#!/usr/bin/env bash

#GERRITHOST=gerrit.libreoffice.org
GERRITHOST=logerrit
GERRITURL="ssh://$GERRITHOST/core"

get_SHA_for_change() {
    SHA=$(ssh "${GERRITHOST?}" gerrit query --all-approvals change:"$1" | grep ref | tail -1 | cut -d: -f2 | sed 's/^ *//')
}

branch_or_default() {
    local branch=$1
    if test -z "${branch}"; then
        # Try to use the tracked branch
        branch=$(git symbolic-ref HEAD|sed 's|refs/heads/||')
        local remote=$(git config branch.${branch}.remote)
        branch=$(git rev-parse --abbrev-ref --symbolic-full-name HEAD@{upstream}|sed "s|${remote}/||")
        if test -z "$branch"; then
            branch=$(git symbolic-ref HEAD 2> /dev/null)
            branch="${branch##refs/heads/}"
            if test -z "${branch}"; then
                echo >&2 "no branch specified, and could not guess the current branch"
                exit 1
            fi
            echo >&2 "no branch specified, guessing current branch ${branch}"
        else
            echo >&2 "no branch specified, guessing tracked branch ${branch}"
        fi
    fi
    echo "${branch}"
}

logerrit() {
    echo "Host logerrit gerrit.libreoffice.org"
    if test -n "${2-}" && test -f "$HOME/.ssh/id_$2"; then
        echo "    IdentityFile ~/.ssh/id_$2"
    fi
    echo "    User $1"
    echo "    Port 29418"
    echo "    HostName gerrit.libreoffice.org"
}

case "$1" in
    help|--help|"")
        echo "Usage: ./logerrit subcommand [options]"
        echo "simple and basic tool to interact with LibreOffice gerrit"
        echo "see https://wiki.documentfoundation.org/Development/gerrit for details."
        echo
        echo "subcommands:"
        echo "             setup                   walking you though your gerrit setup"
        echo "             test                    test your gerrit setup"
        echo
        echo " --- for submitters:"
        echo "             submit [BRANCH]         submit your change for review"
        echo "             submit [BRANCH]%private submit your change as private"
        echo "             submit [BRANCH]%wip     submit your change as work-in-progress"
        echo "             nextchange [BRANCH]     reset branch to the remote to start with the next change"
        echo "             testfeature [BRANCH] [CHANGEID]"
        echo "                                     trigger a test of a feature branch on gerrit"
        echo
        echo "Note: private changes are only visibly to yourself and those that you explicitly add as reviewers."
        echo "For full documentation, see https://gerrit.libreoffice.org/Documentation/intro-user.html#private-changes"
        echo
        echo " --- for reviewers:"
        echo "             checkout CHANGEID       checkout the changes for review"
        echo "             pull CHANGEID           pull (and merge) the changes on current branch"
        echo "             cherry-pick CHANGEID    cherry-pick the change on current branch"
        echo "             patch CHANGEID          show the change as a patch"
        echo "             query ...               query for changes for review on project core"
        echo "             <any other gerrit command>"
        echo
        echo "advanced users should consider using git review instead:"
        echo "https://wiki.documentfoundation.org/Development/GitReview"
        exit
    ;;
    setup)
        script_canonical_file=$(readlink -f "$0")
        script_canonical_dir=$(dirname "$script_canonical_file")
        if ! cd "$script_canonical_dir"; then
            echo "Can't cd to $script_canonical_dir"
            exit 1
        fi
        ssh_home="$HOME/.ssh";
        ssh_key=
        created_ssh=
        if ! test -d "$ssh_home"; then
            echo "It appears that you have no ssh setup, running ssh-keygen to create that:"
            mkdir -m0700 "$ssh_home"
            created_ssh=TRUE
            echo
            echo "Hit enter to generate an ssh key - you will need to enter a pass-phrase"
            echo
            read -r
            all_algo="$(ssh -Q key)"
            if grep -q -x ssh-ed25519 <<< "$all_algo"; then
                algo="ed25519"
            elif grep -q -x ssh-rsa <<< "$all_algo"; then
                algo="rsa"
            else
                echo "Could not find 'ssh-ed25519' or 'ssh-rsa' in the output from 'ssh -Q key'"
                exit 1
            fi
            ssh-keygen -t "$algo" # Generate the key pair using the selected algorithm
        fi
        if test -d "$ssh_home"; then
            # order algos based on the PubkeyAcceptedKeyTypes option from OpenSSH 8.1
            for ssh_key_type in ecdsa ed25519 rsa; do
                pk="$ssh_home/id_${ssh_key_type}.pub"
                ssh_key=""
                if test -f "$pk" && ssh_key="$(< "$pk")" && test -n "$ssh_key"; then
                    break
                fi
            done
        fi
        echo "Please go to https://gerrit.libreoffice.org/ and click the \"Sign in\" link"
        echo "at the top right of the page. You'll be sent to our Single Sign-On portal"
        echo "for authentication (create an account if needs be), and automatically"
        echo "redirected back to gerrit afterwards."
        echo
        echo "Visit https://gerrit.libreoffice.org/settings/#SSHKeys and paste the public"
        if test -z "$ssh_key"; then
            echo "part of your SSH key in the 'New SSH key' form."
        else
            echo "key below in the 'New SSH key' form."
            echo
            printf '%s\n' "$ssh_key"
            echo
        fi
        echo
        echo "Note that you need to register additional email addresses, if you want to"
        echo "commit from them. Each additional email address must be confirmed by"
        echo "following the verification link sent to it."
        echo
        read -r -p 'Which user name did you choose? ' GERRITUSER
        if test -z "$created_ssh"; then
            echo
            echo "Please now add the following to your ~/.ssh/config, creating the file if needed:"
            echo
            logerrit "$GERRITUSER" ${ssh_key:+"$ssh_key_type"}
            echo
        else
        echo "Automatically creating your ssh config"
        logerrit "$GERRITUSER" ${ssh_key:+"$ssh_key_type"} >"$ssh_home/config"
        fi
        # setup the remote properly ...
        git config remote.origin.pushurl ssh://logerrit/core
        echo "To see if your setup was successful, run './logerrit test' then."
        # a good place to make sure the hooks are set up
        ./g -z
    ;;
    test)
        if test -n "$(ssh "$GERRITHOST" 2>&1|grep "Welcome to Gerrit Code Review")"; then
            echo "Your gerrit setup was successful!"
        else
            echo "There seems to be trouble. Please have the output of:"
            echo "ssh -vvvv $GERRITHOST"
            echo "at hand when looking for help."
        fi
    ;;
    submit)
        BRANCH=$(branch_or_default $2)
        TYPE=${3:+"%$3"}

        if [ "$BRANCH" = "master" ]; then
            WEEKOLDDATE=$(date --date="7 days ago" +%s 2> /dev/null)
            if [ "$WEEKOLDDATE" = "" ]; then
                WEEKOLDDATE=$(date -v-7d +%s) # BSD equivalent
            fi
            PARENTDATE=$(git show -s --format=%ct HEAD~1)
            if [[ $PARENTDATE -lt $WEEKOLDDATE ]]; then
                echo "Your branch is older than a week, do './g pull -r' and retry"
                exit 1
            fi
        fi
        git push "$GERRITURL" "HEAD:refs/for/$BRANCH$TYPE"
    ;;
    nextchange)
        if test -n "$(git status -s -uno)"; then
            echo "You have uncommitted changes. Please commit or stash these:"
            git status
            exit 1
        fi
        CHANGEID=$(git log --format=format:%b -1 HEAD|grep Change-Id|cut -d: -f2|tr -d \ )
        if test -z "$CHANGEID"; then
            CHANGEID="NOCHANGEID"
        fi
        BACKUPBRANCH=backup/$CHANGEID-$(date +%F-%H%M%S)
        git branch "$BACKUPBRANCH"
        echo "current state backed up as $BACKUPBRANCH"
        BRANCH=$(branch_or_default $2)
        git reset --hard "remotes/origin/$BRANCH"
    ;;
    checkout)
        get_SHA_for_change "$2"
        git fetch "$GERRITURL" "$SHA" && git checkout FETCH_HEAD
    ;;
    review)
        echo "'./logerrit review' has been removed as obsolete."
        echo "Please use either:"
        echo " - git-review:              https://wiki.documentfoundation.org/Development/GitReview"
        echo " - or the web-UI directly:  https://gerrit.libreoffice.org/"
        echo "Both provide a better experience."
        exit 1;
    ;;
    pull)
        get_SHA_for_change "$2"
        git pull "$GERRITURL" "$SHA"
    ;;
    cherry-pick)
        get_SHA_for_change "$2"
        git fetch "$GERRITURL" "$SHA" && git cherry-pick FETCH_HEAD
    ;;
    patch)
        get_SHA_for_change "$2"
        git fetch "$GERRITURL" "$SHA" && git format-patch -1 --stdout FETCH_HEAD
    ;;
    query)
        shift
        ssh "${GERRITHOST?}" gerrit query project:core "${@@Q}"
    ;;
    testfeature)
        CHANGEID=${3#I}
        if test -n "$3" -a \( ${#3} -ne 41 -o -n "${CHANGEID//[0-9a-f]/}" \); then
            echo "${3} is not a valid Gerrit change id"
            exit 1
        fi
        CHANGEID=$3

        BRANCH=$(branch_or_default $2)
        BRANCH="${BRANCH##feature/}"
        WORKDIR=$(mktemp -d)
        if test -z "$WORKDIR"; then
            echo "could not create work directory."
            exit 1
        fi
        echo "workdir at $WORKDIR"
        git clone -s "$(dirname "$0")" "$WORKDIR/core"

        pushd "$WORKDIR/core" || { echo "Changing directory failed."; exit 1; }
        echo "noop commit: trigger test build for branch feature/$BRANCH" > ../commitmsg
        echo >> ../commitmsg
        echo "branch is at:" >> ../commitmsg
        echo >> ../commitmsg
        git log -1|sed -e "s/Change-Id:/XXXXXX:/" >> ../commitmsg
        if test -n "$CHANGEID"; then
            echo >> ../commitmsg
            echo "Change-Id: $CHANGEID" >> ../commitmsg
        fi
        git fetch https://git.libreoffice.org/core "feature/$BRANCH" && \
            git checkout -b featuretst FETCH_HEAD && \
            cp -a .git-hooks/* .git/hooks && \
            git commit --allow-empty -F ../commitmsg && \
            git push "$GERRITURL" "HEAD:refs/for/feature/$BRANCH"
        popd || { echo "Changing directory failed."; exit 1; }

        rm -rf "$WORKDIR/core"
        rm -f "$WORKDIR/commitmsg"
        rmdir "$WORKDIR"
    ;;
    *)
        ssh "${GERRITHOST?}" gerrit "${@@Q}"
    ;;
esac

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