import os
import subprocess

"""
Trivy class

This class should provide the basic methods required by the command line
interface.
"""
class Trivy:
    """
    Trivy class
    """
    def __init__(self, image: str, tag: str):
        self.image = image
        self.tag = tag
        self.registry_username = os.environ.get("REGISTRY_USERNAME", None)
        self.registry_password = os.environ.get("REGISTRY_PASSWORD", None)

    def scan_critical_severity(self, image_src: str = None):
        base = "trivy image"
        suffix = f"{self.image}:{self.tag}"
        if image_src:
            base = f"{base} --image-src {image_src}"

        base = f"{base} --severity Critical --exit-code 1"

        print("Scanning for critical security vulnerabilities...")
        return self.os_system(base=base, suffix=suffix)

    def full_report(self, image_src: str = None):
        base = "trivy image"
        suffix = f"{self.image}:{self.tag}"
        if image_src:
            base = f"{base} --image-src {image_src}"

        base = f"{base} --exit-code 0"

        print("Generating a full scan report...")
        return self.os_system(base=base, suffix=suffix)

    def generate_cdx_report(self, image_src: str = None):
        base = "trivy image"
        suffix = f"{self.image}:{self.tag}"
        if image_src:
            base = f"{base} --image-src {image_src}"

        base = f"{base} --format cyclonedx --output result.cdx"
        self.clean_cdx_report()
        print("Generating a CycloneDX report...")
        return self.os_system(base=base, suffix=suffix)

    def scan_to_promote(self, image_src: str = None):
        output, return_code = self.scan_critical_severity(image_src=image_src)
        print(output)
        if return_code == 1:
            return self.error()
        return self.success()

    def full_scan(self, image_src: str = None, generate_report: bool = True):
        severity_check, sc_return_code = self.scan_critical_severity(image_src=image_src)
        full_report, _ = self.full_report(image_src=image_src)

        print("Printing full report...")
        print(full_report)

        if sc_return_code == 1:
            print("Failed security check scan...")
            return self.error()
        print("Passed security check scan...")

        if not generate_report:
            return self.success()

        _, _ = self.generate_cdx_report(image_src=image_src)

        result = self.get_result()
        if not result:
            print("Failed to generato cdx report...")
            return self.error()

        print(f"Generated cdx report '{result}' successfully...")
        return self.success()

    def os_system(self, base: str, suffix: str):
        extra_vars = None
        if self.registry_username and self.registry_password:
            extra_vars = f"--username {self.registry_username} --password {self.registry_password}"

        cmd = f"{base} {suffix}"
        if extra_vars:
            cmd = f"{base} {extra_vars} {suffix}"
        cmd_result = subprocess.run(cmd.split(" "), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        return cmd_result.stdout.decode("utf-8"), cmd_result.returncode

    def clean_cdx_report(self):
        cwd = os.getcwd()
        result = f"{cwd}/result.cdx"
        print("Cleaning up old cdx file...")
        try:
            os.remove(result)
        except FileNotFoundError:
            return self.error()

        return self.success()

    def get_result(self):
        cwd = os.getcwd()
        result = f"{cwd}/result.cdx"
        if os.path.isfile(result):
            return result
        else:
            return False

    def success(self):
        return True

    def error(self):
        return False