#!/bin/sh
# Install the pixy client on Linux or macOS.
#
#   curl -fsSL https://get.demotwo.site/install.sh | sh
#
# Environment:
#   PIXY_BASE_URL  download base (default: https://get.demotwo.site)
#   PIXY_INSTALL   install directory (default: /usr/local/bin, or ~/.local/bin
#                  when that is not writable)
set -eu

BASE_URL="${PIXY_BASE_URL:-https://get.demotwo.site}"

die()  { printf '\033[31merror\033[0m: %s\n' "$1" >&2; exit 1; }
info() { printf '  %s\n' "$1"; }

if command -v curl >/dev/null 2>&1; then
	fetch() { curl -fsSL "$1" -o "$2"; }
elif command -v wget >/dev/null 2>&1; then
	fetch() { wget -qO "$2" "$1"; }
else
	die "either curl or wget is required"
fi

os=$(uname -s | tr '[:upper:]' '[:lower:]')
case "$os" in
	linux|darwin) ;;
	*) die "unsupported OS: $os (on Windows use install.ps1)" ;;
esac

arch=$(uname -m)
case "$arch" in
	x86_64|amd64) arch=amd64 ;;
	aarch64|arm64) arch=arm64 ;;
	*) die "unsupported architecture: $arch" ;;
esac

# Prefer a system-wide install, but fall back to the user's own bin directory
# rather than demanding sudo.
dest="${PIXY_INSTALL:-}"
if [ -z "$dest" ]; then
	if [ -w /usr/local/bin ] 2>/dev/null; then
		dest=/usr/local/bin
	else
		dest="$HOME/.local/bin"
	fi
fi
mkdir -p "$dest" || die "cannot create $dest"
[ -w "$dest" ] || die "$dest is not writable (set PIXY_INSTALL, or re-run with sudo)"

tmp=$(mktemp -d)
trap 'rm -rf "$tmp"' EXIT INT TERM

asset="pixy-${os}-${arch}"
info "downloading $asset"
fetch "$BASE_URL/$asset" "$tmp/pixy" || die "download failed: $BASE_URL/$asset"

# Verify against the published checksum list whenever it is reachable.
if fetch "$BASE_URL/checksums.txt" "$tmp/checksums.txt" 2>/dev/null; then
	if command -v sha256sum >/dev/null 2>&1; then
		got=$(sha256sum "$tmp/pixy" | cut -d' ' -f1)
	elif command -v shasum >/dev/null 2>&1; then
		got=$(shasum -a 256 "$tmp/pixy" | cut -d' ' -f1)
	else
		got=""
	fi
	if [ -n "$got" ]; then
		want=$(grep " $asset\$" "$tmp/checksums.txt" | cut -d' ' -f1)
		[ -n "$want" ] || die "no checksum published for $asset"
		[ "$got" = "$want" ] || die "checksum mismatch for $asset"
		info "checksum verified"
	fi
else
	info "could not fetch checksums.txt; skipping verification"
fi

chmod 0755 "$tmp/pixy"
# Replacing a running binary fails on some systems; move rather than copy so an
# in-use file is unlinked instead of written through.
mv -f "$tmp/pixy" "$dest/pixy" || die "could not write $dest/pixy (is pixy running?)"
info "installed $dest/pixy"

printf '\n\033[32m✓\033[0m pixy installed\n\n'
case ":$PATH:" in
	*":$dest:"*) ;;
	*) printf '  Add it to your PATH:\n    export PATH="%s:$PATH"\n\n' "$dest" ;;
esac
printf '  Next:\n    pixy login --token <your-token>\n    pixy\n\n'