#!/usr/bin/env python
"""
This file provides the code generator which transforms gaphor/UML/uml2.gaphor
into gaphor/UML/uml2.py.

Also a distutils tool, build_uml, is provided.
"""


#
# Create a UML 2.0 datamodel from the Gaphor 0.2.0 model file.
#
# To do this we do the following:
# 1. read the model file with the gaphor parser
# 2. Create a object herarcy by ordering elements based on generalizations

# Recreate the model using some very dynamic class, so we can set all
# attributes and traverse them to generate the data model.

from gaphor.parser import parse, base, element, canvas, canvasitem
import sys, string, operator
import override

header = """# This file is generated by build_uml.py. DO NOT EDIT!

from properties import association, attribute, enumeration, derivedunion, redefine
"""

# Make getitem behave more politely
base.__real_getitem__ = base.__getitem__

def base__getitem__(self, key):
    try:
        return self.__real_getitem__(key)
    except KeyError:
        return None

base.__getitem__ = base__getitem__

# redefine 'bool' for Python version < 2.3
if map(int, sys.version[:3].split('.')) < [2, 3]:
    header = header + "bool = int\n"


import re

pattern = r'([A-Z])'
sub = r'_\1'

def camelCase_to_underscore(str):
    """
    >>> camelCase_to_underscore('camelcase')
    'camelcase'
    >>> camelCase_to_underscore('camelCase')
    'camel_case'
    >>> camelCase_to_underscore('camelCamelCase')
    'camel_camel_case'
    """
    return re.sub(pattern, sub, str).lower()

_ = camelCase_to_underscore


def msg(s):
    sys.stderr.write('  ')
    sys.stderr.write(s)
    sys.stderr.write('\n')
    sys.stderr.flush()


class Writer:

    def __init__(self, filename, overridesfile=None):
        self.overrides = overridesfile and override.Overrides(overridesfile) or None
        if filename:
            self.out = open(filename, 'w')
        else:
            self.out = sys.stdout

    def write(self, data):
        self.out.write(data)

    def close(self):
        self.out.close()

    def write_classdef(self, clazz):
        """Write a class definition (class xx(x): pass).
        First the parent classes are examined. After that its own definition
        is written. It is ensured that class definitions are only written
        once.
        """
        if not clazz.written:
            s = ''
            for g in clazz.generalization:
                self.write_classdef(g)
                if s: s += ', '
                s = s + g['name']
            if not s: s = 'object'
            if not self.overrides.write_override(self, clazz['name']):
                self.write('class %s(%s): pass\n' % (clazz['name'], s))
        clazz.written = True

    def write_property(self, full_name, value):
        """Write a property to the file. If the property is overridden, use the
        overridden value. full_name should be like Class.attribute. value is
        free format text.
        """
        if not self.overrides.write_override(self, full_name):
            self.write('%s = %s\n' % (full_name, value))

    def write_attribute(self, a, enumerations={}):
        """Write a definition for attribute a. Enumerations may be a dict
        of enumerations, indexed by ID. These are used to identify enums.
        """
        params = { }
        type = a.typeValue and a.typeValue.get('value')
        if type is None:
            raise ValueError('ERROR! type is not specified for property %s.%s' % (a.class_name, a.name))

        if type.lower() == 'boolean':
            # FixMe: Should this be a boolean or an integer?
            # Integer is save and compattable with python2.2.
            type = 'int'
        elif type.lower() in ('integer', 'unlimitednatural'):
            type = 'int'
        elif type.lower() == 'string':
            # Change to basestr for Python 2.3
            type = 'str'
            #type = '(str, unicode)'

        default = a.defaultValue and a.defaultValue.value
        # Make sure types are represented the Python way:
        if default and default.lower() in ('true', 'false'):
            default = default.title() # True or False...
        if default is not None:
            params['default'] = str(default)

        lower = a.lowerValue and a.lowerValue.value
        if lower and lower != '0':
            params['lower'] = lower
        upper = a.upperValue and a.upperValue.value
        if upper and upper != '1':
            params['upper'] = upper

        #kind, derived, a.name, type, default, lower, upper = parse_attribute(a)

        full_name = "%s.%s" % (a.class_name, a.name)
        if self.overrides.has_override(full_name):
            self.overrides.write_override(self, full_name)
        elif eval(a.isDerived or '0'):
            msg('ignoring derived attribute %s.%s: no definition' % (a.class_name, a.name))
        elif type.endswith('Kind') or type.endswith('Sort'):
            e = filter(lambda e: e['name'] == type, enumerations.values())[0]
            self.write_property("%s.%s" % (a.class_name, a.name),
                                "enumeration('%s', %s, '%s')" % (a.name, e.enumerates, default or e.enumerates[0]))
        else:
            if params:
                attribute = "attribute('%s', %s, %s)" % (a.name, type, ', '.join(map('='.join, params.items())))
            else:
                attribute = "attribute('%s', %s)" % (a.name, type)
            self.write_property("%s.%s" % (a.class_name, a.name), attribute)

    def write_operation(self, o):
        full_name = "%s.%s" % (o.class_name, o.name)
        if self.overrides.has_override(full_name):
            self.overrides.write_override(self, full_name)
        else:
            msg("No override for operation %s" % full_name)

    def write_association(self, head, tail):
        """Write an association for head. False is returned if the association
        is derived.
        The head association end is enriched with the following attributes:
            derived - association is a derived union or not
            name - name of the association end (name of head is found on tail)
            class_name - name of the class this association belongs to
            opposite_class_name - name of the class at the other end of the assoc.
            lower - lower multiplicity
            upper - upper multiplicity
            subsets - derived unions that use the association
            redefines - redefines existing associations
        Returns True if the association is written. False is returned if
        the association should be handled by write_derivedunion() or
        write_redefine().
        """
        navigable = head.get('class_')
        if not navigable:
            # from this side, the association is not navigable
            return True

        name = head.name
        if name is None:
            raise ValueError('ERROR! no name, but navigable: %s (%s.%s)' % (head.id, head.class_name, head.name))

        derived = int(head.isDerived or 0)

        #print head.id, head.lowerValue
        upper = head.upperValue and head.upperValue.value or '*'
        lower = head.lowerValue and head.lowerValue.value or upper
        if lower == '*':
            lower = 0
        subsets, redefines = parse_association_tags(head.taggedValue)

        # Add the values found. These are used later to generate derived unions.
        head.derived = derived
        #head.name = name
        head.class_name = head.class_['name']
        head.opposite_class_name = head.type['name']
        head.lower = lower
        head.upper = upper
        head.subsets = subsets
        head.redefines = redefines

        # Derived unions and redefines are handled separately
        if derived or redefines:
            return False

        a = "association('%s', %s" % (name, head.opposite_class_name)
        if lower not in ('0', 0):
            a += ', lower=%s' % lower
        if upper != '*':
            a += ', upper=%s' % upper
        if head.get('aggregation') == 'composite':
            a += ', composite=True'

        # Add the opposite property if the head itself is navigable:
        navigable = tail.get('class_')
        if navigable:
            try:
                #o_derived, o_name = parse_association_name(tail['name'])
                o_name = tail.name
                o_derived = int(tail.isDerived or 0)
            except KeyError:
                msg('ERROR! no name, but navigable: %s (%s.%s)' %
                    (tail.id, tail.class_name, tail.name))
            else:
                assert not (derived and not o_derived), 'One end is derived, the other end not ???'
                a += ", opposite='%s'" % o_name

        self.write_property("%s.%s" % (head.class_name, name), a + ')')
        return True

    def write_derivedunion(self, d):
        """Write a derived union. If there are no subsets a warning
        is issued. The derivedunion is still created though.
        Derived unions may be created for associations that were returned
        False by write_association()."""
        subs = ''
        for u in d.union:
            if u.derived and not u.written:
                self.write_derivedunion(u)
            if subs: subs += ', '
            subs += '%s.%s' % (u.class_name, u.name)
        if subs:
            self.write_property("%s.%s" % (d.class_name, d.name),
                                "derivedunion('%s', %s, %s, %s)" % (d.name, d.lower, d.upper == '*' and "'*'" or d.upper, subs))
        else:
            if not self.overrides.has_override('%s.%s' % (d.class_name, d.name)):
                msg('no subsets for derived union: %s.%s[%s..%s]' % (d.class_name, d.name, d.lower, d.upper))
            self.write_property("%s.%s" % (d.class_name, d.name),
                                "derivedunion('%s', %s, %s)" % (d.name, d.lower, d.upper == '*' and "'*'" or d.upper))
        d.written = True

    def write_redefine(self, r):
        """Redefines may be created for associations that were returned
        False by write_association()."""
        self.write_property("%s.%s" % (r.class_name, r.name),
                            "redefine('%s', %s, %s)" % (r.name, r.opposite_class_name, r.redefines))


def parse_association_name(name):
    # First remove spaces
    name = name.replace(' ','')
    derived = False
    # Check if this is a derived union
    while name and not name[0].isalpha():
        if name[0] == '/':
            derived = True
        name = name[1:]
    return derived, name


def parse_association_tags(tag):
    subsets = []
    redefines = None

    # subsets has a comma separated syntax. Add all taggedValues together
    if type(tag) is type([]):
        tag = ', '.join(filter(None, map(getattr, tag, ['value'] * len(tag))))
    elif tag:
        tag = tag.value

    #print 'scanning tags: %s' % tag

    if tag and tag.find('subsets') != -1:
        # find the text after 'subsets':
        subsets = tag[tag.find('subsets') + len('subsets'):]
        # remove all whitespaces and stuff
        subsets = subsets.replace(' ', '').replace('\n', '').replace('\r', '')
        subsets = subsets.split(',')

    if tag and tag.find('redefines') != -1:
        # find the text after 'redefines':
        redefines = tag[tag.find('redefines') + len('redefines'):]
        # remove all whitespaces and stuff
        redefines = redefines.replace(' ', '').replace('\n', '').replace('\r', '')
        l = redefines.split(',')
        assert len(l) == 1
        redefines = l[0]

    #print 'found', subsets, redefines
    return subsets, redefines

def generate(filename, outfile=None, overridesfile=None):
    # parse the file
    all_elements = parse(filename)

    def unref(val, attr):
        """Resolve references.
        """
        try:
            refs = val.references[attr]
        except KeyError:
            val.references[attr] = None
            return

        if type(refs) is type([]):
            unrefs = []
            for r in refs:
                unrefs.append(all_elements[r])
            val.references[attr] = unrefs
        else:
            val.references[attr] = all_elements[refs]

    writer = Writer(outfile, overridesfile)

    # extract usable elements from all_elements. Some elements are given
    # some extra attributes.
    classes = { }
    enumerations = { }
    generalizations = { }
    associations = { }
    properties = { }
    operations = { }
    for key, val in all_elements.items():
        # Find classes, *Kind (enumerations) are given special treatment
        if isinstance(val, element):
            if val.type == 'Class' and val.get('name'):
                if val['name'].endswith('Kind') or val['name'].endswith('Sort'):
                    enumerations[key] = val
                else:
                    classes[key] = val
                    # Add extra properties for easy code generation:
                    val.specialization = []
                    val.generalization = []
                    val.written = False
            elif val.type == 'Generalization':
                generalizations[key] = val
            elif val.type == 'Association':
                associations[key] = val
            elif val.type == 'Property':
                properties[key] = val
                unref(val, 'typeValue')
                unref(val, 'defaultValue')
                unref(val, 'lowerValue')
                unref(val, 'upperValue')
                unref(val, 'taggedValue')
            elif val.type == 'Operation':
                operations[key] = val

    # find inheritance relationships
    for g in generalizations.values():
        #assert g.specific and g.general
        specific = g['specific']
        general = g['general']
        classes[specific].generalization.append(classes[general])
        classes[general].specialization.append(classes[specific])

    # add values to enumerations:
    for e in enumerations.values():
        values = []
        for key in e['ownedAttribute']:
            values.append(str(properties[key]['name']))
        e.enumerates = tuple(values)

    # create file header
    writer.write(header)

    # create class definitions
    for c in classes.values():
        writer.write_classdef(c)

    # create attributes and enumerations
    for c in classes.values():
        for p in c.get('ownedAttribute') or []:
            a = properties.get(p)
            # set class_name, since write_attribute depends on it
            a.class_name = c['name']
            if not a.get('association'):
                writer.write_attribute(a, enumerations)

    # create associations, derivedunions are held back
    derivedunions = { } # indexed by name in stead of id
    redefines = [ ]
    for a in associations.values():
        ends = []
        for end in a['memberEnd']:
            end = properties[end]
            end.type = classes[end['type']]
            end.class_ = end.get('class_') and classes[end['class_']] or None
            #assert end.type is not end.class_
            #if not end.get('lowerValue'):
                #end.lowerValue = end.lowerValue.get('value') or ''
            #else:
                #end.lowerValue = ''
            ends.append(end)

        for e1, e2 in ((ends[0], ends[1]), (ends[1], ends[0])):
            if not writer.write_association(e1, e2):
                # At this point the association is parsed, but not written.
                # assure that derived unions do not get overwritten
                if e1.redefines:
                    redefines.append(e1)
                else:
                    assert not derivedunions.get(e1.name), "%s.%s is already in derived union set in class %s" % (e1.class_name, e1.name, derivedunions.get(e1.name).class_name)
                    derivedunions[e1.name] = e1
                    e1.union = [ ]
                    e1.written = False


    # create derived unions, first link the association ends to the d
    for a in [v for v in properties.values() if v.subsets]:
        for s in a.subsets or ():
            try:
                derivedunions[s].union.append(a)
            except KeyError:
                msg('not a derived union: %s.%s' % (a.class_name, s))

    for d in derivedunions.values():
        writer.write_derivedunion(d)

    for r in redefines or ():
        msg('redefining %s -> %s.%s' % (r.redefines, r.class_name, r.name))
        writer.write_redefine(r)

    # create operations
    for c in classes.values():
        for p in c.get('ownedOperation') or []:
            o = operations.get(p)
            o.class_name = c['name']
            writer.write_operation(o)

    writer.close()


if __name__ == '__main__':
    import doctest
    doctest.testmod()
    generate('uml2.gaphor')

# vim:sw=4:et