# ------------------------------------------------------------------------------
# This file is part of Appy, a framework for building applications in the Python
# language. Copyright (C) 2007 Gaetan Delannay

# Appy is free software; you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation; either version 3 of the License, or (at your option) any later
# version.

# Appy is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU General Public License for more details.

# You should have received a copy of the GNU General Public License along with
# Appy. If not, see <http://www.gnu.org/licenses/>.

# ------------------------------------------------------------------------------
import time, os.path, mimetypes, shutil
from DateTime import DateTime
from appy import Object
from appy.fields import Field
from appy.px import Px
from appy.shared import utils as sutils
from appy.shared import UnmarshalledFile, mimeTypesExts

# ------------------------------------------------------------------------------
WRONG_FILE_TUPLE = 'This is not the way to set a file. You can specify a ' \
    '2-tuple (fileName, fileContent) or a 3-tuple (fileName, fileContent, ' \
    'mimeType).'
CONVERSION_ERROR = 'An error occurred. %s'

# ------------------------------------------------------------------------------
class FileInfo:
    '''For a "file" field, its binary content is stored on the filesystem.
       Within the database, we store a FileInfo instance that only stores some
       metadata.'''
    BYTES = 5000
    def __init__(self, fsPath):
        # The path on disk (from the root DB folder) where the file will be
        # stored.
        self.fsPath = fsPath
        self.fsName = None # The name of the file in fsPath
        self.uploadName = None # The name of the uploaded file
        self.size = 0 # Its size, in bytes
        self.mimeType = None # Its MIME type
        self.modified = None # The last modification date for this file.

    def getFilePath(self, obj):
        '''Returns the absolute file name of the file on disk that corresponds
           to this FileInfo instance.'''
        dbFolder, folder = obj.o.getFsFolder()
        return os.path.join(dbFolder, folder, self.fsName)

    def removeFile(self, dbFolder, removeEmptyFolders=False):
        '''Removes the file from the filesystem.'''
        try:
            os.remove(os.path.join(dbFolder, self.fsPath, self.fsName))
        except Exception, e:
            # If the current ZODB transaction is re-triggered, the file may
            # already have been deleted.
            pass
        # Don't leave empty folders on disk. So delete folder and parent folders
        # if this removal leaves them empty (unless p_removeEmptyFolders is
        # False).
        if removeEmptyFolders:
            sutils.FolderDeleter.deleteEmpty(os.path.join(dbFolder,self.fsPath))

    def normalizeFileName(self, name):
        '''Normalizes file p_name.'''
        return name[max(name.rfind('/'), name.rfind('\\'), name.rfind(':'))+1:]

    def getShownSize(self):
        '''Displays this file's size in the user interface.'''
        if self.size < 1024:
            # Display the size in bytes
            return '%d byte(s)' % self.size
        else:
            # Display the size in Kb
            return '%d Kb' % (self.size / 1024)

    def replicateFile(self, src, dest):
        '''p_src and p_dest are open file handlers. This method copies content
           of p_src to p_dest and returns the file size.'''
        size = 0
        while True:
            chunk = src.read(self.BYTES)
            if not chunk: break
            size += len(chunk)
            dest.write(chunk)
        return size

    def writeFile(self, fieldName, fileObj, dbFolder):
        '''Writes to the filesystem the p_fileObj file, that can be:
           - a Zope FileUpload (coming from a HTTP post);
           - a OFS.Image.File object (legacy within-ZODB file object);
           - a tuple (fileName, fileContent, mimeType)
             (see doc in method File.store below).'''
        # Determine p_fileObj's type.
        fileType = fileObj.__class__.__name__
        # Set MIME type.
        if fileType == 'FileUpload':
            mimeType = fileObj.headers.get('content-type')
        elif fileType == 'File':
            mimeType = fileObj.content_type
        else:
            mimeType = fileObj[2]
        self.mimeType = mimeType or File.defaultMimeType
        # Determine the original name of the file to store.
        fileName= fileType.startswith('File') and fileObj.filename or fileObj[0]
        if not fileName:
            # Name it according to field name. Deduce file extension from the
            # MIME type.
            ext = (self.mimeType in mimeTypesExts) and \
                  mimeTypesExts[self.mimeType] or 'bin'
            fileName = '%s.%s' % (fieldName, ext)
        # As a preamble, extract file metadata from p_fileObj and store it in
        # this FileInfo instance.
        name = self.normalizeFileName(fileName)
        self.uploadName = name
        self.fsName = '%s%s' % (fieldName, os.path.splitext(name)[1].lower())
        # Write the file on disk (and compute/get its size in bytes)
        fsName = os.path.join(dbFolder, self.fsPath, self.fsName)
        f = file(fsName, 'wb')
        if fileType == 'FileUpload':
            # Write the FileUpload instance on disk.
            self.size = self.replicateFile(fileObj, f)
        elif fileType == 'File':
            # Write the File instance on disk.
            if fileObj.data.__class__.__name__ == 'Pdata':
                # The file content is splitted in several chunks.
                f.write(fileObj.data.data)
                nextPart = fileObj.data.next
                while nextPart:
                    f.write(nextPart.data)
                    nextPart = nextPart.next
            else:
                # Only one chunk
                f.write(fileObj.data)
            self.size = fileObj.size
        else:
            # Write fileObj[1] on disk.
            if fileObj[1].__class__.__name__ == 'file':
                # It is an open file handler.
                self.size = self.replicateFile(fileObj[1], f)
            else:
                # We have file content directly in fileObj[1]
                self.size = len(fileObj[1])
                f.write(fileObj[1])
        f.close()
        self.modified = DateTime()

    def copyFile(self, fieldName, filePath, dbFolder):
        '''Copies the "external" file stored at _filePath in the db-controlled
           file system, for storing a value for p_fieldName.'''
        # Set names for the file
        name = self.normalizeFileName(filePath)
        self.uploadName = name
        self.fsName = '%s%s' % (fieldName, os.path.splitext(name)[1])
        # Set mimeType
        self.mimeType= mimetypes.guess_type(filePath)[0] or File.defaultMimeType
        # Copy the file
        shutil.copyfile(filePath, self.fsName)
        self.modified = DateTime()
        self.size = os.stat(self.fsName).st_size

    def writeResponse(self, response, dbFolder):
        '''Writes this file in the HTTP p_response object.'''
        # As a preamble, initialise response headers.
        header = response.setHeader
        header('Content-Disposition', 'inline;filename="%s"' % self.uploadName)
        header('Content-Type', self.mimeType)
        header('Content-Length', self.size)
        header('Accept-Ranges', 'bytes')
        header('Last-Modified', self.modified.rfc822())
        #sh('Cachecontrol', 'no-cache')
        #sh('Expires', 'Thu, 11 Dec 1975 12:05:05 GMT')
        # Write the file in the response
        fsName = os.path.join(dbFolder, self.fsPath, self.fsName)
        f = file(fsName, 'rb')
        while True:
            chunk = f.read(self.BYTES)
            if not chunk: break
            response.write(chunk)
        f.close()

    def dump(self, obj, filePath=None, format=None):
        '''Exports this file to disk (outside the db-controller filesystem).
           The tied Appy p_obj(ect) is required. If p_filePath is specified, it
           is the path name where the file will be dumped; folders mentioned in
           it must exist. If not, the file will be dumped in the OS temp folder.
           The absolute path name of the dumped file is returned. If an error
           occurs, the method returns None. If p_format is specified,
           LibreOffice will be called for converting the dumped file to the
           desired format.'''
        if not filePath:
            filePath = '%s/file%f.%s' % (sutils.getOsTempFolder(), time.time(),
                                         self.fsName)
        # Copies the file to disk.
        shutil.copyfile(self.getFilePath(obj), filePath)
        if format:
            # Convert the dumped file using LibreOffice
            errorMessage = obj.tool.convert(filePath, format)
            # Even if we have an "error" message, it could be a simple warning.
            # So we will continue here and, as a subsequent check for knowing if
            # an error occurred or not, we will test the existence of the
            # converted file (see below).
            os.remove(filePath)
            # Return the name of the converted file.
            baseName, ext = os.path.splitext(filePath)
            if (ext == '.%s' % format):
                filePath = '%s.res.%s' % (baseName, format)
            else:
                filePath = '%s.%s' % (baseName, format)
            if not os.path.exists(filePath):
                obj.log(CONVERSION_ERROR % errorMessage, type='error')
                return
        return filePath

# ------------------------------------------------------------------------------
class File(Field):

    pxView = pxCell = Px('''
     <x var="downloadUrl='%s/download?name=%s' % (zobj.absolute_url(), name);
             shownSize=value and value.getShownSize() or 0">
      <x if="value and not field.isImage">
       <a href=":downloadUrl">:value.uploadName</a>&nbsp;&nbsp;-
       <i class="discreet">:shownSize</i>
      </x>
      <x if="value and field.isImage">
       <img src=":downloadUrl"
            title=":'%s, %s' % (value.uploadName, shownSize)"/></x>
      <x if="not value">-</x>
     </x>''')

    pxEdit = Px('''
     <x var="fName=q('%s_file' % name)">
      <x if="value">:field.pxView</x><br if="value"/>
      <x if="value">
       <!-- Keep the file unchanged. -->
       <input type="radio" value="nochange"
              checked=":value and 'checked' or None"
              name=":'%s_delete' % name" id=":'%s_nochange' % name"
              onclick=":'document.getElementById(%s).disabled=true' % fName"/>
       <label lfor=":'%s_nochange' % name">Keep the file unchanged</label><br/>
       <!-- Delete the file. -->
       <x if="not field.required">
        <input type="radio" value="delete"
               name=":'%s_delete' % name" id=":'%s_delete' % name"
               onclick=":'document.getElementById(%s).disabled=true' % fName"/>
        <label lfor=":'%s_delete' % name">Delete the file</label><br/>
       </x>
       <!-- Replace with a new file. -->
       <input type="radio" value=""
              checked=":not value and 'checked' or None"
              name=":'%s_delete' % name" id=":'%s_upload' % name"
              onclick=":'document.getElementById(%s).disabled=false' % fName"/>
       <label lfor=":'%s_upload' % name">Replace it with a new file</label><br/>
      </x>
      <!-- The upload field. -->
      <input type="file" name=":'%s_file' % name" id=":'%s_file' % name"
             size=":field.width"/>
      <script var="isDisabled=not value and 'false' or 'true'"
             type="text/javascript">:'document.getElementById(%s).disabled=%s'%\
                                     (q(fName), q(isDisabled))</script></x>''')

    pxSearch = ''

    def __init__(self, validator=None, multiplicity=(0,1), default=None,
                 show=True, page='main', group=None, layouts=None, move=0,
                 indexed=False, searchable=False, specificReadPermission=False,
                 specificWritePermission=False, width=None, height=None,
                 maxChars=None, colspan=1, master=None, masterValue=None,
                 focus=False, historized=False, mapping=None, label=None,
                 isImage=False, sdefault='', scolspan=1, swidth=None,
                 sheight=None):
        self.isImage = isImage
        Field.__init__(self, validator, multiplicity, default, show, page,
                       group, layouts, move, indexed, False,
                       specificReadPermission, specificWritePermission, width,
                       height, None, colspan, master, masterValue, focus,
                       historized, True, mapping, label, sdefault, scolspan,
                       swidth, sheight)

    @staticmethod
    def getFileObject(filePath, fileName=None, zope=False):
        '''Returns a File instance as can be stored in the database or
           manipulated in code, filled with content from a file on disk,
           located at p_filePath. If you want to give it a name that is more
           sexy than the actual basename of p_filePath, specify it in
           p_fileName.

           If p_zope is True, it will be the raw Zope object = an instance of
           OFS.Image.File. Else, it will be a FileWrapper instance from Appy.'''
        f = file(filePath, 'rb')
        if not fileName:
            fileName = os.path.basename(filePath)
        fileId = 'file.%f' % time.time()
        import OFS.Image
        res = OFS.Image.File(fileId, fileName, f)
        res.filename = fileName
        res.content_type = mimetypes.guess_type(fileName)[0]
        f.close()
        if not zope: res = sutils.FileWrapper(res)
        return res

    def getRequestValue(self, request, requestName=None):
        name = requestName or self.name
        return request.get('%s_file' % name)

    def getDefaultLayouts(self): return {'view':'l-f','edit':'lrv-f'}

    def isEmptyValue(self, value, obj=None):
        '''Must p_value be considered as empty?'''
        if not obj: return Field.isEmptyValue(self, value)
        if value: return False
        # If "nochange", the value must not be considered as empty
        return obj.REQUEST.get('%s_delete' % self.name) != 'nochange'

    imageExts = ('.jpg', '.jpeg', '.png', '.gif')
    def validateValue(self, obj, value):
        form = obj.REQUEST.form
        action = '%s_delete' % self.name
        if (not value or not value.filename) and form.has_key(action) and \
            not form[action]:
            # If this key is present but empty, it means that the user selected
            # "replace the file with a new one". So in this case he must provide
            # a new file to upload.
            return obj.translate('file_required')
        # Check that, if self.isImage, the uploaded file is really an image
        if value and value.filename and self.isImage:
            ext = os.path.splitext(value.filename)[1].lower()
            if ext not in File.imageExts:
                return obj.translate('image_required')

    defaultMimeType = 'application/octet-stream'
    def store(self, obj, value):
        '''Stores the p_value that represents some file. p_value can be:
           a. an instance of Zope class ZPublisher.HTTPRequest.FileUpload. In
              this case, it is file content coming from a HTTP POST;
           b. an instance of Zope class OFS.Image.File (legacy within-ZODB file
              object);
           c. an instance of appy.shared.UnmarshalledFile. In this case, the
              file comes from a peer Appy site, unmarshalled from XML content
              sent via an HTTP request;
           d. a string. In this case, the string represents the path of a file
              on disk;
           e. a 2-tuple (fileName, fileContent) where:
              - fileName is the name of the file (ie "myFile.odt")
              - fileContent is the binary or textual content of the file or an
                open file handler.
           f. a 3-tuple (fileName, fileContent, mimeType) where
              - fileName and fileContent have the same meaning than above;
              - mimeType is the MIME type of the file.
        '''
        zobj = obj.o
        if value:
            # There is a new value to store. Get the folder on disk where to
            # store the new file.
            dbFolder, folder = zobj.getFsFolder(create=True)
            # Remove the previous file if it existed.
            info = getattr(obj.aq_base, self.name, None)
            if info:
                # The previous file can be a legacy File object in an old
                # database we are migrating.
                if isinstance(info, FileInfo): info.removeFile(dbFolder)
                else: delattr(obj, self.name)
            # Store the new file. As a preamble, create a FileInfo instance.
            info = FileInfo(folder)
            cfg = zobj.getProductConfig()
            if isinstance(value, cfg.FileUpload) or isinstance(value, cfg.File):
                # Cases a, b
                info.writeFile(self.name, value, dbFolder)
            elif isinstance(value, UnmarshalledFile):
                # Case c
                fileInfo = (value.name, value.content, value.mimeType)
                info.writeFile(self.name, fileInfo, dbFolder)
            elif isinstance(value, basestring):
                # Case d
                info.copyFile(self.name, value, dbFolder)
            else:
                # Cases e, f. Extract file name, content and MIME type.
                fileName = None
                if len(value) == 2:
                    fileName, fileContent = value
                elif len(value) == 3:
                    fileName, fileContent, mimeType = value
                if not fileName:
                    raise Exception(WRONG_FILE_TUPLE)
                mimeType = mimeType or mimetypes.guess_type(fileName)[0]
                info.writeFile(self.name, (fileName, fileContent, mimeType),
                               dbFolder)
            # Store the FileInfo instance in the database.
            setattr(obj, self.name, info)
        else:
            # I store value "None", excepted if I find in the request the desire
            # to keep the file unchanged.
            action = None
            rq = getattr(zobj, 'REQUEST', None)
            if rq: action = rq.get('%s_delete' % self.name, None)
            if action != 'nochange':
                # Delete the file on disk
                info = getattr(zobj.aq_base, self.name)
                if info:
                    info.removeFile(zobj.getDbFolder(), removeEmptyFolders=True)
                # Delete the FileInfo in the DB
                setattr(zobj, self.name, None)
# ------------------------------------------------------------------------------