#!/usr/bin/bash
set -e

check_arguments() {
    [[ -f "$1" ]] && return

    echo "Missing configuration file argument ($1)"
    exit 1
}

check_venv_path() {
    [[ -n "$VENV_PATH" ]] && \
    [[ -d "$VENV_PATH" ]] && \
    [[ -f "$VENV_PATH/bin/python" ]] && \
    return;

    echo "$VENV_PATH is not a virtual environment"
    exit 1
}

check_requirements_file() {
    [[ -n "$REQUIREMENTS_FILE" ]] && \
    [[ -f "$REQUIREMENTS_FILE" ]] && \
    return;

    echo "$REQUIREMENTS_FILE does not exist"
    exit 1
}

check_repo_path() {
    [[ -n "$REPO_PATH" ]] && \
    [[ -d "$REPO_PATH" ]] && \
    (cd $REPO_PATH && git status) && return;

    echo "$REPO_PATH is not a git repository"
    exit 1
}

check_arguments $1

source $1
echo "Upgrading virtual environment for `basename $1`"

check_venv_path

check_requirements_file

check_repo_path

PIP_PATH=$VENV_PATH/bin/pip

reset_venv() {
    rm -r $VENV_PATH
    python3 -m venv $VENV_PATH
}

update_repo() {
    cd $REPO_PATH
    git fetch
    if [[ `git log HEAD..origin | wc -l` == 0 ]];
    then
        echo "No changes in current branch of repository"
    else
        echo "Changes done in current branch:\n"
        git log HEAD..origin
        echo "\nPull new changes? (y/n)"
        read pull_changes
        [[ "$pull_changes" == "y" ]] && git pull
    fi
}

install_requirements() {
    $PIP_PATH install -r $REQUIREMENTS_FILE
}

echo "Resetting venv..."
reset_venv

update_repo

echo "Installing requirements..."
install_requirements > /dev/null

echo "Done."