#!/data/data/com.termux/files/usr/bin/bash
# Install or upgrade Hermit on Android Termux. Safe to rerun: an existing
# checkout is fast-forwarded, rebuilt and reinstalled.
#
#   bootstrap_termux.sh [DIR] [--no-pull]
#   hermit-update               (installed by this script; same as rerunning it)
set -euo pipefail

main() {
  local repo_url="${HERMIT_REPO:-${CST_AGENT_REPO:-https://git.whcself.xyz/WHC/Hermit.git}}"
  local dir="" pull=1 changed=0 arg
  for arg in "$@"; do
    case "$arg" in
    --no-pull) pull=0 ;;
    --rebuilt) changed=1 ;; # internal: re-exec after a pull
    -h | --help)
      sed -n '2,6p' "$0"
      return 0
      ;;
    *) dir="$arg" ;;
    esac
  done
  if [[ -z "$dir" ]]; then
    if [[ -n "${HERMIT_DIR:-${CST_AGENT_DIR:-}}" ]]; then
      dir="${HERMIT_DIR:-$CST_AGENT_DIR}"
    elif [[ -f Makefile && -f src/main.c && -d .git ]]; then
      dir="$(pwd)"
    elif [[ -d "$HOME/Hermit/.git" ]]; then
      dir="$HOME/Hermit"
    else
      dir="$HOME/CST-agent"
    fi
  fi

  echo "==> Termux packages"
  local need=() p
  for p in git clang make pkg-config binutils libcurl ncurses; do
    dpkg -s "$p" >/dev/null 2>&1 || need+=("$p")
  done
  if ((${#need[@]})); then
    pkg install -y "${need[@]}"
  else
    echo "    all present"
  fi

  local old="" new=""
  if [[ ! -f "$dir/Makefile" ]]; then
    echo "==> git clone $repo_url -> $dir"
    git clone "$repo_url" "$dir"
    changed=1
  elif ((pull)); then
    old="$(git -C "$dir" rev-parse HEAD)"
    if git -C "$dir" diff --quiet && git -C "$dir" diff --cached --quiet; then
      echo "==> git pull ($dir)"
      git -C "$dir" pull --ff-only
    else
      echo "warning: $dir has local changes; skipping git pull" >&2
    fi
    new="$(git -C "$dir" rev-parse HEAD)"
    if [[ "$old" != "$new" ]]; then
      echo "    $(git -C "$dir" log --oneline "$old..$new" | wc -l) new commit(s)"
      # The script itself may have changed: continue with the new version.
      exec bash "$dir/scripts/bootstrap_termux.sh" "$dir" --no-pull --rebuilt
    fi
  fi
  cd "$dir"
  dir="$(pwd)"

  echo "==> build"
  local jobs
  jobs="$(nproc 2>/dev/null || echo 4)"
  if ((changed)); then
    make clean >/dev/null 2>&1 || true
  fi
  make -j"$jobs"
  make check >/dev/null 2>&1 || echo "warning: some tests failed (run 'make check')"

  echo "==> install to $PREFIX/bin"
  make install
  cat >"$PREFIX/bin/hermit-update" <<EOF
#!$PREFIX/bin/bash
exec bash "$dir/scripts/bootstrap_termux.sh" "$dir" "\$@"
EOF
  chmod 0755 "$PREFIX/bin/hermit-update"
  ln -sfr "$PREFIX/bin/hermit-update" "$PREFIX/bin/cst-agent-update" 2>/dev/null || \
    ln -sf hermit-update "$PREFIX/bin/cst-agent-update"

  echo
  echo "OK: $("$PREFIX/bin/hermit" --version 2>/dev/null || "$PREFIX/bin/cst-agent" --version)"
  echo "Run 'hermit' inside a project directory; upgrade later with 'hermit-update'."
  echo "The first start asks for the provider and its API key and saves them."
}

main "$@"