#!/usr/bin/env bash

#
# Check if we need to copy node_modules (e.g. in case it has been modified after last copy)
#
# The reasoning for a (mostly) read-only node_modules folder:
#   ideally we’d symlink the folder directly to the Nix store
#   so that we’re guaranteed to have a reproducible source.
#   Unfortunately react-native wants to build some stuff after the fact
#   and this is incompatible with the concept of a pure Nix package.
#   Therefore we copy the whole source to the repo directory,
#   allow writing only on the folders where it is absolutely required,
#   and therefore we still keep some peace of mind that the rest
#   of node_modules is unchanged the rest of the time.
#

set -Eeuo pipefail

deps="$1"
[ -d $deps ] || exit 1

nodeModulesDir="$STATUS_REACT_HOME/node_modules"

needCopyModules=1

# Check if node_modules exists and is valid
if [ -d "$nodeModulesDir" ]; then
  if [ -f "$nodeModulesDir/.copied~" ]; then
    echo "Checking for modifications in node_modules..."
    modifiedFiles=( $(find $nodeModulesDir -writable -type f -newer $nodeModulesDir/.copied~ \
      -not \( -path "$nodeModulesDir/react-native/third-party/*" -prune \
           -o -path "$nodeModulesDir/react-native/ReactAndroid/build/*" -prune \
           -o -path "$nodeModulesDir/*/android/build/*" -prune \
           -o -path "$nodeModulesDir/realm/src/*" -prune \
           -o -path './resources/icons/*' -prune \) -print) )
    if [ ${#modifiedFiles[@]} -eq 0 ]; then
      needCopyModules=0
      echo "No modifications detected."
    else
      echo "Modifications detected in ${#modifiedFiles[@]} files:\n${modifiedFiles[@]}"
    fi
  fi
  if [ $needCopyModules -eq 1 ]; then
    chmod u+w -R $nodeModulesDir
    rm -rf $nodeModulesDir
  fi
fi

# Replace node_modules if necessary
if [ ! -d "$nodeModulesDir" ]; then
  if [ -n "${IN_CI_ENVIRONMENT:-''}" ]; then
    # CI jobs might run multiple tasks in parallel, so it is possible that another process is setting up node_modules. In that case, let's wait up to 10 seconds for the .tmp dir goes away
    for i in {1..10}; do
      if [ -d "$nodeModulesDir.tmp" ]; then
        echo "$nodeModulesDir.tmp exists, another process is probably setting up node_modules, waiting for 1 second..."
        sleep 1
      else
        break
      fi
    done
  fi
  if [ -d "$nodeModulesDir.tmp" ]; then
    echo "$nodeModulesDir.tmp already exists, another shell session is probably currently setting up node_modules. Please try again in a few moments."
    ls -al $STATUS_REACT_HOME 
    exit 1
  elif [ ! -d "$nodeModulesDir" ]; then
    echo "Copying node_modules from Nix store (${deps}/node_modules)..."
    trap "[ -d \"$nodeModulesDir.tmp\" ] && chmod -R u+w \"$nodeModulesDir.tmp\" && rm -rf \"$nodeModulesDir.tmp\"" ERR INT HUP
    time cp -HRf --preserve=all ${deps}/node_modules/. "$nodeModulesDir.tmp"
    chmod -R u+w "$nodeModulesDir.tmp"
    mv -f "$nodeModulesDir.tmp" $nodeModulesDir
    touch $nodeModulesDir/.copied~
    trap - ERR INT HUP
    echo "Done"
  fi
fi