#!/usr/bin/env bash

set -e

# This is not portable. It has bashisms.

# Like this (bash >= 4.x)
declare -A os_sfx=(
	["linux"]='bin'
	["windows"]='exe'
	["darwin"]='app'
)

BUILD_TIME="$(date '+%s')"
BUILD_USER="$(whoami)"
BUILD_SUDO_USER="${SUDO_USER}"
BUILD_HOST="$(hostname)"

# Check to make sure git is available.
if ! command -v git &> /dev/null; then
	echo "Git is not available; automatic version handling unsupported."
	echo "You must build by calling 'go build' directly in the respective directories."
	exit 0
fi

# Check git directory/repository.
if ! git rev-parse --is-inside-work-tree &> /dev/null; then
	echo "Not running inside a git work tree; automatic version handling unsupported/build script unsupported."
	echo "You must build by calling 'go build' directly in the respective directories instead."
	exit 0
fi

# If it has a tag in the path of the current HEAD that matches a version string...
# I wish git describe supported regex. It does not; only globs. Gross.
# If there's a bug anywhere, it's here.
if git describe --tags --abbrev=0 --match "v[0-9]*" HEAD &> /dev/null; then
	# It has a tag we can use.
	CURRENT_VER="$(git describe --tags --abbrev=0 --match "v[0-9]*" HEAD)"
	COMMITS_SINCE="$(git rev-list --count ${CURRENT_VER}..HEAD)"
else
	# No tag available.
	CURRENT_VER=""
	COMMITS_SINCE=""
fi

# If it's dirty (staged but not committed or unstaged files)...
if ! git diff-index --quiet HEAD; then
	# It's dirty.
	IS_DIRTY="1"
else
	# It's clean.
	IS_DIRTY="0"
fi

# Get the commit hash of the *most recent* commit in the path of current HEAD...
CURRENT_HASH="$(git rev-parse --verify HEAD)"
# The same as above, but abbreviated.
CURRENT_SHORT="$(git rev-parse --verify --short HEAD)"

# Get the module name.
MODPATH="$(sed -n -re 's@^\s*module\s+(.*)(//.*)?$@\1@p' go.mod)"

# Build the ldflags string.
# BEHOLD! BASH WITCHCRAFT.
LDFLAGS_STR="\
-X '${MODPATH}/version.version=${CURRENT_VER}' \
-X '${MODPATH}/version.commitHash=${CURRENT_HASH}' \
-X '${MODPATH}/version.commitShort=${CURRENT_SHORT}' \
-X '${MODPATH}/version.numCommitsAfterTag=${COMMITS_SINCE}' \
-X '${MODPATH}/version.isDirty=${IS_DIRTY}' \
-X '${MODPATH}/version.buildTime=${BUILD_TIME}' \
-X '${MODPATH}/version.buildUser=${BUILD_USER}' \
-X '${MODPATH}/version.buildSudoUser=${BUILD_SUDO_USER}' \
-X '${MODPATH}/version.buildHost=${BUILD_HOST}'"

set -u

# And finally build.
mkdir -p ./bin/
export CGO_ENABLED=0
_origdir="$(pwd)"
_pfx=''
#for cmd in 'discord' 'irc' 'msteams' 'slack' 'xmpp'; do
for cmd_dir in cmd/*; do
	cmd="$(basename "${cmd_dir}")"
	echo "${cmd}..."
	if [ ! -f "${cmd_dir}/main.go" ]; then
		continue
	fi
	cd "${cmd_dir}"
	_bin="${_pfx}${cmd}"
	for ga in 'amd64' 'arm64'; do
			as="${ga}"
			if [[ "${ga}" == 'amd64' ]]; then
				as='x86_64'
			fi
			echo -e "\t${as}..."
			for osnm in "${!os_sfx[@]}"; do
				echo -e "\t\t${osnm}: "
        		_sfx="${os_sfx[$osnm]}"
        		bin="${_origdir}/bin/${_bin}-${as}-${CURRENT_VER:-dev}.${_sfx}"
        		export GOOS="${osnm}"
        		export GOARCH="${ga}"
        		echo -e -n "\t\tBuilding '${bin}'..."
        		go build \
        			-o "${bin}" \
        			-ldflags \
        				"${LDFLAGS_STR}"
#        				"${LDFLAGS_STR}" \
#        			*.go
				echo " Done."
        	done
        	echo -e "\tDone."
	done
	echo "Done."
done

echo -e "\nBuild complete."