#!/bin/sh
# grit installer - downloads a pre-built binary from GitHub Releases
# Usage: curl -fsSL https://grit-scm.com/install | sh

main() {
  set -eu

  REPO="gitbutlerapp/grit"
  INSTALL_DIR="${INSTALL_DIR:-$HOME/.local/bin}"

  for cmd in command uname tr curl tar mkdir; do
    if ! command -v "$cmd" >/dev/null 2>&1; then
      echo "error: required command '$cmd' not found" >&2
      exit 1
    fi
  done

  OS=$(uname -s | tr '[:upper:]' '[:lower:]')
  ARCH=$(uname -m)

  case "$OS" in
    darwin)  OS_TARGET="apple-darwin" ;;
    linux)   OS_TARGET="unknown-linux-gnu" ;;
    mingw*|msys*|cygwin*)
      echo "On Windows, download from: https://github.com/$REPO/releases/latest" >&2
      exit 1
      ;;
    *)
      echo "error: unsupported OS: $OS" >&2
      exit 1
      ;;
  esac

  case "$ARCH" in
    x86_64|amd64)  ARCH_TARGET="x86_64" ;;
    arm64|aarch64) ARCH_TARGET="aarch64" ;;
    *)
      echo "error: unsupported architecture: $ARCH" >&2
      exit 1
      ;;
  esac

  TARGET="${ARCH_TARGET}-${OS_TARGET}"
  URL="https://github.com/$REPO/releases/latest/download/grit-${TARGET}.tar.gz"

  echo "Detected: $OS/$ARCH -> $TARGET"
  echo "Downloading from: $URL"

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

  curl -fSL "$URL" -o "$TMP/grit.tar.gz"
  tar xzf "$TMP/grit.tar.gz" -C "$TMP"

  mkdir -p "$INSTALL_DIR"
  mv "$TMP/grit" "$INSTALL_DIR/grit"
  chmod +x "$INSTALL_DIR/grit"

  echo "Installed grit to $INSTALL_DIR/grit"

  if ! command -v grit >/dev/null 2>&1; then
    echo ""
    echo "Note: $INSTALL_DIR is not on your PATH."
    echo "Add it with:  export PATH=\"$INSTALL_DIR:\$PATH\""
  else
    echo "$(grit --version)"
  fi
}

main "$@"