"""
Print various potentially useful information to debug environment setup
related issues
"""
from __future__ import print_function

import platform
import sys
import os
import pkgutil
import functools

from ctypes import util

# Python 2/3 compatibility
try:
    from StringIO import StringIO
except ImportError:
    from io import StringIO

def _path_diagnostics(print_to_str):
    # Information for PATH related issues
    print_to_str("blpapi 64-bit will be loaded from: \"%s\""
                 % util.find_library("blpapi3_64"))
    print_to_str("blpapi 32-bit will be loaded from: \"%s\""
                 % util.find_library("blpapi3_32"))
    print_to_str("System PATH: (* marks locations where blpapi was found)")
    for p in os.environ["PATH"].split(os.pathsep):
        if p: # Skip empty entries
            dll_32 = os.path.join(p, "blpapi3_32.dll")
            dll_64 = os.path.join(p, "blpapi3_64.dll")
            found_blpapi_dll = os.path.isfile(dll_32) or os.path.isfile(dll_64)
            print_to_str("  %s \"%s\"" % ("*" if found_blpapi_dll else " ", p))
    print_to_str()

def _add_dll_directory_diagnostics(print_to_str):
    print_to_str("This Python version does not use PATH to find dlls")

def get_env_diagnostics():
    """
    Get various potentially useful information to debug environment setup
    related issues
    """

    strIO = StringIO()
    print_to_str = functools.partial(print, file=strIO)

    # General information about the platform
    print_to_str("Platform:", platform.platform())
    print_to_str("Architecture:", platform.architecture())
    print_to_str("Python:", sys.version)
    print_to_str("Python implementation:", platform.python_implementation())
    print_to_str()

    if not 'add_dll_directory' in dir(os):
        _path_diagnostics(print_to_str)
    else:
        _add_dll_directory_diagnostics(print_to_str)
    # Check if the blpapi package has been installed. If not,
    # include information about the current python environment
    blpapi_package_found = False
    for i in pkgutil.iter_modules():
        if i[1] == "blpapi":
            print_to_str("blpapi package at: \"%s\"" % i[0].path)
            blpapi_package_found = True

    if not blpapi_package_found:
        print_to_str("ERROR: Failed to find the blpapi package")
        print_to_str("Python prefix: \"%s\"" % sys.prefix)
        print_to_str("Python path:")
        for p in sys.path:
            print_to_str("    \"%s\"" % p)
    print_to_str()

    # There is currently a known issue where attempting to import blpapi
    # from the local directory (e.g. if trying to run a script in the root
    # of our repository) will fail. Check that this is not the case.
    print_to_str("Current directory: \"%s\"" % os.getcwd())
    if os.path.isfile(os.path.join(".", "blpapi", "__init__.py")):
        print_to_str("WARNING: Using the blpapi module from current path")
        print_to_str("    CWD files:", ", ".join(
            [x for x in os.listdir(".") if os.path.isfile(x)]))
        print_to_str("    CWD dirs:", ", ".join(
            [x for x in os.listdir(".") if not os.path.isfile(x)]))

    return strIO.getvalue()


if __name__ == "__main__":
    env_diagnostics = get_env_diagnostics()

    if len(sys.argv) > 1:
        with open(sys.argv[1], "w") as f:
            print(env_diagnostics, file=f)
    else:
        print(env_diagnostics)