#!/usr/bin/env python
# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai

__license__   = 'GPL v3'
__copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
__docformat__ = 'restructuredtext en'

import copy, traceback

from calibre import prints
from calibre.constants import DEBUG
from calibre.ebooks.metadata.book import SC_COPYABLE_FIELDS
from calibre.ebooks.metadata.book import SC_FIELDS_COPY_NOT_NULL
from calibre.ebooks.metadata.book import STANDARD_METADATA_FIELDS
from calibre.ebooks.metadata.book import TOP_LEVEL_CLASSIFIERS
from calibre.ebooks.metadata.book import ALL_METADATA_FIELDS
from calibre.library.field_metadata import FieldMetadata
from calibre.utils.date import isoformat, format_date
from calibre.utils.formatter import TemplateFormatter


NULL_VALUES = {
                'user_metadata': {},
                'cover_data'   : (None, None),
                'tags'         : [],
                'classifiers'  : {},
                'languages'    : [],
                'device_collections': [],
                'author_sort_map': {},
                'authors'      : [_('Unknown')],
                'title'        : _('Unknown'),
                'language'     : 'und'
}

field_metadata = FieldMetadata()

class SafeFormat(TemplateFormatter):

    def get_value(self, key, args, kwargs):
        try:
            if key != 'title_sort':
                key = field_metadata.search_term_to_field_key(key.lower())
            b = self.book.get_user_metadata(key, False)
            if b and b['datatype'] == 'int' and self.book.get(key, 0) == 0:
                v = ''
            elif b and b['datatype'] == 'float' and b.get(key, 0.0) == 0.0:
                v = ''
            else:
                ign, v = self.book.format_field(key.lower(), series_with_index=False)
            if v is None:
                return ''
            if v == '':
                return ''
            return v
        except:
            if DEBUG:
                traceback.print_exc()
            return key

composite_formatter = SafeFormat()

class Metadata(object):

    '''
    A class representing all the metadata for a book.

    Please keep the method based API of this class to a minimum. Every method
    becomes a reserved field name.
    '''

    def __init__(self, title, authors=(_('Unknown'),), other=None):
        '''
        @param title: title or ``_('Unknown')``
        @param authors: List of strings or []
        @param other: None or a metadata object
        '''
        _data = copy.deepcopy(NULL_VALUES)
        object.__setattr__(self, '_data', _data)
        if other is not None:
            self.smart_update(other)
        else:
            if title:
                self.title = title
            if authors:
                #: List of strings or []
                self.author = list(authors) if authors else []# Needed for backward compatibility
                self.authors = list(authors) if authors else []

    def is_null(self, field):
        null_val = NULL_VALUES.get(field, None)
        val = getattr(self, field, None)
        return not val or val == null_val

    def __getattribute__(self, field):
        _data = object.__getattribute__(self, '_data')
        if field in TOP_LEVEL_CLASSIFIERS:
            return _data.get('classifiers').get(field, None)
        if field in STANDARD_METADATA_FIELDS:
            return _data.get(field, None)
        try:
            return object.__getattribute__(self, field)
        except AttributeError:
            pass
        if field in _data['user_metadata'].iterkeys():
            d = _data['user_metadata'][field]
            val = d['#value#']
            if d['datatype'] != 'composite':
                return val
            if val is None:
                d['#value#'] = 'RECURSIVE_COMPOSITE FIELD (Metadata) ' + field
                val = d['#value#'] = composite_formatter.safe_format(
                                            d['display']['composite_template'],
                                            self,
                                            _('TEMPLATE ERROR'),
                                            self).strip()
            return val

        raise AttributeError(
                'Metadata object has no attribute named: '+ repr(field))

    def __setattr__(self, field, val, extra=None):
        _data = object.__getattribute__(self, '_data')
        if field in TOP_LEVEL_CLASSIFIERS:
            _data['classifiers'].update({field: val})
        elif field in STANDARD_METADATA_FIELDS:
            if val is None:
                val = NULL_VALUES.get(field, None)
            _data[field] = val
        elif field in _data['user_metadata'].iterkeys():
            if _data['user_metadata'][field]['datatype'] == 'composite':
                _data['user_metadata'][field]['#value#'] = None
            else:
                _data['user_metadata'][field]['#value#'] = val
            _data['user_metadata'][field]['#extra#'] = extra
        else:
            # You are allowed to stick arbitrary attributes onto this object as
            # long as they don't conflict with global or user metadata names
            # Don't abuse this privilege
            self.__dict__[field] = val

    def __iter__(self):
        return object.__getattribute__(self, '_data').iterkeys()

    def has_key(self, key):
        return key in object.__getattribute__(self, '_data')

    def deepcopy(self):
        m = Metadata(None)
        m.__dict__ = copy.deepcopy(self.__dict__)
        object.__setattr__(m, '_data', copy.deepcopy(object.__getattribute__(self, '_data')))
        return m

    def deepcopy_metadata(self):
        m = Metadata(None)
        object.__setattr__(m, '_data', copy.deepcopy(object.__getattribute__(self, '_data')))
        return m

    def get(self, field, default=None):
        try:
            return self.__getattribute__(field)
        except AttributeError:
            return default

    def get_extra(self, field):
        _data = object.__getattribute__(self, '_data')
        if field in _data['user_metadata'].iterkeys():
            return _data['user_metadata'][field]['#extra#']
        raise AttributeError(
                'Metadata object has no attribute named: '+ repr(field))

    def set(self, field, val, extra=None):
        self.__setattr__(field, val, extra)

    def get_classifiers(self):
        '''
        Return a copy of the classifiers dictionary.
        The dict is small, and the penalty for using a reference where a copy is
        needed is large. Also, we don't want any manipulations of the returned
        dict to show up in the book.
        '''
        return copy.deepcopy(object.__getattribute__(self, '_data')['classifiers'])

    def set_classifiers(self, classifiers):
        object.__getattribute__(self, '_data')['classifiers'] = classifiers

    # field-oriented interface. Intended to be the same as in LibraryDatabase

    def standard_field_keys(self):
        '''
        return a list of all possible keys, even if this book doesn't have them
        '''
        return STANDARD_METADATA_FIELDS

    def custom_field_keys(self):
        '''
        return a list of the custom fields in this book
        '''
        return object.__getattribute__(self, '_data')['user_metadata'].iterkeys()

    def all_field_keys(self):
        '''
        All field keys known by this instance, even if their value is None
        '''
        _data = object.__getattribute__(self, '_data')
        return frozenset(ALL_METADATA_FIELDS.union(_data['user_metadata'].iterkeys()))

    def metadata_for_field(self, key):
        '''
        return metadata describing a standard or custom field.
        '''
        if key not in self.custom_field_keys():
            return self.get_standard_metadata(key, make_copy=False)
        return self.get_user_metadata(key, make_copy=False)

    def all_non_none_fields(self):
        '''
        Return a dictionary containing all non-None metadata fields, including
        the custom ones.
        '''
        result = {}
        _data = object.__getattribute__(self, '_data')
        for attr in STANDARD_METADATA_FIELDS:
            v = _data.get(attr, None)
            if v is not None:
                result[attr] = v
        # separate these because it uses the self.get(), not _data.get()
        for attr in TOP_LEVEL_CLASSIFIERS:
            v = self.get(attr, None)
            if v is not None:
                result[attr] = v
        for attr in _data['user_metadata'].iterkeys():
            v = self.get(attr, None)
            if v is not None:
                result[attr] = v
                if _data['user_metadata'][attr]['datatype'] == 'series':
                    result[attr+'_index'] = _data['user_metadata'][attr]['#extra#']
        return result

    # End of field-oriented interface

    # Extended interfaces. These permit one to get copies of metadata dictionaries, and to
    # get and set custom field metadata

    def get_standard_metadata(self, field, make_copy):
        '''
        return field metadata from the field if it is there. Otherwise return
        None. field is the key name, not the label. Return a copy if requested,
        just in case the user wants to change values in the dict.
        '''
        if field in field_metadata and field_metadata[field]['kind'] == 'field':
            if make_copy:
                return copy.deepcopy(field_metadata[field])
            return field_metadata[field]
        return None

    def get_all_standard_metadata(self, make_copy):
        '''
        return a dict containing all the standard field metadata associated with
        the book.
        '''
        if not make_copy:
            return field_metadata
        res = {}
        for k in field_metadata:
            if field_metadata[k]['kind'] == 'field':
                res[k] = copy.deepcopy(field_metadata[k])
        return res

    def get_all_user_metadata(self, make_copy):
        '''
        return a dict containing all the custom field metadata associated with
        the book.
        '''
        _data = object.__getattribute__(self, '_data')
        user_metadata = _data['user_metadata']
        if not make_copy:
            return user_metadata
        res = {}
        for k in user_metadata:
            res[k] = copy.deepcopy(user_metadata[k])
        return res

    def get_user_metadata(self, field, make_copy):
        '''
        return field metadata from the object if it is there. Otherwise return
        None. field is the key name, not the label. Return a copy if requested,
        just in case the user wants to change values in the dict.
        '''
        _data = object.__getattribute__(self, '_data')
        _data = _data['user_metadata']
        if field in _data:
            if make_copy:
                return copy.deepcopy(_data[field])
            return _data[field]
        return None

    def set_all_user_metadata(self, metadata):
        '''
        store custom field metadata into the object. Field is the key name
        not the label
        '''
        if metadata is None:
            traceback.print_stack()
        else:
            for key in metadata:
                self.set_user_metadata(key, metadata[key])

    def set_user_metadata(self, field, metadata):
        '''
        store custom field metadata for one column into the object. Field is
        the key name not the label
        '''
        if field is not None:
            if not field.startswith('#'):
                raise AttributeError(
                        'Custom field name %s must begin with \'#\''%repr(field))
            if metadata is None:
                traceback.print_stack()
                return
            metadata = copy.deepcopy(metadata)
            if '#value#' not in metadata:
                if metadata['datatype'] == 'text' and metadata['is_multiple']:
                    metadata['#value#'] = []
                else:
                    metadata['#value#'] = None
            _data = object.__getattribute__(self, '_data')
            _data['user_metadata'][field] = metadata

    def template_to_attribute(self, other, ops):
        '''
        Takes a list [(src,dest), (src,dest)], evaluates the template in the
        context of other, then copies the result to self[dest]. This is on a
        best-efforts basis. Some assignments can make no sense.
        '''
        if not ops:
            return
        for op in ops:
            try:
                src = op[0]
                dest = op[1]
                val = composite_formatter.safe_format\
                    (src, other, 'PLUGBOARD TEMPLATE ERROR', other)
                if dest == 'tags':
                    self.set(dest, [f.strip() for f in val.split(',') if f.strip()])
                elif dest == 'authors':
                    self.set(dest, [f.strip() for f in val.split('&') if f.strip()])
                else:
                    self.set(dest, val)
            except:
                if DEBUG:
                    traceback.print_exc()

    # Old Metadata API {{{
    def print_all_attributes(self):
        for x in STANDARD_METADATA_FIELDS:
            prints('%s:'%x, getattr(self, x, 'None'))
        for x in self.custom_field_keys():
            meta = self.get_user_metadata(x, make_copy=False)
            if meta is not None:
                prints(x, meta)
        prints('--------------')

    def smart_update(self, other, replace_metadata=False):
        '''
        Merge the information in `other` into self. In case of conflicts, the information
        in `other` takes precedence, unless the information in `other` is NULL.
        '''
        def copy_not_none(dest, src, attr):
            v = getattr(src, attr, None)
            if v not in (None, NULL_VALUES.get(attr, None)):
                setattr(dest, attr, copy.deepcopy(v))

        if other.title and other.title != _('Unknown'):
            self.title = other.title
            if hasattr(other, 'title_sort'):
                self.title_sort = other.title_sort

        if other.authors and other.authors[0] != _('Unknown'):
            self.authors = list(other.authors)
            if hasattr(other, 'author_sort_map'):
                self.author_sort_map = dict(other.author_sort_map)
            if hasattr(other, 'author_sort'):
                self.author_sort = other.author_sort

        if replace_metadata:
            # SPECIAL_FIELDS = frozenset(['lpath', 'size', 'comments', 'thumbnail'])
            for attr in SC_COPYABLE_FIELDS:
                setattr(self, attr, getattr(other, attr, 1.0 if \
                        attr == 'series_index' else None))
            self.tags = other.tags
            self.cover_data = getattr(other, 'cover_data',
                                      NULL_VALUES['cover_data'])
            self.set_all_user_metadata(other.get_all_user_metadata(make_copy=True))
            for x in SC_FIELDS_COPY_NOT_NULL:
                copy_not_none(self, other, x)
            if callable(getattr(other, 'get_classifiers', None)):
                self.set_classifiers(other.get_classifiers())
            # language is handled below
        else:
            for attr in SC_COPYABLE_FIELDS:
                copy_not_none(self, other, attr)
            for x in SC_FIELDS_COPY_NOT_NULL:
                copy_not_none(self, other, x)

            if other.tags:
                # Case-insensitive but case preserving merging
                lotags = [t.lower() for t in other.tags]
                lstags = [t.lower() for t in self.tags]
                ot, st = map(frozenset, (lotags, lstags))
                for t in st.intersection(ot):
                    sidx = lstags.index(t)
                    oidx = lotags.index(t)
                    self.tags[sidx] = other.tags[oidx]
                self.tags += [t for t in other.tags if t.lower() in ot-st]

            if getattr(other, 'cover_data', False):
                other_cover = other.cover_data[-1]
                self_cover = self.cover_data[-1] if self.cover_data else ''
                if not self_cover: self_cover = ''
                if not other_cover: other_cover = ''
                if len(other_cover) > len(self_cover):
                    self.cover_data = other.cover_data

            if callable(getattr(other, 'custom_field_keys', None)):
                for x in other.custom_field_keys():
                    meta = other.get_user_metadata(x, make_copy=True)
                    if meta is not None:
                        self_tags = self.get(x, [])
                        self.set_user_metadata(x, meta) # get... did the deepcopy
                        other_tags = other.get(x, [])
                        if meta['is_multiple']:
                            # Case-insensitive but case preserving merging
                            lotags = [t.lower() for t in other_tags]
                            lstags = [t.lower() for t in self_tags]
                            ot, st = map(frozenset, (lotags, lstags))
                            for t in st.intersection(ot):
                                sidx = lstags.index(t)
                                oidx = lotags.index(t)
                                self_tags[sidx] = other.tags[oidx]
                            self_tags += [t for t in other.tags if t.lower() in ot-st]
                            setattr(self, x, self_tags)

            my_comments = getattr(self, 'comments', '')
            other_comments = getattr(other, 'comments', '')
            if not my_comments:
                my_comments = ''
            if not other_comments:
                other_comments = ''
            if len(other_comments.strip()) > len(my_comments.strip()):
                self.comments = other_comments

            # Copy all the non-none classifiers
            if callable(getattr(other, 'get_classifiers', None)):
                d = self.get_classifiers()
                s = other.get_classifiers()
                d.update([v for v in s.iteritems() if v[1] is not None])
                self.set_classifiers(d)
            else:
                # other structure not Metadata. Copy the top-level classifiers
                for attr in TOP_LEVEL_CLASSIFIERS:
                    copy_not_none(self, other, attr)

        other_lang = getattr(other, 'language', None)
        if other_lang and other_lang.lower() != 'und':
            self.language = other_lang

    def format_series_index(self, val=None):
        from calibre.ebooks.metadata import fmt_sidx
        v = self.series_index if val is None else val
        try:
            x = float(v)
        except (ValueError, TypeError):
            x = 1
        return fmt_sidx(x)

    def authors_from_string(self, raw):
        from calibre.ebooks.metadata import string_to_authors
        self.authors = string_to_authors(raw)

    def format_authors(self):
        from calibre.ebooks.metadata import authors_to_string
        return authors_to_string(self.authors)

    def format_tags(self):
        return u', '.join([unicode(t) for t in self.tags])

    def format_rating(self):
        return unicode(self.rating)

    def format_field(self, key, series_with_index=True):
        name, val, ign, ign = self.format_field_extended(key, series_with_index)
        return (name, val)

    def format_field_extended(self, key, series_with_index=True):
        from calibre.ebooks.metadata import authors_to_string
        '''
        returns the tuple (field_name, formatted_value)
        '''

        # Handle custom series index
        if key.startswith('#') and key.endswith('_index'):
            tkey = key[:-6] # strip the _index
            cmeta = self.get_user_metadata(tkey, make_copy=False)
            if cmeta['datatype'] == 'series':
                if self.get(tkey):
                    res = self.get_extra(tkey)
                    return (unicode(cmeta['name']+'_index'),
                            self.format_series_index(res), res, cmeta)
                else:
                    return (unicode(cmeta['name']+'_index'), '', '', cmeta)

        if key in self.custom_field_keys():
            res = self.get(key, None)
            cmeta = self.get_user_metadata(key, make_copy=False)
            name = unicode(cmeta['name'])
            if cmeta['datatype'] != 'composite' and (res is None or res == ''):
                return (name, res, None, None)
            orig_res = res
            cmeta = self.get_user_metadata(key, make_copy=False)
            if res is None or res == '':
                return (name, res, None, None)
            orig_res = res
            datatype = cmeta['datatype']
            if datatype == 'text' and cmeta['is_multiple']:
                res = u', '.join(res)
            elif datatype == 'series' and series_with_index:
                if self.get_extra(key) is not None:
                    res = res + \
                        ' [%s]'%self.format_series_index(val=self.get_extra(key))
            elif datatype == 'datetime':
                res = format_date(res, cmeta['display'].get('date_format','dd MMM yyyy'))
            elif datatype == 'bool':
                res = _('Yes') if res else _('No')
            return (name, unicode(res), orig_res, cmeta)

        # Translate aliases into the standard field name
        fmkey = field_metadata.search_term_to_field_key(key)

        if fmkey in field_metadata and field_metadata[fmkey]['kind'] == 'field':
            res = self.get(key, None)
            fmeta = field_metadata[fmkey]
            name = unicode(fmeta['name'])
            if res is None or res == '':
                return (name, res, None, None)
            orig_res = res
            name = unicode(fmeta['name'])
            datatype = fmeta['datatype']
            if key == 'authors':
                res = authors_to_string(res)
            elif key == 'series_index':
                res = self.format_series_index(res)
            elif datatype == 'text' and fmeta['is_multiple']:
                res = u', '.join(res)
            elif datatype == 'series' and series_with_index:
                res = res + ' [%s]'%self.format_series_index()
            elif datatype == 'datetime':
                res = format_date(res, fmeta['display'].get('date_format','dd MMM yyyy'))
            return (name, unicode(res), orig_res, fmeta)

        return (None, None, None, None)

    def __unicode__(self):
        from calibre.ebooks.metadata import authors_to_string
        ans = []
        def fmt(x, y):
            ans.append(u'%-20s: %s'%(unicode(x), unicode(y)))

        fmt('Title', self.title)
        if self.title_sort:
            fmt('Title sort', self.title_sort)
        if self.authors:
            fmt('Author(s)',  authors_to_string(self.authors) + \
               ((' [' + self.author_sort + ']') if self.author_sort else ''))
        if self.publisher:
            fmt('Publisher', self.publisher)
        if getattr(self, 'book_producer', False):
            fmt('Book Producer', self.book_producer)
        if self.comments:
            fmt('Comments', self.comments)
        if self.isbn:
            fmt('ISBN', self.isbn)
        if self.tags:
            fmt('Tags', u', '.join([unicode(t) for t in self.tags]))
        if self.series:
            fmt('Series', self.series + ' #%s'%self.format_series_index())
        if self.language:
            fmt('Language', self.language)
        if self.rating is not None:
            fmt('Rating', self.rating)
        if self.timestamp is not None:
            fmt('Timestamp', isoformat(self.timestamp))
        if self.pubdate is not None:
            fmt('Published', isoformat(self.pubdate))
        if self.rights is not None:
            fmt('Rights', unicode(self.rights))
        for key in self.custom_field_keys():
            val = self.get(key, None)
            if val:
                (name, val) = self.format_field(key)
                fmt(name, unicode(val))
        return u'\n'.join(ans)

    def to_html(self):
        from calibre.ebooks.metadata import authors_to_string
        ans = [(_('Title'), unicode(self.title))]
        ans += [(_('Author(s)'), (authors_to_string(self.authors) if self.authors else _('Unknown')))]
        ans += [(_('Publisher'), unicode(self.publisher))]
        ans += [(_('Producer'), unicode(self.book_producer))]
        ans += [(_('Comments'), unicode(self.comments))]
        ans += [('ISBN', unicode(self.isbn))]
        ans += [(_('Tags'), u', '.join([unicode(t) for t in self.tags]))]
        if self.series:
            ans += [(_('Series'), unicode(self.series)+ ' #%s'%self.format_series_index())]
        ans += [(_('Language'), unicode(self.language))]
        if self.timestamp is not None:
            ans += [(_('Timestamp'), unicode(self.timestamp.isoformat(' ')))]
        if self.pubdate is not None:
            ans += [(_('Published'), unicode(self.pubdate.isoformat(' ')))]
        if self.rights is not None:
            ans += [(_('Rights'), unicode(self.rights))]
        for key in self.custom_field_keys():
            val = self.get(key, None)
            if val:
                (name, val) = self.format_field(key)
                ans += [(name, val)]
        for i, x in enumerate(ans):
            ans[i] = u'<tr><td><b>%s</b></td><td>%s</td></tr>'%x
        return u'<table>%s</table>'%u'\n'.join(ans)

    def __str__(self):
        return self.__unicode__().encode('utf-8')

    def __nonzero__(self):
        return bool(self.title or self.author or self.comments or self.tags)

    # }}}

