/***********************************************
 * This file includes functions to generate
 * Verilog submodules for wires.
 **********************************************/
#include <string>
#include <algorithm>

/* Headers from vtrutil library */
#include "vtr_assert.h"
#include "vtr_log.h"

/* Headers from openfpgautil library */
#include "openfpga_digest.h"

#include "module_manager.h"
#include "module_manager_utils.h"

#include "openfpga_naming.h"

#include "verilog_constants.h"
#include "verilog_submodule_utils.h"
#include "verilog_writer_utils.h"
#include "verilog_wire.h"

/* begin namespace openfpga */
namespace openfpga {

/********************************************************************
 * Print a Verilog module of a regular wire segment
 * Regular wire, which is 1-input and 1-output
 * This type of wires are used in the local routing architecture
 *              +------+
 *    input --->| wire |---> output
 *              +------+
 *
 *******************************************************************/
static 
void print_verilog_wire_module(const ModuleManager& module_manager, 
                               const CircuitLibrary& circuit_lib,
                               std::fstream& fp,
                               const CircuitModelId& wire_model) {
  /* Ensure a valid file handler*/
  VTR_ASSERT(true == valid_file_stream(fp));

  /* Find the input port, output port*/
  std::vector<CircuitPortId> input_ports = circuit_lib.model_ports_by_type(wire_model, CIRCUIT_MODEL_PORT_INPUT, true);
  std::vector<CircuitPortId> output_ports = circuit_lib.model_ports_by_type(wire_model, CIRCUIT_MODEL_PORT_OUTPUT, true);
  std::vector<CircuitPortId> global_ports = circuit_lib.model_global_ports_by_type(wire_model, CIRCUIT_MODEL_PORT_INPUT, true, true);

  /* Makre sure the port size is what we want */
  VTR_ASSERT (1 == input_ports.size());
  VTR_ASSERT (1 == output_ports.size());
  VTR_ASSERT (1 == circuit_lib.port_size(input_ports[0]));
  VTR_ASSERT (1 == circuit_lib.port_size(output_ports[0]));

  /* Create a Verilog Module based on the circuit model, and add to module manager */
  ModuleId wire_module = module_manager.find_module(circuit_lib.model_name(wire_model)); 
  VTR_ASSERT(true == module_manager.valid_module_id(wire_module));

  /* dump module definition + ports */
  print_verilog_module_declaration(fp, module_manager, wire_module);
  /* Finish dumping ports */

  /* Print the internal logic of Verilog module */
  /* Find the input port of the module */
  ModulePortId module_input_port_id = module_manager.find_module_port(wire_module, circuit_lib.port_lib_name(input_ports[0]));
  VTR_ASSERT(ModulePortId::INVALID() != module_input_port_id);
  BasicPort module_input_port = module_manager.module_port(wire_module, module_input_port_id);

  /* Find the output port of the module */
  ModulePortId module_output_port_id = module_manager.find_module_port(wire_module, circuit_lib.port_lib_name(output_ports[0]));
  VTR_ASSERT(ModulePortId::INVALID() != module_output_port_id);
  BasicPort module_output_port = module_manager.module_port(wire_module, module_output_port_id);

  /* Print wire declaration for the inputs and outputs */
  fp << generate_verilog_port(VERILOG_PORT_WIRE, module_input_port) << ";" << std::endl;
  fp << generate_verilog_port(VERILOG_PORT_WIRE, module_output_port) << ";" << std::endl;

  /* Direct shortcut */
  print_verilog_wire_connection(fp, module_output_port, module_input_port, false);
  
  /* Print timing info */
  print_verilog_submodule_timing(fp, circuit_lib, wire_model);
   
  /* Put an end to the Verilog module */
  print_verilog_module_end(fp, circuit_lib.model_name(wire_model));

  /* Add an empty line as a splitter */
  fp << std::endl;
}

/********************************************************************
 * Top-level function to print wire modules
 *******************************************************************/
void print_verilog_submodule_wires(const ModuleManager& module_manager,
                                   NetlistManager& netlist_manager,
                                   const CircuitLibrary& circuit_lib,
                                   const std::string& submodule_dir) {
  std::string verilog_fname(submodule_dir + std::string(WIRES_VERILOG_FILE_NAME));

  /* Create the file stream */
  std::fstream fp;
  fp.open(verilog_fname, std::fstream::out | std::fstream::trunc);

  check_file_stream(verilog_fname.c_str(), fp);

  /* Print out debugging information for if the file is not opened/created properly */
  VTR_LOG("Writing Verilog netlist for wires '%s'...",
          verilog_fname.c_str()); 

  print_verilog_file_header(fp, "Wires"); 

  /* Print Verilog models for regular wires*/
  print_verilog_comment(fp, std::string("----- BEGIN Verilog modules for regular wires -----"));
  for (const auto& model : circuit_lib.models_by_type(CIRCUIT_MODEL_WIRE)) { 
    /* Bypass user-defined circuit models */
    if (!circuit_lib.model_verilog_netlist(model).empty()) {
      continue;
    }
    print_verilog_wire_module(module_manager, circuit_lib, fp, model);
  }
  print_verilog_comment(fp, std::string("----- END Verilog modules for regular wires -----"));

  /* Close the file stream */
  fp.close();

  /* Add fname to the netlist name list */
  NetlistId nlist_id = netlist_manager.add_netlist(verilog_fname);
  VTR_ASSERT(NetlistId::INVALID() != nlist_id);
  netlist_manager.set_netlist_type(nlist_id, NetlistManager::SUBMODULE_NETLIST);

  VTR_LOG("Done\n");
}

} /* end namespace openfpga */