform: ${OS}/${ARCH}"
}

# Check dependencies
check_dependencies() {
    local deps=("curl" "tar")
    local missing=()

    for dep in "${deps[@]}"; do
        if ! command -v "$dep" &>/dev/null; then
            missing+=("$dep")
        fi
    done

    if [[ ${#missing[@]} -gt 0 ]]; then
        log_error "Missing dependencies: ${missing[*]}"
        log_info "Please install them and try again"
        exit 1
    fi
}

# Create system user
create_user() {
    if id "$TYTO_USER" &>/dev/null; then
        log_info "User $TYTO_USER already exists"
    else
        log_info "Creating user $TYTO_USER..."
        useradd --system --no-create-home --shell /sbin/nologin "$TYTO_USER"
        log_success "User created"
    fi
}

# Create directories
create_directories() {
    log_info "Creating directories..."

    mkdir -p "$TYTO_INSTALL_DIR"/{bin,etc,logs}
    mkdir -p "$TYTO_DATA_DIR"/{db,certs}

    chown -R "$TYTO_USER:$TYTO_USER" "$TYTO_DATA_DIR"
    chmod 700 "$TYTO_DATA_DIR/certs"

    log_success "Directories created"
}

# Download and install binary
install_binary() {
    local binary_name="tyto"
    local download_url

    if [[ "$TYTO_VERSION" == "latest" ]]; then
        download_url="https://${TYTO_REPO}/releases/latest/download/tyto-${OS}-${ARCH}.tar.gz"
    else
        download_url="https://${TYTO_REPO}/releases/download/${TYTO_VERSION}/tyto-${OS}-${ARCH}.tar.gz"
    fi

    log_info "Downloading Tyto from $download_url..."

    local tmp_dir
    tmp_dir=$(mktemp -d)
    trap "rm -rf $tmp_dir" EXIT

    if ! curl -fsSL "$download_url" -o "$tmp_dir/tyto.tar.gz"; then
        log_error "Failed to download Tyto"
        exit 1
    fi

    tar -xzf "$tmp_dir/tyto.tar.gz" -C "$tmp_dir"

    mv "$tmp_dir/tyto" "$TYTO_INSTALL_DIR/bin/"
    chmod +x "$TYTO_INSTALL_DIR/bin/tyto"

    # Create symlink
    ln -sf "$TYTO_INSTALL_DIR/bin/tyto" /usr/local/bin/tyto

    log_success "Binary installed to $TYTO_INSTALL_DIR/bin/tyto"
}

# Create configuration file
create_config() {
    local config_file="$TYTO_INSTALL_DIR/etc/config.yaml"

    if [[ -f "$config_file" ]]; then
        log_warn "Config file already exists, backing up..."
        cp "$config_file" "${config_file}.bak"
    fi

    log_info "Creating configuration for mode: $TYTO_MODE"

    cat > "$config_file" << EOF
# Tyto System Monitor Configuration
# Generated by install script

mode: $TYTO_MODE

http:
  port: 8080
  host: "0.0.0.0"

refresh_rate: 5

# Database (for server mode)
database:
  type: sqlite
  path: $TYTO_DATA_DIR/db/tyto.db

# Server settings (for multi-device)
server:
  grpc_port: 9849
  tls:
    enabled: false
    # ca_cert: $TYTO_DATA_DIR/certs/ca.crt
    # server_cert: $TYTO_DATA_DIR/certs/server.crt
    # server_key: $TYTO_DATA_DIR/certs/server.key

# Log settings
logging:
  level: info
  format: text

# Alerts
alerts:
  enabled: true
  thresholds:
    cpu: 90
    memory: 85
    disk: 90
EOF

    chown "$TYTO_USER:$TYTO_USER" "$config_file"
    chmod 640 "$config_file"

    log_success "Configuration created"
}

# Create systemd service
create_systemd_service() {
    local service_file="/etc/systemd/system/tyto.service"

    log_info "Creating systemd service..."

    cat > "$service_file" << EOF
[Unit]
Description=Tyto System Monitor
Documentation=https://somegit.dev/vikingowl/tyto
After=network.target

[Service]
Type=simple
User=$TYTO_USER
Group=$TYTO_USER
ExecStart=$TYTO_INSTALL_DIR/bin/tyto --config $TYTO_INSTALL_DIR/etc/config.yaml
Restart=always
RestartSec=5
StandardOutput=append:$TYTO_INSTALL_DIR/logs/tyto.log
StandardError=append:$TYTO_INSTALL_DIR/logs/tyto.log

# Security hardening
NoNewPrivileges=true
ProtectSystem=strict
ProtectHome=true
PrivateTmp=true
ReadWritePaths=$TYTO_DATA_DIR $TYTO_INSTALL_DIR/logs
ReadOnlyPaths=/proc /sys

# Resource limits
MemoryMax=256M
CPUQuota=50%

[Install]
WantedBy=multi-user.target
EOF

    systemctl daemon-reload

    log_success "Systemd service created"
}

# Enable and start service
start_service() {
    log_info "Enabling and starting Tyto..."

    systemctl enable tyto
    systemctl start tyto

    sleep 2

    if systemctl is-active --quiet tyto; then
        log_success "Tyto is running!"
    else
        log_error "Tyto failed to start. Check logs: journalctl -u tyto"
        exit 1
    fi
}

# Print installation summary
print_summary() {
    local ip
    ip=$(hostname -I | awk '{print $1}')

    echo ""
    echo "=========================================="
    echo -e "${GREEN}Tyto installation complete!${NC}"
    echo "=========================================="
    echo ""
    echo "Installation Details:"
    echo "  Mode:        $TYTO_MODE"
    echo "  Binary:      $TYTO_INSTALL_DIR/bin/tyto"
    echo "  Config:      $TYTO_INSTALL_DIR/etc/config.yaml"
    echo "  Data:        $TYTO_DATA_DIR"
    echo "  Logs:        $TYTO_INSTALL_DIR/logs/"
    echo ""
    echo "Service Commands:"
    echo "  Status:      systemctl status tyto"
    echo "  Logs:        journalctl -u tyto -f"
    echo "  Restart:     systemctl restart tyto"
    echo "  Stop:        systemctl stop tyto"
    echo ""
    echo "Access Dashboard:"
    echo "  http://${ip}:8080"
    echo ""
}

# Main installation flow
main() {
    echo ""
    echo "  _____     _       "
    echo " |_   _|   | |      "
    echo "   | |_   _| |_ ___ "
    echo "   | | | | | __/ _ \\"
    echo "   | | |_| | || (_) |"
    echo "   |_|\__, |\__\___/"
    echo "       __/ |        "
    echo "      |___/         "
    echo ""
    echo "Tyto System Monitor - Installation Script"
    echo "=========================================="
    echo ""

    check_root
    detect_platform
    check_dependencies
    create_user
    create_directories
    install_binary
    create_config
    create_systemd_service
    start_service
    print_summary
}

main "$@"