#!/bin/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/^ *//')
}

submit() {
        BRANCH=$1
        TYPE=${2:-''}
        if test -z "$BRANCH"
        then
            BRANCH=$(git symbolic-ref HEAD 2> /dev/null)
            BRANCH="${BRANCH##refs/heads/}"
            if test -z "$BRANCH"
            then
                echo "no branch specified, and could not guess the current branch"
                exit 1
            fi
            echo "no branch specified, guessing current branch $BRANCH"
        fi
        git push "$GERRITURL" "HEAD:refs/for/$BRANCH$TYPE"
}

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 "$1" in
    help|--help|"")
        echo "Usage: ./logerrit subcommand [options]"
        echo "simple and basic tool to interact with LibreOffice gerrit"
        echo "see https://wiki.documentfoundation.org/Development/gerrit for details."
        echo
        echo "subcommands:"
        echo "             setup                   walking you though your gerrit setup"
        echo "             test                    test your gerrit setup"
        echo
        echo " --- for submitters:"
        echo "             submit [BRANCH]         submit your change for review"
        echo "             submit-private [BRANCH] submit your change as private"
        echo "             submit-wip [BRANCH]     submit your change as work-in-progress"
        echo "             nextchange [BRANCH]     reset branch to the remote to start with the next change"
        echo "             testfeature [BRANCH]    trigger a test of a feature branch on gerrit"
        echo "Note: private changes are only visibly to yourself and those that you explicitly add as reviewers."
        echo "For full documentation, see https://gerrit.libreoffice.org/Documentation/intro-user.html#private-changes"
        echo
        echo " --- for reviewers:"
        echo "             checkout CHANGEID       checkout the changes for review"
        echo "             pull CHANGEID           pull (and merge) the changes on current branch"
        echo "             cherry-pick CHANGEID    cherry-pick the change on current branch"
        echo "             patch CHANGEID          show the change as a patch"
        echo "             query ...               query for changes for review on project core"
        echo "             <any other gerrit command>"
        echo
        echo "advanced users should consider using git review instead:"
        echo "https://wiki.documentfoundation.org/Development/GitReview"
        exit
    ;;
    setup)
        script_canonical_file=$(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
	    ssh-keygen -t rsa -f "$ssh_home/id_rsa" # default type as of OpenSSH 8.1
	fi
    if test -d "$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:"
    echo " - press the 'register' button in the top right corner"
    echo " - after login set yourself a username (it is recommended to use your IRC-nick)"
	if test -z "$ssh_key"; then
        echo " - add your public ssh-key into the ssh keys settings."
    else
	    echo " - paste the key below into the 'Add SSH Public Key' box."
        echo
        printf '%s\n' "$ssh_key"
        echo
	fi
        echo
        echo "Note that you need to register additional email addresses, if you want to"
        echo "commit from them. Additional emails must be confirmed by replying to the"
        echo "invitation mail it sends you."
        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)
        submit "$2"
    ;;
    submit-private)
        submit "$2" '%private'
    ;;
    submit-wip)
        submit "$2" '%wip'
    ;;
    submit-draft)
        echo "Please use submit-private instead of submit-draft."
        exit 1
    ;;
    nextchange)
        if test -n "$(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=$2
        if test -z "$BRANCH"
        then
            BRANCH=$(git symbolic-ref HEAD 2> /dev/null)
            BRANCH="${BRANCH##refs/heads/}"
            if test -z "$BRANCH"
            then
                echo "no branch specified, and could not guess the current branch"
                exit 1
            fi
            echo "no branch specified, guessing current branch $BRANCH"
        fi
        git reset --hard "remotes/origin/$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)
        BRANCH=$2
        if test -z "$BRANCH"
        then
            BRANCH=$(git symbolic-ref HEAD 2> /dev/null)
            BRANCH="${BRANCH##refs/heads/}"
            if test -z "$BRANCH"
            then
                echo "no branch specified, and could not guess the current branch"
                exit 1
            fi
            echo "no branch specified, guessing current branch $BRANCH"
        fi
        BRANCH="${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
        git log -1|sed -e "s/Change-Id:/XXXXXX:/" >> ../commitmsg
        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"
    ;;
    *)
        ssh "${GERRITHOST?}" gerrit "${@@Q}"
    ;;
esac