#!/bin/bash

# Ported from deno:
# Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
# https://github.com/denoland/deno/blob/master/LICENSE

set -e

deno_install="${DENO_INSTALL:-$HOME/.deno}"
bin_dir="$deno_install/bin"

download_deno() {
	local target_version=$1

	if [ "$(uname -m)" != "x86_64" ]; then
		echo "Error: Unsupported architecture $(uname -m). Only x64 binaries are available." 1>&2
		exit 1
	fi

	if ! command -v unzip >/dev/null; then
		echo "Error: unzip is required to install Deno (see: https://github.com/denoland/deno_install#unzip-is-required)." 1>&2
		exit 1
	fi

	if [ "$OS" = "Windows_NT" ]; then
		local target="x86_64-pc-windows-msvc"
	else
		case $(uname -s) in
		Darwin) local target="x86_64-apple-darwin" ;;
		*) local target="x86_64-unknown-linux-gnu" ;;
		esac
	fi

	if [ -z "$target_version" ]; then
		local deno_asset_path=$(
			curl -sSf https://github.com/denoland/deno/releases |
				grep -o "/denoland/deno/releases/download/.*/deno-${target}\\.zip" |
				head -n 1
		)
		if [ ! "$deno_asset_path" ]; then
			echo "Error: Unable to find latest Deno release on GitHub." 1>&2
			exit 1
		fi
		echo "deno is not found, devo will download it first"
		local deno_uri="https://github.com${deno_asset_path}"
	else
		echo "deno $target_version is not found, devo will download it first"
		local deno_uri="https://github.com/denoland/deno/releases/download/${version}/deno-${target}.zip"
	fi

	local devo_dir="$bin_dir/.devo"
	local deno_zip_path="$devo_dir/$deno_fname.zip"

	if [ ! -d "$bin_dir" ]; then
		mkdir -p "$bin_dir"
	fi

	mkdir -p "$devo_dir"
	curl --fail --location --progress-bar --output "$deno_zip_path" "$deno_uri"
	cd "$devo_dir"
	unzip -o "$deno_zip_path" -d "$deno_fname" > /dev/null
	chmod +x "$deno_fname/deno"
	mv "$deno_fname/deno" "../$deno_fname"
	rm -r "$deno_fname" "$deno_fname.zip"

	echo "Deno was installed successfully to $bin_dir/$deno_fname"
	if command -v deno >/dev/null; then
		echo "Run 'deno --help' to get started"
	else
		case $SHELL in
		/bin/zsh) shell_profile=".zshrc" ;;
		*) shell_profile=".bash_profile" ;;
		esac
		echo "Manually add the directory to your \$HOME/$shell_profile (or similar)"
		echo "  export DENO_INSTALL=\"$deno_install\""
		echo "  export PATH=\"\$DENO_INSTALL/bin:\$PATH\""
		echo "Run '$bin_dir/$deno_fname --help' to get started"
	fi
}

if [ -e ".devo" ]; then
	version="$(cat .devo)"
fi

reg="^v[0-9]+\.[0-9]+\.[0-9]+$"
if [[ $1 =~ $reg ]]; then
	version="$1"
fi

if [ "$1" = "global" ]; then
	if [ -z $2 ]; then
		echo "Specify the version"
		exit 1
	fi
	version="$2"
fi

if [ -z "$version" ]; then
	deno_fname="deno"
else
	deno_fname="deno_$version"
fi

exec="$bin_dir/$deno_fname"

if [ ! -e "$exec" ]; then
	download_deno "$version"
fi

if [[ $1 =~ $reg ]]; then
	"$exec" ${@:2}
elif [ "$1" = "global" ]; then
	cp "$exec" "$bin_dir/deno"
	echo "Global version change successful"
else
	"$exec" "$@"
fi