#!/bin/sh
# Install the Indent CLI.
#
# Usage:
#   curl -sf https://install.indent.com | sh
#   curl -sf https://install.indent.com | INDENT_VERSION=1.2.3 sh
#
# Environment:
#   INDENT_VERSION   Pin a specific version (defaults to the latest published).
#   INDENT_INSTALL   Install prefix (defaults to /usr/local/bin, falls back to $HOME/.local/bin).
#   INDENT_HOST      Override the install host (defaults to https://install.indent.com).

set -eu

HOST="${INDENT_HOST:-https://install.indent.com}"
BIN_NAME="indent"

say() { printf '\033[1;34m==>\033[0m %s\n' "$*"; }
die() { printf '\033[1;31merror:\033[0m %s\n' "$*" >&2; exit 1; }

detect_target() {
  os=$(uname -s | tr '[:upper:]' '[:lower:]')
  arch=$(uname -m)
  case "$arch" in
    x86_64|amd64) arch=x64 ;;
    aarch64|arm64) arch=arm64 ;;
    *) die "Unsupported architecture: $arch" ;;
  esac
  case "$os" in
    linux) echo "indent-linux-${arch}" ;;
    darwin)
      if [ "$arch" != "arm64" ]; then
        die "Unsupported macOS architecture: $arch. Only arm64 (Apple Silicon) is supported."
      fi
      echo "indent-darwin-arm64"
      ;;
    *) die "Unsupported OS: $os (use the Windows installer instead)" ;;
  esac
}

choose_prefix() {
  if [ -n "${INDENT_INSTALL:-}" ]; then
    echo "$INDENT_INSTALL"
    return
  fi
  if [ -w /usr/local/bin ] 2>/dev/null; then
    echo /usr/local/bin
  else
    mkdir -p "$HOME/.local/bin"
    echo "$HOME/.local/bin"
  fi
}

main() {
  target=$(detect_target)

  if [ -n "${INDENT_VERSION:-}" ]; then
    version="$INDENT_VERSION"
  else
    say "Resolving latest version from ${HOST}..."
    version=$(curl -sf "${HOST}/latest" | tr -d '[:space:]')
    [ -n "$version" ] || die "Unable to determine latest version from ${HOST}/latest"
  fi

  url="${HOST}/bin/${target}"
  say "Downloading ${url}"

  tmp=$(mktemp -d)
  trap 'rm -rf "$tmp"' EXIT
  curl -sfL "$url" -o "$tmp/$BIN_NAME"
  curl -sfL "${url}.sha256" -o "$tmp/${BIN_NAME}.sha256" \
    || die "Failed to download checksum (${url}.sha256); refusing to install without integrity verification."

  say "Verifying checksum"
  expected=$(awk '{print $1}' "$tmp/${BIN_NAME}.sha256")
  [ -n "$expected" ] || die "Checksum file is empty"
  if command -v sha256sum >/dev/null 2>&1; then
    actual=$(sha256sum "$tmp/$BIN_NAME" | awk '{print $1}')
  elif command -v shasum >/dev/null 2>&1; then
    actual=$(shasum -a 256 "$tmp/$BIN_NAME" | awk '{print $1}')
  else
    die "Neither sha256sum nor shasum is available; cannot verify checksum"
  fi
  [ "$expected" = "$actual" ] || die "Checksum mismatch: expected $expected, got $actual"

  chmod +x "$tmp/$BIN_NAME"
  prefix=$(choose_prefix)
  dest="$prefix/$BIN_NAME"
  mv "$tmp/$BIN_NAME" "$dest"

  say "Installed ${BIN_NAME} ${version} to ${dest}"
  case ":$PATH:" in
    *":$prefix:"*) ;;
    *)
      say "Note: ${prefix} is not on your PATH; add it to your shell profile."
      ;;
  esac
}

main "$@"