#!/usr/bin/env bash

# This bash script is a collection of functions to interact with the GitHub
# release and git/tag APIs. It essentially provides a bash based DSL for
# uploading GitHub release artefacts.

# NOTE-1: These functions make use of your ".netrc" file to authenticate
# with GitHub. In order to use these functions, make sure you have **both**
# "api.github.com" and "upload.github.com" in this file. For example:
#
#    machine api.github.com
#      login foca
#      password <an access token>
#    machine uploads.github.com
#      login foca
#      password <an access token>
#
# You can generate the required access token at
#    https://github.com/settings/tokens
# Make sure this access token has access to the "repo" scope.
#
# NOTE-2: These functions require the "jq" library to parse the JSON
# returned by the GitHub APIs.

#############################
function deleteReleaseByTag {

  [ -n "$1" ] || (echo "deleteReleaseByTag: missing repository"; exit 1);
  [ -n "$2" ] || (echo "deleteReleaseByTag: missing releaseTag"; exit 1);

  REPO=$1
  releaseTag=$2

  echo ""
  echo "deleting the release tagged $releaseTag"
  echo "  from the repository $REPO"
  echo ""

  echo "looking for an existing '$releaseTag' release in the repo $REPO"

  response=$(
    curl --fail \
         --netrc \
         --silent \
         --location \
         --request "GET" \
         "https://api.github.com/repos/${REPO}/releases"
  )

  releaseID=$(echo $response |				\
    jq --arg releaseTag $releaseTag			\
      '.[] | select(.tag_name == $releaseTag) | .id')

  echo ""
  echo "releaseID(s): $releaseID"
  echo ""

  if [ -n "$releaseID" ] ; then

    for aReleaseID in $releaseID 
    do
      echo "deleting an existing '$releaseTag'($aReleaseID) release in the repo $REPO"
      response=$(
        curl --fail \
             --netrc \
             --silent \
             --location \
             --request "DELETE" \
             "https://api.github.com/repos/${REPO}/releases/$aReleaseID"
      )
    done
    echo ""
  fi

  echo "looking for an existing '$releaseTag' git/tag in the repo $REPO"

  response=$(
    curl --fail \
         --netrc \
         --silent \
         --location \
         --request "GET" \
         "https://api.github.com/repos/${REPO}/git/matching-refs/tags/$releaseTag"
  )

  tagURL=$(echo $response | jq '.[].url')
  tagURL="${tagURL%\"}"
  tagURL="${tagURL#\"}"

  if [ -n "$tagURL" ]; then
    echo "deleting an existing '$releaseTag' git/tag in the repo $REPO"
    response=$(
      curl --fail \
           --netrc \
           --silent \
           --location \
           --request "DELETE" \
           $tagURL
    )
  fi
}

###########################
function createNewRelease {
# returns: upload_url (envVar)

  [ -n "$1" ] || (echo "createNewRelease: missing repository"; exit 1);
  [ -n "$2" ] || (echo "createNewRelease: missing releaseTag"; exit 1);
  [ -n "$3" ] || (echo "createNewRelease: missing release name"; exit 1);
  [ -n "$4" ] || (echo "createNewRelease: missing release description filename"; exit 1);

  REPO=$1
  TAG=$2
  NAME=$3
  BODY=$(cat $4)

  echo ""
  echo "Creating a new release in the repository $REPO"
  echo "  with tag $TAG"
  echo "  and name $NAME"
  echo "  using the message in the file $4"
  echo "--------------------------------------------------------------"
  echo $BODY
  echo "--------------------------------------------------------------"

  payload=$(
    jq --null-input \
       --arg tag "$TAG" \
       --arg name "$NAME" \
       --arg body "$BODY" \
       '{ tag_name: $tag, name: $name, body: $body, draft: false, prerelease: true }'
  )

  response=$(
    curl --fail \
         --netrc \
         --silent \
         --location \
         --data "$payload" \
         "https://api.github.com/repos/${REPO}/releases"
  )

  upload_url="$(echo "$response" |			\
    jq -r .upload_url | sed -e "s/{?name,label}//")"

  echo ""
  echo "upload_url:"
  echo $upload_url
}

########################
function uploadAnAsset {

  [ -n "$1" ] || (echo "uploadAnAsset: missing upload url"; exit 1);
  [ -n "$2" ] || (echo "uploadAnAsset: missing file name"; exit 1);
  [ -n "$3" ] || (echo "uploadAnAsset: missing file type"; exit 1);

  upload_url=$1
  file=$2
  fileType=$3

  echo ""
  echo "uploading the asset $file"
  echo "  of type $fileType"

  curl --netrc \
       --silent \
       --header "Content-Type:$fileType" \
       --data-binary "@$file" \
       "$upload_url?name=$(basename "$file")"
  echo ""
}

# The above has been heavily modified into a collection of bash functions
# by Stephen Gaito working on the pdf2htmlEX project.
#
# It has been based upon the code in:
#   https://gist.github.com/foca/38d82e93e32610f5241709f8d5720156
# on 2019-11-28
#
# The relevant GitHub API can be found at:
#   https://developer.github.com/v3/git/refs/
#   https://developer.github.com/v3/repos/releases/
#
# The original code has been used under the following (MIT-like) license:

# Copyright (c) 2016 Nicolas Sanguinetti <hi@nicolassanguinetti.info>
# 
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
# 
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
