#!/bin/bash

#=================================================
# PACKAGE UPDATING HELPER
#=================================================

# This script is meant to be run by GitHub Actions
# The YunoHost-Apps organisation offers a template Action to run this script periodically
# Since each app is different, maintainers can adapt its contents so as to perform
# automatic actions when a new upstream release is detected.

#=================================================
# FETCHING LATEST RELEASE AND ITS ASSETS
#=================================================

# Fetching information
current_version=$(cat manifest.json | jq -j '.version|split("~")[0]')
repo=$(cat manifest.json | jq -j '.upstream.code|split("https://github.com/")[1]')
# Some jq magic is needed, because the latest upstream release is not always the latest version (e.g. security patches for older versions)
version=$(curl --silent "https://api.github.com/repos/$repo/releases" | jq -r '.[] | select( .prerelease != true ) | .tag_name' | sort -V | tail -1)

# Later down the script, we assume the version has only digits and dots
# Sometimes the release name starts with a "v", so let's filter it out.
# You may need more tweaks here if the upstream repository has different naming conventions.
if [[ ${version:0:1} == "v" || ${version:0:1} == "V" ]]; then
    version=${version:1}
fi

asset="https://buildbot.libretro.com/stable/$version/emscripten/RetroArch.7z"

# Setting up the environment variables
echo "Current version: $current_version"
echo "Latest release from upstream: $version"
echo "VERSION=$version" >> $GITHUB_ENV
echo "REPO=$repo" >> $GITHUB_ENV
# For the time being, let's assume the script will fail
echo "PROCEED=false" >> $GITHUB_ENV

same_version=false
# Proceed only if the retrieved version is greater or equal than the current one
if dpkg --compare-versions "$current_version" "gt" "$version" ; then
    echo "::warning ::Well, somehow the current version here is higher than the latest released."
    exit 0
elif dpkg --compare-versions "$current_version" "eq" "$version" ; then
    echo "::notice ::No new version available, let's check if the built file has changed though..."
    same_version=true
# Proceed only if a PR for this new version does not already exist
elif git ls-remote -q --exit-code --heads https://github.com/$GITHUB_REPOSITORY.git ci-auto-update-v$version ; then
    echo "::warning ::New version available, but a branch already exists for this update."
    exit 0
fi

#=================================================
# UPDATE SOURCE FILES
#=================================================

# Let's download the asset and calculate its checksum

# If no new version has been released, we still need to download the file again because
# RetroArch's staff tend to silently update their build without releasing a new version...
# Seriously, that's unsafe and not cool. 🔔

# Create the temporary directory
tempdir="$(mktemp -d)"

# Download sources and calculate checksum
filename=${asset##*/}
curl --silent -4 -L $asset -o "$tempdir/$filename"
checksum=$(sha256sum "$tempdir/$filename" | head -c 64)

# Delete temporary directory
rm -rf $tempdir

source conf/app.src
if [ "$checksum" == "466e1f86e2deebfc25c0bfd56f555881a80db37a22d75a3fec350ae7949f44b9" ]; then
    echo "::error ::Uh oh, something went wrong with the downloaded file."
    exit 1
elif [ "$checksum" == "$SOURCE_SUM" ]; then
    echo "::notice ::No new version available, and the built file has not changed."
    exit 0
elif [ "$same_version" == "true" ]; then
    echo "::notice ::No new version available, but the built file has been silently changed upstream. 🔔"
fi

# Rewrite source file
cat <<EOT > conf/app.src
SOURCE_URL=$asset
SOURCE_SUM=$checksum
SOURCE_SUM_PRG=sha256sum
SOURCE_FORMAT=7z
SOURCE_FILENAME=retroarch.7z
SOURCE_EXTRACT=false
EOT
echo "... conf/app.src updated"

#=================================================
# SPECIFIC UPDATE STEPS
#=================================================

# Any action on the app's source code can be done.
# The GitHub Action workflow takes care of committing all changes after this script ends.

#=================================================
# GENERIC FINALIZATION
#=================================================

# Replace new version in manifest
echo "$(jq -s --indent 4 ".[] | .version = \"$version~ynh1\"" manifest.json)" > manifest.json

# No need to update the README, yunohost-bot takes care of it

# The Action will proceed only if the PROCEED environment variable is set to true
echo "PROCEED=true" >> $GITHUB_ENV
exit 0