#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "tree.h"
#include "gimple-expr.h"
#include "predict.h"
#include "alloc-pool.h"
#include "tree-pass.h"
#include "cgraph.h"
#include "diagnostic.h"
#include "fold-const.h"
#include "gimple-fold.h"
#include "symbol-summary.h"
#include "tree-vrp.h"
#include "ipa-prop.h"
#include "tree-pretty-print.h"
#include "tree-inline.h"
#include "ipa-fnsummary.h"
#include "ipa-utils.h"
#include "tree-ssa-ccp.h"
#include "stringpool.h"
#include "attribs.h"
#include "tree-ssa-alias.h"
#include "tree-ssanames.h"
#include "gimple.h"
#include "cfg.h"
#include "gimple-iterator.h"
#include "gimple-ssa.h"

#include "types-inlines.h"
#include <set>
#include <string>

#include "name-types.h"
#include "type-walker.hpp"

// Using std::string because it will manage memory for us
// And we don't know whether the user will free the memory.
// Also that's why we are returning a value rather than a
// pointer...

static const std::string
type_to_string_simple(const_tree type)
{
  gcc_assert(type);
  const enum tree_code code = TREE_CODE(type);
  bool valid_input = false;
  switch (code)
  {
    case VOID_TYPE:
    case INTEGER_TYPE:
    case REAL_TYPE:
    case FIXED_POINT_TYPE:
    case COMPLEX_TYPE:
    case ENUMERAL_TYPE:
    case BOOLEAN_TYPE:
    case OFFSET_TYPE:
      valid_input = true;
    break;
    default:
      valid_input = false;
    break;
  }
  gcc_assert(valid_input);


  return std::string(get_tree_code_name(code));
}

static const std::string
type_to_string_get_field_name(const_tree field)
{
  assert_is_type(field, FIELD_DECL);
  const_tree decl_name = DECL_NAME(field);
  if (!decl_name) return std::string("");

  const char* identifier = IDENTIFIER_POINTER(decl_name);
  return std::string(identifier);
}

static const unsigned
type_to_string_get_field_offset(const_tree field)
{
  assert_is_type(field, FIELD_DECL);
  tree cst = byte_position(field);
  gcc_assert(cst);
  unsigned offset = tree_to_uhwi (cst);
  return offset;
}

static const unsigned
type_to_string_get_type_size(const_tree type)
{
  gcc_assert(type);
  const_tree type_size = TYPE_SIZE(type);
  const bool is_incomplete = NULL_TREE == type_size;
  if (is_incomplete) return 0;

  const bool fits_uhwi = tree_fits_uhwi_p(type_size);
  if (fits_uhwi) return tree_to_uhwi (type_size);

  const bool fits_shwi = tree_fits_shwi_p(type_size);
  if (fits_shwi) return tree_to_shwi (type_size);

  return 0;
}

const std::string
get_type_identifier(const_tree type)
{
  tree name = TYPE_NAME(type);
  // The TYPE_NAME will be NULL_TREE for a type
  // that is not a built-in type, the result of a typedef
  // or a named class type.
  const bool no_name = NULL_TREE == name;
  if (no_name) return std::string("");

  const enum tree_code name_code = TREE_CODE(name);
  const bool is_name_type_decl = TYPE_DECL == name_code;
  name = is_name_type_decl ? DECL_NAME(name) : name;
  const char* identifier_ptr = IDENTIFIER_POINTER(name);
  gcc_assert(identifier_ptr);
  return std::string(identifier_ptr);
}

static const std::string
type_to_string_get_record_name(const_tree type)
{
  assert_is_type(type, RECORD_TYPE);
  tree name = TYPE_NAME(type);
  // The TYPE_NAME will be NULL_TREE for a type
  // that is not a built-in type, the result of a typedef
  // or a named class type.
  const bool no_name = NULL_TREE == name;
  if (no_name) return std::string("");

  const enum tree_code name_code = TREE_CODE(name);
  const bool is_name_type_decl = TYPE_DECL == name_code;
  name = is_name_type_decl ? DECL_NAME(name) : name;
  const char* identifier_ptr = IDENTIFIER_POINTER(name);
  gcc_assert(identifier_ptr);
  return std::string(identifier_ptr);
}

static const std::string
type_to_string_get_record_or_union_name(const_tree type)
{

  const enum tree_code code = TREE_CODE(type);
  const bool is_record = RECORD_TYPE == code;
  const bool is_union = UNION_TYPE == code;
  const bool is_valid_input = is_record || is_union;
  gcc_assert(is_valid_input);
  tree name = TYPE_NAME(type);

  // The TYPE_NAME will be NULL_TREE for a type
  // that is not a built-in type, the result of a typedef
  // or a named class type.
  const bool no_name = NULL_TREE == name;
  if (no_name) return std::string("");

  const enum tree_code name_code = TREE_CODE(name);
  const bool is_name_type_decl = TYPE_DECL == name_code;
  name = is_name_type_decl ? DECL_NAME(name) : name;
  const char* identifier_ptr = IDENTIFIER_POINTER(name);
  gcc_assert(identifier_ptr);
  return std::string(identifier_ptr);
}

/*
 * The idea behind this function is to receive either
 * a record or a union type and return a string that 
 * represents this type.
 * The output should look something like this:
 * 0: astruct {
 * 0: int a
 * 8: int b
 * 16: bstruct*
 * 24: cstruct {
 * 0: int a
 * }
 * 32: {
 * }
 * }
 * The question I have now... is... should we follos bstruct*
 * to see what it points to? Because, maybe there's two bstruct*s
 * defined in different TU?
 * So maybe more like this:
 * 0: astruct {
 * 0: int a
 * 8: int b
 * 16: bstruct {
 * 0: int a
 * }*
 * 24: cstruct {
 * 0: int a
 * }
 * 32: {
 * }
 */
static const std::string
type_to_string_record_or_union(const_tree type)
{
  gcc_assert(type);
  const enum tree_code code = TREE_CODE(type);
  const bool is_record = RECORD_TYPE == code;
  const bool is_union = UNION_TYPE == code;
  const bool is_valid_input = is_record || is_union;
  gcc_assert(is_valid_input);

  std::string name = type_to_string_get_record_or_union_name(type);
  std::string aggregate = name + std::string(" {");

  for (tree field = TYPE_FIELDS(type); field; field = DECL_CHAIN(field))
  {
    //std::string field_name = type_to_string_get_field_name(field);
    const_tree field_type = TREE_TYPE(field);
    const unsigned field_offset = type_to_string_get_field_offset(field);
    std::string field_type_name = type_to_string(field_type, field_offset);
    aggregate += field_type_name + std::string(";");
  }

  aggregate += "}";
  return aggregate;
}

static const std::string
type_to_string_record(const_tree type)
{
  assert_is_type(type, RECORD_TYPE);
  return type_to_string_record_or_union(type);
}

static const std::string
type_to_string_union(const_tree type)
{
  assert_is_type(type, UNION_TYPE);
  return type_to_string_record_or_union(type);
}

static const std::string
type_to_string_wrapper(const_tree type)
{
  gcc_assert(type);
  const enum tree_code code = TREE_CODE(type);
  bool is_valid_input = false;
  switch (code)
  {
    case POINTER_TYPE:
    case ARRAY_TYPE:
    case REFERENCE_TYPE:
      is_valid_input = true;
    break;
    default:
      is_valid_input = false;
    break;
  }
  gcc_assert(is_valid_input);

  const_tree inner_type = TREE_TYPE(type);
  return type_to_string(inner_type, 0, false);
}

static const std::string
type_to_string_pointer(const_tree type)
{
  assert_is_type(type, POINTER_TYPE);
  return type_to_string_wrapper(type) + std::string("*");
}

static const std::string
type_to_string_array(const_tree type)
{
  assert_is_type(type, ARRAY_TYPE);
  return type_to_string_wrapper(type) + std::string("[]");
}

static const std::string
type_to_string_reference(const_tree type)
{
  assert_is_type(type, REFERENCE_TYPE);
  return type_to_string_wrapper(type) + std::string("&");
}

static const std::string
type_to_string_function_or_method(const_tree type)
{
  gcc_assert(type);
  const enum tree_code code = TREE_CODE(type);
  const bool is_function = FUNCTION_TYPE == code;
  const bool is_method = METHOD_TYPE == code;
  const bool is_valid = is_function || is_method;
  gcc_assert(is_valid);

  const_tree return_type = TREE_TYPE(type);
  gcc_assert(return_type);

  const std::string return_type_name = type_to_string(return_type, 0, false);

  std::string aggregate("");

  for(tree param = TYPE_ARG_TYPES(type); param; param = TREE_CHAIN(param))
  {
     const_tree param_type = TREE_VALUE(param);
     //TODO: Why no param type?
     //gcc_assert(param_type);
     const bool has_more_params = TREE_CHAIN(param);
     aggregate += type_to_string(param_type);
     if (!has_more_params) break;

     aggregate += std::string(", ");
  }

  //TODO: Add base_type for method types
  std::string retval = return_type_name + std::string("(") + aggregate + std::string(")");
  return retval;
}

static const std::string
type_to_string_function(const_tree type)
{
  assert_is_type(type, FUNCTION_TYPE);
  return type_to_string_function_or_method(type);
}

static const std::string
type_to_string_method(const_tree type)
{
  assert_is_type(type, METHOD_TYPE);
  return type_to_string_function_or_method(type);
}


const std::string
type_to_string(const_tree type, const unsigned field_offset, const bool add_prelude)
{
  gcc_assert(type);
  const enum tree_code code = TREE_CODE(type);
  const unsigned size = type_to_string_get_type_size(type);
  std::string prelude = add_prelude ? std::to_string(field_offset) + std::string(",") + std::to_string(field_offset + size) + std::string(":") : std::string("");

  switch (code)
  {
    case VOID_TYPE:
    case INTEGER_TYPE:
    case REAL_TYPE:
    case FIXED_POINT_TYPE:
    case COMPLEX_TYPE:
    case ENUMERAL_TYPE:
    case BOOLEAN_TYPE:
    case OFFSET_TYPE:
      return prelude + type_to_string_simple(type);
    break;
    default:
    break;
  }

  switch (code)
  {
    case RECORD_TYPE:
      return prelude + type_to_string_record(type);
    break;
    case UNION_TYPE:
      return prelude + type_to_string_union(type);
    break;
    case POINTER_TYPE:
      return prelude + type_to_string_pointer(type);
    break;
    case REFERENCE_TYPE:
      return prelude + type_to_string_reference(type);
    break;
    case ARRAY_TYPE:
      return prelude + type_to_string_array(type);
    break;
    case FUNCTION_TYPE:
      return prelude + type_to_string_function(type);
    break;
    case METHOD_TYPE:
      return prelude + type_to_string_method(type);
    break;
    case QUAL_UNION_TYPE:
    case LANG_TYPE:
    default:
      // unimplemented
      gcc_unreachable();
    break;
  }

  gcc_unreachable();
  return std::string("you shouldn't ever see this");
}

namespace test_naming_types {

void test_generic_to_string(const enum tree_code code, const char * expected_char_array)
{
  std::string expected_value(expected_char_array);
  tree type = make_node(code);
  std::string observed_value = type_to_string(type);
  const bool success = expected_value.compare(observed_value) == 0;
  gcc_assert(success);

}
void test_simple_to_string()
{
  test_generic_to_string(VOID_TYPE,        "0:void_type");
  test_generic_to_string(INTEGER_TYPE,     "0:integer_type");
  test_generic_to_string(REAL_TYPE,        "0:real_type");
  test_generic_to_string(FIXED_POINT_TYPE, "0:fixed_point_type");
  test_generic_to_string(COMPLEX_TYPE,     "0:complex_type");
  test_generic_to_string(ENUMERAL_TYPE,    "0:enumeral_type");
  test_generic_to_string(BOOLEAN_TYPE,     "0:boolean_type");
  test_generic_to_string(OFFSET_TYPE,      "0:offset_type");
}

void run_tests()
{
  test_simple_to_string();
}
};