#!/bin/sh
# Install Parallex: https://parallex.mandip.dev
#
#   curl -fsSL https://parallex.mandip.dev/install | sh
#
# Downloads the latest release from parallex.mandip.dev, checks it against
# the SHA-256 checksum published with it, and puts Parallex in /Applications
# (or ~/Applications when that isn't writable). A download made this way
# isn't marked as coming from the internet, so macOS opens it without the
# "Open Anyway" step. Read it first if you like: it's short.
#
# PARALLEX_INSTALL_DIR  install somewhere else
# PARALLEX_NO_OPEN=1    don't open Parallex afterwards
set -eu

say() { printf '%s\n' "$*"; }
fail() { printf 'Parallex: %s\n' "$*" >&2; exit 1; }

[ "$(uname -s)" = "Darwin" ] || fail "Parallex is a Mac app."
major=$(sw_vers -productVersion | cut -d. -f1)
[ "$major" -ge 14 ] || fail "Parallex needs macOS 14 or later."

dest="${PARALLEX_INSTALL_DIR:-/Applications}"
if [ -z "${PARALLEX_INSTALL_DIR:-}" ] && [ ! -w "$dest" ]; then
    dest="$HOME/Applications"
fi
mkdir -p "$dest"

# Never replace the Parallex that's running.
if pgrep -f "$dest/Parallex.app/Contents/MacOS/" >/dev/null 2>&1; then
    fail "Parallex is running. Update it from Parallex › Check for Updates, or quit it and run this again."
fi

say "Finding the latest Parallex…"
# parallex.mandip.dev counts Terminal installs (macOS version and chip
# only; see parallex.mandip.dev/privacy).
chip=$(uname -m)
release=$(curl -fsSL --connect-timeout 10 --max-time 30 --retry 2 -H "Accept: application/json" -H "X-Parallex-Installer: 1" \
        -H "X-Parallex-OS: $(sw_vers -productVersion | cut -d. -f1-2)" -H "X-Parallex-Arch: $chip" \
        "https://parallex.mandip.dev/api/v1/releases/latest") \
    || fail "couldn't reach parallex.mandip.dev. Check your connection and try again."
zip_url=$(printf '%s' "$release" | grep -o '"browser_download_url": *"[^"]*/Parallex-[0-9.]*\.zip"' | head -1 | sed 's/.*"\(https[^"]*\)"/\1/')
sum_url=$(printf '%s' "$release" | grep -o '"browser_download_url": *"[^"]*/Parallex-[0-9.]*\.zip\.sha256"' | head -1 | sed 's/.*"\(https[^"]*\)"/\1/')
[ -n "$zip_url" ] || fail "couldn't find the download in the latest release."
[ -n "$sum_url" ] || fail "the latest release has no checksum; download the DMG from parallex.mandip.dev instead."
version=$(printf '%s' "$zip_url" | sed 's/.*Parallex-\([0-9.]*\)\.zip/\1/')

work=$(mktemp -d)
trap 'rm -rf "$work"' EXIT

say "Downloading Parallex ${version}…"
curl -fsSL "$zip_url" -o "$work/Parallex.zip" || fail "the download failed."
expected=$(curl -fsSL "$sum_url" | awk '{print $1}') || fail "couldn't get the checksum."
actual=$(shasum -a 256 "$work/Parallex.zip" | awk '{print $1}')
[ -n "$expected" ] && [ "$expected" = "$actual" ] || fail "the download doesn't match its checksum; nothing was installed."

ditto -x -k "$work/Parallex.zip" "$work/unpacked" || fail "couldn't unpack the download."
[ -d "$work/unpacked/Parallex.app" ] || fail "the download doesn't contain Parallex.app."
codesign --verify --deep "$work/unpacked/Parallex.app" 2>/dev/null || fail "the app's signature doesn't check out; nothing was installed."

if [ -d "$dest/Parallex.app" ]; then
    rm -rf "$work/previous"
    mv "$dest/Parallex.app" "$work/previous" || fail "couldn't replace $dest/Parallex.app."
fi
mv "$work/unpacked/Parallex.app" "$dest/Parallex.app" || {
    [ -d "$work/previous" ] && mv "$work/previous" "$dest/Parallex.app"
    fail "couldn't install into $dest."
}

say "Installed Parallex $version in $dest."
if [ "${PARALLEX_NO_OPEN:-}" != "1" ]; then
    open "$dest/Parallex.app"
fi