#!/bin/bash
########################################################################
# A shell script to install / upgrade SimpleHelp on a Linux system.
#
# Configure the installation directory below (install=...) or pass it in
# as the first argument. This script will always download the latest
# public release of SimpleHelp unless --source is specified.
#
# If an existing installation is detected the server will be overwritten
# and the server's configuration will be preserved.
#
# Usage:
#   simplehelp-upgrade.sh [INSTALL_DIR] [--source <somesource>]
#
########################################################################

set -euo pipefail
trap 'echo "[ERROR] Script failed at line $LINENO" >&2; exit 1' ERR

# Defaults
install="/opt/SimpleHelp"
source_arg=""

# Initialise
now=$(date +"%Y%m%d_%H%M%S")
initial_dir="$PWD"

# Download helper: uses curl if available, else wget
download() {
    # usage: download <url> [--stdout]
    if command -v curl >/dev/null 2>&1; then
        if [ "${2:-}" = "--stdout" ]; then
            curl -fsSL "$1"
        else
            curl -fsSLO "$1"
        fi
    elif command -v wget >/dev/null 2>&1; then
        if [ "${2:-}" = "--stdout" ]; then
            wget -qO- "$1"
        else
            wget -q "$1"
        fi
    else
        echo "[ERROR] Neither curl nor wget found on this system." >&2
        exit 1
    fi
}

# Parse arguments
install_set="0"
while [ $# -gt 0 ]; do
    case "$1" in
        --source)
            if [ -n "$2" ]; then
                source_arg="$2"
                shift 2
                continue
            else
                echo "[ERROR] --source requires an argument (e.g. --source value)" >&2
                exit 1
            fi
            ;;
        -h|--help)
            echo "Usage: $0 [INSTALL_DIR] [--source <alternative source>]"; exit 0 ;;
        --*)
            echo "[ERROR] Unknown option: $1" >&2; exit 1 ;;
        *)
            if [ "$install_set" = "0" ]; then
                install="$1"
                install_set="1"
                shift
                continue
            else
                echo "[ERROR] Unexpected argument: $1" >&2
                exit 1
            fi
            ;;
    esac
    shift
done

# Determine base download URL
base_url="https://simple-help.com/releases"
if [ -n "$source_arg" ]; then
    base_url="https://simple-help.com/releases/previous/$source_arg"
fi

# Check permissions
parentdir="$(dirname "$install")"
if [ ! -w "$parentdir" ]; then
    echo "[ERROR] Insufficient permissions to write installation files in $parentdir" >&2
    exit 1
fi
if [ -d "$install" ]; then
    if [ ! -w "$install" ]; then
        echo "[ERROR] Insufficient permissions to write installation files in $install" >&2
        exit 1
    fi
fi

# Query Version.txt to display the version being installed
version_txt_url="$base_url/Version.txt"
version_output=$(download "$version_txt_url" --stdout 2>/dev/null || true)
if [ -z "$version_output" ]; then
    if [ -z "$source_arg" ]; then
        echo "[ERROR] No SimpleHelp release was found"
    else
        echo "[ERROR] No SimpleHelp release was found for source \"$source_arg\""
    fi
    exit 1
fi
version=$(echo "$version_output" | awk -F':' '/^Version[[:space:]]*/ { gsub(/^[ \t]+/, "", $2); print $2; exit }')
if [ -n "$version" ]; then
    echo "--- Installing SimpleHelp Server v$version"
else
    echo "[ERROR] Unable to identify SimpleHelp Server version."
    exit 1
fi

echo "--- Managing SimpleHelp installation in $install"

# Stop the server
if [ -d "$install" ]; then
    echo "--- Stopping SimpleHelp..."
    cd "$install"
    sh serverstop.sh >/dev/null 2>&1
    sleep 10
    cd ..
    echo "--- Backing up the SimpleHelp installation to SimpleHelp_backup_$now"
    mv "$install" "SimpleHelp_backup_$now"
fi

uname_out=`uname -m`
case "$uname_out" in
    *aarch64*|*arm64*)
        echo "--- Using the Linux ARM 64bit Release"
        sh_binary="SimpleHelp-linux-arm64.tar.gz"
        sh_url="$base_url/SimpleHelp-linux-arm64.tar.gz"
    ;;
    *aarch*|*arm*)
        echo "--- Using the Linux ARM 32bit Release"
        sh_binary="SimpleHelp-linux-arm32.tar.gz"
        sh_url="$base_url/SimpleHelp-linux-arm32.tar.gz"
    ;;
    *64*)
        echo "--- Using the Linux Intel 64bit Release"
        sh_binary="SimpleHelp-linux-amd64.tar.gz"
        sh_url="$base_url/SimpleHelp-linux-amd64.tar.gz"
    ;;
    *)
        echo "--- Using the Linux Intel 32bit Release"
        sh_binary="SimpleHelp-linux.tar.gz"
        sh_url="$base_url/SimpleHelp-linux.tar.gz"
    ;;
esac

rm -f "$sh_binary"

echo "--- Downloading ($sh_url)..."
download "$sh_url"
if [ ! -s "$sh_binary" ]; then
    echo "[ERROR] Failed to download $sh_binary from $sh_url"
    exit 1
fi

echo "--- Extracting..."
tar -xzf "$sh_binary" >/dev/null
rm -f "$sh_binary"
if [ ! -d "SimpleHelp" ]; then
    echo "[ERROR] Archive did not extract the expected 'SimpleHelp' directory."
    exit 1
fi

if [ "$install" != "$PWD/SimpleHelp" ]; then
    echo "--- Moving install to $install"
    mv SimpleHelp "$install"
fi

# Copy across the old configuration folder
if [ -d "SimpleHelp_backup_$now/configuration" ]; then
    echo "--- Copying across configuration files"
    if command -v rsync >/dev/null 2>&1; then
        rsync -a "SimpleHelp_backup_$now/configuration/" "$install/configuration/"
    else
        (
          shopt -s dotglob nullglob
          cp -R "SimpleHelp_backup_$now/configuration/"* "$install/configuration/" 2>/dev/null || true
        )
    fi
fi

# Start the new server
echo "--- Starting SimpleHelp"
cd "$install"
sh serverstart.sh
cd "$initial_dir"