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Source code for pysecret.sh_helper

# -*- coding: utf-8 -*-

"""
Shell script variable support. Read and write syntax like ``export key="value"``
in shell script.
"""

import os
import re


export_pattern = re.compile('export [a-zA-Z0-9_]{1,128}="[\d\D]{1,128}"')
"""Limitation, key, value length can't be greater than 128. 
"""


def append_line_if_not_exists(path: str, line: str):
    """
    Append a line to a text file at `path` if the line not exists in its content.

    :param path: text file absolute path
    :param line: text string.

    :return: None
    """
    if not os.path.exists(path):  # pragma: no cover
        with open(path, "wb") as f:
            f.write("".encode("utf-8"))

    if "\n" in line:  # pragma: no cover
        raise ValueError("'\\n' should not be in the line")

    # check if the line exists
    striped_line = line.strip()
    with open(path, "rb") as f:
        content = f.read().decode("utf-8")
        flag_endswith_new_line = content.endswith("\n") or content.endswith("\n\r")
        for line_ in content.split("\n"):
            if striped_line in line_:
                return

    with open(path, "ab") as f:
        if flag_endswith_new_line:  # pragma: no cover
            f.write((line + "\n").encode("utf-8"))
        else:  # pragma: no cover
            f.write(("\n" + line + "\n").encode("utf-8"))


def load_var_value_from_shell_script_content(content: str) -> dict:
    """
    Extract variable definition such as ``export var="value"`` from shell script
    content text.

    :param content: text content of a shell script

    :return:
    """
    # find possible text token
    candidate_line_list = list()
    for line in content.split("\n"):
        line_striped = line.strip()
        for item in re.findall(export_pattern, line_striped):
            if item == line:
                candidate_line_list.append(item)

    results = dict()
    for item in candidate_line_list:
        # validate line
        if item.startswith("export ") and ('="' in item) and item.endswith('"'):
            item = item[7:]
            key, value = item.split("=", 1)
            value = value[1:-1]
            results[key] = value

    return results


def load_var_value_from_shell_script(path_shell_script: str) -> dict:
    """
    Extract ``export key="value"`` key value data from a shell script.

    :param path_shell_script: shell script absolute path

    :return: key value pair dictionary data
    """
    if not os.path.exists(path_shell_script):
        return {}
    with open(path_shell_script, "rb") as f:
        content = f.read().decode("utf-8")
        return load_var_value_from_shell_script_content(content)