#!/bin/bash
#
#    Copyright © 2016 Zetok Zalbavar <zetok@openmailbox.org>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.


# Source for bash functions used in `/{merge,test}-pr.sh`.
#
# Only to be sourced in those files.

set -e -o pipefail

# check if supplied var is a number; if not exit
is_pr_number() {
    [[ "$@" =~ ^[[:digit:]]+$ ]]
}

exit_if_not_pr() {
    is_pr_number $@ \
    || (echo "Not a PR number!" \
        && exit 1 )
}

# check if remote is present
is_remote_present() {
    git remote \
        | grep $@ > /dev/null
}

# there's no qTox remote, add it
# if `https` is supplied, https version of repo is used
add_remote() {
    local remote_url="git@github.com:qTox/qTox.git"
    local remote_name="upstream"

    # change to https if needed
    [[ "$@" == "https" ]] \
        && local remote_url="https://github.com/qTox/qTox.git"

    is_remote_present $remote_name \
        || git remote add $remote_name "${remote_url}"
}


# print the message only if the merge was successful
#
# supply either `merge`, `test` or whatever else merge branch name you want
after_merge_msg() {
    echo ""
    echo "PR #$PR was merged into «$@$PR» branch."
    echo "To compare with master:"
    echo ""
    echo "  git diff master..$@$PR"
    echo ""
    if [[ "$@" == "merge" ]]
    then
        echo "To push that to master on github:"
        echo ""
        echo "  git checkout master && git merge --ff $@$PR && git push upstream master"
        echo ""
        echo "After pushing to master, delete branches:"
        echo ""
        echo "  git branch -d {$@,}$PR"
        echo ""
    fi
    echo "To discard any changes:"
    echo ""
    echo "  git checkout master && git branch -D {$@,}$PR"
    echo ""
}

# print the message only if some merge step failed
after_merge_failure_msg() {
    echo ""
    echo "Merge failed."
    echo ""
    echo "You may want to remove not merged branches, if they exist:"
    echo ""
    echo "  git checkout master && git branch -D {$@,}$PR"
    echo ""
}

# force delete merged and fetched branches
rm_obsolete_branch() {
    git branch -D {$merge_branch,}$PR 2>/dev/null || true
}

get_sources() {
    add_remote
    rm_obsolete_branch
    git fetch $remote_name && \
    git checkout master && \
    git rebase $remote_name/master master && \
    git fetch $remote_name pull/$PR/head:$PR && \
    git checkout master -b $merge_branch$PR
}

# check whether to sign
merge() {
    "${@}" --no-ff $PR -m "Merge pull request #$PR
$OPT_MSG
$(git shortlog master..$PR)"
}