#!/bin/bash -x

# Usage: (cd <project root>; ghpages.sh -v <version> -b -c)

set -e

# Set default props like MAVEN_PATH, ROOT_FOLDER etc.
function set_default_props() {
    # The script should be executed from the root folder
    ROOT_FOLDER=`pwd`
    echo "Current folder is ${ROOT_FOLDER}"

    if [[ ! -e "${ROOT_FOLDER}/.git" ]]; then
        echo "You're not in the root folder of the project!"
        exit 1
    fi

    # Prop that will let commit the changes
    COMMIT_CHANGES="no"
    MAVEN_PATH=${MAVEN_PATH:-}
    if [ -e "${ROOT_FOLDER}/mvnw" ]; then
        MAVEN_EXEC="$ROOT_FOLDER/mvnw"
    else
        MAVEN_EXEC="${MAVEN_PATH}mvn"
    fi
    echo "Path to Maven is [${MAVEN_EXEC}]"
    if [ -z $REPO_NAME ]; then
        REPO_NAME=$(git remote -v | grep origin | head -1 | sed -e 's!.*/!!' -e 's/ .*//' -e 's/\.git.*//')
    fi
    echo "Repo name is [${REPO_NAME}]"
    SPRING_CLOUD_STATIC_REPO=${SPRING_CLOUD_STATIC_REPO:-git@github.com:spring-cloud/spring-cloud-static.git}
    echo "Spring Cloud Static repo is [${SPRING_CLOUD_STATIC_REPO}"
}

# Check if gh-pages exists and docs have been built
function check_if_anything_to_sync() {
    git remote set-url --push origin `git config remote.origin.url | sed -e 's/^git:/https:/'`

    if ! (git remote set-branches --add origin gh-pages && git fetch -q) && [[ "${RELEASE_TRAIN}" != "yes" ]] ; then
        echo "No gh-pages, so not syncing"
        exit 0
    fi

    if ! [ -d docs/target/generated-docs ] && ! [ "${BUILD}" == "yes" ]; then
        echo "No gh-pages sources in docs/target/generated-docs, so not syncing"
        exit 0
    fi
}

function retrieve_current_branch() {
    # Code getting the name of the current branch. For master we want to publish as we did until now
    # http://stackoverflow.com/questions/1593051/how-to-programmatically-determine-the-current-checked-out-git-branch
    # If there is a branch already passed will reuse it - otherwise will try to find it
    CURRENT_BRANCH=${BRANCH}
    if [[ -z "${CURRENT_BRANCH}" ]] ; then
      CURRENT_BRANCH=$(git symbolic-ref -q HEAD)
      CURRENT_BRANCH=${CURRENT_BRANCH##refs/heads/}
      CURRENT_BRANCH=${CURRENT_BRANCH:-HEAD}
    fi
    echo "Current branch is [${CURRENT_BRANCH}]"
    git checkout ${CURRENT_BRANCH} || echo "Failed to check the branch... continuing with the script"
    PREVIOUS_BRANCH=${CURRENT_BRANCH}
}

# Switches to the provided value of the release version. We always prefix it with `v`
function switch_to_tag() {
    if [[ "${RELEASE_TRAIN}" != "yes" ]] ; then
        git checkout v${VERSION}
    fi
}

# Build the docs if switch is on
function build_docs_if_applicable() {
    if [[ "${BUILD}" == "yes" ]] ; then
        ./mvnw clean install -P docs -pl docs -DskipTests
    fi
}

# Get the name of the `docs.main` property
# Get whitelisted branches - assumes that a `docs` module is available under `docs` profile
function retrieve_doc_properties() {
    MAIN_ADOC_VALUE=$("${MAVEN_EXEC}" -q \
        -Dexec.executable="echo" \
        -Dexec.args='${docs.main}' \
        org.codehaus.mojo:exec-maven-plugin:1.3.1:exec \
        -P docs \
        -pl docs | tail -1 )
    echo "Extracted 'main.adoc' from Maven build [${MAIN_ADOC_VALUE}]"


    WHITELIST_PROPERTY=${WHITELIST_PROPERTY:-"docs.whitelisted.branches"}
    WHITELISTED_BRANCHES_VALUE=$("${MAVEN_EXEC}" -q \
        -Dexec.executable="echo" \
        -Dexec.args="\${${WHITELIST_PROPERTY}}" \
        org.codehaus.mojo:exec-maven-plugin:1.3.1:exec \
        -P docs \
        -pl docs | tail -1 )
    echo "Extracted '${WHITELIST_PROPERTY}' from Maven build [${WHITELISTED_BRANCHES_VALUE}]"
}

# Stash any outstanding changes
function stash_changes() {
    git diff-index --quiet HEAD && dirty=$? || (echo "Failed to check if the current repo is dirty. Assuming that it is." && dirty="1")
    if [ "$dirty" != "0" ]; then git stash; fi
}

# Switch to gh-pages branch to sync it with current branch
function add_docs_from_target() {
    local DESTINATION_REPO_FOLDER
    if [[ -z "${DESTINATION}" && -z "${CLONE}" ]] ; then
        DESTINATION_REPO_FOLDER=${ROOT_FOLDER}
    elif [[ "${CLONE}" == "yes" ]]; then
        mkdir -p ${ROOT_FOLDER}/target
        local clonedStatic=${ROOT_FOLDER}/target/spring-cloud-static
        if [[ ! -e "${clonedStatic}/.git" ]]; then
            echo "Cloning Spring Cloud Static to target"
            git clone ${SPRING_CLOUD_STATIC_REPO} ${clonedStatic} && cd ${clonedStatic} && git checkout gh-pages
        else
            echo "Spring Cloud Static already cloned - will pull changes"
            cd ${clonedStatic} && git checkout gh-pages && git pull origin gh-pages
        fi
        if [[ -z "${RELEASE_TRAIN}" ]] ; then
            DESTINATION_REPO_FOLDER=${clonedStatic}/${REPO_NAME}
        else
            DESTINATION_REPO_FOLDER=${clonedStatic}
        fi
        mkdir -p ${DESTINATION_REPO_FOLDER}
    else
        if [[ ! -e "${DESTINATION}/.git" ]]; then
            echo "[${DESTINATION}] is not a git repository"
            exit 1
        fi
        if [[ -z "${RELEASE_TRAIN}" ]] ; then
            DESTINATION_REPO_FOLDER=${DESTINATION}/${REPO_NAME}
        else
            DESTINATION_REPO_FOLDER=${DESTINATION}
        fi
        mkdir -p ${DESTINATION_REPO_FOLDER}
        echo "Destination was provided [${DESTINATION}]"
    fi
    cd ${DESTINATION_REPO_FOLDER}
    git checkout gh-pages
    git pull origin gh-pages

    # Add git branches
    ###################################################################
    if [[ -z "${VERSION}" && -z "${RELEASE_TRAIN}" ]] ; then
        copy_docs_for_current_version
    else
        copy_docs_for_provided_version
    fi
    commit_changes_if_applicable
}


# Copies the docs by using the retrieved properties from Maven build
function copy_docs_for_current_version() {
    if [[ "${CURRENT_BRANCH}" == "master" ]] ; then
        echo -e "Current branch is master - will copy the current docs only to the root folder"
        for f in docs/target/generated-docs/*; do
            file=${f#docs/target/generated-docs/*}
            if ! git ls-files -i -o --exclude-standard --directory | grep -q ^$file$; then
                # Not ignored...
                cp -rf $f ${ROOT_FOLDER}/
            fi
        done
        git add -A ${ROOT_FOLDER}
        COMMIT_CHANGES="yes"
    else
        echo -e "Current branch is [${CURRENT_BRANCH}]"
        # http://stackoverflow.com/questions/29300806/a-bash-script-to-check-if-a-string-is-present-in-a-comma-separated-list-of-strin
        if [[ ",${WHITELISTED_BRANCHES_VALUE}," = *",${CURRENT_BRANCH},"* ]] ; then
            mkdir -p ${ROOT_FOLDER}/${CURRENT_BRANCH}
            echo -e "Branch [${CURRENT_BRANCH}] is whitelisted! Will copy the current docs to the [${CURRENT_BRANCH}] folder"
            for f in docs/target/generated-docs/*; do
                file=${f#docs/target/generated-docs/*}
                if ! git ls-files -i -o --exclude-standard --directory | grep -q ^$file$; then
                    # Not ignored...
                    # We want users to access 1.0.0.RELEASE/ instead of 1.0.0.RELEASE/spring-cloud.sleuth.html
                    if [[ "${file}" == "${MAIN_ADOC_VALUE}.html" ]] ; then
                        # We don't want to copy the spring-cloud-sleuth.html
                        # we want it to be converted to index.html
                        cp -rf $f ${ROOT_FOLDER}/${CURRENT_BRANCH}/index.html
                        git add -A ${ROOT_FOLDER}/${CURRENT_BRANCH}/index.html
                    else
                        cp -rf $f ${ROOT_FOLDER}/${CURRENT_BRANCH}
                        git add -A ${ROOT_FOLDER}/${CURRENT_BRANCH}/$file
                    fi
                fi
            done
            COMMIT_CHANGES="yes"
        else
            echo -e "Branch [${CURRENT_BRANCH}] is not on the white list! Check out the Maven [${WHITELIST_PROPERTY}] property in
             [docs] module available under [docs] profile. Won't commit any changes to gh-pages for this branch."
        fi
    fi
}

# Copies the docs by using the explicitly provided version
function copy_docs_for_provided_version() {
    local FOLDER=${DESTINATION_REPO_FOLDER}/${VERSION}
    mkdir -p ${FOLDER}
    echo -e "Current tag is [v${VERSION}] Will copy the current docs to the [${FOLDER}] folder"
    for f in ${ROOT_FOLDER}/docs/target/generated-docs/*; do
        file=${f#${ROOT_FOLDER}/docs/target/generated-docs/*}
        copy_docs_for_branch ${file} ${FOLDER}
    done
    COMMIT_CHANGES="yes"
    CURRENT_BRANCH="v${VERSION}"
}

# Copies the docs from target to the provided destination
# Params:
# $1 - file from target
# $2 - destination to which copy the files
function copy_docs_for_branch() {
    local file=$1
    local destination=$2
    if ! git ls-files -i -o --exclude-standard --directory | grep -q ^${file}$; then
        # Not ignored...
        # We want users to access 1.0.0.RELEASE/ instead of 1.0.0.RELEASE/spring-cloud.sleuth.html
        if [[ ("${file}" == "${MAIN_ADOC_VALUE}.html") || ("${file}" == "${REPO_NAME}.html") ]] ; then
            # We don't want to copy the spring-cloud-sleuth.html
            # we want it to be converted to index.html
            cp -rf $f ${destination}/index.html
        else
            cp -rf $f ${destination}
        fi
        git add -A ${destination}
    fi
}

function commit_changes_if_applicable() {
    if [[ "${COMMIT_CHANGES}" == "yes" ]] ; then
        COMMIT_SUCCESSFUL="no"
        git commit -a -m "Sync docs from ${CURRENT_BRANCH} to gh-pages" && COMMIT_SUCCESSFUL="yes" || echo "Failed to commit changes"

        # Uncomment the following push if you want to auto push to
        # the gh-pages branch whenever you commit to master locally.
        # This is a little extreme. Use with care!
        ###################################################################
        if [[ "${COMMIT_SUCCESSFUL}" == "yes" ]] ; then
            git push origin gh-pages
        fi
    fi
}

# Switch back to the previous branch and exit block
function checkout_previous_branch() {
    # If -version was provided we need to come back to root project
    cd ${ROOT_FOLDER}
    git checkout ${PREVIOUS_BRANCH} || echo "Failed to check the branch... continuing with the script"
    if [ "$dirty" != "0" ]; then git stash pop; fi
    exit 0
}

# Assert if properties have been properly passed
function assert_properties() {
echo "VERSION [${VERSION}], RELEASE_TRAIN [${RELEASE_TRAIN}], DESTINATION [${DESTINATION}], CLONE [${CLONE}]"
if [[ "${VERSION}" != "" && (-z "${DESTINATION}" && -z "${CLONE}") ]] ; then echo "Version was set but destination / clone was not!"; exit 1;fi
if [[ ("${DESTINATION}" != "" && "${CLONE}" != "") && -z "${VERSION}" ]] ; then echo "Destination / clone was set but version was not!"; exit 1;fi
if [[ "${DESTINATION}" != "" && "${CLONE}" == "yes" ]] ; then echo "Destination and clone was set. Pick one!"; exit 1;fi
if [[ "${RELEASE_TRAIN}" != "" && -z "${VERSION}" ]] ; then echo "Release train was set but no version was passed!"; exit 1;fi
}

# Prints the usage
function print_usage() {
cat <<EOF
The idea of this script is to update gh-pages branch with the generated docs. Without any options
the script will work in the following manner:

- if there's no gh-pages / target for docs module then the script ends
- for master branch the generated docs are copied to the root of gh-pages branch
- for any other branch (if that branch is whitelisted) a subfolder with branch name is created
    and docs are copied there
- if the version switch is passed (-v) then a tag with (v) prefix will be retrieved and a folder
    with that version number will be created in the gh-pages branch. WARNING! No whitelist verification will take place
- if the destination switch is passed (-d) then the script will check if the provided dir is a git repo and then will
    switch to gh-pages of that repo and copy the generated docs to `docs/<project-name>/<version>`
- if the destination switch is passed (-d) then the script will check if the provided dir is a git repo and then will
    switch to gh-pages of that repo and copy the generated docs to `docs/<project-name>/<version>`
- if the release train switch is passed (-r) then the script will check if the provided dir is a git repo and then will
    switch to gh-pages of that repo and copy the generated docs to `docs/<version>`

USAGE:

You can use the following options:

-v|--version        - the script will apply the whole procedure for a particular library version
-r|--releasetrain   - instead of nesting the docs under the project_name/version folder the docs will end up in version
-d|--destination    - the root of destination folder where the docs should be copied. You have to use the full path.
                        E.g. point to spring-cloud-static folder. Can't be used with (-c)
-b|--build          - will run the standard build process after checking out the branch
-c|--clone          - will automatically clone the spring-cloud-static repo instead of providing the destination.
                        Obviously can't be used with (-d)

EOF
}


# ==========================================
#    ____   ____ _____  _____ _____ _______
#  / ____|/ ____|  __ \|_   _|  __ \__   __|
# | (___ | |    | |__) | | | | |__) | | |
#  \___ \| |    |  _  /  | | |  ___/  | |
#  ____) | |____| | \ \ _| |_| |      | |
# |_____/ \_____|_|  \_\_____|_|      |_|
#
# ==========================================

while [[ $# > 0 ]]
do
key="$1"
case ${key} in
    -v|--version)
    VERSION="$2"
    shift # past argument
    ;;
    -r|--releasetrain)
    RELEASE_TRAIN="yes"
    ;;
    -d|--destination)
    DESTINATION="$2"
    shift # past argument
    ;;
    -b|--build)
    BUILD="yes"
    ;;
    -c|--clone)
    CLONE="yes"
    ;;
    -h|--help)
    print_usage
    exit 0
    ;;
    *)
    echo "Invalid option: [$1]"
    print_usage
    exit 1
    ;;
esac
shift # past argument or value
done

assert_properties
set_default_props
check_if_anything_to_sync
retrieve_current_branch
if echo $VERSION | egrep -q 'SNAPSHOT' || [[ -z "${VERSION}" ]]; then
    CLONE=""
    VERSION=""
    echo "You've provided a version variable but it's a snapshot one. Due to this will not clone spring-cloud-static and publish docs over there"
else
    switch_to_tag
fi
build_docs_if_applicable
retrieve_doc_properties
stash_changes
add_docs_from_target
checkout_previous_branch