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

import os
import sys

from enum import Enum
from lxcmgr import lxcmgr

from .imagebuilder import ImageBuilder, ImageExistsError, ImageNotFoundError
from .imagepacker import ImagePacker
from .packer import PackageExistsError

class BuildType(Enum):
    NORMAL = 1
    FORCE = 2
    SCRATCH = 3
    METADATA = 4

class Image:
    def __init__(self):
        self.name = None
        self.conf = {}
        self.lxcfile = None
        self.build_dir = None
        self.build_type = BuildType.NORMAL
        self.pack = False

    def build_and_pack(self, lxcfile):
        self.lxcfile = lxcfile
        self.build_dir = os.path.dirname(lxcfile)
        self.conf['build'] = True
        builder = ImageBuilder(self)
        try:
            builder.build()
            # Packaging needs to happen in any case after a successful build in order to prevent outdated packages
            self.pack = True
        except ImageExistsError as e:
            # If container already exists and build hasn't been forced, rerun the build just for metadata which are still needed for packaging
            print('Image {} already exists, skipping build tasks'.format(e))
            self.build_type = BuildType.METADATA
            builder.build()
        except ImageNotFoundError as e:
            # If one of the layers is missing, cleanup and die
            print('Image {} not found, can\'t build {}'.format(e, self.name))
            builder.clean()
            sys.exit(1)
        except:
            # If build fails with another exception, cleanup (unless we were doing scratch build) and re-raise
            if not self.build_type == BuildType.SCRATCH:
                builder.clean()
            raise
        del self.conf['build']
        # If we're doing a scratch build, regenerate the final LXC container configuration including ephemeral layer
        if self.build_type == BuildType.SCRATCH:
            lxcmgr.create_container(self.name, self.conf)
        else:
            try:
                packer = ImagePacker(self)
                packer.pack()
            except PackageExistsError as e:
                print('Package {} already exists, skipping packaging tasks'.format(e))

    def remove(self):
        builder = ImageBuilder(self)
        builder.clean()
        packer = ImagePacker(self)
        packer.remove()