import os
import subprocess

from error_codes  import *
from errors       import error_info, is_error, print_errors
from errors_tsg   import ask_install_error_codes
from helpers      import update_pkg_manager
from .check_os    import check_os
from .check_oms   import check_oms
from .check_files import check_filesystem
from .check_pkgs  import check_packages

DFS_PATH = "/opt/microsoft/omsagent/tst/files/datafiles/"



# check space in MB for each main directory
def check_space():
    success = NO_ERROR
    dirnames = ["/etc", "/opt", "/var"]
    for dirname in dirnames:
        space = os.statvfs(dirname)
        free_space = space.f_bavail * space.f_frsize / 1024 / 1024
        if (free_space < 500):
            error_info.append((dirname, free_space))
            success = ERR_FREE_SPACE
    return success



# check certificate
def check_cert():
    crt_path = "/etc/opt/microsoft/omsagent/certs/oms.crt"
    try:
        crt_info = subprocess.check_output(['openssl','x509','-in',crt_path,'-text','-noout'],\
                        universal_newlines=True, stderr=subprocess.STDOUT)
        if (crt_info.startswith("Certificate:\n")):
            return NO_ERROR
        error_info.append((crt_path,))
        return ERR_CERT
    # error with openssl
    except subprocess.CalledProcessError as e:
        try:
            err = e.output.split('\n')[1].split(':')[5]
            # openssl permissions error
            if (err == "Permission denied"):
                error_info.append((crt_path,))
                return ERR_SUDO_PERMS
            # openssl file existence error
            elif (err == "No such file or directory"):
                error_info.append(("file", crt_path))
                return ERR_FILE_MISSING
            # openssl some other error
            else:
                error_info.append((crt_path, err))
                return ERR_FILE_ACCESS
        # catch-all in case of fluke error
        except:
            error_info.append((crt_path, e.output))
            return ERR_FILE_ACCESS
    # general error
    except:
        error_info.append((crt_path,))
        return ERR_CERT



# check RSA private key
def check_key():
    key_path = "/etc/opt/microsoft/omsagent/certs/oms.key"
    key_info = subprocess.check_output(['openssl','rsa','-in',key_path,'-check'],\
                    universal_newlines=True, stderr=subprocess.STDOUT)
    # check if successful
    if ("RSA key ok\n" in key_info):
        return NO_ERROR

    try:
        err = e.output.split('\n')[1].split(':')[5]
        # openssl permissions error
        if (err == "Permission denied"):
            error_info.append((key_path,))
            return ERR_SUDO_PERMS
        # openssl file existence error
        elif (err == "No such file or directory"):
            error_info.append(("file", key_path))
            return ERR_FILE_MISSING
        # openssl some other error
        else:
            error_info.append((key_path, err))
            return ERR_FILE_ACCESS
    # cert error
    except:
        error_info.append((key_path,))
        return ERR_RSA_KEY




# check all packages are installed
def check_installation(interactive, err_codes=True, prev_success=NO_ERROR):
    print("CHECKING INSTALLATION...")
    # keep track of if all tests have been successful
    success = prev_success
    
    if (interactive and err_codes):
        if (ask_install_error_codes() == USER_EXIT):
            return USER_EXIT

    # check OS
    print("Checking if running a supported OS version...")
    checked_os = check_os()
    if (is_error(checked_os)):
        return print_errors(checked_os)
    else:
        success = print_errors(checked_os)
    
    # check space available
    print("Checking if enough disk space is available...")
    checked_space = check_space()
    if (is_error(checked_space)):
        return print_errors(checked_space)
    else:
        success = print_errors(checked_space)

    # check package manager
    print("Checking if machine has a supported package manager...")
    checked_pkg_manager = update_pkg_manager()
    if (is_error(checked_pkg_manager)):
        return print_errors(checked_pkg_manager)
    else:
        success = print_errors(checked_pkg_manager)
    
    # check packages are installed
    print("Checking if packages installed correctly...")
    checked_packages = check_packages()
    if (is_error(checked_packages)):
        return print_errors(checked_packages)
    else:
        success = print_errors(checked_packages)

    # check OMS version
    print("Checking if running a supported version of OMS...")
    checked_oms = check_oms(interactive)
    if (is_error(checked_oms)):
        return print_errors(checked_oms)
    else:
        success = print_errors(checked_oms)

    # check all files
    if (os.path.isdir(DFS_PATH)):
        print("Checking if all files installed correctly (may take some time)...")
        checked_files = check_filesystem(DFS_PATH)
        if (is_error(checked_files)):
            return print_errors(checked_files)
        else:
            success = print_errors(checked_files)
    else:
        print("WARNING (INTERNAL): Datafiles have not been successfully copied over.")
        print("Skipping all files installed correctly check...")

    # check certs
    print("Checking certificate and RSA key are correct...")
    # check cert
    checked_cert = check_cert()
    if (checked_cert != NO_ERROR):
        success = print_errors(checked_cert)
    # check key
    checked_key = check_key()
    if (checked_key != NO_ERROR):
        success = print_errors(checked_key)
    # return if at least one is false
    if (is_error(checked_cert) or is_error(checked_key)):
        return ERR_FOUND
    
    return success