#!/usr/bin/env bash
# Checks prerequisites (Go, Python 3, and its packages), then launches the
# interactive server-panel TUI (tui-panel/server-panel.py). Run this instead
# of the TUI directly so missing prerequisites get a clear message instead of
# a Python traceback.
set -uo pipefail
cd "$(dirname "$0")"

ok()   { echo "[ok] $*"; }
warn() { echo "[WARN] $*"; }
die()  { echo "[ERROR] $*" >&2; exit 1; }

echo "== Checking prerequisites =="

PROBLEMS=0

# --- Go -----------------------------------------------------------------
if command -v go >/dev/null 2>&1; then
  ok "Go found: $(go version)"
else
  warn "Go is not installed (needed to build owpengram-server / owpengram-admin-panel)"
  echo "       Install it from: https://go.dev/dl/"
  PROBLEMS=1
fi

# --- Python ---------------------------------------------------------------
# Just checking `command -v` isn't enough: on Windows, `python3` (and
# sometimes `python`) can resolve to the Microsoft Store app-execution-alias
# stub, which exists on PATH but fails as soon as it's actually run instead
# of launching real Python. Validate the version output too.
PYTHON=""
PYTHON_VERSION=""
# A local .venv/ (created per this script's own advice below, to install
# tui-panel/requirements-panel.txt without touching a Debian/Ubuntu
# system Python) takes priority over PATH -- once it exists, every later run
# should keep using it instead of silently falling back to an older/
# unrelated system interpreter.
if [[ -x ".venv/bin/python" ]]; then
  if VER_OUT="$(.venv/bin/python --version 2>&1)" && [[ "$VER_OUT" == Python\ 3* ]]; then
    PYTHON=".venv/bin/python"
    PYTHON_VERSION="$VER_OUT"
  fi
fi
if [[ -z "$PYTHON" ]]; then
  for cand in python3 python; do
    if command -v "$cand" >/dev/null 2>&1; then
      if VER_OUT="$("$cand" --version 2>&1)" && [[ "$VER_OUT" == Python\ 3* ]]; then
        PYTHON="$cand"
        PYTHON_VERSION="$VER_OUT"
        break
      fi
    fi
  done
fi

if [[ -z "$PYTHON" ]]; then
  warn "Python 3 is not installed (needed to run the server-panel TUI)"
  echo "       Install it from: https://www.python.org/downloads/"
  PROBLEMS=1
else
  ok "Python found: ${PYTHON_VERSION} (${PYTHON})"
fi

# --- Python dependencies ----------------------------------------------------
if [[ -n "$PYTHON" ]]; then
  MISSING="$("$PYTHON" tui-panel/check_deps.py)"
  if [[ -n "$MISSING" ]]; then
    warn "Missing or outdated Python packages: $(echo "$MISSING" | tr '\n' ' ')"
    echo "       Install them with: $PYTHON -m pip install -U -r tui-panel/requirements-panel.txt"
    echo "       On Debian/Ubuntu this usually fails with 'externally-managed-environment'"
    echo "       against the system Python -- use a venv instead, then just re-run this script"
    echo "       (it prefers .venv/ automatically once one exists):"
    echo "         python3 -m venv .venv && .venv/bin/pip install -r tui-panel/requirements-panel.txt"
    PROBLEMS=1
  else
    ok "Python dependencies OK (textual, psutil, cryptography)"
  fi
fi

if [[ "$PROBLEMS" -ne 0 ]]; then
  echo
  die "missing prerequisites above -- install them and re-run this script"
fi

echo
echo "[cfg] All prerequisites OK, launching server panel..."
echo
exec "$PYTHON" tui-panel/server-panel.py "$@"