#########################################################################################
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.                    #
# SPDX-License-Identifier: MIT-0                                                        #
#                                                                                       #
# Permission is hereby granted, free of charge, to any person obtaining a copy of this  #
# software and associated documentation files (the "Software"), to deal in the Software #
# without restriction, including without limitation the rights to use, copy, modify,    #
# merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    #
# permit persons to whom the Software is furnished to do so.                            #
#                                                                                       #
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   #
# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         #
# PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    #
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION     #
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE        #
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#########################################################################################

import paramiko


def execute_cmd(host, username, key, cmd, using_key):
    output = ''
    error = ''
    ssh = None
    try:
        ssh = open_ssh(host, username, key, using_key)
        if ssh is None:
            error = "Not able to get the SSH connection for the host " + host
            print(error)
        else:
            stdin, stdout, stderr = ssh.exec_command(cmd)  # nosec B601
            for line in stdout.readlines():
                output = output + line
            for line in stderr.readlines():
                error = error + line
    except IOError as io_error:
        error = "Unable to execute the command " + cmd + " due to " + \
                str(io_error)
        print(error)
    except paramiko.SSHException as ssh_exception:
        error = "Unable to execute the command " + cmd + " due to " + \
                str(ssh_exception)
        print(error)
    finally:
        if ssh is not None:
            ssh.close()
    return output, error


def open_ssh(host, username, key_pwd, using_key):
    ssh = None
    try:
        if using_key:
            private_key = paramiko.RSAKey.from_private_key_file(key_pwd)
            ssh = paramiko.SSHClient()
            ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
            ssh.connect(hostname=host, username=username, pkey=private_key)
        else:
            ssh = paramiko.SSHClient()
            ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
            ssh.connect(hostname=host, username=username, password=key_pwd)
    except IOError as io_error:
        error = "Unable to connect to host " + host + " with username " + \
                username + " due to " + str(io_error)
        print(error)
    except paramiko.SSHException as ssh_exception:
        error = "Unable to connect to host " + host + " with username " + \
                username + " due to " + str(ssh_exception)
        print(error)
    return ssh


def find_distribution(host, username, key_pwd, using_key):
    distribution = "linux"
    output, error = execute_cmd(host, username, key_pwd, "cat /etc/*release",
                                using_key)
    if "ubuntu" in output:
        distribution = "ubuntu"
    elif "fedora" in output:
        distribution = "fedora"
    elif "suse" in output:
        distribution = "suse"
    return distribution


def install_wget(host, username, key_pwd, using_key):
    ssh = None
    try:
        # Find the distribution
        distribution = find_distribution(host, username, key_pwd, using_key)
        print("")
        print("***** Installing wget *****")
        ssh = open_ssh(host, username, key_pwd, using_key)
        if distribution == "ubuntu":
            ssh.exec_command("sudo apt-get update")  # nosec B601
            stdin, stdout, stderr = ssh.exec_command(  # nosec B601
                "sudo DEBIAN_FRONTEND=noninteractive apt-get install wget")
        elif distribution == "suse":
            stdin, stdout, stderr = ssh.exec_command("sudo zypper install wget")  # nosec B601
            stdin.write('Y\n')
            stdin.flush()
        else:
            # This condition works with centos, fedora and RHEL distributions
            ssh.exec_command("sudo yum update")  # nosec B601
            stdin, stdout, stderr = ssh.exec_command("sudo yum install wget -y")  # nosec B601
        # Check if there is any error while installing wget
        error = ''
        for line in stderr.readlines():
            error = error + line
        if not error:
            print("wget got installed successfully")
            # Execute the command wget and check if it got configured correctly
            stdin, stdout, stderr = ssh.exec_command("wget")  # nosec B601
            error = ''
            for line in stderr.readlines():
                error = error + line
            if "not found" in error or "command-not-found" in error:
                print(
                    "wget is not recognized, unable to proceed! due to " + error)
        else:
            print("something went wrong while installing wget ", error)
    finally:
        if ssh is not None:
            ssh.close()


def check_python(host, username, key_pwd, using_key):
    output, error = execute_cmd(host, username, key_pwd, "python --version",
                                using_key)
    if error:
        if "Python 2" in error:
            return True
        else:
            return False
    else:
        return True


def check_python3(host, username, key_pwd, using_key):
    output, error = execute_cmd(host, username, key_pwd, "python3 --version",
                                using_key)
    if error:
        if "Python 3" in error:
            return True
        else:
            return False
    else:
        return True


def install_python3(host, username, key_pwd, using_key):
    ssh = None
    try:
        print("")
        print("***** Installing python3 *****")
        ssh = open_ssh(host, username, key_pwd, using_key)
        # Find the distribution
        distribution = find_distribution(host, username, key_pwd, using_key)
        if distribution == "ubuntu":
            ssh.exec_command("sudo apt-get update")  # nosec B601
            command = "sudo DEBIAN_FRONTEND=noninteractive apt-get install " \
                      "python3"
            stdin, stdout, stderr = ssh.exec_command(command)  # nosec B601
            stdin.write('Y\n')
            stdin.flush()
        elif distribution == 'suse':
            stdin, stdout, stderr = ssh.exec_command("sudo zypper install python3")  # nosec B601
            stdin.write('Y\n')
            stdin.flush()
        elif distribution == "fedora":
            stdin, stdout, stderr = ssh.exec_command("sudo dnf install python3")  # nosec B601
            stdin.write('Y\n')
            stdin.flush()
        else: #This installs on centos
            ssh.exec_command("sudo yum update")  # nosec B601
            ssh.exec_command("sudo yum install centos-release-scl")  # nosec B601
            ssh.exec_command("sudo yum install rh-python36")  # nosec B601
            ssh.exec_command("scl enable rh-python36 bash")  # nosec B601
            stdin, stdout, stderr = ssh.exec_command("python --version")  # nosec B601
        error = ''
        for line in stderr.readlines():
            error = error + line
        if not error:
            print("python got installed successfully")
        else:
            print(error)
    finally:
        if ssh is not None:
            ssh.close()


def install_cloud_endure(host, username, key_pwd, using_key, install_token):
    print("")
    print("")
    print("--------------------------------------------------------")
    print("- Installing CloudEndure for:  "+ host + " -")
    print("--------------------------------------------------------")
    try:
        output = None
        error = None
        command = "wget -O ./installer_linux.py " \
              "https://console.cloudendure.com/installer_linux.py"
        output, error = execute_cmd(host=host, username=username, key=key_pwd,
                                cmd=command, using_key=using_key)
        if "not found" in error or "No such file or directory" in error:
            install_wget(host, username, key_pwd, using_key)
            output, error = execute_cmd(host=host, username=username, key=key_pwd,
                                    cmd=command, using_key=using_key)
        # Check if python is already installed if not install python3
        python_str = "python"
        if not check_python(host, username, key_pwd, using_key):
            if not check_python3(host, username, key_pwd, using_key):
                install_python3(host, username, key_pwd, using_key)
                python_str = "python3"
            else:
                python_str = "python3"
        # Step 2 - execute linux installer
        command = "sudo " + python_str + " ./installer_linux.py -t " + \
              install_token + " --no-prompt"
        print("Executing " + command)
        output, error = execute_cmd(host=host, username=username, key=key_pwd,
                                cmd=command, using_key=using_key)
        print(output)
    except Exception as e:
        error = 'Got exception! ' + str(e)
    if not error and 'Error: Installation failed' not in output:
        print("***** CloudEndure installation completed successfully on "
              +host+ "*****")
        return True
    else:
        print("Unable to install CloudEndure on "+host+" due to: ")
        print("")
        if output:
            print(output)
        print(error)
        return False