#include "Compiler.h"
#include <chrono>
#include <thread>
#include "CompilerException.h"
#include "IR.h"
#include "common/link_types.h"
#include "goalc/make/Tools.h"
#include "goalc/regalloc/Allocator.h"
#include "goalc/regalloc/Allocator_v2.h"
#include "third-party/fmt/core.h"

using namespace goos;

Compiler::Compiler(std::unique_ptr<ReplWrapper> repl)
    : m_debugger(&m_listener, &m_goos.reader), m_repl(std::move(repl)) {
  m_listener.add_debugger(&m_debugger);
  m_ts.add_builtin_types();
  m_global_env = std::make_unique<GlobalEnv>();
  m_none = std::make_unique<None>(m_ts.make_typespec("none"));

  // let the build system run us
  m_make.add_tool(std::make_shared<CompilerTool>(this));

  // load GOAL library
  Object library_code = m_goos.reader.read_from_file({"goal_src", "goal-lib.gc"});
  compile_object_file("goal-lib", library_code, false);

  // add built-in forms to symbol info
  for (auto& builtin : g_goal_forms) {
    m_symbol_info.add_builtin(builtin.first);
  }

  // load auto-complete history, only if we are running in the interactive mode.
  if (m_repl) {
    m_repl->load_history();
  }

  // add GOOS forms that get info from the compiler
  setup_goos_forms();
}

ReplStatus Compiler::execute_repl(bool auto_listen) {
  // init repl
  m_repl->print_welcome_message();
  auto examples = m_repl->examples;
  auto regex_colors = m_repl->regex_colors;
  m_repl->init_default_settings();
  using namespace std::placeholders;
  m_repl->get_repl().set_completion_callback(
      std::bind(&Compiler::find_symbols_by_prefix, this, _1, _2, std::cref(examples)));
  m_repl->get_repl().set_hint_callback(
      std::bind(&Compiler::find_hints_by_prefix, this, _1, _2, _3, std::cref(examples)));
  m_repl->get_repl().set_highlighter_callback(
      std::bind(&Compiler::repl_coloring, this, _1, _2, std::cref(regex_colors)));

  if (auto_listen) {
    m_listener.connect_to_target();
  }

  while (!m_want_exit && !m_want_reload) {
    try {
      // 1). get a line from the user (READ)
      std::string prompt = fmt::format(fmt::emphasis::bold | fg(fmt::color::cyan), "g > ");
      if (m_listener.is_connected()) {
        prompt = fmt::format(fmt::emphasis::bold | fg(fmt::color::lime_green), "gc> ");
      }
      if (m_debugger.is_halted()) {
        prompt = fmt::format(fmt::emphasis::bold | fg(fmt::color::magenta), "gs> ");
      } else if (m_debugger.is_attached()) {
        prompt = fmt::format(fmt::emphasis::bold | fg(fmt::color::red), "gr> ");
      }

      auto code = m_goos.reader.read_from_stdin(prompt, *m_repl);
      if (!code) {
        continue;
      }

      // 2). compile
      auto obj_file = compile_object_file("repl", *code, m_listener.is_connected());
      if (m_settings.debug_print_ir) {
        obj_file->debug_print_tl();
      }

      if (!obj_file->is_empty()) {
        // 3). color
        color_object_file(obj_file);

        // 4). codegen
        auto data = codegen_object_file(obj_file);

        // 4). send!
        if (m_listener.is_connected()) {
          m_listener.send_code(data);
          if (!m_listener.most_recent_send_was_acked()) {
            print_compiler_warning("Runtime is not responding. Did it crash?\n");
          }
        }
      }

    } catch (std::exception& e) {
      print_compiler_warning("REPL Error: {}\n", e.what());
    }
  }

  if (m_listener.is_connected()) {
    m_listener.send_reset(false);  // reset the target
    m_listener.disconnect();
  }

  if (m_want_exit) {
    return ReplStatus::WANT_EXIT;
  }

  if (m_want_reload) {
    return ReplStatus::WANT_RELOAD;
  }

  return ReplStatus::OK;
}

FileEnv* Compiler::compile_object_file(const std::string& name,
                                       goos::Object code,
                                       bool allow_emit) {
  auto file_env = m_global_env->add_file(name);
  Env* compilation_env = file_env;

  file_env->add_top_level_function(
      compile_top_level_function("top-level", std::move(code), compilation_env));

  if (!allow_emit && !file_env->is_empty()) {
    throw std::runtime_error("Compilation generated code, but wasn't supposed to");
  }

  return file_env;
}

std::unique_ptr<FunctionEnv> Compiler::compile_top_level_function(const std::string& name,
                                                                  const goos::Object& code,
                                                                  Env* env) {
  auto fe = std::make_unique<FunctionEnv>(env, name, &m_goos.reader);
  fe->set_segment(TOP_LEVEL_SEGMENT);

  auto result = compile_error_guard(code, fe.get());

  // only move to return register if we actually got a result
  if (!dynamic_cast<const None*>(result)) {
    fe->emit_ir<IR_Return>(code, fe->make_gpr(result->type()), result->to_gpr(code, fe.get()),
                           emitter::gRegInfo.get_gpr_ret_reg());
  }

  if (!fe->code().empty()) {
    fe->emit_ir<IR_Null>(code);
  }

  fe->finish();
  return fe;
}

Val* Compiler::compile_error_guard(const goos::Object& code, Env* env) {
  try {
    return compile(code, env);
  } catch (CompilerException& ce) {
    if (ce.print_err_stack) {
      auto obj_print = code.print();
      if (obj_print.length() > 80) {
        obj_print = obj_print.substr(0, 80);
        obj_print += "...";
      }
      bool term;
      auto loc_info = m_goos.reader.db.get_info_for(code, &term);
      if (term) {
        fmt::print(fg(fmt::color::yellow) | fmt::emphasis::bold, "Location:\n");
        fmt::print(loc_info);
      }

      fmt::print(fg(fmt::color::yellow) | fmt::emphasis::bold, "Code:\n");
      fmt::print("{}\n", obj_print);

      if (term) {
        ce.print_err_stack = false;
      }
      std::string line(80, '-');
      line.push_back('\n');
      fmt::print(line);
    }
    throw ce;
  }

  catch (std::runtime_error& e) {
    fmt::print(fg(fmt::color::crimson) | fmt::emphasis::bold, "-- Compilation Error! --\n");
    fmt::print(fmt::emphasis::bold, "{}\n", e.what());

    auto obj_print = code.print();
    if (obj_print.length() > 80) {
      obj_print = obj_print.substr(0, 80);
      obj_print += "...";
    }
    bool term;
    auto loc_info = m_goos.reader.db.get_info_for(code, &term);
    if (term) {
      fmt::print(fg(fmt::color::yellow) | fmt::emphasis::bold, "Location:\n");
      fmt::print(loc_info);
    }

    fmt::print(fg(fmt::color::yellow) | fmt::emphasis::bold, "Code:\n");
    fmt::print("{}\n", obj_print);

    CompilerException ce("Compiler Exception");
    if (term) {
      ce.print_err_stack = false;
    }
    std::string line(80, '-');
    line.push_back('\n');
    fmt::print(line);
    throw ce;
  }
}

void Compiler::color_object_file(FileEnv* env) {
  int num_spills_in_file = 0;
  for (auto& f : env->functions()) {
    AllocationInput input;
    input.is_asm_function = f->is_asm_func;
    for (auto& i : f->code()) {
      input.instructions.push_back(i->to_rai());
      input.debug_instruction_names.push_back(i->print());
    }

    for (auto& reg_val : f->reg_vals()) {
      if (reg_val->forced_on_stack()) {
        input.force_on_stack_regs.insert(reg_val->ireg().id);
      }
    }

    input.max_vars = f->max_vars();
    input.constraints = f->constraints();
    input.stack_slots_for_stack_vars = f->stack_slots_used_for_stack_vars();
    input.function_name = f->name();

    if (m_settings.debug_print_regalloc) {
      input.debug_settings.print_input = true;
      input.debug_settings.print_result = true;
      input.debug_settings.print_analysis = true;
      input.debug_settings.allocate_log_level = 2;
    }

    m_debug_stats.total_funcs++;

    auto regalloc_result_2 = allocate_registers_v2(input);

    if (regalloc_result_2.ok) {
      if (regalloc_result_2.num_spilled_vars > 0) {
        // fmt::print("Function {} has {} spilled vars.\n", f->name(),
        //  regalloc_result_2.num_spilled_vars);
      }
      num_spills_in_file += regalloc_result_2.num_spills;
      f->set_allocations(std::move(regalloc_result_2));
    } else {
      fmt::print(
          "Warning: function {} failed register allocation with the v2 allocator. Falling back to "
          "the v1 allocator.\n",
          f->name());
      m_debug_stats.funcs_requiring_v1_allocator++;
      auto regalloc_result = allocate_registers(input);
      m_debug_stats.num_spills_v1 += regalloc_result.num_spills;
      num_spills_in_file += regalloc_result.num_spills;
      f->set_allocations(std::move(regalloc_result));
    }
  }

  m_debug_stats.num_spills += num_spills_in_file;
}

std::vector<u8> Compiler::codegen_object_file(FileEnv* env) {
  try {
    auto debug_info = &m_debugger.get_debug_info_for_object(env->name());
    debug_info->clear();
    CodeGenerator gen(env, debug_info);
    bool ok = true;
    auto result = gen.run(&m_ts);
    for (auto& f : env->functions()) {
      if (f->settings.print_asm) {
        fmt::print("{}\n",
                   debug_info->disassemble_function_by_name(f->name(), &ok, &m_goos.reader));
      }
    }
    auto stats = gen.get_obj_stats();
    m_debug_stats.num_moves_eliminated += stats.moves_eliminated;
    return result;
  } catch (std::exception& e) {
    throw_compiler_error_no_code("Error during codegen: {}", e.what());
  }
  return {};
}

bool Compiler::codegen_and_disassemble_object_file(FileEnv* env,
                                                   std::vector<u8>* data_out,
                                                   std::string* asm_out) {
  auto debug_info = &m_debugger.get_debug_info_for_object(env->name());
  debug_info->clear();
  CodeGenerator gen(env, debug_info);
  *data_out = gen.run(&m_ts);
  bool ok = true;
  *asm_out = debug_info->disassemble_all_functions(&ok, &m_goos.reader);
  return ok;
}

void Compiler::compile_and_send_from_string(const std::string& source_code) {
  if (!connect_to_target()) {
    throw std::runtime_error(
        "Compiler failed to connect to target for compile_and_send_from_string.");
  }

  auto code = m_goos.reader.read_from_string(source_code);
  auto compiled = compile_object_file("test-code", code, true);
  assert(!compiled->is_empty());
  color_object_file(compiled);
  auto data = codegen_object_file(compiled);
  m_listener.send_code(data);
  if (!m_listener.most_recent_send_was_acked()) {
    print_compiler_warning("Runtime is not responding after sending test code. Did it crash?\n");
  }
}

std::vector<std::string> Compiler::run_test_from_file(const std::string& source_code) {
  try {
    if (!connect_to_target()) {
      throw std::runtime_error("Compiler::run_test_from_file couldn't connect!");
    }

    auto code = m_goos.reader.read_from_file({source_code});
    auto compiled = compile_object_file("test-code", code, true);
    if (compiled->is_empty()) {
      return {};
    }
    color_object_file(compiled);
    auto data = codegen_object_file(compiled);
    m_listener.record_messages(ListenerMessageKind::MSG_PRINT);
    m_listener.send_code(data);
    if (!m_listener.most_recent_send_was_acked()) {
      print_compiler_warning("Runtime is not responding after sending test code. Did it crash?\n");
    }
    return m_listener.stop_recording_messages();
  } catch (std::exception& e) {
    fmt::print("[Compiler] Failed to compile test program {}: {}\n", source_code, e.what());
    throw e;
  }
}

std::vector<std::string> Compiler::run_test_from_string(const std::string& src,
                                                        const std::string& obj_name) {
  try {
    if (!connect_to_target()) {
      throw std::runtime_error("Compiler::run_test_from_file couldn't connect!");
    }

    auto code = m_goos.reader.read_from_string({src});
    auto compiled = compile_object_file(obj_name, code, true);
    if (compiled->is_empty()) {
      return {};
    }
    color_object_file(compiled);
    auto data = codegen_object_file(compiled);
    m_listener.record_messages(ListenerMessageKind::MSG_PRINT);
    m_listener.send_code(data);
    if (!m_listener.most_recent_send_was_acked()) {
      print_compiler_warning("Runtime is not responding after sending test code. Did it crash?\n");
    }
    return m_listener.stop_recording_messages();
  } catch (std::exception& e) {
    fmt::print("[Compiler] Failed to compile test program from string {}: {}\n", src, e.what());
    throw e;
  }
}

bool Compiler::connect_to_target() {
  if (!m_listener.is_connected()) {
    for (int i = 0; i < 1000; i++) {
      m_listener.connect_to_target();
      std::this_thread::sleep_for(std::chrono::microseconds(10000));
      if (m_listener.is_connected()) {
        break;
      }
    }
    if (!m_listener.is_connected()) {
      return false;
    }
  }
  return true;
}

/*!
 * Just run the front end on a string. Will not do register allocation or code generation.
 * Useful for typechecking, defining types,  or running strings that invoke the compiler again.
 */
void Compiler::run_front_end_on_string(const std::string& src) {
  auto code = m_goos.reader.read_from_string({src});
  compile_object_file("run-on-string", code, true);
}

/*!
 * Just run the front end on a file. Will not do register allocation or code generation.
 * Useful for typechecking, defining types,  or running strings that invoke the compiler again.
 */
void Compiler::run_front_end_on_file(const std::vector<std::string>& path) {
  auto code = m_goos.reader.read_from_file(path);
  compile_object_file("run-on-file", code, true);
}

/*!
 * Run the entire compilation process on the input source code. Will generate an object file, but
 * won't save it anywhere.
 */
void Compiler::run_full_compiler_on_string_no_save(const std::string& src) {
  auto code = m_goos.reader.read_from_string({src});
  auto compiled = compile_object_file("run-on-string", code, true);
  color_object_file(compiled);
  codegen_object_file(compiled);
}

std::vector<std::string> Compiler::run_test_no_load(const std::string& source_code) {
  auto code = m_goos.reader.read_from_file({source_code});
  compile_object_file("test-code", code, true);
  return {};
}

void Compiler::shutdown_target() {
  if (m_debugger.is_attached()) {
    m_debugger.detach();
  }

  if (m_listener.is_connected()) {
    m_listener.send_reset(true);
  }
}

void Compiler::typecheck(const goos::Object& form,
                         const TypeSpec& expected,
                         const TypeSpec& actual,
                         const std::string& error_message) {
  (void)form;
  if (!m_ts.typecheck_and_throw(expected, actual, error_message, false, false)) {
    throw_compiler_error(form, "Typecheck failed. For {}, got a \"{}\" when expecting a \"{}\"",
                         error_message, actual.print(), expected.print());
  }
}

/*!
 * Like typecheck, but will allow Val* to be #f if the destination isn't a number.
 * Also will convert to register types for the type checking.
 */
void Compiler::typecheck_reg_type_allow_false(const goos::Object& form,
                                              const TypeSpec& expected,
                                              const Val* actual,
                                              const std::string& error_message) {
  if (!m_ts.typecheck_and_throw(m_ts.make_typespec("number"), expected, "", false, false)) {
    auto as_sym_val = dynamic_cast<const SymbolVal*>(actual);
    if (as_sym_val && as_sym_val->name() == "#f") {
      return;
    }
  }
  typecheck(form, expected, coerce_to_reg_type(actual->type()), error_message);
}

bool Compiler::knows_object_file(const std::string& name) {
  return m_debugger.knows_object(name);
}

void Compiler::setup_goos_forms() {
  m_goos.register_form("get-enum-vals", [&](const goos::Object& form, goos::Arguments& args,
                                            const std::shared_ptr<goos::EnvironmentObject>& env) {
    m_goos.eval_args(&args, env);
    va_check(form, args, {goos::ObjectType::SYMBOL}, {});
    std::vector<Object> enum_vals;

    const auto& enum_name = args.unnamed.at(0).as_symbol()->name;
    auto enum_type = m_ts.try_enum_lookup(enum_name);
    if (!enum_type) {
      throw_compiler_error(form, "Unknown enum {} in get-enum-vals", enum_name);
    }

    std::vector<std::pair<std::string, s64>> sorted_values;
    for (auto& val : enum_type->entries()) {
      sorted_values.emplace_back(val.first, val.second);
    }

    std::sort(sorted_values.begin(), sorted_values.end(),
              [](const std::pair<std::string, s64>& a, const std::pair<std::string, s64>& b) {
                return a.second < b.second;
              });

    for (auto& thing : sorted_values) {
      enum_vals.push_back(PairObject::make_new(m_goos.intern(thing.first),
                                               goos::Object::make_integer(thing.second)));
    }

    return goos::build_list(enum_vals);
  });
}