#!/usr/bin/env python3

r"""
This module provides functions which are useful for running plug-ins.
"""

import glob
import os
import sys

import gen_misc as gm
import gen_print as gp

# Some help text that is common to more than one program.
plug_in_dir_paths_help_text = (
    "This is a colon-separated list of plug-in directory paths.  If one"
    + " of the entries in the list is a plain directory name (i.e. no"
    + " path info), it will be taken to be a native plug-in.  In that case,"
    + ' %(prog)s will search for the native plug-in in the "plug-ins"'
    + " subdirectory of each path in the PATH environment variable until it"
    + " is found.  Also, integrated plug-ins will automatically be appended"
    + " to your plug_in_dir_paths list.  An integrated plug-in is any plug-in"
    + ' found using the PATH variable that contains a file named "integrated".'
)

mch_class_help_text = (
    'The class of machine that we are testing (e.g. "op" = "open power",'
    + ' "obmc" = "open bmc", etc).'
)

PATH_LIST = gm.return_path_list()


def get_plug_in_base_paths():
    r"""
    Get plug-in base paths and return them as a list.

    This function searches the PATH_LIST (created from PATH environment variable) for any paths that have a
    "plug_ins" subdirectory.  All such paths are considered plug_in_base paths.
    """

    global PATH_LIST

    plug_in_base_path_list = []

    for path in PATH_LIST:
        candidate_plug_in_base_path = path + "plug_ins/"
        if os.path.isdir(candidate_plug_in_base_path):
            plug_in_base_path_list.append(candidate_plug_in_base_path)

    return plug_in_base_path_list


# Define global plug_in_base_path_list and call get_plug_in_base_paths to set its value.
plug_in_base_path_list = get_plug_in_base_paths()


def find_plug_in_package(plug_in_name):
    r"""
    Find and return the normalized directory path of the specified plug in.  This is done by searching the
    global plug_in_base_path_list.

    Description of arguments:
    plug_in_name                    The unqualified name of the plug-in package.
    """

    global plug_in_base_path_list
    for plug_in_base_dir_path in plug_in_base_path_list:
        candidate_plug_in_dir_path = (
            os.path.normpath(plug_in_base_dir_path + plug_in_name) + os.sep
        )
        if os.path.isdir(candidate_plug_in_dir_path):
            return candidate_plug_in_dir_path

    return ""


def validate_plug_in_package(plug_in_dir_path, mch_class="obmc"):
    r"""
    Validate the plug in package and return the normalized plug-in directory path.

    Description of arguments:
    plug_in_dir_path                The "relative" or absolute path to a plug in package directory.
    mch_class                       The class of machine that we are testing (e.g. "op" = "open power",
                                    "obmc" = "open bmc", etc).
    """

    gp.dprint_executing()

    if os.path.isabs(plug_in_dir_path):
        # plug_in_dir_path begins with a slash so it is an absolute path.
        candidate_plug_in_dir_path = (
            os.path.normpath(plug_in_dir_path) + os.sep
        )
        if not os.path.isdir(candidate_plug_in_dir_path):
            gp.print_error_report(
                'Plug-in directory path "'
                + plug_in_dir_path
                + '" does not exist.\n'
            )
            exit(1)
    else:
        # The plug_in_dir_path is actually a simple name (e.g. "OBMC_Sample")...
        candidate_plug_in_dir_path = find_plug_in_package(plug_in_dir_path)
        if candidate_plug_in_dir_path == "":
            global PATH_LIST
            gp.print_error_report(
                'Plug-in directory path "'
                + plug_in_dir_path
                + '" could not be found'
                + " in any of the following directories:\n"
                + gp.sprint_var(PATH_LIST)
            )
            exit(1)
    # Make sure that this plug-in supports us...
    supports_file_path = candidate_plug_in_dir_path + "supports_" + mch_class
    if not os.path.exists(supports_file_path):
        gp.print_error_report(
            "The following file path could not be"
            + " found:\n"
            + gp.sprint_varx("supports_file_path", supports_file_path)
            + "\nThis file is necessary to indicate that"
            + " the given plug-in supports the class of"
            + ' machine we are testing, namely "'
            + mch_class
            + '".\n'
        )
        exit(1)

    return candidate_plug_in_dir_path


def return_integrated_plug_ins(mch_class="obmc"):
    r"""
    Return a list of integrated plug-ins.  Integrated plug-ins are plug-ins which are selected without regard
    for whether the user has specified them.  In other words, they are "integrated" into the program suite.
    The programmer designates a plug-in as integrated by putting a file named "integrated" into the plug-in
    package directory.

    Description of arguments:
    mch_class                       The class of machine that we are testing (e.g. "op" = "open power",
                                    "obmc" = "open bmc", etc).
    """

    global plug_in_base_path_list

    integrated_plug_ins_list = []

    DEBUG_SKIP_INTEGRATED = int(os.getenv("DEBUG_SKIP_INTEGRATED", "0"))

    if DEBUG_SKIP_INTEGRATED:
        return integrated_plug_ins_list

    for plug_in_base_path in plug_in_base_path_list:
        # Get a list of all plug-in paths that support our mch_class.
        mch_class_candidate_list = glob.glob(
            plug_in_base_path + "*/supports_" + mch_class
        )
        for candidate_path in mch_class_candidate_list:
            integrated_plug_in_dir_path = (
                os.path.dirname(candidate_path) + os.sep
            )
            integrated_file_path = integrated_plug_in_dir_path + "integrated"
            if os.path.exists(integrated_file_path):
                plug_in_name = os.path.basename(
                    os.path.dirname(candidate_path)
                )
                if plug_in_name not in integrated_plug_ins_list:
                    # If this plug-in has not already been added to the list...
                    integrated_plug_ins_list.append(plug_in_name)

    return integrated_plug_ins_list


def return_plug_in_packages_list(plug_in_dir_paths, mch_class="obmc"):
    r"""
    Return a list of plug-in packages given the plug_in_dir_paths string.  This function calls
    validate_plug_in_package so it will fail if plug_in_dir_paths contains any invalid plug-ins.

    Description of arguments:
    plug_in_dir_path                The "relative" or absolute path to a plug in package directory.
    mch_class                       The class of machine that we are testing (e.g. "op" = "open power",
                                    "obmc" = "open bmc", etc).
    """

    if plug_in_dir_paths != "":
        plug_in_packages_list = plug_in_dir_paths.split(":")
    else:
        plug_in_packages_list = []

    # Get a list of integrated plug-ins (w/o full path names).
    integrated_plug_ins_list = return_integrated_plug_ins(mch_class)
    # Put both lists together in plug_in_packages_list with no duplicates.  NOTE: This won't catch
    # duplicates if the caller specifies the full path name of a native plug-in but that should be rare
    # enough.

    plug_in_packages_list = plug_in_packages_list + integrated_plug_ins_list

    plug_in_packages_list = list(
        set(
            [
                validate_plug_in_package(path, mch_class)
                for path in plug_in_packages_list
            ]
        )
    )

    return plug_in_packages_list