#pragma once

/*!
 * @file Interpreter.h
 * The GOOS Interpreter and implementation of special and "built-in forms"
 */

#include <memory>
#include <optional>

#include "Object.h"
#include "Reader.h"

namespace goos {
class Interpreter {
 public:
  Interpreter(const std::string& user_profile = "#f");
  ~Interpreter();
  void execute_repl(REPL::Wrapper& repl);
  void throw_eval_error(const Object& o, const std::string& err);
  Object eval_with_rewind(const Object& obj, const std::shared_ptr<EnvironmentObject>& env);
  bool get_global_variable_by_name(const std::string& name, Object* dest);
  void set_global_variable_by_name(const std::string& name, const Object& value);
  void set_global_variable_to_symbol(const std::string& name, const std::string& value);
  void set_global_variable_to_int(const std::string& name, int value);
  Object eval(Object obj, const std::shared_ptr<EnvironmentObject>& env);
  Object intern(const std::string& name);
  InternedSymbolPtr intern_ptr(const std::string& name);
  void disable_printfs();
  Object eval_symbol(const Object& sym, const std::shared_ptr<EnvironmentObject>& env);
  bool eval_symbol(const Object& sym,
                   const std::shared_ptr<EnvironmentObject>& env,
                   Object* result);
  Arguments get_args(const Object& form, const Object& rest, const ArgumentSpec& spec);
  Arguments get_args_no_named(const Object& form, const Object& rest, const ArgumentSpec& spec);
  void set_args_in_env(const Object& form,
                       const Arguments& args,
                       const ArgumentSpec& arg_spec,
                       const std::shared_ptr<EnvironmentObject>& env);
  Object eval_list_return_last(const Object& form,
                               Object rest,
                               const std::shared_ptr<EnvironmentObject>& env);
  bool truthy(const Object& o);

  void register_form(
      const std::string& name,
      const std::function<
          Object(const Object&, Arguments&, const std::shared_ptr<EnvironmentObject>&)>& form);
  void eval_args(Arguments* args, const std::shared_ptr<EnvironmentObject>& env);

  Reader reader;
  Object global_environment;
  Object goal_env;

 private:
  friend class Goal;
  void load_goos_library();
  void define_var_in_env(Object& env, const Object& var, const std::string& name);
  void expect_env(const Object& form, const Object& o);
  void vararg_check(
      const Object& form,
      const Arguments& args,
      const std::vector<std::optional<ObjectType>>& unnamed,
      const std::unordered_map<std::string, std::pair<bool, std::optional<ObjectType>>>& named);

  Object eval_pair(const Object& o, const std::shared_ptr<EnvironmentObject>& env);

 public:
  ArgumentSpec parse_arg_spec(const Object& form, Object& rest);

 private:
  Object quasiquote_helper(const Object& form, const std::shared_ptr<EnvironmentObject>& env);

  IntType number_to_integer(const Object& obj);
  FloatType number_to_float(const Object& obj);

  template <typename T>
  T number(const Object& obj);

  template <typename T>
  Object num_lt(const Object& form, Arguments& args, const std::shared_ptr<EnvironmentObject>& env);
  template <typename T>
  Object num_gt(const Object& form, Arguments& args, const std::shared_ptr<EnvironmentObject>& env);
  template <typename T>
  Object num_leq(const Object& form,
                 Arguments& args,
                 const std::shared_ptr<EnvironmentObject>& env);
  template <typename T>
  Object num_geq(const Object& form,
                 Arguments& args,
                 const std::shared_ptr<EnvironmentObject>& env);
  template <typename T>
  Object num_plus(const Object& form,
                  Arguments& args,
                  const std::shared_ptr<EnvironmentObject>& env);
  template <typename T>
  Object num_minus(const Object& form,
                   Arguments& args,
                   const std::shared_ptr<EnvironmentObject>& env);
  template <typename T>
  Object num_divide(const Object& form,
                    Arguments& args,
                    const std::shared_ptr<EnvironmentObject>& env);
  template <typename T>
  Object num_times(const Object& form,
                   Arguments& args,
                   const std::shared_ptr<EnvironmentObject>& env);

  Object eval_eval(const Object& form,
                   Arguments& args,
                   const std::shared_ptr<EnvironmentObject>& env);
  Object eval_equals(const Object& form,
                     Arguments& args,
                     const std::shared_ptr<EnvironmentObject>& env);
  Object eval_exit(const Object& form,
                   Arguments& args,
                   const std::shared_ptr<EnvironmentObject>& env);
  Object eval_begin(const Object& form,
                    Arguments& args,
                    const std::shared_ptr<EnvironmentObject>& env);
  Object eval_read(const Object& form,
                   Arguments& args,
                   const std::shared_ptr<EnvironmentObject>& env);
  Object eval_read_data_file(const Object& form,
                             Arguments& args,
                             const std::shared_ptr<EnvironmentObject>& env);
  Object eval_read_file(const Object& form,
                        Arguments& args,
                        const std::shared_ptr<EnvironmentObject>& env);
  Object eval_load_file(const Object& form,
                        Arguments& args,
                        const std::shared_ptr<EnvironmentObject>& env);
  Object eval_try_load_file(const Object& form,
                            Arguments& args,
                            const std::shared_ptr<EnvironmentObject>& env);
  Object eval_print(const Object& form,
                    Arguments& args,
                    const std::shared_ptr<EnvironmentObject>& env);
  Object eval_inspect(const Object& form,
                      Arguments& args,
                      const std::shared_ptr<EnvironmentObject>& env);
  Object eval_plus(const Object& form,
                   Arguments& args,
                   const std::shared_ptr<EnvironmentObject>& env);
  Object eval_minus(const Object& form,
                    Arguments& args,
                    const std::shared_ptr<EnvironmentObject>& env);
  Object eval_times(const Object& form,
                    Arguments& args,
                    const std::shared_ptr<EnvironmentObject>& env);
  Object eval_divide(const Object& form,
                     Arguments& args,
                     const std::shared_ptr<EnvironmentObject>& env);
  Object eval_numequals(const Object& form,
                        Arguments& args,
                        const std::shared_ptr<EnvironmentObject>& env);
  Object eval_lt(const Object& form,
                 Arguments& args,
                 const std::shared_ptr<EnvironmentObject>& env);
  Object eval_gt(const Object& form,
                 Arguments& args,
                 const std::shared_ptr<EnvironmentObject>& env);
  Object eval_leq(const Object& form,
                  Arguments& args,
                  const std::shared_ptr<EnvironmentObject>& env);
  Object eval_geq(const Object& form,
                  Arguments& args,
                  const std::shared_ptr<EnvironmentObject>& env);
  Object eval_car(const Object& form,
                  Arguments& args,
                  const std::shared_ptr<EnvironmentObject>& env);
  Object eval_cdr(const Object& form,
                  Arguments& args,
                  const std::shared_ptr<EnvironmentObject>& env);
  Object eval_set_car(const Object& form,
                      Arguments& args,
                      const std::shared_ptr<EnvironmentObject>& env);
  Object eval_set_cdr(const Object& form,
                      Arguments& args,
                      const std::shared_ptr<EnvironmentObject>& env);
  Object eval_gensym(const Object& form,
                     Arguments& args,
                     const std::shared_ptr<EnvironmentObject>& env);
  Object eval_cons(const Object& form,
                   Arguments& args,
                   const std::shared_ptr<EnvironmentObject>& env);
  Object eval_null(const Object& form,
                   Arguments& args,
                   const std::shared_ptr<EnvironmentObject>& env);
  Object eval_type(const Object& form,
                   Arguments& args,
                   const std::shared_ptr<EnvironmentObject>& env);
  Object eval_format(const Object& form,
                     Arguments& args,
                     const std::shared_ptr<EnvironmentObject>& env);
  Object eval_error(const Object& form,
                    Arguments& args,
                    const std::shared_ptr<EnvironmentObject>& env);
  Object eval_string_ref(const Object& form,
                         Arguments& args,
                         const std::shared_ptr<EnvironmentObject>& env);
  Object eval_string_length(const Object& form,
                            Arguments& args,
                            const std::shared_ptr<EnvironmentObject>& env);
  Object eval_string_append(const Object& form,
                            Arguments& args,
                            const std::shared_ptr<EnvironmentObject>& env);
  Object eval_string_starts_with(const Object& form,
                                 Arguments& args,
                                 const std::shared_ptr<EnvironmentObject>& env);
  Object eval_string_ends_with(const Object& form,
                               Arguments& args,
                               const std::shared_ptr<EnvironmentObject>& env);
  Object eval_string_split(const Object& form,
                           Arguments& args,
                           const std::shared_ptr<EnvironmentObject>& env);
  Object eval_string_substr(const Object& form,
                            Arguments& args,
                            const std::shared_ptr<EnvironmentObject>& env);
  Object eval_ash(const Object& form,
                  Arguments& args,
                  const std::shared_ptr<EnvironmentObject>& env);
  Object eval_symbol_to_string(const Object& form,
                               Arguments& args,
                               const std::shared_ptr<EnvironmentObject>& env);
  Object eval_string_to_symbol(const Object& form,
                               Arguments& args,
                               const std::shared_ptr<EnvironmentObject>& env);
  Object eval_int_to_string(const Object& form,
                            Arguments& args,
                            const std::shared_ptr<EnvironmentObject>& env);
  Object eval_get_env(const Object& form,
                      Arguments& args,
                      const std::shared_ptr<EnvironmentObject>& env);

  // specials
  Object eval_define(const Object& form,
                     const Object& rest,
                     const std::shared_ptr<EnvironmentObject>& env);
  Object eval_quote(const Object& form,
                    const Object& rest,
                    const std::shared_ptr<EnvironmentObject>& env);
  Object eval_set(const Object& form,
                  const Object& rest,
                  const std::shared_ptr<EnvironmentObject>& env);
  Object eval_lambda(const Object& form,
                     const Object& rest,
                     const std::shared_ptr<EnvironmentObject>& env);
  Object eval_cond(const Object& form,
                   const Object& rest,
                   const std::shared_ptr<EnvironmentObject>& env);
  Object eval_or(const Object& form,
                 const Object& rest,
                 const std::shared_ptr<EnvironmentObject>& env);
  Object eval_and(const Object& form,
                  const Object& rest,
                  const std::shared_ptr<EnvironmentObject>& env);
  Object eval_quasiquote(const Object& form,
                         const Object& rest,
                         const std::shared_ptr<EnvironmentObject>& env);
  Object eval_macro(const Object& form,
                    const Object& rest,
                    const std::shared_ptr<EnvironmentObject>& env);
  Object eval_while(const Object& form,
                    const Object& rest,
                    const std::shared_ptr<EnvironmentObject>& env);
  Object eval_let(const Object& form,
                  const Object& rest,
                  const std::shared_ptr<EnvironmentObject>& env);
  Object eval_let_star(const Object& form,
                       const Object& rest,
                       const std::shared_ptr<EnvironmentObject>& env);
  Object eval_let_common(const Object& form,
                         const Object& rest,
                         const std::shared_ptr<EnvironmentObject>& env,
                         bool star);

  Object eval_make_string_hash_table(const Object& form,
                                     Arguments& args,
                                     const std::shared_ptr<EnvironmentObject>& env);
  Object eval_hash_table_try_ref(const Object& form,
                                 Arguments& args,
                                 const std::shared_ptr<EnvironmentObject>& env);
  Object eval_hash_table_set(const Object& form,
                             Arguments& args,
                             const std::shared_ptr<EnvironmentObject>& env);

  const Object& true_or_false(bool val);

  void init_special_forms(
      const std::unordered_map<std::string,
                               Object (Interpreter::*)(const Object&,
                                                       const Object&,
                                                       const std::shared_ptr<EnvironmentObject>&)>&
          forms);

  void init_builtin_forms(
      const std::unordered_map<std::string,
                               Object (Interpreter::*)(const Object&,
                                                       Arguments&,
                                                       const std::shared_ptr<EnvironmentObject>&)>&
          forms);

  bool want_exit = false;
  bool disable_printing = false;

  std::unordered_map<
      void*,
      Object (Interpreter::*)(const Object&, Arguments&, const std::shared_ptr<EnvironmentObject>&)>
      builtin_forms;

  std::vector<std::pair<
      void*,
      std::function<Object(const Object&, Arguments&, const std::shared_ptr<EnvironmentObject>&)>>>
      m_custom_forms;

  std::vector<std::pair<void*,
                        Object (Interpreter::*)(const Object& form,
                                                const Object& rest,
                                                const std::shared_ptr<EnvironmentObject>& env)>>
      special_forms;
  int64_t gensym_id = 0;

  std::unordered_map<std::string, ObjectType> string_to_type;

  const char* m_false_sym = nullptr;
  const char* m_true_sym = nullptr;
  Object m_false_object, m_true_object;
};
}  // namespace goos