#!/bin/bash
#
#  Copyright (c) 2020, The OpenThread Authors.
#  All rights reserved.
#
#  Redistribution and use in source and binary forms, with or without
#  modification, are permitted provided that the following conditions are met:
#  1. Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer.
#  2. Redistributions in binary form must reproduce the above copyright
#     notice, this list of conditions and the following disclaimer in the
#     documentation and/or other materials provided with the distribution.
#  3. Neither the name of the copyright holder nor the
#     names of its contributors may be used to endorse or promote products
#     derived from this software without specific prior written permission.
#
#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
#  POSSIBILITY OF SUCH DAMAGE.
#
#    Description:
#      A tool to download projects with the ability to apply dependent PRs.
#

set -euxo pipefail

apply_dependencies()
{
    local project_name

    project_name=$(git remote get-url origin | grep -oE '[^/:]+/[^/:]+\.git$' | cut -d. -f1)
    echo "project name: ${project_name}"

    git config user.name || git config user.name 'OpenThread Git'
    git config user.email || git config user.email 'git@openthread'

    while read -r dependency; do
        echo "${dependency}"
        depends_on_pr="$(echo "${dependency}" | tr -d '\r\n' | cut -d# -f2)"
        echo "pr: #${depends_on_pr}"
        git pull --no-edit origin "pull/${depends_on_pr}/merge"
    done < <(grep -E "^Depends-On: *${project_name}" || true)
}

get_pr_body()
{
    local pr

    [[ ${GITHUB_ACTIONS+x} && ${GITHUB_REF-} =~ ^refs/pull/[0-9]+/merge ]] || {
        echo 'Not a pull request.' >&2
        return 0
    }

    pr="$(echo "${GITHUB_REF}" | cut -d/ -f3)"

    # do not print GITHUB_TOKEN
    set +x
    curl -H "authorization: Bearer ${GITHUB_TOKEN}" -H 'content-type: application/json' \
        "https://api.github.com/repos/${GITHUB_REPOSITORY}/pulls/${pr}" \
        | jq -r .body
    set -x
}

try_update()
{
    cd "$1"

    get_pr_body | apply_dependencies
}

try_clone()
{
    local dest_dir

    dest_dir="$(git clone "$@" 2>&1 | tee | cut -d\' -f2)"

    cd "${dest_dir}"
    get_pr_body | apply_dependencies
}

print_help()
{
    echo "EXAMPLES:
    $0 http://github.com/openthread/ot-br-posix.git
    $0 http://github.com/openthread/ot-ns.git --depth 1 /tmp/ot-ns"
}

main()
{
    if [[ $# == 0 ]]; then
        print_help
        return 0
    fi

    case $1 in
        update)
            shift
            try_update "$@"
            ;;
        clone)
            shift
            try_clone "$@"
            ;;
        *)
            print_help
            return 1
            ;;
    esac
}

main "$@"