#####################################################################
# Python script to execute modelsim simulation for a given testbench netlist
# This script will
# - Create the tcl script to enable modelsim simulation
# - Run modelsim simulation
# - Analyze output log files and return succeed or failure
#####################################################################

import os
from os.path import dirname, abspath, isfile
import shutil
import re
import argparse
import logging
import subprocess

#####################################################################
# Initialize logger
#####################################################################
logging.basicConfig(format='%(levelname)s: %(message)s', level=logging.INFO)

#####################################################################
# Parse the options
#####################################################################
parser = argparse.ArgumentParser(description='Run ModelSim verification for a testbench')
parser.add_argument('--verilog_testbench', required=True,
                    help='Specify the file path for the Verilog testbench as input')
parser.add_argument('--project_path', required=True,
                    help='Specify the file path to create the ModelSim project')
parser.add_argument('--testbench_name', required=True,
                    help='Specify the top-level module of the testbench')
args = parser.parse_args()

#####################################################################
# Check options:
# - Input testbench file must be valid
#   Otherwise, error out
# - If the modelsim project path does not exist, create it
#####################################################################
if not isfile(args.verilog_testbench):
  logging.error("Invalid Verilog testbench: " + args.verilog_testbench + "\nFile does not exist!\n")
  exit(1)

project_abs_path = os.path.abspath(args.project_path)
if not os.path.isdir(project_abs_path):
  logging.debug("Creating ModelSim project directory : " + project_abs_path + " ...\n")
  os.makedirs(project_abs_path, exist_ok=True)
  logging.debug("Done\n")

#####################################################################
# Create the Tcl script for Modelsim
#####################################################################
# Get modelsim process tcl file path
msim_proc_tcl_path = os.path.abspath(__file__)
msim_proc_tcl_path = re.sub(os.path.basename(msim_proc_tcl_path), "modelsim_proc.tcl", msim_proc_tcl_path)
if not isfile(msim_proc_tcl_path):
  logging.error("Invalid process script for ModelSim: " + msim_proc_tcl_path + "\nFile does not exist!\n")
  exit(1)

# Create output file handler
tcl_file_path = project_abs_path + "/" + os.path.basename(args.testbench_name) + ".tcl"
logging.debug("Generating Tcl script for ModelSim: " + tcl_file_path)
tcl_file = open(tcl_file_path, "w")

# A string buffer to write tcl content
tcl_lines = []

tcl_lines.append("echo \"==============================\"")
tcl_lines.append("pwd")
tcl_lines.append("echo \"==============================\"")
tcl_lines.append("\n")
tcl_lines.append("set project_name " + args.testbench_name)
tcl_lines.append("set top_tb " + args.testbench_name)
tcl_lines.append("\n")
tcl_lines.append("set project_path \"" + project_abs_path  + "\"")
tcl_lines.append("set verilog_files \"" + os.path.abspath(args.verilog_testbench)  + "\"")
tcl_lines.append("\n")
tcl_lines.append("source " + msim_proc_tcl_path)
tcl_lines.append("\n")
tcl_lines.append("try {")
tcl_lines.append("\ttop_create_new_project $project_name $verilog_files $project_path $top_tb")
tcl_lines.append("} finally {")
tcl_lines.append("\tquit")
tcl_lines.append("}")

for line in tcl_lines:
  tcl_file.write(line + "\n")

tcl_file.close()
logging.debug("Done")

#####################################################################
# Run ModelSim simulation
#####################################################################
curr_dir = os.getcwd()
# Change to the project directory
os.chdir(project_abs_path)
logging.debug("Changed to directory: " + project_abs_path)

# Run ModelSim
vsim_log_file_path = project_abs_path + "/vsim_run_log"
vsim_bin = "/uusoc/facility/cad_tools/Mentor/modelsim10.7b/modeltech/bin/vsim"
vsim_cmd = vsim_bin + " -c -do " + os.path.abspath(tcl_file_path) + " > " + vsim_log_file_path
logging.debug("Running modelsim by : " + vsim_cmd)
subprocess.run(vsim_cmd, shell=True, check=True)

# Go back to current directory
os.chdir(curr_dir)

#####################################################################
# Parse log files and report any errors
#####################################################################
vsim_log_file = open(vsim_log_file_path, "r")

# Error counter
num_err = 0
num_err_lines_found = 0
verification_passed = False

for line in vsim_log_file:
  # Check errors from self-testing testbench output
  if line.startswith("# Simulation finish with") :
    num_sim_err = int(re.findall("# Simulation finish with(\s+)(\d+) errors", line)[0][1])
    num_err_lines_found = num_err_lines_found + 1
    if (0 < num_sim_err) : 
      logging.error("Simulation failed with " + str(num_sim_err) + " errors!\n")
      # Add to total errors
      num_err = num_err + num_sim_err
  # Check total errors by Modelsim
  if line.startswith("# Errors:") :
    num_msim_err = int(re.findall("# Errors:(\s)(\d+),", line)[0][1])
    num_err_lines_found = num_err_lines_found + 1
    num_err = num_err + num_msim_err

vsim_log_file.close()

if (0 == num_err_lines_found) :    
  logging.error("No error lines found!Something wrong in setting up modelsim simulation\n")
elif (0 < num_err) :
  logging.error("ModelSim failed with " + str(num_err) + " errors!\n")
else :
  verification_passed = True

if (verification_passed) :
  logging.info(args.testbench_name + "...[Passed]\n")
else :
  logging.error(args.testbench_name + "...[Failed]\n")