#!/bin/bash

# Exit values are keyed as follows:
#   0 = No error
#   1 < 250 = Easy fix
#   250 <= 255 = Will not fix

#testing
#export PATH=/home/jhunk/.local/bin:/usr/lib64/qt-3.3/bin:/usr/lib64/ccache:/usr/local/bin:/usr/bin:/home/jhunk/bin:/usr/local/sbin:/usr/sbin

#
# Begin global configuration
#

OS=`uname -s`
PLATFORM=`uname -p`
FETCH=
FETCH_ARGS=

CONTINUUM_BASE=https://repo.continuum.io/miniconda
CONTINUUM_RELEASE=Miniconda3
CONTINUUM_VERSION=latest
CONTINUUM_ARCH=x86_64
CONTINUUM_PLATFORM=
CONTINUUM_EXT=".sh"

STSCI_BASE=http://ssb.stsci.edu
STSCI_RELEASES=(
    conda
    conda-x
    conda-dev
)

# Update this as needed.
# We cannot simply on setting "2" or "3" here because of how repos store data.
PYTHON_VERSIONS=(
    2.7
    3.5
)
_VERSION=$(echo ${CONTINUUM_RELEASE} | awk '{print tolower($0)}')
_INSTALL_PATH="$HOME/$_VERSION"
INSTALL_PATH="$_INSTALL_PATH"
INSTALL_ALTERNATE_PATH="$HOME/$_VERSION"_stsci
INSTALL_REQUIRED=0
REINSTALL=0

#
# Begin function delarations
#

function preamble
{
cat << 'PREAMBLE'
################################################################################

                        ____  _____  ____         ___ 
                       / ___||_   _|/ ___|   ___ |_ _|
                       \___ \  | |  \___ \  / __| | | 
                        ___) | | |   ___) || (__  | | 
                       |____/  |_|  |____/  \___||___|
                                                      
                       Space Telecope Science Institute
                            Distribution Installer
                                     
################################################################################

If you have any questions or problems, please send an email to <help@stsci.edu>

################################################################################
PREAMBLE
echo "Press any key to continue..."
read accept
}

function repo_alive
{
    retval=1
    local REPO="$1"
    if [ -z "$REPO" ]; then
        echo "repo_alive requires an argument." >&2
        echo "usage: repo_alive {repo_url}" >&2
        exit 1
    fi
    REPO_ALIVE="$REPO/repo_alive.txt"
    ALIVE_FILE="$(basename $REPO_ALIVE)"

    $FETCH $FETCH_ARGS $REPO_ALIVE &>/dev/null

    if [ -f "$ALIVE_FILE" ]; then
        rm -f "$ALIVE_FILE"
        retval=0
    fi

    return $retval
}

function check_conflicts
{
    # Note, we do not care about the user's "root" or various builtin environments. 
    # This does not restrict people from installing our software on their own terms.
    local conflict=0
    local ENVIRONMENTS=`conda env list | egrep -v '#|^_|^root' | awk '{ print $1 }'`

    echo "Scanning Conda environment for conflicts:"
    for environ in $ENVIRONMENTS
    do
        msg="NO CONFLICT"

        # Check for metapackages in current $environ
        conda list -n "$environ" -f '^stsci$|^stsci-.*' &>/dev/null
        retval=$?

        if [[ $retval > 0 ]]; then
            # Found nothing.
            continue
        else
            for python_version in "${PYTHON_VERSIONS[@]}"
            do
                for release in "${STSCI_RELEASES[@]}"
                do
                    if [[ "stsci-$release-$python_version" == $environ ]]; then
                        # Our environment is already installed.
                        ((conflict++))
                    fi
                done
            done
        fi

        if [[ $conflict > 0 ]]; then
            msg="CONFLICT"
        fi

        printf "+ %-20s:%20s\n" "$environ" "$msg"

    done
    echo

    return $conflict
}

function init_specs
{
    case "$OS" in
        Linux)
        CONTINUUM_PLATFORM=Linux
        FETCH="wget"
        FETCH_ARGS="-c"
        ;;
        Darwin)
        CONTINUUM_PLATFORM=MacOSX
        FETCH="curl"
        FETCH_ARGS="-O"
        ;;
    esac
    
    case "$PLATFORM" in
        i*86)
        CONTINUUM_ARCH=x86
        ;;
    esac

    INSTALLER="$CONTINUUM_RELEASE-$CONTINUUM_VERSION-$CONTINUUM_PLATFORM-$CONTINUUM_ARCH${CONTINUUM_EXT}"
    CONTINUUM_URL="$CONTINUUM_BASE/$INSTALLER"
}

function check_sanity
{
    if [[ $CONTINUUM_ARCH != x86_64 ]]; then
        echo "STScI does not support '$ARCH' packages."
        exit 255
    fi
    
    if [ -z "$CONTINUUM_PLATFORM" ]; then
        echo "STScI does not support '$OS'."
        exit 254
    fi
    
    if [ ! -x "`which $FETCH`" ]; then
        echo "Please install '$FETCH'. Unable to continue."
        exit 253
    fi
}


function do_preinstall
{
    local CONDA=`which conda 2>/dev/null`

    # Pass 1 - If not on PATH, check if installed (by us)
    if [ ! -x "$CONDA" ]; then
        echo -n "Checking for inactive installation..."
        if [[ -d $INSTALL_PATH ]]; then
            echo "found (assimilating)"
            echo
            export PATH=$INSTALL_PATH/bin:$PATH
            CONDA=`which conda 2>/dev/null`
        else
            echo "none found"
            echo
            INSTALL_REQUIRED=1
        fi
    fi

    # Pass 2 - If on PATH, setup installer
    if [ -x "$CONDA" ]; then
        printf "An Anaconda installation is present on your system:\n\t$CONDA\n"
        echo
    
        /bin/echo -n "Do you wish to use your existing conda installation? (recommended) [Y/n]"
        read choice
        case "$choice" in
            N*|n*)
                INSTALL_PATH="$INSTALL_ALTERNATE_PATH"
                INSTALL_REQUIRED=1
            ;;
            *)
            ;;
        esac

        check_conflicts
        found=$?
        if [[ $found > 0 ]]; then
            echo "Conflicts discovered: $found"
            echo
            echo "The following operation will:"
            echo "* REMOVE all conflicting distributions"
            echo "* REINSTALL all distributions"
            echo
            echo "CUSTOMIZATIONS MADE TO THESE ENVIRONMENTS WILL BE *LOST*"
            echo
            echo "Hint:"
            echo "Refer to [url_here] to learn how to properly *update* packages."
            echo
            /bin/echo -n "Do you wish to continue? [y/N] "
            read choice
            case "$choice" in
                Y*|y*)
                # Nuke the site from orbit
                REINSTALL=1
                ;;
                *)
                exit 0
                ;;
            esac
            echo
        fi
    
    fi
    echo
}

function do_install_continuum
{    
    if [[ $INSTALL_REQUIRED == 0 ]]; then
        return 0
    fi

    # Perform scripted installation
    echo "Downloading ${CONTINUUM_URL}..."
    $FETCH $FETCH_ARGS $CONTINUUM_URL 2>/dev/null
    chmod +x "$INSTALLER"

    echo "Executing ${INSTALLER}..."
    ./"$INSTALLER" -b -p "$INSTALL_PATH"

    # If the miniconda installer fails, we need to stop.
    install_status=$?
    if [[ $install_status != 0 ]]; then
        echo "Installation failed. Unable to continue." >&2
        exit 6
    fi
    
    # Assimilate new installation
    export PATH="$INSTALL_PATH/bin:$PATH"

    echo "Control returned to $(basename $0)"
}

function do_install_stsci
{
    # Repository installation

    if [[ $REINSTALL != 0 ]]; then
        install_type='re'
    fi
    echo "Installation in progress..."
    for python_version in ${PYTHON_VERSIONS[@]}
    do
        echo "+ Performing Python $python_version ${install_type}installation:"
        for release in ${STSCI_RELEASES[@]}
        do
            STSCI_URL="$STSCI_BASE/$release"
            release="stsci-$release-$python_version"
            logfile="/tmp/install-${release}.log"
        
            /bin/echo -n "- $release ... "
            repo_alive "$STSCI_URL"
            alive=$?
            if [[ $alive > 0 ]]; then
                echo "skipped (repository is unavailable)"
                continue
            fi

            if [[ $REINSTALL != 0 ]]; then
                ( conda env remove -y -n "$release" 2>&1 ) >/dev/null
            fi
            ( conda create -q -y -n "$release" -c "$STSCI_URL" python=$python_version stsci 2>&1 ) > "$logfile"
            retval=$?
        
            if [[ $retval > 0 ]]; then
                printf "failed\nA problem occurred while installing %s\nPlease review the installation log: %s\n" "$release" "$logfile" >&2
                echo
                # die... 
                return 1
            else
                echo "complete"
            fi
        done
        echo
    done

    return 0
}

function do_overview
{
    local ENVIRONMENTS="`conda env list \
        | egrep '^stsci-conda.*' \
        | awk '{ print $1 }'`"

    echo "Activate the desired environment with *one* the following:"
    for environ in $ENVIRONMENTS
    do
        printf "source activate %s\n" "$environ"
    done
    echo
}

#
# Main
#

preamble
init_specs
check_sanity

do_preinstall
do_install_continuum
do_install_stsci

show_overview=$?
if [[ $show_overview == 0 ]]; then
    do_overview
fi
echo