//: Phase 2: Filter loaded recipes through an extensible list of 'transforms'.
//:
//:   The process of running Mu code:
//:     load -> transform -> run
//:
//: The hope is that this framework of transform tools will provide a
//: deconstructed alternative to conventional compilers.
//:
//: We're going to have many transforms in Mu, and getting their order right
//: (not the same as ordering of layers) is a well-known problem. Some tips:
//:   a) Design each layer to rely on as few previous layers as possible.
//:
//:   b) When positioning transforms, try to find the tightest constraint in
//:   each transform relative to previous layers.
//:
//:   c) Even so you'll periodically need to try adjusting each transform
//:   relative to those in previous layers to find a better arrangement.

:(before "End recipe Fields")
int transformed_until;
:(before "End recipe Constructor")
transformed_until = -1;

:(before "End Types")
typedef void (*transform_fn)(const recipe_ordinal);

:(before "End Globals")
vector<transform_fn> Transform;

:(before "End One-time Setup")
initialize_transforms();
:(code)
void initialize_transforms() {
  // Begin Transforms
    // Begin Instruction Inserting/Deleting Transforms
    // End Instruction Inserting/Deleting Transforms

    // Begin Instruction Modifying Transforms
    // End Instruction Modifying Transforms
  // End Transforms

  // Begin Checks
  // End Checks
}

void transform_all() {
  trace(9990, "transform") << "=== transform_all()" << end();
  for (int t = 0;  t < SIZE(Transform);  ++t) {
    for (map<recipe_ordinal, recipe>::iterator p = Recipe.begin();  p != Recipe.end();  ++p) {
      recipe& r = p->second;
      if (r.transformed_until != t-1) continue;
      // End Transform Checks
      (*Transform.at(t))(/*recipe_ordinal*/p->first);
      r.transformed_until = t;
    }
  }
  parse_int_reagents();  // do this after all other transforms have run
  // End transform_all
}

//: Even though a run will involve many calls to transform_all() for tests,
//: our logical model is to load all code, then transform all code, then run.
//: If you load new code that should cause already-transformed recipes to
//: change, that's not supported. To help detect such situations and raise
//: helpful errors we track a count of the number of calls made to
//: transform_all().
:(before "End Globals")
int Num_calls_to_transform_all = 0;
:(after "void transform_all()")
  ++Num_calls_to_transform_all;

:(code)
void parse_int_reagents() {
  trace(9991, "transform") << "--- parsing any uninitialized reagents as integers" << end();
  for (map<recipe_ordinal, recipe>::iterator p = Recipe.begin();  p != Recipe.end();  ++p) {
    recipe& r = p->second;
    if (r.steps.empty()) continue;
    for (int index = 0;  index < SIZE(r.steps);  ++index) {
      instruction& inst = r.steps.at(index);
      for (int i = 0;  i < SIZE(inst.ingredients);  ++i) {
        populate_value(inst.ingredients.at(i));
      }
      for (int i = 0;  i < SIZE(inst.products);  ++i) {
        populate_value(inst.products.at(i));
      }
    }
  }
}

void populate_value(reagent& r) {
  if (r.initialized) return;
  // End Reagent-parsing Exceptions
  if (!is_integer(r.name)) return;
  r.set_value(to_integer(r.name));
}

// helper for tests -- temporarily suppress run
void transform(string form) {
  load(form);
  transform_all();
}