#!/usr/bin/python
# -*- coding: utf-8 -*-

# Hive Appier Framework
# Copyright (C) 2008-2012 Hive Solutions Lda.
#
# This file is part of Hive Appier Framework.
#
# Hive Appier Framework 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.
#
# Hive Appier Framework 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 Hive Appier Framework. If not, see <http://www.gnu.org/licenses/>.

__author__ = "João Magalhães joamag@hive.pt>"
""" The author(s) of the module """

__version__ = "1.0.0"
""" The version of the module """

__revision__ = "$LastChangedRevision$"
""" The revision number of the module """

__date__ = "$LastChangedDate$"
""" The last change date of the module """

__copyright__ = "Copyright (c) 2008-2012 Hive Solutions Lda."
""" The copyright for the module """

__license__ = "GNU General Public License (GPL), Version 3"
""" The license for the module """

import os
import types
import base64
import hashlib
import tempfile
import cStringIO

import base
import util

class Type(object):

    def json_v(self):
        return str(self)

class File(Type):

    def __init__(self, file):
        file_t = type(file)
        if file_t == types.DictType: self.build_b64(file)
        elif isinstance(file, tuple): self.build_t(file)
        elif isinstance(file, File): self.build_i(file)
        else: self.build_f(file)

    def __repr__(self):
        return "<File: %s>" % self.file_name

    def __str__(self):
        return self.file_name

    def __len__(self):
        return self.size

    def build_b64(self, file_m):
        name = file_m["name"]
        data_b64 = file_m["data"]
        mime = file_m.get("mime", None)

        is_valid = name and data_b64
        data = base64.b64decode(data_b64) if is_valid else None
        size = len(data) if is_valid else 0
        etag = self._etag(data)

        self.data = data
        self.data_b64 = data_b64
        self.file = None
        self.size = size
        self.file_name = name
        self.mime = mime
        self.etag = etag

    def build_t(self, file_t):
        name, content_type, data = file_t

        is_valid = name and data
        data_b64 = base64.b64encode(data) if is_valid else None
        size = len(data) if is_valid else 0
        etag = self._etag(data)

        self.data = data
        self.data_b64 = data_b64
        self.file = None
        self.size = size
        self.file_name = name
        self.mime = content_type
        self.etag = etag

    def build_i(self, file):
        self.file = file.file
        self.size = file.size
        self.file_name = file.file_name
        self.mime = file.mime
        self.etag = file.etag
        self.data = file.data
        self.data_b64 = file.data_b64

    def build_f(self, file):
        self.file = file
        self.size = file.content_length
        self.file_name = file.filename
        self.mime = file.content_type
        self.etag = None
        self.data = None
        self.data_b64 = None

        self._flush()

    def read(self):
        return self.data

    def json_v(self):
        return dict(
            name = self.file_name,
            data = self.data_b64,
            mime = self.mime
        ) if self.is_valid() else None

    def is_valid(self):
        return self.file_name or (self.data or self.data_b64)

    def is_empty(self):
        return self.size <= 0

    def _etag(self, data):
        if not data: return None
        hash = hashlib.md5(data)
        digest = hash.hexdigest()
        return digest

    def _flush(self):
        if not self.file_name: return
        if self.data: return

        path = tempfile.mkdtemp()
        path_f = os.path.join(path, self.file_name)
        self.file.save(path_f)

        file = open(path_f, "rb")
        try: data = file.read()
        finally: file.close()

        self.data = data
        self.data_b64 = base64.b64encode(data)
        self.size = len(data)
        self.etag = self._etag(data)

class Files(Type):

    def __init__(self, files):
        if isinstance(files, Files): self.build_i(files)
        else: self.build_f(files)

    def __repr__(self):
        return "<Files: %d files>" % len(self._files)

    def __len__(self):
        return self._files.__len__()

    def __iter__(self):
        return self._files.__iter__()

    def __getitem__(self, key):
        return self._files.__getitem__(key)

    def base(self):
        return File

    def build_i(self, files):
        self._files = files._files

    def build_f(self, files):
        self._files = []
        base = self.base()
        if not type(files) == types.ListType: files = [files]
        for file in files:
            _file = base(file)
            if not _file.is_valid(): continue
            self._files.append(_file)

    def json_v(self):
        return [file.json_v() for file in self._files]

    def is_empty(self):
        return len(self._files) == 0

    def _flush(self):
        for file in self._files: file._flush()

class ImageFile(File):

    def build_b64(self, file_m):
        File.build_b64(self, file_m)
        self.width = file_m.get("width", 0)
        self.height = file_m.get("height", 0)

    def build_t(self, file_t):
        File.build_t(self, file_t)
        self.width, self.height = self._size()

    def build_i(self, file):
        File.build_i(self, file)
        self.width = file.width
        self.height = file.height

    def build_f(self, file):
        File.build_f(self, file)
        self.width, self.height = self._size()

    def json_v(self):
        return dict(
            name = self.file_name,
            data = self.data_b64,
            mime = self.mime,
            width = self.width,
            height = self.height
        ) if self.is_valid() else None

    def _size(self):
        try: return self._size_image()
        except: return self._size_default()

    def _size_image(self):
        import PIL.Image
        if not self.data: return self._size_default()
        buffer = cStringIO.StringIO(self.data)
        try:
            image = PIL.Image.open(buffer)
            size = image.size
        finally:
            buffer.close()
        return size

    def _size_default(self):
        return (0, 0)

class ImageFiles(Files):

    def base(self):
        return ImageFile

def image(width = None, height = None, format = "png"):

    class _ImageFile(ImageFile):

        def build_t(self, file_t):
            name, content_type, data = file_t
            try: _data = self._resize(data)
            except: _data = data
            file_t = (name, content_type, _data)
            ImageFile.build_t(self, file_t)

        def _resize(self, data):
            import PIL.Image
            if not data: return data

            is_resized = True if width or height else False
            if not is_resized: return data

            size = (width, height)
            in_buffer = cStringIO.StringIO(data)
            out_buffer = cStringIO.StringIO()
            try:
                image = PIL.Image.open(in_buffer)
                image = self.__resize(image, size)
                image.save(out_buffer, format)
                data = out_buffer.getvalue()
            finally:
                in_buffer.close()
                out_buffer.close()

            return data

        def __resize(self, image, size):
            import PIL.Image

            # unpacks the provided tuple containing the size dimension into the
            # with and the height an in case one of these values is not defined
            # an error is raises indicating the problem
            width, height = size
            if not height and not width: raise AttributeError("invalid values")

            # retrieves the size of the loaded image and uses the values to calculate
            # the aspect ration of the provided image, this value is going to be
            # used latter for some of the resizing calculus
            image_width, image_height = image.size
            image_ratio = float(image_width) / float(image_height)

            # in case one of the size dimensions has not been specified
            # it must be calculated from the base values taking into account
            # that the aspect ration should be preserved
            if not height: height = int(image_height * width / float(image_width))
            if not width: width = int(image_width * height / float(image_height))

            # re-constructs the size tuple with the new values for the width
            # the height that have been calculated from the ratios
            size = (width, height)

            # calculates the target aspect ration for the image that is going
            # to be resized, this value is going to be used in the comparison
            # with the original image's aspect ration for determining the type
            # of image (horizontal or vertical) that we're going to resize
            size_ratio = width / float(height)

            # in case the image ratio is bigger than the size ratio this image
            # should be cropped horizontally meaning that some of the horizontal
            # image is going to disappear (horizontal cropping)
            if image_ratio > size_ratio:
                x_offset = int((image_width - size_ratio * image_height) / 2.0)
                image = image.crop((x_offset, 0, image_width - x_offset, image_height))

            # otherwise, in case the image ratio is smaller than the size ratio
            # the image is going to be cropped vertically
            elif image_ratio < size_ratio:
                y_offset = int((image_height - image_width / size_ratio) / 2.0)
                image = image.crop((0, y_offset, image_width, image_height - y_offset))

            # resizes the already cropped image into the target size using an
            # anti alias based algorithm (default expectations)
            image = image.resize(size, PIL.Image.ANTIALIAS)
            return image

    return _ImageFile

def images(width = None, height = None, format = "png"):

    image_c = image(
        width = width,
        height = height,
        format = format
    )

    class _ImageFiles(ImageFiles):

        def base(self):
            return image_c

    return _ImageFiles

def reference(target, name = None, eager = False):
    name = name or "id"
    target_t = type(target)
    is_reference = target_t in types.StringTypes

    class Reference(Type):

        _name = name
        """ The name of the key (join) attribute for the
        reference that is going to be created, this name
        may latter be used to cast the value """

        def __init__(self, id):
            self.__start__()
            if isinstance(id, Reference): self.build_i(id)
            else: self.build(id)

        def __len__(self):
            is_empty = self.id == "" or self.id == None
            return 0 if is_empty else 1

        def __getattr__(self, name):
            self.resolve()
            exists = hasattr(self._object, name)
            if exists: return getattr(self._object, name)
            raise AttributeError("'%s' not found" % name)

        def __setattr__(self, name, value):
            # verifies if the reference object exists in the current
            # reference instance, that's the case if the object name is
            # defined in the dictionary and the referenced object contains
            # an attribute with the name referred, for those situations
            # defers the setting of the attribute to the reference object
            exists = "_object" in self.__dict__ and hasattr(self._object, name)
            if exists: return setattr(self._object, name, value)

            # otherwise this is a normal attribute setting and the current
            # object's dictionary must be changed so that the new value is set
            self.__dict__[name] = value

        def __start__(self):
            if is_reference: self._target = getattr(base.APP.models, target)
            else: self._target = target
            meta = getattr(self._target, name)
            self._type = meta.get("type", str)

        @classmethod
        def _default(cls):
            return cls(None)

        def build(self, id):
            self.id = id
            self._object = None

        def build_i(self, reference):
            self.id = reference.id
            self._object = reference._object

        def ref_v(self):
            return self.value()

        def json_v(self):
            if eager: self.resolve(); return self._object
            else: return self.value()

        def value(self):
            is_empty = self.id == "" or self.id == None
            if is_empty: return None
            return self._type(self.id)

        def resolve(self):
            # verifies if the underlying object reference exists
            # in the current names dictionary and if it exists
            # verifies if it's valid (value is valid) if that's
            # the case returns the current value immediately
            exists = "_object" in self.__dict__
            if exists and self._object: return self._object

            # verifies if there's an id value currently set in
            # the reference in case it does not exists sets the
            # object value in the current instance with a none
            # value and then returns this (invalid value)
            if not self.id:
                object = None
                self.__dict__["object"] = object
                return object

            # creates the map of keyword based arguments that is going
            # to be used in the resolution of the reference and uses the
            # data source based get attribute to retrieve the object
            # that represents the reference
            kwargs = {
                name : self.id
            }
            _object = self._target.get(**kwargs)

            # sets the resolved object (using the current id attribute)
            # in the current instance's dictionary and then returns this
            # value to the caller method as the resolved value
            self.__dict__["_object"] = _object
            return _object

    return Reference

def references(target, name = None, eager = False):
    name = name or "id"
    reference_c = reference(target, name = name, eager = eager)

    class References(Type):

        _name = name
        """ The name of the key (join) attribute for the
        reference that is going to be created, this name
        may latter be used to cast the value """

        def __init__(self, ids):
            if isinstance(ids, References): self.build_i(ids)
            else: self.build(ids)

        def __len__(self):
            return self.objects.__len__()

        def __iter__(self):
            return self.objects.__iter__()

        def __getitem__(self, key):
            return self.objects.__getitem__(key)

        def __contains__(self, item):
            return self.contains(item)

        @classmethod
        def _default(cls):
            return cls([])

        def build(self, ids):
            is_valid = not ids == None
            is_iterable = util.is_iterable(ids)
            if is_valid and not is_iterable: ids = [ids]

            self.ids = ids
            self.objects = []
            self.objects_m = {}

            self.set_ids(self.ids)

        def build_i(self, references):
            self.ids = references.ids
            self.objects = references.objects
            self.objects_m = references.objects_m

        def set_ids(self, ids):
            ids = ids or []
            for id in ids:
                if id == "" or id == None: continue
                object = reference_c(id)
                self.objects.append(object)
                self.objects_m[id] = object

        def ref_v(self):
            return [object.ref_v() for object in self.objects]

        def json_v(self):
            return [object.json_v() for object in self.objects]

        def list(self):
            return [object.value() for object in self.objects]

        def is_empty(self):
            ids_l = len(self.ids)
            return ids_l == 0

        def append(self, id):
            is_object = hasattr(id, self._name)
            if is_object: id = getattr(id, self._name)
            object = reference_c(id)
            self.ids.append(id)
            self.objects.append(object)
            self.objects_m[id] = object

        def remove(self, id):
            is_object = hasattr(id, self._name)
            if is_object: id = getattr(id, self._name)
            object = self.objects_m[id]
            self.ids.remove(id)
            self.objects.remove(object)
            del self.objects_m[id]

        def contains(self, id):
            is_object = hasattr(id, self._name)
            if is_object: id = getattr(id, self._name)
            return id in self.objects_m

    return References
