//: Phase 3: Start running a loaded and transformed recipe.
//:
//: So far we've seen recipes as lists of instructions, and instructions point
//: at other recipes. To kick things off mu needs to know how to run certain
//: 'primitive' recipes. That will then give the ability to run recipes
//: containing these primitives.
//:
//: This layer defines a skeleton with just two primitive recipes: IDLE which
//: does nothing, and COPY, which can copy numbers from one memory location to
//: another. Later layers will add more primitives.

:(scenario copy_literal)
recipe main [
  1:number <- copy 23
]
+run: 1:number <- copy 23
+mem: storing 23 in location 1

:(scenario copy)
recipe main [
  1:number <- copy 23
  2:number <- copy 1:number
]
+run: 2:number <- copy 1:number
+mem: location 1 is 23
+mem: storing 23 in location 2

:(scenario copy_multiple)
recipe main [
  1:number, 2:number <- copy 23, 24
]
+mem: storing 23 in location 1
+mem: storing 24 in location 2

:(before "End Types")
// Book-keeping while running a recipe.
//: Later layers will change this.
struct routine {
  recipe_ordinal running_recipe;
  long long int running_step_index;
  routine(recipe_ordinal r) :running_recipe(r), running_step_index(0) {}
  bool completed() const;
};

:(before "End Globals")
routine* Current_routine = NULL;

:(code)
void run(recipe_ordinal r) {
  routine rr(r);
  Current_routine = &rr;
  run_current_routine();
}

void run_current_routine()
{  // curly on a separate line, because later layers will modify header
  while (!Current_routine->completed())  // later layers will modify condition
  {
    // Running One Instruction
    if (current_instruction().is_label) { ++current_step_index(); continue; }
    trace(Initial_callstack_depth+Callstack_depth, "run") << current_instruction().to_string() << end();
    if (Memory[0] != 0) {
      raise << "something wrote to location 0; this should never happen\n" << end();
      Memory[0] = 0;
    }
    // Read all ingredients from memory.
    // Each ingredient loads a vector of values rather than a single value; mu
    // permits operating on reagents spanning multiple locations.
    vector<vector<double> > ingredients;
    for (long long int i = 0; i < SIZE(current_instruction().ingredients); ++i) {
      ingredients.push_back(read_memory(current_instruction().ingredients.at(i)));
    }
    // Instructions below will write to 'products'.
    vector<vector<double> > products;
    switch (current_instruction().operation) {
      // Primitive Recipe Implementations
      case COPY: {
        copy(ingredients.begin(), ingredients.end(), inserter(products, products.begin()));
        break;
      }
      // End Primitive Recipe Implementations
      default: {
        cout << "not a primitive op: " << current_instruction().operation << '\n';
      }
    }
    if (SIZE(products) < SIZE(current_instruction().products)) {
      raise << SIZE(products) << " vs " << SIZE(current_instruction().products) << ": failed to write to all products! " << current_instruction().to_string() << end();
    }
    else {
      for (long long int i = 0; i < SIZE(current_instruction().products); ++i) {
        write_memory(current_instruction().products.at(i), products.at(i));
      }
    }
    // End of Instruction
    ++current_step_index();
  }
  stop_running_current_routine:;
}

//: Some helpers.
//: We'll need to override these later as we change the definition of routine.
//: Important that they return referrences into the routine.

inline long long int& current_step_index() {
  return Current_routine->running_step_index;
}

inline const string& current_recipe_name() {
  return Recipe[Current_routine->running_recipe].name;
}

inline const instruction& current_instruction() {
  return Recipe[Current_routine->running_recipe].steps.at(Current_routine->running_step_index);
}

inline bool routine::completed() const {
  return running_step_index >= SIZE(Recipe[running_recipe].steps);
}

:(before "End Commandline Parsing")
// Loading Commandline Files
if (argc > 1) {
  for (int i = 1; i < argc; ++i) {
    load_permanently(argv[i]);
  }
}

:(before "End Main")
if (!Run_tests) {
  setup();
//?   Trace_file = "interactive"; //? 2
//?   START_TRACING_UNTIL_END_OF_SCOPE; //? 2
//?   Trace_stream->collect_layer.insert("app"); //? 1
  transform_all();
  recipe_ordinal r = Recipe_ordinal[string("main")];
  if (r) run(r);
//?   dump_memory(); //? 1
  teardown();
}

:(code)
void cleanup_main() {
  if (!Trace_file.empty() && Trace_stream) {
    ofstream fout(Trace_file.c_str());
    fout << Trace_stream->readable_contents("");
    fout.close();
  }
}
:(before "End One-time Setup")
atexit(cleanup_main);

:(code)
void load_permanently(string filename) {
  ifstream fin(filename.c_str());
  fin.peek();
  if (!fin) {
    raise << "no such file " << filename << '\n' << end();
    return;
  }
  fin >> std::noskipws;
  load(fin);
  transform_all();
  fin.close();
  // freeze everything so it doesn't get cleared by tests
  recently_added_recipes.clear();
  // End load_permanently.
}

//:: On startup, load everything in core.mu
:(before "End Load Recipes")
load_permanently("core.mu");

:(code)
// helper for tests
void run(string form) {
//?   cerr << form << '\n'; //? 1
  vector<recipe_ordinal> tmp = load(form);
  if (tmp.empty()) return;
  transform_all();
  run(tmp.front());
}

//:: Reading from memory, writing to memory.

vector<double> read_memory(reagent x) {
//?   cout << "read_memory: " << x.to_string() << '\n'; //? 2
  vector<double> result;
  if (is_literal(x)) {
    result.push_back(x.value);
    return result;
  }
  long long int base = x.value;
  long long int size = size_of(x);
  for (long long int offset = 0; offset < size; ++offset) {
    double val = Memory[base+offset];
    trace(Primitive_recipe_depth, "mem") << "location " << base+offset << " is " << val << end();
    result.push_back(val);
  }
  return result;
}

void write_memory(reagent x, vector<double> data) {
  if (is_dummy(x)) return;
  if (is_literal(x)) return;
  long long int base = x.value;
  if (size_mismatch(x, data)) {
    raise << current_recipe_name() << ": size mismatch in storing to " << x.original_string << " at '" << current_instruction().to_string() << "'\n" << end();
    return;
  }
  for (long long int offset = 0; offset < SIZE(data); ++offset) {
    trace(Primitive_recipe_depth, "mem") << "storing " << data.at(offset) << " in location " << base+offset << end();
    Memory[base+offset] = data.at(offset);
  }
}

:(code)
long long int size_of(const reagent& r) {
  if (r.types.empty()) return 0;
  // End size_of(reagent) Cases
  return size_of(r.types);
}
long long int size_of(const vector<type_ordinal>& types) {
  if (types.empty()) return 0;
  // End size_of(types) Cases
  return 1;
}

bool size_mismatch(const reagent& x, const vector<double>& data) {
  if (x.types.empty()) return true;
  // End size_mismatch(x) Cases
//?   if (size_of(x) != SIZE(data)) cerr << size_of(x) << " vs " << SIZE(data) << '\n'; //? 2
  return size_of(x) != SIZE(data);
}

bool is_dummy(const reagent& x) {
  return x.name == "_";
}

bool is_literal(const reagent& r) {
  return SIZE(r.types) == 1 && r.types.at(0) == 0;
}

:(scenario run_label)
recipe main [
  +foo
  1:number <- copy 23
  2:number <- copy 1:number
]
+run: 1:number <- copy 23
+run: 2:number <- copy 1:number
-run: +foo

:(scenario run_dummy)
recipe main [
  _ <- copy 0
]
+run: _ <- copy 0

:(scenario write_to_0_disallowed)
recipe main [
  0 <- copy 34
]
-mem: storing 34 in location 0