#!@BASH_PATH@
#
# Copyright 2012-2023 the Pacemaker project contributors
#
# The version control history for this file may have further details.
#
# This source code is licensed under the GNU General Public License version 2
# or later (GPLv2+) WITHOUT ANY WARRANTY.
#

# List regular expressions (not globs) that match all of a library's public API
# headers. Any files ending in "internal.h" will be excluded from matches.
declare -A HEADERS
HEADERS[cib]="include/crm/cib.h include/crm/cib/.*.h"
HEADERS[crmcommon]="include/crm/crm.h
                    include/crm/msg_xml.h
                    include/crm/common/.*.h"
HEADERS[crmcluster]="include/crm/cluster.h include/crm/cluster/.*.h"
HEADERS[crmservice]="include/crm/services.*.h"
HEADERS[lrmd]="include/crm/lrmd.*.h"
HEADERS[pacemaker]="include/pacemaker.*.h"
HEADERS[pe_rules]="include/crm/pengine/ru.*.h"
HEADERS[pe_status]="include/crm/pengine/[^r].*.h include/crm/pengine/r[^u].*.h"
HEADERS[stonithd]="include/crm/stonith-ng.h include/crm/fencing/.*.h"

yesno() {
    local RESPONSE

    read -p "$1 " RESPONSE
    case $(echo "$RESPONSE" | tr '[:upper:]' '[:lower:]') in
        y|yes|ano|ja|si|oui) return 0 ;;
        *) return 1 ;;
    esac
}

prompt_to_continue() {
    yesno "Continue?" || exit 0
}

sed_in_place() {
    cp -p "$1" "$1.$$"
    sed -e "$2" "$1" > "$1.$$"
    mv "$1.$$" "$1"
}

find_last_release() {
    if [ -n "$1" ]; then
        echo "$1"
    else
        git tag -l | grep Pacemaker | grep -v rc | sort -Vr | head -n 1
    fi
}

find_libs() {
    find lib -name "*.am" -exec grep "lib.*_la_LDFLAGS.*version-info" \{\} \; \
        | sed -e 's/lib\(.*\)_la_LDFLAGS.*/\1/'
}

find_makefile() {
    find lib -name Makefile.am -exec grep -l "lib${1}_la.*version-info" \{\} \;
}

find_sources() {
    local LIB="$1"
    local AMFILE="$2"
    local SOURCES

    # Library makefiles should use "+=" to break up long sources lines rather
    # than backslashed continuation lines, to allow this script to detect
    # source files correctly. Warn if that's not the case.
    if
        grep "lib${LIB}_la_SOURCES.*\\\\" "$AMFILE"
    then
        echo -e "\033[1;35m -- Sources list for lib$LIB is probably truncated! --\033[0m"
        echo "Edit to use '+=' rather than backslashed continuation lines"
        prompt_to_continue
    fi

    SOURCES=$(grep "^lib${LIB}_la_SOURCES" "$AMFILE" \
        | sed -e 's/.*=//' -e 's/\\//' -e 's:\.\./gnu/:lib/gnu/:')

    for SOURCE in $SOURCES; do
        if
            echo "$SOURCE" | grep -q "/"
        then
            echo "$SOURCE"
        else
            echo "$(dirname "$AMFILE")/$SOURCE"
        fi
    done
}

find_headers_as_of() {
    local TAG
    local LIB
    local FILE
    local PATTERN

    TAG="$1"
    LIB="$2"

    for FILE in $(git ls-tree -r --name-only "$TAG"); do
        for PATTERN in ${HEADERS[$LIB]}; do
            if [[ $FILE =~ $PATTERN ]] && [[ ! $FILE =~ internal.h$ ]]; then
                echo "$FILE"
                break
            fi
        done
    done
}

extract_version() {
    grep "lib${1}_la.*version-info" | sed -e 's/.*version-info\s*\(\S*\)/\1/'
}

shared_lib_name() {
    local LIB="$1"
    local VERSION="$2"

    echo "lib${LIB}.so.$(echo "$VERSION" | cut -d: -f 1)"
}

process_lib() {
    local LIB="$1"
    local LAST_RELEASE="$2"
    local AMFILE
    local SOURCES
    local HEADERS_LAST
    local HEADERS_HEAD
    local HEADERS_DIFF
    local HEADERS_GONE
    local HEADERS_ADDED
    local CHANGE
    local DEFAULT_CHANGE

    if [ -z "${HEADERS[$LIB]}" ]; then
        echo "Can't check lib$LIB until this script is updated with its headers"
        prompt_to_continue
    fi

    AMFILE="$(find_makefile "$LIB")"

    # Get current shared library version
    VER_NOW=$(extract_version "$LIB" < "$AMFILE")

    # Check whether library existed at last release
    if ! git cat-file -e "$LAST_RELEASE:$AMFILE" 2>/dev/null; then
        echo "lib$LIB is new, not changing version ($VER_NOW)"
        prompt_to_continue
        echo ""
        return
    fi

    HEADERS_LAST="$(find_headers_as_of "$LAST_RELEASE" "$LIB")"
    HEADERS_HEAD="$(find_headers_as_of "HEAD" "$LIB")"
    HEADERS_DIFF="$(diff <(echo "$HEADERS_LAST") <(echo "$HEADERS_HEAD"))"
    HEADERS_GONE="$(echo "$HEADERS_DIFF" | sed -n -e 's/^< //p')"
    HEADERS_ADDED="$(echo "$HEADERS_DIFF" | sed -n -e 's/^> //p')"

    # Check whether there were any changes to headers or sources
    SOURCES="$(find_sources "$LIB" "$AMFILE")"
    if [ -n "$HEADERS_GONE" ]; then
        DEFAULT_CHANGE="i" # Removed public header is incompatible change
    elif [ -n "$HEADERS_ADDED" ]; then
        DEFAULT_CHANGE="c" # Additions are likely compatible
    elif git diff --quiet -w "$LAST_RELEASE..HEAD" $HEADERS_HEAD $SOURCES ; then
        echo "No changes to $LIB interface"
        prompt_to_continue
        echo ""
        return
    else
        DEFAULT_CHANGE="f" # Sources changed, so it's at least a fix
    fi

    # Show all header changes since last release
    echo "- Changes in lib$LIB public headers since $LAST_RELEASE:"
    if [ -n "$HEADERS_GONE" ]; then
        for HEADER in $HEADERS_GONE; do
            echo "-- $HEADER was removed"
        done
    fi
    if [ -n "$HEADERS_ADDED" ]; then
        for HEADER in $HEADERS_ADDED; do
            echo "++ $HEADER is new"
        done
    fi
    git --no-pager diff --color -w "$LAST_RELEASE..HEAD" $HEADERS_HEAD

    echo ""
    if yesno "Show commits (minus refactor/build/merge) touching lib$LIB since $LAST_RELEASE [y/N]?"
    then
        git log --color "$LAST_RELEASE..HEAD" -z $HEADERS_HEAD $SOURCES "$AMFILE" \
            | grep -vzE "Refactor:|Build:|Merge pull request"
        echo
        prompt_to_continue
    fi

    # @TODO this seems broken ...
    #echo ""
    #if yesno "Show merged PRs touching lib$LIB since $LAST_RELEASE [y/N]?"
    #then
    #    git log --merges $LAST_RELEASE..HEAD $HEADERS_HEAD $SOURCES $AMFILE
    #    echo
    #    prompt_to_continue
    #fi

    # Show summary of source changes since last release
    echo ""
    echo "- Headers: $HEADERS_HEAD"
    echo "- Changed sources since $LAST_RELEASE:"
    git --no-pager diff --color -w "$LAST_RELEASE..HEAD" --stat $SOURCES
    echo ""

    # Ask for human guidance
    echo "Are the changes to lib$LIB:"
    read -p "[c]ompatible additions, [i]ncompatible additions/removals or [f]ixes? [$DEFAULT_CHANGE]: " CHANGE
    [ -z "$CHANGE" ] && CHANGE="$DEFAULT_CHANGE"

    # Get (and show) shared library version at last release
    VER=$(git show "$LAST_RELEASE:$AMFILE" | extract_version "$LIB")
    VER_1=$(echo "$VER" | awk -F: '{print $1}')
    VER_2=$(echo "$VER" | awk -F: '{print $2}')
    VER_3=$(echo "$VER" | awk -F: '{print $3}')
    echo "lib$LIB version at $LAST_RELEASE: $VER"

    # Show current shared library version if changed
    if [ "$VER_NOW" != "$VER" ]; then
        echo "lib$LIB version currently: $VER_NOW"
    fi

    # Calculate new library version
    case $CHANGE in
        i|I)
            echo "New backwards-incompatible version: x+1:0:0"
            (( VER_1++ ))
            VER_2=0
            VER_3=0

            # Some headers define constants for shared library names,
            # update them if the name changed
            for H in $HEADERS_HEAD; do
                sed_in_place "$H" "s/$(shared_lib_name "$LIB" "$VER_NOW")/$(shared_lib_name "$LIB" "$VER_1:0:0")/"
            done
            ;;
        c|C)
            echo "New version with backwards-compatible extensions: x+1:0:z+1"
            (( VER_1++ ))
            VER_2=0
            (( VER_3++ ))
            ;;
        F|f)
            echo "Code changed though interfaces didn't: x:y+1:z"
            (( VER_2++ ))
            ;;
        *)
            echo "Not updating lib$LIB version"
            prompt_to_continue
            CHANGE=""
            ;;
    esac
    VER_NEW=$VER_1:$VER_2:$VER_3

    if [ -n "$CHANGE" ]; then
        if [ "$VER_NEW" != "$VER_NOW" ]; then
            echo "Updating lib$LIB version from $VER_NOW to $VER_NEW"
            prompt_to_continue
            sed_in_place "$AMFILE" "s/version-info\s*$VER_NOW/version-info $VER_NEW/"
        else
            echo "No version change needed for lib$LIB"
            prompt_to_continue
        fi
    fi
    echo ""
}

echo "Definitions:"
echo "- Compatible additions: new public API functions, structs, etc."
echo "- Incompatible additions/removals: new arguments to public API functions,"
echo "  new members added to the middle of public API structs,"
echo "  removal of any public API, etc."
echo "- Fixes: any other code changes at all"
echo ""
echo "When possible, improve backward compatibility first:"
echo "- move new members to the end of structs"
echo "- use bitfields instead of booleans"
echo "- when adding arguments, create a new function that the old one can wrap"
echo ""
prompt_to_continue

LAST_RELEASE=$(find_last_release "$1")
for LIB in $(find_libs); do
    process_lib "$LIB" "$LAST_RELEASE"
done

# Show all proposed changes
git --no-pager diff --color -w