#!/usr/bin/env bash
#
# diffweb installer — macOS and Linux.
#   curl -fsSL https://diffweb.pages.dev/install | bash
#   curl -fsSL https://diffweb.pages.dev/install | bash -s -- --uninstall
#
set -euo pipefail

# Release tarball from `npm run build:version`. Update this once it is hosted.
URL="${DIFFWEB_URL:-https://raw.githubusercontent.com/acharyarupak391/diffweb/main/bin/diffweb.tar.gz}"
DIR="${DIFFWEB_HOME:-$HOME/.local/share/diffweb}"
BIN="${DIFFWEB_BIN:-$HOME/.local/bin}"
MIN_NODE=16

green=$'\033[32m'; red=$'\033[31m'; yellow=$'\033[33m'; dim=$'\033[2m'; reset=$'\033[0m'
ok()   { printf '  %s✓%s %s\n' "$green" "$reset" "$*"; }
step() { printf '  %s→%s %s\n' "$dim" "$reset" "$*"; }
die()  { printf '\n  %serror%s %s\n\n' "$red" "$reset" "$*" >&2; exit 1; }

if [ "${1:-}" = "--uninstall" ]; then
  rm -f "$BIN/diffweb"
  rm -rf "$DIR"
  ok "diffweb removed"
  exit 0
fi

command -v node >/dev/null 2>&1 || die "Node.js $MIN_NODE+ is required. Install it from https://nodejs.org"
major="$(node -v | sed 's/^v//; s/\..*//')"
[ "$major" -ge "$MIN_NODE" ] 2>/dev/null || die "Node.js $MIN_NODE+ is required, found $(node -v)"

printf '\n  %sdiffweb%s installer\n\n' "$dim" "$reset"

step "downloading $URL"
mkdir -p "$DIR"
if command -v curl >/dev/null 2>&1; then
  curl -fsSL "$URL" | tar -xz -C "$DIR" --strip-components=1 || die "download failed"
elif command -v wget >/dev/null 2>&1; then
  wget -qO- "$URL" | tar -xz -C "$DIR" --strip-components=1 || die "download failed"
else
  die "neither curl nor wget is available"
fi
[ -f "$DIR/server.js" ] || die "the archive is missing server.js"

step "installing launcher"
mkdir -p "$BIN"
cat > "$BIN/diffweb" <<LAUNCH
#!/bin/sh
# diffweb launcher
exec node "$DIR/server.js" "\$@"
LAUNCH
chmod +x "$BIN/diffweb"

ok "diffweb $(node "$DIR/server.js" --version) installed to $DIR"
ok "launcher $BIN/diffweb"

case ":$PATH:" in
  *":$BIN:"*) ;;
  *) printf '\n  %s! %s is not on your PATH. Add it:%s\n    export PATH="%s:$PATH"\n' \
       "$yellow" "$BIN" "$reset" "$BIN" ;;
esac
printf '\n  Try it:\n    %sdiffweb old.txt new.txt%s\n\n' "$green" "$reset"