# bash

#
# Copyright (c) 2022 Wind River Systems, Inc.
#
# SPDX-License-Identifier: Apache-2.0
#

source $(dirname "${BASH_SOURCE[0]}")/utils.sh || exit 1
source $(dirname "${BASH_SOURCE[0]}")/glob_utils.sh || exit 1

# used by need_build() below
NEED_BUILD_PATTERNS=(

    "! cgcs-root/stx/docs/*"
    "! cgcs-root/stx/test/*"
    "! cgcs-root/local-build-data/*"
    "! cgcs-root/wrs/docs/*"

    "  cgcs-root/wrs/titanium-tools/docker-images/*"  # used by *_SDK_Build
    "  cgcs-root/wrs/titanium-tools/lab/*"
    "! cgcs-root/wrs/titanium-tools/*"

#    "  stx-tools/centos-mirror-tools/yum.conf.sample"
#    "  stx-tools/centos-mirror-tools/config/centos/$LAYER"
#    "! stx-tools/*"

    "  cgcs-root/build-tools/signing/*"
    "  cgcs-root/build-tools/certificats/*"
    "  cgcs-root/build-tools/build-docker-images/*"
    "  cgcs-root/build-tools/build-wheels/*"
    "! cgcs-root/build-tools/*"
)

# Usage: ( cd $MY_REPO_ROOT_DIR && print_last_commits ; ) >LAST_COMMITS
print_last_commits() {
    local dir padded_dir
    for dir in ./.repo/manifests $( find . \( -path './.repo' -prune \) -o \( -xtype d -name .git -printf '%h\n' \) | sort ) ; do
        pushd "$dir" >/dev/null || exit 1
        padded_dir="$(printf "%-52s" "$dir")"
        git log --pretty=tformat:"$padded_dir %H" -n 1 || exit 1
        popd >/dev/null || exit 1
    done
}

#
# Usage: diff_last_commits MY_WORKSPACE/../LAST_COMMITS [PATTERNS...]
#
# Diff git HEADs with a LAST_COMMITS file generated by another build
# Return true (0) if there are no differences
#
# PATTERNS may be used to filter out changes in some files when comparing
#
# If any file changed since LAST_COMMITs matches a PATTERN, we return
# false (ie changes detected & a rebuild is required). If it matches a
# "negative" pattern that begins with "!", we continue to the next file
# instead. Patterns are matched in order until a match is found. A
# combination of positive and negative patterns may be used to skip parts
# of the source tree.
#
# Patterns are similar to shell glob patterns, except "*" and "?" match
# any character including "/".
# Leading and trailing whitespace as well as leading "./" in patterns
# are not significant.
# Changes in files that didn't match any patterns are treated as positive
# matches.
#
# EXAMPLE:
#
# diff_last_commits $MY_WORKSPACE/../LAST_COMMITS \
#   # detect changes in this file \
#   "stx-tools/centos-mirror-tools/yum.conf.sample" \
#   # ignore other changes under centos-mirror-tools \
#   "!stx-tools/centos/mirror-tools/*" \
#   # detect changes everywhere else (implied)
#   "*"
#

diff_last_commits() {
    local last_commits_file="$1" ; shift || :
    local debug=2
    local dir dir_regex
    local last_commit
    local commit_files_str
    local -a commit_files
    local file
    local match pattern_expr pattern regex

    # no previous builds: assume builds different
    if [[ ! -f "$last_commits_file" ]] ; then
        [[ "$debug" == 0 ]] || echo "## file \`$last_commits_file' doesn't exist: return false" >&2
        return 1
    fi

    # find all gits
    [[ "$debug" == 0 ]] || echo "## looking for diffs between \`$PWD' and \`$last_commits_file'" >&2
    for dir in ./.repo/manifests $( find . \( -path './.repo' -prune \) -o \( -xtype d -name .git -printf '%h\n' \) | sort ) ; do
        [[ "$debug" == 0 ]] || echo "## checking \`$dir'" >&2

        if [[ "$dir" == "." ]] ; then
            dir_prefix=""
        else
            dir_prefix="${dir#./}"/
        fi

        # find last commit for this dir
        # create a regex LAST_COMMITS, eg: ./cgcs-root/stx/config => ^[.][/]cgcs-root[/]stx[/]config[^a-zA-Z0-9/_-]
        dir_regex="$(echo "$dir" | sed \
            -e 's:/:[/]:g' \
            -e 's:$:[^a-zA-Z0-9/_-]:' \
            -e 's:^[.][.]:^[.][.]:' \
            -e 's:^[.]:^[.]:' \
        )"
        last_commit=$(grep "$dir_regex" "$last_commits_file" | awk ' { print $2 } ')

        # it didn't exist in previous buid: assume builds different
        if [[ -z "$last_commit" ]] ; then
            [[ "$debug" == 0 ]] || echo "## $dir: not present in \`$last_commits_file': return false" >&2
            return 1
        fi

        # get all files changed since last_commit
        commit_files_str="$(cd "$dir" && git diff-tree --no-commit-id --name-only -r $last_commit..HEAD)" || exit 1
        readarray -t commit_files < <(echo -n "$commit_files_str")

        # check each file against PATTERNs
        for file in "${commit_files[@]}" ; do
            match=0
            for pattern_expr in "$@" ; do
                # convert glob pattern to regex
                pattern="$(echo "$pattern_expr" | sed -r -e 's/^\s*[!]?\s*//' -e 's/\s*$//')"
                regex="$(glob_to_basic_regex "$pattern")"
                [[ "$debug" -lt 2 ]] || echo "##   trying to match pattern \`$pattern' / regex \`$regex'" >&2
                # check if the file matches
                if echo "${dir_prefix}$file" | grep -q -E "$regex" >/dev/null || \
                   echo "$dir/$file" | grep -q -E "$regex" >/dev/null ; then
                    # pattern doesn't begin with "!": assume builds different
                    if ! echo "$pattern_expr" | grep -q -E '^\s*[!]' ; then
                        [[ "$debug" == 0 ]] || echo "## file \`${dir_prefix}$file' matched positive pattern \`$pattern_expr': return false" >&2
                        return 1
                    fi
                    # "!" pattern: continue to next file
                    [[ "$debug" == 0 ]] || echo "## file \`${dir_prefix}$file' matched negative pattern \`$pattern_expr': continue to next file" >&2
                    match=1
                    break
                fi
            done # for pattern_expr ...
            if [[ $match == 0 ]] ; then
                [[ "$debug" == 0 ]] || echo "## file \`${dir_prefix}$file' didn't match any negative patterns: return false" >&2
                return 1
            fi
        done # for file ...

    done # for dir ...

    [[ "$debug" == 0 ]] || echo "## no diffs found: return true" >&2
    return 0

}

#
# Usage: print_changelog LAST_COMMITS_FILE [DEFAULT_FROM_TIMESTAMP]
#
# Print out the change log since LAST_COMMITS_FILE.
#
# DEFAULT_FROM_TIMESTAMP will be used for repos missing from LAST_COMMITS_FILE
# and must be a date or date/time in ISO format. Defaults to the value of
# BUILD_TIMESTAMP global variable minus 1 day at midnight, or yesterday's midnight.
#
# LAST_COMMITS_FILE need not exist.
#
print_changelog() {
    local last_commits_file="$1"

    local default_from_timestamp
    if [[ -n "$2" ]] ; then
        default_from_timestamp="$2"
    else
        local build_date
        build_date="${BUILD_TIMESTAMP:0:10}"
        [[ -n "$build_date" ]] || build_date=$(date '+%Y-%m-%d') || return 1
        default_from_timestamp="$(date --date="$build_date - 1 day" '+%Y-%m-%d 00:00:00')" || return 1
    fi

    local dir
    for dir in ./.repo/manifests $( find . \( -path './.repo' -prune \) -o \( -xtype d -name .git -printf '%h\n' \) | sort ) ; do (
        set -e
        padded_dir="$(printf "%-52s" "$dir")"
        commit=
        if [[ -f "$last_commits_file" ]] ; then
            # create a regex LAST_COMMITS, eg: ./cgcs-root/stx/config => ^[.][/]cgcs-root[/]stx[/]config[^a-zA-Z0-9/_-]
            regex="$(echo "$dir" | sed \
                -e 's:/:[/]:g' \
                -e 's:$:[^a-zA-Z0-9/_-]:' \
                -e 's:^[.][.]:^[.][.]:' \
                -e 's:^[.]:^[.]:' \
            )"
            commit=$(grep "$regex" "$last_commits_file" | awk ' { print $2 } ')
        fi
        if [[ -n "$commit" ]] ; then
            git_log_args=("$commit..")
        else
            git_log_args=(--after "$default_from_timestamp")
        fi
        pushd "$dir" >/dev/null
        git log --date=iso --pretty=tformat:"$padded_dir  %H  %cd%x09%cn%x09%s" "${git_log_args[@]}"
        popd >/dev/null
    ) ; done
}

#
# Usage: print_changelog_since TIMESTAMP
#
print_changelog_since() {
    print_changelog "" "$1"
}

# Usage: create_standard_changelogs
#
# Create changelog files in $MY_WORKSPACE:
#
#   CHANGELOG
#     changes since LAST_COMMITS left by most recent successful build,
#     used for rebuild calculations
#
#   CHANGELOG.OLD
#     changes since midnight of previous day (24-48 hours)
#
#   CHANGELOG.IMG_DEV
#     changes since LAST_COMMITS left by most recent dev images build
#
#   CHANGELOG.IMG_STABLE
#     changes since LAST_COMMITS left by most recent stable images build
#
#   LAST_COMMITS
#     SHA's of each git's HEAD
#
create_standard_changelogs() {
    require_env "MY_REPO_ROOT_DIR" "MY_WORKSPACE"
    local deploy_dir="${DEPLOY_DIR:-$MY_WORKSPACE/..}"
    local changelog_file="$MY_WORKSPACE/CHANGELOG"

    local build_date
    build_date="${BUILD_TIMESTAMP:0:10}"
    [[ -n "$build_date" ]] || build_date=$(date '+%Y-%m-%d') || return 1

    local default_from_timestamp
    default_from_timestamp="$(date --date="$build_date - 1 day" '+%Y-%m-%d 00:00:00')" || return 1

    # CHANGELOG
    echo "## creating $changelog_file (since last iso build)"
    (
        set -e
        cd "$MY_REPO_ROOT_DIR"
        print_changelog "$deploy_dir/LAST_COMMITS" "$default_from_timestamp"
    ) >"$changelog_file" || exit 1

    # CHANGELOG.OLD
    echo "## creating $changelog_file.OLD (since yesterday midnight)"
    (
        set -e
        cd "$MY_REPO_ROOT_DIR"
        print_changelog "" "$default_from_timestamp"
    ) >"$changelog_file.OLD" || exit 1

    # CHNAGELOG.IMG_DEV
    echo "## creating $changelog_file.IMG_DEV (since last dev images build)"
    (
        set -e
        cd "$MY_REPO_ROOT_DIR"
        print_changelog "$deploy_dir/LAST_COMMITS_IMG_DEV" "$default_from_timestamp"
    ) >"$changelog_file.IMG_DEV" || exit 1

    # CHNAGELOG.IMG_STABLE
    echo "## creating $changelog_file.IMG_STABLE (since last stable images build)"
    (
        set -e
        cd "$MY_REPO_ROOT_DIR"
        print_changelog "$deploy_dir/LAST_COMMITS_IMG_STABLE" "$default_from_timestamp"
    ) >"$changelog_file.IMG_STABLE" || exit 1

    # LAST_COMMITS
    (
        set -e
        cd "$MY_REPO_ROOT_DIR"
        print_last_commits
    ) >"$MY_WORKSPACE/LAST_COMMITS" || exit 1

    echo "## LAST_COMMITS" >&2
    cat "$MY_WORKSPACE/LAST_COMMITS" >&2
    echo "## END LAST_COMMITS" >&2

    echo "## CHANGELOG" >&2
    cat "$changelog_file" >&2
    echo "## END CHANGELOG" >&2
}

# Usage: need_build [BUILD_DATE]
#
# Return true if build is required. BUILD_DATE defaults
# to BUILD_TIMESTAMP global var, or today's date.
#
# This will create either a NEED_BUID or NO_BUILD_REQUIRED file
# in MY_WORKSPACE.
#
# If any of these job parameters are set to true, this function returns true:
#  FORCE_BUILD
#  BUILD_DOCKER_IMAGES_DEV
#  BUILD_DOCKER_IMAGES_STABLE
#
# These job parameters/env vars must be set to the week days when
# images should be built, eg:
#
#  BUILD_DOCKER_IMAGES_DAYS_DEV=""
#  BUILD_DOCKER_IMAGES_DAYS_STABLE="mon tue"
#  FORCE_BUILD_DAYS="sat"
#
need_build() {
    local build_date build_weekday build_reason
    build_date="$1"
    [[ -n "$build_date" ]] || build_date="${BUILD_TIMESTAMP:0:10}"
    [[ -n "$build_date" ]] || build_date=$(date '+%Y-%m-%d') || return 1
    build_weekday=$(get_weekday "$build_date") || exit 1
    local deploy_dir="${DEPLOY_DIR:-$MY_WORKSPACE/..}"

    require_env MY_WORKSPACE MY_REPO_ROOT_DIR FORCE_BUILD BUILD_DOCKER_IMAGES_DEV BUILD_DOCKER_IMAGES_STABLE
    rm -f "$MY_WORKSPACE/NO_BUILD_REQUIRED" "$MY_WORKSPACE/NEED_BUILD" || exit 1
    if $FORCE_BUILD ; then
        build_reason="forced"
    elif in_list "$build_weekday" $(normalize_weekdays $FORCE_BUILD_DAYS) ; then
        build_reason="forced:schedule"
    elif $BUILD_DOCKER_IMAGES_DEV ; then
        build_reason="dev_images_forced"
    elif $BUILD_DOCKER_IMAGES_STABLE ; then
        build_reason="stable_images_forced"
    elif ! diff_last_commits "$deploy_dir/LAST_COMMITS" "${NEED_BUILD_PATTERNS[@]}" ; then
        build_reason="changes_detected"
    elif in_list "$build_weekday" $(normalize_weekdays $BUILD_DOCKER_IMAGES_DAYS_DEV) && \
        ! diff_last_commits "$deploy_dir/LAST_COMMITS_IMG_DEV" "${NEED_BUILD_PATTERNS[@]}" ; then
        build_reason="dev_images_changes_detected"
    elif in_list "$build_weekday" $(normalize_weekdays $BUILD_DOCKER_IMAGES_DAYS_STABLE) && \
        ! diff_last_commits "$deploy_dir/LAST_COMMITS_IMG_STABLE" "${NEED_BUILD_PATTERNS[@]}" ; then
        build_reason="stable_images_changes_detected"
    else
        touch "$MY_WORKSPACE/NO_BUILD_REQUIRED" || exit 1
        echo "## No new content. Build not required."
        return 1
    fi
    echo "REASON=$build_reason" >"$MY_WORKSPACE/NEED_BUILD" || exit 1
    echo "## Build required ($build_reason)"
    return 0
}

#
# Return true if the build is being forced:
#   FORCE_BUILD is "true" -- OR
#   FORCE_BUILD_DAYS matches the build time stamp
#
is_build_forced() {
    [[ -f "$MY_WORKSPACE/NEED_BUILD" ]] || return 1
    grep -E -q "^\\s*REASON=['\"]?forced:?" "$MY_WORKSPACE/NEED_BUILD" >/dev/null
}