# See LICENSE for licensing information.
#
# Copyright (c) 2016-2019 Regents of the University of California and The Board
# of Regents for the Oklahoma Agricultural and Mechanical College
# (acting for and on behalf of Oklahoma State University)
# All rights reserved.
#
"""
This is called globals.py, but it actually parses all the arguments
and performs the global OpenRAM setup as well.
"""
import os
import debug
import shutil
import optparse
import options
import sys
import re
import copy
import importlib

VERSION = "1.1.3"
NAME = "OpenRAM v{}".format(VERSION)
USAGE = "openram.py [options] <config file>\nUse -h for help.\n"

OPTS = options.options()
CHECKPOINT_OPTS = None


def parse_args():
    """ Parse the optional arguments for OpenRAM """

    global OPTS

    option_list = {
        optparse.make_option("-b",
                             "--backannotated",
                             action="store_true",
                             dest="use_pex",
                             help="Back annotate simulation"),
        optparse.make_option("-o",
                             "--output",
                             dest="output_name",
                             help="Base output file name(s) prefix",
                             metavar="FILE"),
        optparse.make_option("-p", "--outpath",
                             dest="output_path",
                             help="Output file(s) location"),
        optparse.make_option("-i",
                             "--inlinecheck",
                             action="store_true",
                             help="Enable inline LVS/DRC checks",
                             dest="inline_lvsdrc"),
        optparse.make_option("-n", "--nocheck",
                             action="store_false",
                             help="Disable all LVS/DRC checks",
                             dest="check_lvsdrc"),
        optparse.make_option("-v",
                             "--verbose",
                             action="count",
                             dest="debug_level",
                             help="Increase the verbosity level"),
        optparse.make_option("-t",
                             "--tech",
                             dest="tech_name",
                             help="Technology name"),
        optparse.make_option("-s",
                             "--spice",
                             dest="spice_name",
                             help="Spice simulator executable name"),
        optparse.make_option("-r",
                             "--remove_netlist_trimming",
                             action="store_false",
                             dest="trim_netlist",
                             help="Disable removal of noncritical memory cells during characterization"),
        optparse.make_option("-c",
                             "--characterize",
                             action="store_false",
                             dest="analytical_delay",
                             help="Perform characterization to calculate delays (default is analytical models)"),
        optparse.make_option("-d",
                             "--dontpurge",
                             action="store_false",
                             dest="purge_temp",
                             help="Don't purge the contents of the temp directory after a successful run")
        # -h --help is implicit.
    }

    parser = optparse.OptionParser(option_list=option_list,
                                   description=NAME,
                                   usage=USAGE,
                                   version=VERSION)

    (options, args) = parser.parse_args(values=OPTS)
    # If we don't specify a tech, assume scmos.
    # This may be overridden when we read a config file though...
    if OPTS.tech_name == "":
        OPTS.tech_name = "scmos"
    # Alias SCMOS to 180nm
    if OPTS.tech_name == "scmos":
        OPTS.tech_name = "scn4m_subm"

    return (options, args)


def print_banner():
    """ Conditionally print the banner to stdout """
    global OPTS
    if OPTS.is_unit_test:
        return

    debug.print_raw("|==============================================================================|")
    debug.print_raw("|=========" + NAME.center(60) + "=========|")
    debug.print_raw("|=========" + " ".center(60) + "=========|")
    debug.print_raw("|=========" + "VLSI Design and Automation Lab".center(60) + "=========|")
    debug.print_raw("|=========" + "Computer Science and Engineering Department".center(60) + "=========|")
    debug.print_raw("|=========" + "University of California Santa Cruz".center(60) + "=========|")
    debug.print_raw("|=========" + " ".center(60) + "=========|")
    user_info = "Usage help: openram-user-group@ucsc.edu"
    debug.print_raw("|=========" + user_info.center(60) + "=========|")
    dev_info = "Development help: openram-dev-group@ucsc.edu"
    debug.print_raw("|=========" + dev_info.center(60) + "=========|")
    temp_info = "Temp dir: {}".format(OPTS.openram_temp)
    debug.print_raw("|=========" + temp_info.center(60) + "=========|")
    debug.print_raw("|=========" + "See LICENSE for license info".center(60) + "=========|")
    debug.print_raw("|==============================================================================|")


def check_versions():
    """ Run some checks of required software versions. """

    # Now require python >=3.5
    major_python_version = sys.version_info.major
    minor_python_version = sys.version_info.minor
    major_required = 3
    minor_required = 5
    if not (major_python_version == major_required and minor_python_version >= minor_required):
        debug.error("Python {0}.{1} or greater is required.".format(major_required,minor_required),-1)
 
    # FIXME: Check versions of other tools here??
    # or, this could be done in each module (e.g. verify, characterizer, etc.)
    global OPTS
 
    try:
        import coverage
        OPTS.coverage = 1
    except:
        OPTS.coverage = 0

        
def init_openram(config_file, is_unit_test=True):
    """ Initialize the technology, paths, simulators, etc. """

    check_versions()

    debug.info(1, "Initializing OpenRAM...")

    setup_paths()
    
    read_config(config_file, is_unit_test)

    import_tech()

    set_default_corner()

    init_paths()

    from sram_factory import factory
    factory.reset()

    global OPTS
    global CHECKPOINT_OPTS

    # This is a hack. If we are running a unit test and have checkpointed
    # the options, load them rather than reading the config file.
    # This way, the configuration is reloaded at the start of every unit test.
    # If a unit test fails,
    # we don't have to worry about restoring the old config values
    # that may have been tested.
    if is_unit_test and CHECKPOINT_OPTS:
        OPTS.__dict__ = CHECKPOINT_OPTS.__dict__.copy()
        return
    
    # Import these to find the executables for checkpointing
    import characterizer
    import verify
    # Make a checkpoint of the options so we can restore
    # after each unit test
    if not CHECKPOINT_OPTS:
        CHECKPOINT_OPTS = copy.copy(OPTS)

        
def setup_bitcell():
    """
    Determine the correct custom or parameterized bitcell for the design.
    """
    global OPTS

    # If we have non-1rw ports,
    # and the user didn't over-ride the bitcell manually,
    # figure out the right bitcell to use
    if (OPTS.bitcell == "bitcell"):
        
        if (OPTS.num_rw_ports == 1 and OPTS.num_w_ports == 0 and OPTS.num_r_ports == 0):
            OPTS.bitcell = "bitcell"
            OPTS.replica_bitcell = "replica_bitcell"
            OPTS.dummy_bitcell = "dummy_bitcell"
        else:
            ports = ""
            if OPTS.num_rw_ports > 0:
                ports += "{}rw_".format(OPTS.num_rw_ports)
            if OPTS.num_w_ports > 0:
                ports += "{}w_".format(OPTS.num_w_ports)
            if OPTS.num_r_ports > 0:
                ports += "{}r".format(OPTS.num_r_ports)

            OPTS.bitcell = "bitcell_"+ports
            OPTS.replica_bitcell = "replica_bitcell_"+ports
            OPTS.dummy_bitcell = "dummy_bitcell_"+ports
    else:
        OPTS.replica_bitcell = "replica_" + OPTS.bitcell
        OPTS.replica_bitcell = "dummy_" + OPTS.bitcell
                
    # See if bitcell exists
    try:
        __import__(OPTS.bitcell)
        __import__(OPTS.replica_bitcell)
        __import__(OPTS.dummy_bitcell)
    except ImportError:
        # Use the pbitcell if we couldn't find a custom bitcell
        # or its custom replica  bitcell
        # Use the pbitcell (and give a warning if not in unit test mode)
        OPTS.bitcell = "pbitcell"
        OPTS.replica_bitcell = "replica_pbitcell"
        OPTS.replica_bitcell = "dummy_pbitcell"
        if not OPTS.is_unit_test:
            debug.warning("Using the parameterized bitcell which may have suboptimal density.")
    debug.info(1, "Using bitcell: {}".format(OPTS.bitcell))


def get_tool(tool_type, preferences, default_name=None):
    """
    Find which tool we have from a list of preferences and return the
    one selected and its full path. If default is specified,
    find that one only and error otherwise.
    """
    debug.info(2, "Finding {} tool...".format(tool_type))

    if default_name:
        exe_name = find_exe(default_name)
        if exe_name == None:
            debug.error("{0} not found. Cannot find {1} tool.".format(default_name,
                                                                      tool_type),
                        2)
        else:
            debug.info(1, "Using {0}: {1}".format(tool_type, exe_name))
            return(default_name, exe_name)
    else:
        for name in preferences:
            exe_name = find_exe(name)
            if exe_name != None:
                debug.info(1, "Using {0}: {1}".format(tool_type, exe_name))
                return(name, exe_name)
            else:
                debug.info(1,
                           "Could not find {0}, trying next {1} tool.".format(name,
                                                                              tool_type))
        else:
            return(None, "")

    
def read_config(config_file, is_unit_test=True):
    """
    Read the configuration file that defines a few parameters. The
    config file is just a Python file that defines some config
    options. This will only actually get read the first time. Subsequent
    reads will just restore the previous copy (ask mrg)
    """
    global OPTS

    # it is already not an abs path, make it one
    if not os.path.isabs(config_file):
        config_file = os.getcwd() + "/" +  config_file
        
    # Make it a python file if the base name was only given
    config_file = re.sub(r'\.py$', "", config_file)
        
    
    # Expand the user if it is used
    config_file = os.path.expanduser(config_file)
    
    OPTS.config_file = config_file + ".py"
    # Add the path to the system path
    # so we can import things in the other directory
    dir_name = os.path.dirname(config_file)
    module_name = os.path.basename(config_file)

    # Prepend the path to avoid if we are using the example config
    sys.path.insert(0, dir_name)
    # Import the configuration file of which modules to use
    debug.info(1, "Configuration file is " + config_file + ".py")
    try:
        config = importlib.import_module(module_name)
    except:
        debug.error("Unable to read configuration file: {0}".format(config_file),2)

    OPTS.overridden = {}
    for k, v in config.__dict__.items():
        # The command line will over-ride the config file
        # except in the case of the tech name! This is because the tech name
        # is sometimes used to specify the config file itself (e.g. unit tests)
        # Note that if we re-read a config file, nothing will get read again!
        if k not in OPTS.__dict__ or k == "tech_name":
            OPTS.__dict__[k] = v
            OPTS.overridden[k] = True

    # Massage the output path to be an absolute one
    if not OPTS.output_path.endswith('/'):
        OPTS.output_path += "/"
    if not OPTS.output_path.startswith('/'):
        OPTS.output_path = os.getcwd() + "/" + OPTS.output_path
    debug.info(1, "Output saved in " + OPTS.output_path)

    # Remember if we are running unit tests to reduce output
    OPTS.is_unit_test = is_unit_test

    # If we are only generating a netlist, we can't do DRC/LVS
    if OPTS.netlist_only:
        OPTS.check_lvsdrc = False
        
    # If config didn't set output name, make a reasonable default.
    if (OPTS.output_name == ""):
        ports = ""
        if OPTS.num_rw_ports > 0:
            ports += "{}rw_".format(OPTS.num_rw_ports)
        if OPTS.num_w_ports > 0:
            ports += "{}w_".format(OPTS.num_w_ports)
        if OPTS.num_r_ports > 0:
            ports += "{}r_".format(OPTS.num_r_ports)
        OPTS.output_name = "sram_{0}b_{1}_{2}{3}".format(OPTS.word_size,
                                                         OPTS.num_words,
                                                         ports,
                                                         OPTS.tech_name)

        
def end_openram():
    """ Clean up openram for a proper exit """
    cleanup_paths()

    if OPTS.check_lvsdrc:
        import verify
        verify.print_drc_stats()
        verify.print_lvs_stats()
        verify.print_pex_stats()
    
    
def cleanup_paths():
    """
    We should clean up the temp directory after execution.
    """
    global OPTS
    if not OPTS.purge_temp:
        debug.info(0,
                   "Preserving temp directory: {}".format(OPTS.openram_temp))
        return
    elif os.path.exists(OPTS.openram_temp):
        debug.info(1,
                   "Purging temp directory: {}".format(OPTS.openram_temp))
        # This annoyingly means you have to re-cd into
        # the directory each debug iteration
        # shutil.rmtree(OPTS.openram_temp, ignore_errors=True)
        contents = [os.path.join(OPTS.openram_temp, i) for i in os.listdir(OPTS.openram_temp)]
        for i in contents:
            if os.path.isfile(i) or os.path.islink(i):
                os.remove(i)
            else:
                shutil.rmtree(i)
        
            
def setup_paths():
    """ Set up the non-tech related paths. """
    debug.info(2, "Setting up paths...")

    global OPTS

    try:
        OPENRAM_HOME = os.path.abspath(os.environ.get("OPENRAM_HOME"))
    except:
        debug.error("$OPENRAM_HOME is not properly defined.", 1)
    debug.check(os.path.isdir(OPENRAM_HOME),
                "$OPENRAM_HOME does not exist: {0}".format(OPENRAM_HOME))

    # Add all of the subdirs to the python path
    # These subdirs are modules and don't need
    # to be added: characterizer, verify
    subdirlist = [ item for item in os.listdir(OPENRAM_HOME) if os.path.isdir(os.path.join(OPENRAM_HOME, item)) ]
    for subdir in subdirlist:
        full_path = "{0}/{1}".format(OPENRAM_HOME, subdir)
        debug.check(os.path.isdir(full_path),
                    "$OPENRAM_HOME/{0} does not exist: {1}".format(subdir, full_path))
        if "__pycache__" not in full_path:
            sys.path.append("{0}".format(full_path)) 

    if not OPTS.openram_temp.endswith('/'):
        OPTS.openram_temp += "/"
    debug.info(1, "Temporary files saved in " + OPTS.openram_temp)


def is_exe(fpath):
    """ Return true if the given is an executable file that exists. """
    return os.path.exists(fpath) and os.access(fpath, os.X_OK)


def find_exe(check_exe):
    """ 
    Check if the binary exists in any path dir
    and return the full path. 
    """
    # Check if the preferred spice option exists in the path
    for path in os.environ["PATH"].split(os.pathsep):
        exe = os.path.join(path, check_exe)
        # if it is found, then break and use first version
        if is_exe(exe):
            return exe
    return None


def init_paths():
    """ Create the temp and output directory if it doesn't exist """

    # make the directory if it doesn't exist
    try:
        debug.info(1,
                   "Creating temp directory: {}".format(OPTS.openram_temp))
        os.makedirs(OPTS.openram_temp, 0o750)
    except OSError as e:
        if e.errno == 17:  # errno.EEXIST
            os.chmod(OPTS.openram_temp, 0o750)
    
    # Don't delete the output dir, it may have other files!
    # make the directory if it doesn't exist
    try:
        os.makedirs(OPTS.output_path, 0o750)
    except OSError as e:
        if e.errno == 17:  # errno.EEXIST
            os.chmod(OPTS.output_path, 0o750)
    except:
        debug.error("Unable to make output directory.", -1)

        
def set_default_corner():
    """ Set the default corner. """

    import tech
    # Set some default options now based on the technology...
    if (OPTS.process_corners == ""):
        if OPTS.nominal_corner_only:
            OPTS.process_corners = ["TT"]
        else:
            OPTS.process_corners = tech.spice["fet_models"].keys()
    if (OPTS.supply_voltages == ""):
        if OPTS.nominal_corner_only:
            OPTS.supply_voltages = [tech.spice["supply_voltages"][1]]
        else:
            OPTS.supply_voltages = tech.spice["supply_voltages"]
    if (OPTS.temperatures == ""):
        if OPTS.nominal_corner_only:
            OPTS.temperatures = [tech.spice["temperatures"][1]]
        else:
            OPTS.temperatures = tech.spice["temperatures"]
    
    
def import_tech():
    """ Dynamically adds the tech directory to the path and imports it. """
    global OPTS

    debug.info(2,
               "Importing technology: " + OPTS.tech_name)

    # environment variable should point to the technology dir
    try:
        OPENRAM_TECH = os.path.abspath(os.environ.get("OPENRAM_TECH"))
    except:
        debug.error("$OPENRAM_TECH environment variable is not defined.", 1)

    # Add all of the paths
    for tech_path in OPENRAM_TECH.split(":"):
        debug.check(os.path.isdir(tech_path),
                    "$OPENRAM_TECH does not exist: {0}".format(tech_path))
        sys.path.append(tech_path)
        debug.info(1, "Adding technology path: {}".format(tech_path))

    # Import the tech 
    try:
        tech_mod = __import__(OPTS.tech_name)
    except ImportError:
        debug.error("Nonexistent technology module: {0}".format(OPTS.tech_name), -1)

    OPTS.openram_tech = os.path.dirname(tech_mod.__file__) + "/"

    # Add the tech directory
    tech_path = OPTS.openram_tech
    sys.path.append(tech_path)
    try:
        import tech
    except ImportError:
        debug.error("Could not load tech module.", -1)

    # Add custom modules of the technology to the path, if they exist
    custom_mod_path = os.path.join(tech_path, "modules/")
    if os.path.exists(custom_mod_path):
        sys.path.append(custom_mod_path)


def print_time(name, now_time, last_time=None, indentation=2):
    """ Print a statement about the time delta. """
    global OPTS
    
    # Don't print during testing
    if not OPTS.is_unit_test or OPTS.debug_level > 0:
        if last_time:
            time = str(round((now_time-last_time).total_seconds(),1)) + " seconds"
        else:
            time = now_time.strftime('%m/%d/%Y %H:%M:%S')
        debug.print_raw("{0} {1}: {2}".format("*"*indentation, name, time))


def report_status():
    """ 
    Check for valid arguments and report the
    info about the SRAM being generated 
    """
    global OPTS
    
    # Check if all arguments are integers for bits, size, banks
    if type(OPTS.word_size) != int:
        debug.error("{0} is not an integer in config file.".format(OPTS.word_size))
    if type(OPTS.num_words) != int:
        debug.error("{0} is not an integer in config file.".format(OPTS.sram_size))
    if type(OPTS.write_size) is not int and OPTS.write_size is not None:
        debug.error("{0} is not an integer in config file.".format(OPTS.write_size))

    # If a write mask is specified by the user, the mask write size should be the same as
    # the word size so that an entire word is written at once.
    if OPTS.write_size is not None:
        if (OPTS.word_size % OPTS.write_size != 0):
            debug.error("Write size needs to be an integer multiple of word size.")
        # If write size is more than half of the word size,
        # then it doesn't need a write mask. It would be writing
        # the whole word.
        if (OPTS.write_size < 1 or OPTS.write_size > OPTS.word_size/2):
            debug.error("Write size needs to be between 1 bit and {0} bits/2.".format(OPTS.word_size))

    if not OPTS.tech_name:
        debug.error("Tech name must be specified in config file.")

    debug.print_raw("Technology: {0}".format(OPTS.tech_name))
    total_size = OPTS.word_size*OPTS.num_words*OPTS.num_banks
    debug.print_raw("Total size: {} bits".format(total_size))
    if total_size >= 2**14:
        debug.warning("Requesting such a large memory size ({0}) will have a large run-time. ".format(total_size) +
                      "Consider using multiple smaller banks.")
    debug.print_raw("Word size: {0}\nWords: {1}\nBanks: {2}".format(OPTS.word_size,
                                                                    OPTS.num_words,
                                                                    OPTS.num_banks))
    if (OPTS.write_size != OPTS.word_size):
        debug.print_raw("Write size: {}".format(OPTS.write_size))
    debug.print_raw("RW ports: {0}\nR-only ports: {1}\nW-only ports: {2}".format(OPTS.num_rw_ports,
                                                                                 OPTS.num_r_ports,
                                                                                 OPTS.num_w_ports))

    if OPTS.netlist_only:
        debug.print_raw("Netlist only mode (no physical design is being done, netlist_only=False to disable).")
    
    if not OPTS.route_supplies:
        debug.print_raw("Design supply routing skipped. Supplies will have multiple must-connect pins. (route_supplies=True to enable supply routing).")
        
    if not OPTS.inline_lvsdrc:
        debug.print_raw("DRC/LVS/PEX is only run on the top-level design to save run-time (inline_lvsdrc=True to do inline checking).")

    if not OPTS.check_lvsdrc:
        debug.print_raw("DRC/LVS/PEX is disabled (check_lvsdrc=True to enable).")

    if OPTS.analytical_delay:
        debug.print_raw("Characterization is disabled (using analytical delay models) (analytical_delay=False to simulate).")
    else:
        if OPTS.spice_name != "":
            debug.print_raw("Performing simulation-based characterization with {}".format(OPTS.spice_name))
        if OPTS.trim_netlist:
            debug.print_raw("Trimming netlist to speed up characterization (trim_netlist=False to disable).")
    if OPTS.nominal_corner_only:
        debug.print_raw("Only characterizing nominal corner.")        
