#!/usr/bin/env bash
set -e

## Check parameters & set defaults.

if [[ -z "$ARCH_AND_OS" ]]; then
	echo "ARCH_AND_OS is required"
	exit 1
fi

if [[ -z "$SCCACHE_AZURE_CONNECTION_STRING" ]]; then
	echo "SCCACHE_AZURE_CONNECTION_STRING is required"
	exit 1
fi

SCCACHE_LOG=${SCCACHE_LOG:-info} # set to 'debug' or 'trace' for more verbose logging
SUDO=${SUDO:-false}


## Ensure Github Actions print stdout and stderr data in correct order.
exec 2>&1


## Download and install sccache.
if [[ ! -e /usr/local/bin/sccache ]]; then
	echo "::group::Download sccache"
	wget --output-document sccache.tar.gz "https://github.com/mozilla/sccache/releases/download/v0.8.2/sccache-v0.8.2-$ARCH_AND_OS.tar.gz"
	echo "::endgroup::"
	set -x
	tar xzf sccache.tar.gz
	rm sccache.tar.gz
	sudo mv sccache*/sccache /usr/local/bin/sccache
	rm -rf sccache*
fi


## Set up sccache as a compiler wrapper.
set -x
echo "PATH=/usr/local/libexec/sccache:/usr/local/bin:$PATH" >> "$GITHUB_ENV"
sudo mkdir -p /usr/local/libexec/sccache
for PROG in cc c++; do
	FULLPATH=$(command -v "$PROG")
	echo '#!/bin/sh' > "$PROG"
	echo "exec /usr/local/bin/sccache $FULLPATH \"\$@\"" >> "$PROG"
	chmod +x "$PROG"
	sudo mv "$PROG" /usr/local/libexec/sccache/
done


## Update environment variables.

HAS_SCCACHE_IN_PATH=$(ruby -e 'puts ENV["PATH"].split(":").include?("/usr/local/bin")')
if ! $HAS_SCCACHE_IN_PATH; then
	echo "PATH=/usr/local/bin:$PATH" >> "$GITHUB_ENV"
fi

HAS_COMPILER_WRAPPERS_IN_PATH=$(ruby -e 'puts ENV["PATH"].split(":").include?("/usr/local/libexec/sccache")')
if $HAS_COMPILER_WRAPPERS_IN_PATH; then
	# When starting the sccache server, the compiler wrappers must *not* be in PATH
	# so that the sccache server uses the non-wrapped compilers.
	PATH=$(ruby -e 'paths = ENV["PATH"].split(":"); paths.delete("/usr/local/libexec/sccache"); puts paths.join(":")')
	export PATH
else
	echo "PATH=/usr/local/libexec/sccache:$PATH" >> "$GITHUB_ENV"
fi


## Start sccache server.

rm -f sccache.log
export RUST_LOG_STYLE=always
export SCCACHE_LOG
export SCCACHE_IDLE_TIMEOUT=0
export SCCACHE_ERROR_LOG="$(pwd)/sccache.log"
echo "SCCACHE_ERROR_LOG=$SCCACHE_ERROR_LOG" >> "$GITHUB_ENV"

if $SUDO; then
	sudo -E env SCCACHE_START_SERVER=1 sccache
else
	env SCCACHE_START_SERVER=1 sccache
fi

set +x
echo "Waiting until sccache server is started..."
while [[ ! -e sccache.log ]]; do
	sleep 0.1
done
sleep 0.5
echo "sccache server is started."