Release templates (#4226)

* add creation of release templates to ci and update guide

* touchups to markdown

* correct create release property

* correctly set fetch-depth and release body

* fix replacements, remove arrows

* check if there are no betas

* add extra output

* typo

.ci/prep_release.sh

@@ -0,0 +1,103 @@
+#!/bin/bash
+# sets the properties of ci releases
+# this doesn't have to be 100% foolproof
+# the releases are first made as drafts and will be vetted by a human
+# it just has to provide a template
+# this requires the repo to be unshallowed
+template_path=".ci/release_template.md"
+body_path="/tmp/release.md"
+beta_regex='beta'
+name_regex='set\(GIT_TAG_RELEASENAME "([[:print:]]+)")'
+whitespace='^\s*$'
+
+if [[ $1 ]]; then
+  TAG="$1"
+fi
+
+# check env
+if [[ ! $TAG ]]; then
+  echo "::error file=$0::TAG is missing"
+  exit 2
+fi
+
+# create title
+if [[ $TAG =~ $beta_regex ]]; then
+  echo "::set-output name=is_beta::yes"
+  title="$TAG"
+  echo "creating beta release '$title'"
+elif [[ ! $(cat CMakeLists.txt) =~ $name_regex ]]; then
+  echo "::error file=$0::could not find releasename in CMakeLists.txt"
+  exit 1
+else
+  echo "::set-output name=is_beta::no"
+  name="${BASH_REMATCH[1]}"
+  version="${TAG##*-}"
+  title="Cockatrice $version: $name"
+  no_beta=1
+  echo "::set-output name=friendly_name::$name"
+  echo "creating full release '$title'"
+fi
+echo "::set-output name=title::$title"
+
+# add release notes template
+if [[ $no_beta ]]; then
+  body="$(cat "$template_path")"
+  if [[ ! $body ]]; then
+    echo "::warning file=$0::could not find release template"
+  fi
+  body="${body//--REPLACE-WITH-RELEASE-TITLE--/$title}"
+else
+  body="Included commits over previous version:
+--REPLACE-WITH-GENERATED-LIST--"
+fi
+
+# add git log to release notes
+all_tags="
+$(git tag)" # tags are ordered alphabetically
+before="${all_tags%%
+$TAG*}" # strip line with current tag an all lines after it
+# note the extra newlines are needed to always have a last line
+if [[ $all_tags == $before ]]; then
+  echo "::warning file=$0::could not find current tag"
+else
+  while
+    previous="${before##*
+}" # get the last line
+    # skip this tag if this is a full release and it's a beta or if empty
+    [[ $no_beta && $previous =~ $beta_regex || ! $previous ]]
+  do
+    beta_list+=" $previous" # add to list of skipped betas
+    next_before="${before%
+*}" # strip the last line
+    if [[ $next_before == $before ]]; then
+      unset previous
+      break
+    fi
+    before="$next_before"
+  done
+  if [[ $previous ]]; then
+    if generated_list="$(git log "$previous..$TAG" --pretty="- %s")"; then
+      count="$(git rev-list --count "$previous..$TAG")"
+      echo "adding list of commits to release notes:"
+      echo "'$previous' to '$TAG' ($count commits)"
+      # --> is the markdown comment escape sequence, emojis are way better
+      generated_list="${generated_list//-->/→}"
+      body="${body//--REPLACE-WITH-GENERATED-LIST--/$generated_list}"
+      if [[ $beta_list =~ $whitespace ]]; then
+        beta_list="-n there are no betas to delete!"
+      else
+        echo "the following betas should be deleted after publishing:"
+        echo "$beta_list"
+      fi
+      body="${body//--REPLACE-WITH-BETA-LIST--/$beta_list}"
+    else
+      echo "::warning file=$0::failed to produce git log"
+    fi
+  else
+    echo "::warning file=$0::could not find previous tag"
+  fi
+fi
+
+# write to file
+echo "::set-output name=body_path::$body_path"
+echo "$body" >"$body_path"