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# Copyright (C) 2019 VMWare, Inc.                                      #
# All Rights Reserved                                                  #
########################################################################

'''
Define the base class for _ReleaseCollection and concrete classes
BaseImageCollection and AddonCollection, which are dictionaries of
specific release types.

Provide functionality such as serialization to a directory, deserialization
from a dictionary, adding single release object from JSON spec.
'''

import os
import sys
import shutil
from copy import deepcopy

from .Addon import Addon
from .BaseImage import BaseImage
from .Errors import (ReleaseUnitIOError, ReleaseUnitConflictError,
                     ManifestValidationError)
from .Manifest import Manifest
from .Solution import Solution
from .Utils.Misc import isPython3OrLater

genReleaseUnitFileName = lambda x: x.replace(':', '_') + '.json'

def _ToStr(spec):
   """Convert bytes to str.
   """
   if isinstance(spec, bytes):
      spec = spec.decode("utf-8")
   return spec

def _CheckDirectory(path, operation):
   """Check a path is a directory or not. If not, ReleaseUnitIOError
      is raised.
   """
   if not os.path.isdir(path):
      msg = 'Failed to %s ReleaseCollection, %s is not a directory.' % \
            (operation, path)
      raise ReleaseUnitIOError(msg)

def _CheckSupportedBIVersionOverlap(biVersions, biVersionsToAdd):
   """Checks if there is any overlap in two given lists of supported base
      image versions.
      The supported base image versions are full or partial base image versions
      without wild cards (*).

      Example:
         Version1: 7.1
         Version2: 7.1.0
         Version3: 7.1.0-1.1.12345
         Version4: 7.1.1-2.2.23456
         Version1 conflicts with Version2, Version3 and Version4
         Version2 conflicts with Version3

      Params:
         * biVersions - Supported base image versions of an existing manifest
         * biVersionsToAdd - Supported base image versions of the manifest to
                             be added

      Return:
         True if there is overlap between two lists of supported base image
         versions
   """
   for v1 in biVersions:
      for v2 in biVersionsToAdd:
         if v1.startswith(v2) or v2.startswith(v1):
            return True
   return False

class _ReleaseCollection(dict):
   """The parent class to hold the common code for the release unit
      collection classes.
   """

   def update(self, other):
      """Merge another ReleaseCollection into the current one: check whether
         unequal release units share the same release ID.

         Exceptions:
            ReleaseUnitConflictError : When unequal release units share the
                                       same release ID.
      """
      for releaseID in other:
         if releaseID in self:
            if self[releaseID] != other[releaseID]:
               releaseType = self[releaseID].releaseType.lower()
               msg = ('Two %ss share the same releaseID: %s' %
                      (releaseType, releaseID))
               raise ReleaseUnitConflictError(releaseID, releaseType, msg)
         else:
            self[releaseID] = other[releaseID]

   def __add__(self, other):
      """Adds two ReleaseCollections and return a new collection.
      """
      newCollection = self.__class__()
      newCollection.update(self)
      newCollection.update(other)
      return newCollection

   def __iadd__(self, other):
      """Adds the items of second ReleaseCollection into this one.
      """
      self.update(other)
      return self

   def ToDirectory(self, path):
      """Write release unit objects to directory.
            Parameters:
               * path - A string specifying a directory name.

            Exceptions:
               * ReleaseUnitIOError - The specified directory is not a directory
                                      or cannot create an empty directory
      """

      if not self:
         return

      try:
         if os.path.isdir(path):
            shutil.rmtree(path)
         os.makedirs(path)
      except EnvironmentError as e:
         msg = 'Could not create dir %s for %s: %s' % \
               (path, self.__class__.__name__, e)
         raise ReleaseUnitIOError(msg)

      _CheckDirectory(path, 'write')

      for ut in self.values():
         filepath = os.path.join(path, genReleaseUnitFileName(ut.releaseID))
         try:
            with open(filepath, 'wb') as f:
               f.write(ut.ToJSON().encode('utf-8'))
         except (EnvironmentError, IOError) as e:
            msg = ('Failed to write %s file %s: %s' %
                   (ut.releaseUnitType, filepath, e))
            raise ReleaseUnitIOError(msg)

   def FromDirectory(self, path, validate=False):
      """Populate this _ReleaseColelction instance from a directory of
         base image or addon JSON files.
            Parameters:
               * path - A string specifying a directory name.
               * validate - If true perform metadata schema validation.

            Raises:
               * ReleaseUnitIOError - Path not found, or read error
               * ValueError     - When the spec doesn't contain mandatory data
      """

      if not os.path.exists(path):
         msg = 'The directory %s for base image/addon does not exist.' % (path)
         raise ReleaseUnitIOError(msg)

      _CheckDirectory(path, 'read')

      for root, dirs, files in os.walk(path, topdown=True):
         for name in files:
            filepath = os.path.join(root, name)
            try:
               with open(filepath, 'r') as fp:
                  self.AddFromJSON(fp.read(), validate=validate)
            except (EnvironmentError, IOError) as e:
               raise ReleaseUnitIOError("Could not read the file %s: %s" %
                                    (filepath, e))

class BaseImageCollection(_ReleaseCollection):

   def AddBaseImage(self, baseImageToAdd, replace=False):
      """Adds a Base Image to the collection

         Params:
            * baseImageToAdd - The Base Image to add to the collection
            * replace - If a Base Image already exists with the same version
                        or release ID, replace it.

         Exceptions:
            * KeyError - When attempting to add a Base Image whose version
                         or release ID already exists in the the collection
                         and replace=False
      """
      version = baseImageToAdd.versionSpec.version.versionstring
      if self.HasBaseImage(version):
         if replace:
            self.RemoveBaseImage(version)
         else:
            raise KeyError('A Base Image with Version: %s already'
                           ' exists in the collection' % version)

      if baseImageToAdd.releaseID in self:
         if replace:
            del self[baseImageToAdd.releaseID]
         else:
            raise KeyError('A Base Image with Release ID: %s already exists in'
                           ' the collection' % baseImageToAdd.releaseID)

      self[baseImageToAdd.releaseID] = baseImageToAdd

   def HasBaseImage(self, version):
      """Checks if a Base Image with a version exists in the collection

      Params:
         * version - The version of the Base Image

      Return:
         True if the Base Image is in the collection, otherwise false
      """
      try:
         self.GetBaseImage(version)
      except:
         return False
      return True

   def GetBaseImage(self, version):
      """Gets a Base Image based upon a version from the collection

         Params:
            * version - The version of the Base Image to get

         Return:
            A Base Image with version from the collection

         Exceptions:
            * KeyError - When no Base Image of the specified version exists
                         in the collection
      """
      for baseImage in self.values():
         if baseImage.versionSpec.version.versionstring == version:
            return baseImage

      raise KeyError('Unable to find a Base Image with Version: %s' % version)

   def RemoveBaseImage(self, version):
      """Removes a Base Image from the collection

         Params:
            * version - The version of the Base Image to remove

         Exceptions:
            * KeyError - When no Base Image of the specified version exists
                         in the collection
      """
      baseImageToRemove = self.GetBaseImage(version)
      del self[baseImageToRemove.releaseID]

   def AddFromJSON(self, spec, validate=False):
      """The interface method to add base image object from JSON string.
      """
      spec = _ToStr(spec)
      image = BaseImage.FromJSON(spec, validation=validate)
      self[image.releaseID] = image

class AddonCollection(_ReleaseCollection):

   def AddAddon(self, addonToAdd, replace=False):
      """Adds an Addon to the collection

         Params:
            * addOnToAdd - The Addon to add to the collection
            * replace - If an Addon already exists with the same name/version
                        or release ID, replace it.

         Exceptions:
            * KeyError - When attempting to add an Addon whose name, version
                         or release Id already exists in the the collection
                         and replace=False
      """
      if self.HasAddon(addonToAdd.nameSpec.name,
                       addonToAdd.versionSpec.version.versionstring):
         if replace:
            self.RemoveAddon(addonToAdd.nameSpec.name,
                             addonToAdd.versionSpec.version.versionstring)
         else:
            raise KeyError('An Addon with Name: %s and Version: %s already'
                           ' exists in the collection' %
                            (addonToAdd.nameSpec.name,
                             addonToAdd.versionSpec.version.versionstring))

      # There could be the case where the ID we generate is already used
      if addonToAdd.releaseID in self:
         if replace:
            del self[addonToAdd.releaseID]
         else:
            raise KeyError('An Addon with Release ID: %s already exists in the'
                           ' collection' % addonToAdd.releaseID)

      self[addonToAdd.releaseID] = addonToAdd

   def HasAddon(self, name, version):
      """Checks if an Addon with name and version exists in the collection

         Params:
            * name - The name of the Addon
            * version - The version of the Addon

         Return:
            True if the Addon was in the collection, otherwise false.
      """
      try:
         self.GetAddon(name, version)
      except:
         return False
      return True

   def GetAddonsFromNameSpec(self, nameSpec):
      """Gets a list of Addons based upon name or name:version from the collection

         Params:
            * nameSpec - name or name:version of Addon to get

         Returns:
            A list of addon with name or name:version

         Exceptions:
            * KeyError - When the Addon we are trying to find doesn't
                         exist in the collection
      """
      addonList = []
      if ':' in nameSpec:
         # Colon Spec.
         name, version = nameSpec.split(':')
         addon = self.GetAddon(name, version)
         addonList.append(addon)
      else:
         name = nameSpec
         for addon in self.values():
            if addon.nameSpec.name == name:
               addonList.append(addon)
      return addonList


   def GetAddon(self, name, version):
      """Gets an Addon based upon name and version from the collection

         Params:
            * name - The name of the Addon to get
            * version - The version of the Addon to get

         Returns:
            An addon with name and version

         Exceptions:
            * KeyError - When the Addon we are trying to find doesn't
                         exist in the collection
      """
      for addon in self.values():
         if (addon.nameSpec.name == name and
             addon.versionSpec.version.versionstring == version):
            return addon

      raise KeyError('Unable to find an Addon with Name: %s and Version: %s'
                     % (name, version))

   def RemoveAddon(self, name, version):
      """Removes an Addon from the collection

         Params:
            * name - The name of the Addon to remove
            * version - The version of the Addon to remove

         Exceptions:
            * KeyError - When the Addon we are trying to find doesn't
                         exist in the collection
      """
      addonToRemove = self.GetAddon(name, version)
      del self[addonToRemove.releaseID]

   def AddFromJSON(self, spec, validate=False):
      """The interface method to add addon object from JSON string.
      """
      spec = _ToStr(spec)
      addon = Addon.FromJSON(spec, validation=validate)
      self[addon.releaseID] = addon

   def Copy(self):
      '''Copies AddonCollection object.'''
      addons = AddonCollection()
      for releaseId, addon in self.items():
         addons[releaseId] = addon.Copy()
      return addons

class SolutionCollection(_ReleaseCollection):
   def AddFromJSON(self, spec, validate=False):
      """The interface method to add solution object from JSON string.
      """
      spec = _ToStr(spec)
      solution = Solution.FromJSON(spec, validation=validate)
      self[solution.releaseID] = solution

   def AddSolution(self, solutionToAdd, replace=False):
      """Adds a Solution to the collection

         Params:
            * solutionToAdd - The Solution to add to the collection
            * replace - If an Solution already exists with the same
                         name/version or release ID, replace it.

         Exceptions:
            * KeyError - When attempting to add an Solution whose name/version
                         or release Id already exists in the the collection
                         and replace=False
      """
      if self.HasSolution(solutionToAdd.nameSpec.name,
                          solutionToAdd.versionSpec.version.versionstring):
         if replace:
            self.RemoveSolution(solutionToAdd.nameSpec.name,
                                solutionToAdd.versionSpec.version.versionstring)
         else:
            raise KeyError('An Solution with Name: %s and Version: %s already'
                           ' exists in the collection' %
                            (solutionToAdd.nameSpec.name,
                             solutionToAdd.versionSpec.version.versionstring))

      if solutionToAdd.releaseID in self:
         if replace:
            del self[solutionToAdd.releaseID]
         else:
            raise KeyError('An Solution with Release ID: %s already exists in'
                           ' the collection' % solutionToAdd.releaseID)

      self[solutionToAdd.releaseID] = solutionToAdd

   def HasSolution(self, name, version):
      """Checks if a solution with a name and version exists in the collection

         Params:
            * name - The name of the solution
            * version - The version of the solution

         Return:
            True if the solution was in the collection, otherwise false.
      """
      try:
         self.GetSolution(name, version)
      except:
         return False
      return True

   def GetSolution(self, name, version):
      """Gets a solution base upon name and version from the collection

         Params:
            * name - The name of the solution to get
            * version - The version of the solution to get

         Exception:
            * KeyError - When a Solution with name and version can't be
                         found

         Return:
            A solution with name and version
      """
      for solution in self.values():
         if (solution.nameSpec.name == name and
             solution.versionSpec.version.versionstring == version):
            return solution

      raise KeyError('Unable to find a Solution with Name: %s and Version: %s'
                      % (name, version))

   def RemoveSolution(self, name, version):
      """Removes a solution to the Solution Collection

         Exception:
            * KeyError - When a Solution with name and version can't be
                         found
         Params:
            * name - The name of the solution to remove
            * version - The version of the solution to remove

      """
      solutionToRemove = self.GetSolution(name, version)
      del self[solutionToRemove.releaseID]

class ManifestCollection(_ReleaseCollection):

   def update(self, other):
      for manifest in other.values():
         self._CheckManifestConflict(manifest)
      super(ManifestCollection, self).update(other)

   def AddManifest(self, manifestToAdd, replace=False):
      """Adds a manifest to the collection

         Params:
            * manifestToAdd - The manifest to add to the collection
            * replace - If a manifest already exists with the same release ID,
                        replace it.

         Exceptions:
            * KeyError - When attempting to add a manifest whose release ID
                         already exists in the the collection and replace is
                         False
      """
      self._CheckManifestConflict(manifestToAdd)
      releaseID = manifestToAdd.releaseID
      if releaseID in self:
         if replace:
            del self[releaseID]
         else:
            raise KeyError('A manifest with Release ID: %s already exists in'
                           ' the collection' % releaseID)
      self[releaseID] = manifestToAdd

   def _CheckManifestConflict(self, manifestToAdd):
      """Check if the manifest to be added has same hardware support information
         and overlapping supported base image versions of any existing manifests
         in the manifest collection

         Params:
            * manifestToAdd - The manifest to be added to the manifest
                              collection

         Exceptions:
            * ManifestValidationError -
                         When attempting to add a manifest that has same
                         hardware support information with an existing manifest
                         and has overlapping supported base image versions with
                         the existing manifest
      """
      for manifest in self.values():
         if manifest.releaseID == manifestToAdd.releaseID:
            continue
         if (manifest.hardwareSupportInfo == manifestToAdd.hardwareSupportInfo
             and _CheckSupportedBIVersionOverlap(
                    manifest.supportedBaseImageVersions,
                    manifestToAdd.supportedBaseImageVersions)):
            msg = ('An existing manifest: %s and the manifest to be added: %s'
                   ' have same hardware support information and overlapping'
                   ' supported base image versions'
                   % (manifest.releaseID, manifestToAdd.releaseID))
            raise ManifestValidationError(msg)

   def HasManifest(self, releaseID):
      """Checks if a manifest with a releaseID exists in the collection

      Params:
         * releaseID - The releaseID of the manifest

      Return:
         True if the manifest is in the collection, otherwise false
      """
      return releaseID in self

   def GetManifest(self, releaseID):
      """Gets a manifest based upon a releaseID from the collection

         Params:
            * releaseID - The version of the manifest to get

         Return:
            A manifest with releaseID from the collection

         Exceptions:
            * KeyError - When no manifest of the specified releaseID exists
                         in the collection
      """
      try:
         return self[releaseID]
      except KeyError:
         raise KeyError('Unable to find a manifest with release ID: %s' %
                        releaseID)

   def RemoveManifest(self, releaseID):
      """Removes a manifest from the collection

         Params:
            * releaseID - The releaseID of the manifest to remove

         Exceptions:
            * KeyError - When no manifest of the specified releaseID exists
                         in the collection
      """
      manifestToRemove = self.GetManifest(releaseID)
      del self[manifestToRemove.releaseID]

   def AddFromJSON(self, spec, validate=False):
      """The interface method to add manifest object from JSON string.
      """
      spec = _ToStr(spec)
      manifest = Manifest.FromJSON(spec, validate)
      self.AddManifest(manifest, True)

   def Copy(self):
      '''Copies ManifestCollection object.'''
      manifests = ManifestCollection()
      for releaseId, manifest in self.items():
         manifests[releaseId] = manifest.Copy()
      return manifests