#!/bin/sh
set -e

. "$1"

if [ -z "$UPSTREAM_ARCHIVE" ]; then exit; fi

# TODO: Inaccurate.
escape_regex() {
  echo "$1" | sed -E 's,[\\+*?.{}<>],\\\0,g'
}

TAR_REGEX="(\.tar(\.(gz|bz2|xz)))"

if [ -z "$RELEASE_SEARCH_PAGE" ]; then
  case "$UPSTREAM_SITE" in
  https://github.com/*/releases/*)
    RELEASE_SEARCH_PAGE=$(echo "$UPSTREAM_SITE" | grep -Eo '.*/releases/');;
  *) RELEASE_SEARCH_PAGE="$UPSTREAM_SITE/";;
  esac
fi

if [ -z "$VERSION_REGEX" ]; then
  VERSION_REGEX="([0-9]+\.[0-9]+(\.[0-9]+)*)"
fi

if [ -z "$RELEASE_REGEX" ]; then
  RELEASE_REGEX=$(echo "$UPSTREAM_ARCHIVE" |
                  sed -E 's,\+,\\+,g' |
                  sed -E "s,$VERSION_REGEX(\.tar.*),$(escape_regex "$VERSION_REGEX"),")
fi

if [ -z "$UPSTREAM_SITE_TEMPLATE" ]; then
  UPSTREAM_SITE_TEMPLATE="$UPSTREAM_SITE"
fi

if [ -z "$UPSTREAM_ARCHIVE_TEMPLATE" ]; then
  UPSTREAM_ARCHIVE_TEMPLATE=$(echo "$UPSTREAM_ARCHIVE" |
                  sed -E 's,([0-9]+\.[0-9]+(\.[0-9]+)*)(\.tar.*),%v%e,')
fi

if [ -z "$RELEASE_SEARCH_REGEX" ]; then
  RELEASE_SEARCH_REGEX="\<$RELEASE_REGEX$TAR_REGEX\>"
fi

case "$UPSTREAM_ARCHIVE" in
*.tar) EXTENSION=.tar;;
*.tar.gz) EXTENSION=.tar.gz;;
*.tar.bz2) EXTENSION=.tar.bz2;;
*.tar.xz) EXTENSION=.tar.xz;;
esac

instantiate() {
  echo "$1" |
  sed -E \
   -e "s,%v,$2,g" \
   -e "s,%M,$(echo "$2" | sed -E 's,([0-9]+)\.([0-9]+)(\.([0-9]+))?.*,\1,'),g" \
   -e "s,%m,$(echo "$2" | sed -E 's,([0-9]+)\.([0-9]+)(\.([0-9]+))?.*,\2,'),g" \
   -e "s,%p,$(echo "$2" | sed -E 's,([0-9]+)\.([0-9]+)(\.([0-9]+))?.*,\4,'),g" \
   -e "s,%e,$EXTENSION,g"
}

# git tag search

LATEST=$(curl -Ls "$RELEASE_SEARCH_PAGE" | grep -Eo "$RELEASE_SEARCH_REGEX" | sort -Vu | tail -1)
case "$LATEST" in
*.tar) EXTENSION=.tar;;
*.tar.gz) EXTENSION=.tar.gz;;
*.tar.bz2) EXTENSION=.tar.bz2;;
*.tar.xz) EXTENSION=.tar.xz;;
esac
NEW_VERSION="$(echo "$LATEST" | sed -E "s,$RELEASE_SEARCH_REGEX,\1,")"

if [ -z "$NEW_VERSION" ]; then
  echo "\e[91m$UPSTREAM_ARCHIVE failed to find available versions: $RELEASE_SEARCH_PAGE | grep -E '$RELEASE_SEARCH_REGEX'\e[m"
  exit 1
fi

NEW_UPSTREAM_SITE=$(instantiate "$UPSTREAM_SITE_TEMPLATE" "$NEW_VERSION")
NEW_UPSTREAM_ARCHIVE=$(instantiate "$UPSTREAM_ARCHIVE_TEMPLATE" "$NEW_VERSION")

if ! wget -q "$NEW_UPSTREAM_SITE/$NEW_UPSTREAM_ARCHIVE" -O /dev/null; then
  echo "\e[91m$NAME failed to download: $NEW_UPSTREAM_SITE/$NEW_UPSTREAM_ARCHIVE\e[m"
  exit 1
fi

if [ "$VERSION" != "$NEW_VERSION" ]; then
  echo "\e[1;92m$NAME $VERSION -> $NEW_VERSION $NEW_UPSTREAM_SITE/$NEW_UPSTREAM_ARCHIVE\e[m"
else
  # Confirmed to actually be up to date.
  case "$NAME" in
  flex|gcc|grub|texinfo|libiconv|libtheora|libSDL|libz|nyancat|pkg-config)
    echo "\e[92m$NAME $VERSION is up to date\e[m"
    ;;
  *)
    echo "$NAME $VERSION is up to date"
    ;;
  esac
fi