#!/usr/bin/env bash
# SPDX-License-Identifier: Apache-2.0
# Copyright (C) 2021 Arm Limited or its affiliates and Contributors. All rights reserved.

[[ "$TRACE" ]] && set -x
set -euo pipefail

print_help() {
    echo 'Usage: manyclangs-build-month MM YYYY'
    echo ''
    echo 'manyclangs-build-month is a "set it and forget it" script that builds'
    echo 'the specified month and produces a .pack file.'
}

list_month() {
    MONTH="$1"
    YEAR="$2"

    ((NEXT_YEAR=YEAR))
    ((NEXT_MONTH=10#$MONTH+1))
    if [ $NEXT_MONTH -eq 13 ]; then
        ((NEXT_YEAR=NEXT_YEAR+1))
        ((NEXT_MONTH=1))
    fi

    git-list-between origin/main \
        "$MONTH/01/$YEAR" "$NEXT_MONTH/01/$NEXT_YEAR" -- llvm clang
}

build_month() {
    BUILD_DIR="$1"
    MONTH="$2"
    YEAR="$3"
    list_month "$MONTH" "$YEAR" | awk '{print $1}' \
        | manyclangs-build-commits "$BUILD_DIR" llvm clang
}

store_month() {
    BUILD_DIR="$1"
    MONTH="$2"
    YEAR="$3"

    # Include all .o and .h in ./build
    FIND_COMMAND=(find ./build -type f -name "'*.o'" -or -name "'*.h'"
        # Also include all LICENSE files, .log files the README and link.sh
        # available at the root of ./build.
        '&&' find ./build -maxdepth 1 -type f
            -name link.sh
            -or -name README
            -or -name "'LICENSE*'"
            -or -name "'*.log'")

    list_month "$MONTH" "$YEAR" | awk -v root="$(realpath "$BUILD_DIR")/" '{print root$1" "$2}' \
        | (cd "$BUILD_DIR/elfshaker" && elfshaker-store-all "${FIND_COMMAND[*]}")
}

pack_month() {
    BUILD_DIR="$1"
    MONTH="$2"
    YEAR="$3"

    cd "$BUILD_DIR/elfshaker"
    elfshaker pack "$YEAR$MONTH" --verbose
}

main() {
    MONTH="$1"
    YEAR="$2"
    date -d "$MONTH/01/$YEAR" 1>/dev/null || (print_help && exit 1)

    BUILD_DIR="builds-$YEAR$MONTH"
    if [ -d "$BUILD_DIR" ]; then
        echo "$BUILD_DIR already exists! Aborting..."
        exit 1
    fi

    mkdir -p "$BUILD_DIR/elfshaker/elfshaker_data/packs"
    echo "Builds will be done in $BUILD_DIR."

    build_month "$BUILD_DIR" "$MONTH" "$YEAR"
    store_month "$BUILD_DIR" "$MONTH" "$YEAR"
    pack_month "$BUILD_DIR" "$MONTH" "$YEAR"

    echo "Pack is available at $BUILD_DIR/elfshaker/elfshaker_data/packs/$YEAR$MONTH.pack"
}

case "${1:--h}" in
    -h | --help)
        print_help
        [ $# -ne 0 ]
        exit $?
        ;;
    *)
        main "$@"
        ;;
esac