#!/bin/bash

r_pkgs=( DESeq2 genefilter biomaRt ggplot2 gplots RColorBrewer )
pip_pkgs=( biopython )

if [[ $(id -u) -ne 0 ]]; then
    echo "Error: run this script as the root user, not EUID $(id -u)."
    exit 1
fi

set -e				# Make most errors fatal.

ubuntu_update () {
    apt-get update
    apt-get -y upgrade
}

ubuntu_install_r_cran () {
    cat <<EOF > /etc/apt/sources.list.d/cgi-r-cran.list
# Newest R version from CRAN per
# https://cran.r-project.org/bin/linux/ubuntu/
deb https://cran.fhcrc.org/bin/linux/ubuntu $(lsb_release -cs)/
EOF
    local key=E084DAB9
    grep -q $key <( apt-key list ) ||
	apt-key adv --keyserver keyserver.ubuntu.com --recv-keys $key
    apt-get update
    apt-get -y install r-base-dev
    # Dependencies of RCurl:
    apt-get -y install libxml2-dev libcurl4-gnutls-dev
}

python_install_packages() {
    apt-get -y install python-pip python-dev
    pip install --upgrade ${pip_pkgs[@]}
}

r_install_packages() {
    local pkgs=$@
    pkgs=\"$(printf "\",\"%s" $pkgs)\"
    Rscript --vanilla - <<EOF
options(echo = TRUE)
dir.create(Sys.getenv("R_LIBS_USER"), recursive = TRUE)
.libPaths(Sys.getenv("R_LIBS_USER"))
setwd(paste(Sys.getenv("R_HOME")))
source("https://bioconductor.org/biocLite.R")
biocLite(c(${pkgs:3}))
EOF
}

rstudio_url() {
    python - <<EOF
import urllib2

from lxml import etree

# Provide a header to avoid HTTP 403 Forbidden.
headers = {'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.64 Safari/537.11'}
request = urllib2.Request("https://www.rstudio.com/products/rstudio/download2/", headers=headers)
response = urllib2.urlopen(request)
html = response.read()

root = etree.HTML(html)
urls = root.xpath('.//table[@class="downloads"][1]/tbody/tr/td/a/@href')
url = next(url for url in urls if url.endswith('amd64.deb'))
print(url)
EOF
}

rstudio_install() {
    url=$(rstudio_url)
    pkg=$(basename $url)
    ver_new=$(echo $pkg | awk -vFS=- '{print $2}')
    ver_old=$(dpkg-query --showformat='${Version}' --show rstudio) || ver_old=
    if [[ ! $ver_new == $ver_old ]]; then
	wget -qc $url
	dpkg -i $pkg
    fi
}

main () {
    ubuntu_update
    ubuntu_install_r_cran

    python_install_packages
    
    # Install R libraries in the user home directory so that updating
    # the libraries later on does not triggering the "unwritable
    # directory" warning.
    export -f r_install_packages
    su cgi_user -c "bash -c \"r_install_packages ${r_pkgs[*]}\""
    unset r_install_packages

    rstudio_install
}

main