#!/bin/sh
# Compute CLI installer — https://compute.cx/install.sh
# Usage: curl -fsSL https://compute.cx/install.sh | sh
#
# Installs the `compute` CLI from a prebuilt wheel (PyPI comes in v0.2).
# Requires Python ≥3.10 on macOS or Linux.
#
# Optional integrity:
#   COMPUTE_WHEEL_SHA256=<hex>   require exact digest of the downloaded wheel
#   COMPUTE_MANIFEST_URL=<url>   JSON with {"version","sha256","wheel_url"}

set -eu

COMPUTE_VERSION="${COMPUTE_VERSION:-0.1.5}"
COMPUTE_BASE_URL="${COMPUTE_BASE_URL:-https://compute.cx}"
WHEEL_URL="${COMPUTE_WHEEL_URL:-${COMPUTE_BASE_URL}/releases/compute-${COMPUTE_VERSION}-py3-none-any.whl}"
MANIFEST_URL="${COMPUTE_MANIFEST_URL:-${COMPUTE_BASE_URL}/releases/compute-${COMPUTE_VERSION}.json}"
PREFIX="${COMPUTE_PREFIX:-${HOME}/.local}"
BIN_DIR="${PREFIX}/bin"
VENV_DIR="${PREFIX}/share/compute/venv"

# Prefer mktemp so the staging dir is unpredictable (not TMPDIR/compute-install-$$).
if command -v mktemp >/dev/null 2>&1; then
  TMP_DIR="$(mktemp -d "${TMPDIR:-/tmp}/compute-install.XXXXXX")"
else
  TMP_DIR="${TMPDIR:-/tmp}/compute-install-$$"
  mkdir -m 700 -p "${TMP_DIR}"
fi

cleanup() {
  rm -rf "${TMP_DIR}"
}
trap cleanup EXIT INT HUP

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

need_cmd() {
  command -v "$1" >/dev/null 2>&1 || err "missing required command: $1"
}

python_ok() {
  "$1" - <<'PY' 2>/dev/null
import sys
raise SystemExit(0 if sys.version_info >= (3, 10) else 1)
PY
}

resolve_python() {
  for candidate in python3.14 python3.13 python3.12 python3.11 python3.10 python3; do
    if command -v "${candidate}" >/dev/null 2>&1 && python_ok "${candidate}"; then
      command -v "${candidate}"
      return 0
    fi
  done
  return 1
}

sha256_file() {
  if command -v sha256sum >/dev/null 2>&1; then
    sha256sum "$1" | awk '{print $1}'
  elif command -v shasum >/dev/null 2>&1; then
    shasum -a 256 "$1" | awk '{print $1}'
  else
    err "need sha256sum or shasum to verify the wheel digest"
  fi
}

need_cmd curl
need_cmd mkdir
need_cmd chmod

PYTHON="$(resolve_python)" || err "Python ≥3.10 is required (macOS or Linux)"

EXPECTED_SHA256="${COMPUTE_WHEEL_SHA256:-}"
# Best-effort: load digest from release manifest when present.
if [ -z "${EXPECTED_SHA256}" ]; then
  MANIFEST_PATH="${TMP_DIR}/manifest.json"
  if curl -fsSL "${MANIFEST_URL}" -o "${MANIFEST_PATH}" 2>/dev/null; then
    EXPECTED_SHA256="$(
      "${PYTHON}" - "${MANIFEST_PATH}" <<'PY'
import json, sys
doc = json.load(open(sys.argv[1], encoding="utf-8"))
print(doc.get("sha256") or "")
PY
    )" || EXPECTED_SHA256=""
    MANIFEST_WHEEL="$("${PYTHON}" - "${MANIFEST_PATH}" <<'PY'
import json, sys
doc = json.load(open(sys.argv[1], encoding="utf-8"))
print(doc.get("wheel_url") or "")
PY
    )" || MANIFEST_WHEEL=""
    if [ -n "${MANIFEST_WHEEL}" ]; then
      WHEEL_URL="${MANIFEST_WHEEL}"
    fi
  fi
fi

say "Installing Compute CLI ${COMPUTE_VERSION}"
say "  python: ${PYTHON}"
say "  wheel:  ${WHEEL_URL}"
say "  bin:    ${BIN_DIR}/compute"

mkdir -p "${BIN_DIR}" "$(dirname "${VENV_DIR}")"

if [ ! -x "${VENV_DIR}/bin/python" ]; then
  "${PYTHON}" -m venv "${VENV_DIR}"
fi

# Ensure pip exists; do not upgrade pip globally — use ensurepip only.
"${VENV_DIR}/bin/python" -m ensurepip --upgrade >/dev/null 2>&1 || true

WHEEL_PATH="${TMP_DIR}/compute-${COMPUTE_VERSION}-py3-none-any.whl"
curl -fsSL "${WHEEL_URL}" -o "${WHEEL_PATH}"

if [ -n "${EXPECTED_SHA256}" ]; then
  ACTUAL_SHA256="$(sha256_file "${WHEEL_PATH}")"
  if [ "${ACTUAL_SHA256}" != "${EXPECTED_SHA256}" ]; then
    err "wheel sha256 mismatch (expected ${EXPECTED_SHA256}, got ${ACTUAL_SHA256})"
  fi
  say "  sha256: ${ACTUAL_SHA256} (verified)"
else
  say "  sha256: (unchecked — set COMPUTE_WHEEL_SHA256 or publish a release manifest)"
fi

"${VENV_DIR}/bin/python" -m pip install --upgrade --no-cache-dir "${WHEEL_PATH}"

ln -sfn "${VENV_DIR}/bin/compute" "${BIN_DIR}/compute"
chmod 755 "${BIN_DIR}/compute"

case ":${PATH}:" in
  *":${BIN_DIR}:"*) ;;
  *)
    say ""
    say "Add ${BIN_DIR} to your PATH, for example:"
    say "  export PATH=\"${BIN_DIR}:\$PATH\""
    ;;
esac

say ""
"${BIN_DIR}/compute" --version
say "Next:"
say "  compute setup"
say "  compute credits add 10"
say "  compute run path/to/file.py::fn --gpu H100"