#!/bin/bash

set -e

# Function to set default values for environment variables
set_defaults() {
  export CONFIG_DIR="${CONFIG_DIR:-/opt/config}"
  export CONFIG="$CONFIG_DIR/config.json"
  export NODEBB_INIT_VERB="${NODEBB_INIT_VERB:-install}"
  export NODEBB_BUILD_VERB="${NODEBB_BUILD_VERB:-build}"
  export START_BUILD="${START_BUILD:-${FORCE_BUILD_BEFORE_START:-false}}"
  export SETUP="${SETUP:-}"
  export PACKAGE_MANAGER="${PACKAGE_MANAGER:-npm}"
  export OVERRIDE_UPDATE_LOCK="${OVERRIDE_UPDATE_LOCK:-false}"
}

# Function to check if a directory exists and is writable
check_directory() {
  local dir="$1"
  if [ ! -d "$dir" ]; then
    echo "Error: Directory $dir does not exist. Creating..."
    mkdir -p "$dir" || {
      echo "Error: Failed to create directory $dir"
      exit 1
    }
  fi
  if [ ! -w "$dir" ]; then
    echo "Warning: No write permission for directory $dir, attempting to fix..."
    chown -R $USER:$USER "$dir" || true # attempt to change ownership, do not exit on failure
    chmod -R 760 "$dir" || true # attempt to change permissions, do not exit on failure
    if [ ! -w "$dir" ]; then
      echo "Error: No write permission for directory $dir. Exiting..."
      exit 1
    fi
  fi
}

# Function to copy or link package.json and lock files based on package manager
copy_or_link_files() {
  local src_dir="$1"
  local dest_dir="$2"
  local package_manager="$3"
  local lock_file

  case "$package_manager" in
    yarn) lock_file="yarn.lock" ;;
    npm) lock_file="package-lock.json" ;;
    pnpm) lock_file="pnpm-lock.yaml" ;;
    *)
      echo "Unknown package manager: $package_manager"
      exit 1
      ;;
  esac

  # Check if source and destination files are the same
  if [ "$(realpath "$src_dir/package.json")" != "$(realpath "$dest_dir/package.json")" ] || [ "$OVERRIDE_UPDATE_LOCK" = true ]; then
    cp "$src_dir/package.json" "$dest_dir/package.json"
  fi

  if [ "$(realpath "$src_dir/$lock_file")" != "$(realpath "$dest_dir/$lock_file")" ] || [ "$OVERRIDE_UPDATE_LOCK" = true ]; then
    cp "$src_dir/$lock_file" "$dest_dir/$lock_file"
  fi

  # Remove unnecessary lock files in src_dir
  rm -f "$src_dir/"{yarn.lock,package-lock.json,pnpm-lock.yaml}

  # Symbolically link the copied files in src_dir to dest_dir
  ln -fs "$dest_dir/package.json" "$src_dir/package.json"
  ln -fs "$dest_dir/$lock_file" "$src_dir/$lock_file"
}

# Function to install dependencies using pnpm
install_dependencies() {
  case "$PACKAGE_MANAGER" in
    yarn) yarn install || {
      echo "Failed to install dependencies with yarn"
      exit 1
    } ;;
    npm) npm install || {
      echo "Failed to install dependencies with npm"
      exit 1
    } ;;
    pnpm) pnpm install || {
      echo "Failed to install dependencies with pnpm"
      exit 1
    } ;;
    *)
      echo "Unknown package manager: $PACKAGE_MANAGER"
      exit 1
      ;;
  esac
}

# Function to start setup session
start_setup_session() {
  local config="$1"
  echo "Starting setup session"
  exec /usr/src/app/nodebb setup --config="$config"
}

# Handle building and upgrading NodeBB
build_forum() {
  local config="$1"
  local start_build="$2"
  local package_hash=$(md5sum install/package.json | head -c 32)
  if [ "$package_hash" != "$(cat $CONFIG_DIR/install_hash.md5 || true)" ]; then
      echo "package.json was updated. Upgrading..."
      /usr/src/app/nodebb upgrade --config="$config" || {
          echo "Failed to build NodeBB. Exiting..."
          exit 1
        }
  elif [ "$start_build" = true ]; then
    echo "Build before start is enabled. Building..."
    /usr/src/app/nodebb "${NODEBB_BUILD_VERB}" --config="$config" || {
        echo "Failed to build NodeBB. Exiting..."
        exit 1
      }
  else
    echo "No changes in package.json. Skipping build..."
    return
  fi
  echo -n $package_hash > $CONFIG_DIR/install_hash.md5
}


# Function to start forum
start_forum() {
  local config="$1"
  local start_build="$2"

  build_forum "$config" "$start_build"

  case "$PACKAGE_MANAGER" in
    yarn)
      yarn start --config="$config" --no-silent --no-daemon || {
        echo "Failed to start forum with yarn"
        exit 1
      }
      ;;
    npm)
      npm start -- --config="$config" --no-silent --no-daemon || {
        echo "Failed to start forum with npm"
        exit 1
      }
      ;;
    pnpm)
      pnpm start -- --config="$config" --no-silent --no-daemon || {
        echo "Failed to start forum with pnpm"
        exit 1
      }
      ;;
    *)
      echo "Unknown package manager: $PACKAGE_MANAGER"
      exit 1
      ;;
  esac
}

# Function to start installation session
start_installation_session() {
  local nodebb_init_verb="$1"
  local config="$2"

  echo "Config file not found at $config"
  echo "Starting installation session"
  exec /usr/src/app/nodebb "$nodebb_init_verb" --config="$config"
}

# Function for debugging and logging
debug_log() {
  local message="$1"
  echo "DEBUG: $message"
}

# Main function
main() {
  set_defaults
  check_directory "$CONFIG_DIR"
  copy_or_link_files /usr/src/app "$CONFIG_DIR" "$PACKAGE_MANAGER"
  install_dependencies

  debug_log "PACKAGE_MANAGER: $PACKAGE_MANAGER"
  debug_log "CONFIG location: $CONFIG"
  debug_log "START_BUILD: $START_BUILD"

  if [ -n "$SETUP" ]; then
    start_setup_session "$CONFIG"
  fi

  if [ -f "$CONFIG" ]; then
    start_forum "$CONFIG" "$START_BUILD"
  else
    start_installation_session "$NODEBB_INIT_VERB" "$CONFIG"
  fi
}

# Execute main function
main "$@"