#!/bin/bash
set -e

# -- SECURITY CHECK: Root only --
if [ "$EUID" -ne 0 ]; then
	echo "ERROR: This script must be run as root!"
	echo "Please use: sudo $0"
	exit 1
fi

# Configuration
RUNNER_USER="git"
RUNNER_GROUP="git"
SERVICE_NAME="gitea-runner"
INSTALL_DIR="/usr/local/bin"
BINARY_NAME="gitea-runner"
CONFIG_DIR="/var/lib/gitea-runner"

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

echo -e "${GREEN}=== Gitea Runner Update Checker ===${NC}"

# Get current installed version
if ! command -v ${BINARY_NAME} &> /dev/null; then
    echo -e "${RED}Error: ${BINARY_NAME} not found in PATH${NC}"
    exit 1
fi

CURRENT_VERSION=$(${BINARY_NAME} --version 2>&1 | grep -oP 'v\K[0-9]+\.[0-9]+\.[0-9]+')
if [ -z "$CURRENT_VERSION" ]; then
    echo -e "${RED}Error: Could not determine current version${NC}"
    exit 1
fi

echo -e "Current version: ${YELLOW}v${CURRENT_VERSION}${NC}"

# Fetch latest version from Gitea API
echo "Checking for latest version..."
API_URL="https://gitea.com/api/v1/repos/gitea/runner/releases/latest"

LATEST_INFO=$(curl -s "${API_URL}")
if [ $? -ne 0 ]; then
    echo -e "${RED}Error: Failed to fetch release information from Gitea API${NC}"
    exit 1
fi

# Parse version (improved parsing from your script)
LATEST_VERSION=$(echo "${LATEST_INFO}" | grep -o '"tag_name":"[^"]*"' | cut -d'"' -f4 | sed 's/^v//')

if [ -z "$LATEST_VERSION" ]; then
    echo -e "${RED}Error: Could not parse latest version from API response${NC}"
    exit 1
fi

echo -e "Latest version:  ${YELLOW}v${LATEST_VERSION}${NC}"

# Compare versions using sort -V (semantic version comparison)
if [ "$CURRENT_VERSION" = "$LATEST_VERSION" ]; then
    echo -e "${GREEN}✓ You already have the latest version installed!${NC}"
    exit 0
fi

# Check if update is needed
NEWER=$(printf '%s\n%s' "$CURRENT_VERSION" "$LATEST_VERSION" | sort -V | tail -n1)
if [ "$NEWER" = "$CURRENT_VERSION" ]; then
    echo -e "${YELLOW}Warning: Installed version appears newer than latest release${NC}"
    read -p "Continue anyway? [y/N]: " -n 1 -r
    echo
    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
        exit 0
    fi
fi

echo -e "\n${YELLOW}New version available: v${CURRENT_VERSION} → v${LATEST_VERSION}${NC}"

# Ask for update confirmation
read -p "Do you want to update? [Y/n]: " -n 1 -r
echo
if [[ ! $REPLY =~ ^[Yy]$ ]]; then
    echo "Update cancelled."
    exit 0
fi

# Determine architecture
ARCH=$(uname -m)
case ${ARCH} in
    x86_64) ARCH_FILE="amd64" ;;
    aarch64) ARCH_FILE="arm64" ;;
    *) 
        echo -e "${RED}Error: Unsupported architecture: ${ARCH}${NC}"
        exit 1
        ;;
esac

# Prepare download variables
DL_FILE="${BINARY_NAME}-${LATEST_VERSION}-linux-${ARCH_FILE}"
DL_URL="https://dl.gitea.com/gitea-runner/${LATEST_VERSION}/${DL_FILE}"

echo -e "\n${GREEN}Downloading version v${LATEST_VERSION}...${NC}"
cd ${INSTALL_DIR} || exit 1

# Download binary and checksum
wget -N "${DL_URL}"
wget -N "${DL_URL}.sha256"

# Verify checksum (your method, improved output)
echo "Verifying checksum..."
if sha256sum --check "${DL_FILE}.sha256" &> /dev/null; then
    echo -e "${GREEN}✓ Checksum verification passed${NC}"
else
    echo -e "${RED}✗ Checksum verification FAILED! Aborting update.${NC}"
    rm -f "${DL_FILE}" "${DL_FILE}.sha256"
    exit 1
fi

# Stop the service before updating
echo "Stopping ${SERVICE_NAME}..."
systemctl stop ${SERVICE_NAME}

# Backup old binary
if [ -f "${BINARY_NAME}" ]; then
    cp "${BINARY_NAME}" "${BINARY_NAME}.backup.${CURRENT_VERSION}"
    echo -e "Backup created: ${YELLOW}${BINARY_NAME}.backup.${CURRENT_VERSION}${NC}"
fi

# Install new binary (your symlink approach preserved)
echo "Installing new version..."
chmod +x "${DL_FILE}"
chown ${RUNNER_USER}:${RUNNER_GROUP} "${DL_FILE}"
ln -sf "${DL_FILE}" "${BINARY_NAME}"

# Clean up
rm -f "${DL_FILE}.sha256"

# Verify installation
NEW_VERSION=$(${BINARY_NAME} --version 2>&1 | grep -oP 'v\K[0-9]+\.[0-9]+\.[0-9]+')
if [ "$NEW_VERSION" != "$LATEST_VERSION" ]; then
    echo -e "${RED}Error: Version mismatch after installation!${NC}"
    echo "Expected: v${LATEST_VERSION}, Got: v${NEW_VERSION}"
    # Restore backup
    if [ -f "${BINARY_NAME}.backup.${CURRENT_VERSION}" ]; then
        mv "${BINARY_NAME}.backup.${CURRENT_VERSION}" "${BINARY_NAME}"
        echo "Restored backup."
    fi
    systemctl start ${SERVICE_NAME}
    exit 1
fi

echo -e "${GREEN}✓ Successfully updated to v${NEW_VERSION}${NC}"

# Ask for service restart confirmation
read -p "Do you want to restart the ${SERVICE_NAME} service now? [Y/n]: " -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
    echo "Starting ${SERVICE_NAME}..."
    systemctl start ${SERVICE_NAME}
    
    # Check service status
    sleep 2
    if systemctl is-active --quiet ${SERVICE_NAME}; then
        echo -e "${GREEN}✓ Service started successfully${NC}"
        echo ""
        systemctl status ${SERVICE_NAME} --no-pager -l
    else
        echo -e "${RED}✗ Service failed to start! Check logs with: journalctl -u ${SERVICE_NAME}${NC}"
        exit 1
    fi
else
    echo -e "${YELLOW}Service not restarted. Please restart manually when ready:${NC}"
    echo "  sudo systemctl restart ${SERVICE_NAME}"
fi

# Clean old backups (keep last 3)
ls -t ${BINARY_NAME}.backup.* 2>/dev/null | tail -n +4 | xargs -r rm

echo -e "\n${GREEN}=== Update complete! ===${NC}"