#!/bin/bash
#
# Writes `.generated/module.modulemap` for the `jsi` Clang module.
#
# The umbrella header is referenced by absolute path so the modulemap works
# regardless of where Pods lives. The `Pods/Headers/Public` path exists in
# non-frameworks and prebuilt-RN layouts; under static frameworks +
# source-built RN it doesn't, so we fall back to the canonical RN source.
# Stored outside `.build/` so SwiftPM state can be wiped without losing this
# file.
#
# Idempotent: re-running with the same inputs rewrites identical content.
# Switching PODS_ROOT updates the umbrella header path.
#
# Used by build-xcframework.sh and test.sh; can also be run manually before
# opening the package in Xcode.
#
# Usage:
#   PODS_ROOT=/path/to/Pods scripts/generate-modulemap.sh

set -eo pipefail

PACKAGE_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"

if [[ -z "${PODS_ROOT:-}" ]]; then
  echo "error: PODS_ROOT is not set" >&2
  exit 1
fi
if [[ ! -d "$PODS_ROOT" ]]; then
  echo "error: PODS_ROOT does not exist: $PODS_ROOT" >&2
  exit 1
fi
PODS_ROOT="$(cd "$PODS_ROOT" && pwd)"

GENERATED_DIR="${PACKAGE_DIR}/.generated"
GENERATED_MODULE_MAP="${GENERATED_DIR}/module.modulemap"
mkdir -p "$GENERATED_DIR"

JSI_UMBRELLA="${PODS_ROOT}/Headers/Public/React-jsi/jsi/jsi.h"
if [[ ! -f "$JSI_UMBRELLA" ]]; then
  # Resolution order matches build-xcframework.sh: RN_ROOT (forwarded by the
  # build script), REACT_NATIVE_PATH (exported by Xcode for hosts like Expo Go
  # that build RN from a submodule), node resolve, then a relative fallback.
  RN="${RN_ROOT:-${REACT_NATIVE_PATH:-$(node -p 'require("path").dirname(require.resolve("react-native/package.json"))' 2>/dev/null || echo "${PODS_ROOT}/../../node_modules/react-native")}}"
  JSI_UMBRELLA="${RN}/ReactCommon/jsi/jsi/jsi.h"
fi
[[ -f "$JSI_UMBRELLA" ]] || { echo "error: cannot locate jsi.h" >&2; exit 1; }

# Avoid touching the file when contents would be identical, so the xcframework
# hash cache and Xcode don't see a spurious change when inputs are unchanged.
NEW_CONTENT="module jsi {
  umbrella header \"${JSI_UMBRELLA}\"

  export *
  module * { export * }
}"
if [[ ! -f "$GENERATED_MODULE_MAP" ]] || [[ "$(cat "$GENERATED_MODULE_MAP")" != "$NEW_CONTENT" ]]; then
  printf '%s\n' "$NEW_CONTENT" > "$GENERATED_MODULE_MAP"
fi