#!/usr/bin/env bash
#
# OpenEng AI Engine - one-line installer (Linux & macOS; Windows via WSL / Git Bash).
#
# Downloads a prebuilt `openeng` engine binary from openeng.ai and installs it.
# The engine runs open-weight models on your machine and dials out to reach the
# web app (app.openeng.ai) - it opens no inbound port and is not a server. One
# engine per machine. No source code, no Rust toolchain, no build step - just the binary.
#
#   curl -fsSL https://openeng.ai/engine/install.sh | bash
#
# Tunables (environment):
#   OPENENG_ENGINE_URL  base URL for binaries    (default: https://openeng.ai/engine/bin)
#   OPENENG_BIN_DIR     install directory        (default: ~/.local/bin)
#   OPENENG_NO_MODELS=1 skip the default model pull (serve downloads what a config needs)
#
# NOTE: keep this script pure ASCII (macOS bash 3.2 + set -u, see the cli installer).
#
set -eu

if [ -t 1 ]; then
  esc=$(printf '\033')
  BLUE="${esc}[36m"; GRN="${esc}[32m"; RED="${esc}[31m"; DIM="${esc}[2m"; NC="${esc}[0m"
else
  BLUE=''; GRN=''; RED=''; DIM=''; NC=''
fi
say()  { printf "${BLUE}==>${NC} %s\n" "$1"; }
ok()   { printf "${GRN}ok:${NC} %s\n" "$1"; }
warn() { printf "${RED}!${NC} %s\n" "$1" >&2; }
die()  { printf "${RED}error: %s${NC}\n" "$1" >&2; exit 1; }
have() { command -v "$1" >/dev/null 2>&1; }

OPENENG_ENGINE_URL="${OPENENG_ENGINE_URL:-https://openeng.ai/engine/bin}"
OPENENG_BIN_DIR="${OPENENG_BIN_DIR:-$HOME/.local/bin}"

printf "${BLUE}+--- OpenEng AI Engine installer --------------+${NC}\n"

# -- detect platform ---------------------------------------------------------
os="$(uname -s 2>/dev/null || echo unknown)"
arch="$(uname -m 2>/dev/null || echo unknown)"
case "$os" in
  Linux)  OS=linux ;;
  Darwin) OS=darwin ;;
  MINGW*|MSYS*|CYGWIN*)
    die "Windows shell detected. Use PowerShell: irm https://openeng.ai/engine/install.ps1 | iex" ;;
  *) die "unsupported OS '${os}'." ;;
esac
case "$arch" in
  x86_64|amd64)  ARCH=x86_64 ;;
  arm64|aarch64) ARCH=aarch64 ;;
  *) die "unsupported architecture '${arch}'." ;;
esac
ASSET="openeng-${OS}-${ARCH}"
URL="${OPENENG_ENGINE_URL}/${ASSET}"

# -- prerequisites -----------------------------------------------------------
have curl || die "curl is required."

# -- download ----------------------------------------------------------------
say "Downloading openeng (${OS}/${ARCH}) ..."
TMP="$(mktemp 2>/dev/null || echo "${TMPDIR:-/tmp}/openeng.$$")"
curl -fSL --proto '=https' --tlsv1.2 "$URL" -o "$TMP" \
  || die "could not download ${URL} -- no engine binary published for ${OS}/${ARCH} yet."

# A static host may answer a missing file with its SPA/HTML page (HTTP 200). Real
# binaries never start with '<', so reject an HTML page up front.
if [ "$(head -c 1 "$TMP" 2>/dev/null)" = "<" ]; then
  rm -f "$TMP"
  die "no engine binary published for ${OS}/${ARCH} yet (the URL returned a web page)."
fi

# -- verify checksum (enforced only if a real .sha256 is published) ----------
if curl -fsSL "${URL}.sha256" -o "${TMP}.sha256" 2>/dev/null; then
  WANT="$(cut -d' ' -f1 < "${TMP}.sha256" 2>/dev/null || echo)"
  rm -f "${TMP}.sha256"
  if printf '%s' "$WANT" | grep -Eq '^[0-9a-fA-F]{64}$'; then
    if   have sha256sum; then GOT="$(sha256sum "$TMP" | cut -d' ' -f1)"
    elif have shasum;    then GOT="$(shasum -a 256 "$TMP" | cut -d' ' -f1)"
    else GOT=""; fi
    if [ -n "$GOT" ] && [ "$GOT" != "$WANT" ]; then
      rm -f "$TMP"; die "checksum mismatch for ${ASSET} (got ${GOT}, want ${WANT})."
    fi
    [ -n "$GOT" ] && ok "checksum verified"
  fi
fi

chmod 0755 "$TMP"
if [ "$OS" = "darwin" ]; then xattr -d com.apple.quarantine "$TMP" >/dev/null 2>&1 || true; fi
# Sanity: the engine binary runs (it prints usage on --help).
"$TMP" --help >/dev/null 2>&1 || { rm -f "$TMP"; die "the downloaded engine did not run (wrong platform or corrupt download)."; }

# -- install on PATH ---------------------------------------------------------
mkdir -p "$OPENENG_BIN_DIR"
mv -f "$TMP" "$OPENENG_BIN_DIR/openeng"
chmod 0755 "$OPENENG_BIN_DIR/openeng"
ok "installed ${OPENENG_BIN_DIR}/openeng"

case ":$PATH:" in
  *":$OPENENG_BIN_DIR:"*) ;;
  *)
    LINE="export PATH=\"$OPENENG_BIN_DIR:\$PATH\""
    for rc in "$HOME/.bashrc" "$HOME/.zshrc" "$HOME/.profile"; do
      if [ -f "$rc" ] && ! grep -qF "$OPENENG_BIN_DIR" "$rc" 2>/dev/null; then
        printf '\n# OpenEng Engine\n%s\n' "$LINE" >> "$rc"
      fi
    done
    warn "Added ${OPENENG_BIN_DIR} to your shell rc - run \`${LINE}\` or open a new terminal." ;;
esac

mkdir -p "$HOME/.openeng"
ok "agent root at ${HOME}/.openeng"

# -- Default on-device model (GGUF) ------------------------------------------
# The engine downloads whatever a config references on `serve --config`, but pulling
# the default chat weight now means `openeng serve` answers a turn out of the box.
if [ "${OPENENG_NO_MODELS:-0}" = "1" ]; then
  say "skipping model pull (OPENENG_NO_MODELS=1) - serve downloads what a config needs"
else
  say "Pulling the default chat model (a few GB; can take a while)..."
  "$OPENENG_BIN_DIR/openeng" pull chat || warn "model pull did not finish - run 'openeng pull chat' later"
fi

printf "\n"
ok "Done. Start the engine:  ${BLUE}openeng serve${NC}   ${DIM}(then open https://app.openeng.ai — it connects automatically)${NC}"