"""Generate yuml

https://yuml.me/diagram/scruffy/class/samples

"""
import logging
import os
from typing import Union, TextIO, Set, List, Optional, Callable, cast

import click
import requests
from rdflib import Namespace

from linkml_runtime.linkml_model.meta import ClassDefinitionName, SchemaDefinition, SlotDefinition, \
    ClassDefinition
from linkml_runtime.utils.formatutils import camelcase, underscore
from linkml.utils.generator import Generator, shared_arguments

yuml_is_a = '^-'
yuml_uses = 'uses -.->'
yuml_injected = '< -.- inject'
yuml_slot_type = ':'
yuml_inline = '++- '
yuml_inline_rev = '-++'
yuml_ref = '- '

yuml_base = 'https://yuml.me/diagram/nofunky'
yuml_scale = ''                # ';scale:180' ';scale:80' for small
yuml_dir = ';dir:TB'           # '
yuml_class = '/class/'
YUML = Namespace(yuml_base + yuml_scale + yuml_dir + yuml_class)


class YumlGenerator(Generator):
    generatorname = os.path.basename(__file__)
    generatorversion = "0.1.1"
    valid_formats = ['yuml', 'png', 'pdf', 'jpg', 'json', 'svg']
    visit_all_class_slots = False

    def __init__(self, schema: Union[str, TextIO, SchemaDefinition], **args) -> None:
        super().__init__(schema, **args)
        self.referenced:Optional[Set[ClassDefinitionName]] = None        # List of classes that have to be emitted
        self.generated:Optional[Set[ClassDefinitionName]] = None         # List of classes that have been emitted
        self.box_generated:Optional[Set[ClassDefinitionName]] = None     # Class boxes that have been emitted
        self.associations_generated:Optional[Set[ClassDefinitionName]] = None    # Classes with associations generated
        self.focus_classes: Optional[Set[ClassDefinitionName]] = None   # Classes to be completely filled
        self.gen_classes:Optional[Set[ClassDefinitionName]] = None           # Classes to be generated
        self.output_file_name: Optional[str] = None             # Location of output file if directory used

    def visit_schema(self, classes: Set[ClassDefinitionName]=None, directory: Optional[str] = None,
                     load_image: bool=True, **_) -> None:
        if directory:
            os.makedirs(directory, exist_ok=True)
        if classes is not None:
            for cls in classes:
                if cls not in self.schema.classes:
                    raise ValueError(f"Unknown class name: {cls}")
        self.box_generated = set()
        self.associations_generated = set()
        self.focus_classes = classes
        if classes:
            self.gen_classes = self.neighborhood(list(classes)).classrefs.union(classes)
        else:
            self.gen_classes = self.synopsis.roots.classrefs
        self.referenced = self.gen_classes
        self.generated = set()
        yumlclassdef: List[str] = []
        while self.referenced.difference(self.generated):
            cn = sorted(list(self.referenced.difference(self.generated)), reverse=True)[0]
            self.generated.add(cn)
            assocs = self.class_associations(ClassDefinitionName(cn), cn in self.referenced)
            if assocs:
                yumlclassdef.append(assocs)
            else:
                yumlclassdef.append(self.class_box(ClassDefinitionName(cn)))

        yuml_url = str(YUML) + ','.join(yumlclassdef) + \
                   (('.' + self.format) if self.format not in ('yuml', 'svg') else '')
        file_suffix = '.svg' if self.format == 'yuml' else '.' + self.format
        if directory:
            self.output_file_name = os.path.join(directory,
                                    camelcase(sorted(classes)[0] if classes else self.schema.name) + file_suffix)
            if load_image:
                resp = requests.get(yuml_url, stream=True)
                if resp.ok:
                    with open(self.output_file_name, 'wb') as f:
                        for chunk in resp.iter_content(chunk_size=2048):
                            f.write(chunk)
                else:
                    self.logger.error(f"{resp.reason} accessing {yuml_url}")
        else:
            print(str(YUML)+','.join(yumlclassdef), end='')

    def class_box(self, cn: ClassDefinitionName) -> str:
        """ Generate a box for the class.  Populate its interior only if (a) it hasn't previously been generated and
        (b) it appears in the gen_classes list

        @param cn:
        @return:
        """
        slot_defs: List[str] = []
        if cn not in self.box_generated and (not self.focus_classes or cn in self.focus_classes):
            cls = self.schema.classes[cn]
            for slot in self.filtered_cls_slots(cn, all_slots=True, filtr=lambda s: s.range not in self.schema.classes):
                if True or cn in slot.domain_of:
                    mod = self.prop_modifier(cls, slot)
                    slot_defs.append(underscore(self.aliased_slot_name(slot)) +
                                     mod + ':' +
                                     underscore(slot.range) + self.cardinality(slot))
            self.box_generated.add(cn)
        self.referenced.add(cn)
        return '[' + camelcase(cn) + ('|' + ';'.join(slot_defs) if slot_defs else '') + ']'

    def class_associations(self, cn: ClassDefinitionName, must_render: bool=False) -> str:
        """ Emit all associations for a focus class.  If none are specified, all classes are generated

        @param cn: Name of class to be emitted
        @param must_render: True means render even if this is a target (class is specifically requested)
        @return: YUML representation of the association
        """

        # NOTE: YUML diagrams draw in the opposite order in which they are created, so we work from bottom to top and
        # from right to left
        assocs: List[str] = []
        if cn not in self.associations_generated and (not self.focus_classes or cn in self.focus_classes):
            cls = self.schema.classes[cn]

            # Slots that reference other classes
            for slot in self.filtered_cls_slots(cn, False, lambda s: s.range in self.schema.classes)[::-1]:
                # Swap the two boxes because, in the case of self reference, the last definition wins
                if not slot.range in self.associations_generated and cn in slot.domain_of:
                    rhs = self.class_box(cn)
                    lhs = self.class_box(cast(ClassDefinitionName, slot.range))
                    assocs.append(lhs + '<' + self.aliased_slot_name(slot) + self.prop_modifier(cls, slot) +
                                  self.cardinality(slot, False) + (yuml_inline_rev if slot.inlined else yuml_ref) + rhs)

            # Slots in other classes that reference this
            for slotname in sorted(self.synopsis.rangerefs.get(cn, [])):
                slot = self.schema.slots[slotname]
                # Don't do self references twice
                # Also, slot must be owned by the class
                if cls.name not in slot.domain_of and cls.name not in self.associations_generated:
                    for dom in [self.schema.classes[dof] for dof in slot.domain_of]:
                        assocs.append(self.class_box(dom.name) + (yuml_inline if slot.inlined else yuml_ref) +
                                      self.aliased_slot_name(slot) + self.prop_modifier(dom, slot) +
                                      self.cardinality(slot, False) + '>' + self.class_box(cn))

            # Mixins used in the class
            for mixin in cls.mixins:
                assocs.append(self.class_box(cn) + yuml_uses + self.class_box(mixin))

            # Classes that use the class as a mixin
            if cls.name in self.synopsis.mixinrefs:
                for mixin in sorted(self.synopsis.mixinrefs[cls.name].classrefs, reverse=True):
                    assocs.append(self.class_box(ClassDefinitionName(mixin)) + yuml_uses + self.class_box(cn))

            # Classes that inject information
            if cn in self.synopsis.applytos.classrefs:
                for injector in sorted(self.synopsis.applytorefs[cn].classrefs, reverse=True):
                    assocs.append(self.class_box(cn) + yuml_injected + self.class_box(ClassDefinitionName(injector)))
            self.associations_generated.add(cn)

            # Children
            if cn in self.synopsis.isarefs:
                for is_a_cls in sorted(self.synopsis.isarefs[cn].classrefs, reverse=True):
                    assocs.append(self.class_box(cn) + yuml_is_a + self.class_box(ClassDefinitionName(is_a_cls)))

            # Parent
            if cls.is_a and cls.is_a not in self.associations_generated:
                assocs.append(self.class_box(cls.is_a) + yuml_is_a + self.class_box(cn))
        return ','.join(assocs)

    @staticmethod
    def cardinality(slot: SlotDefinition, is_attribute: bool = True) -> str:
        if is_attribute:
            if slot.multivalued:
                return ' %2B' if slot.required else ' *'
            else:
                return '' if slot.required else ' %3F'
        else:
            if slot.multivalued:
                return ' 1..*' if slot.required else ' 0..*'
            else:
                return ' 1..1' if slot.required else ' 0..1'

    def filtered_cls_slots(self,
                           cn: ClassDefinitionName,
                           all_slots: bool=True,
                           filtr: Callable[[SlotDefinition], bool] = None) -> List[SlotDefinition]:
        """ Return the set of slots associated with the class that meet the filter criteria.  Slots will be returned
        in defining order, with class slots returned last

        @param cn: name of class to filter
        @param all_slots: True means include attributes
        @param filtr: Slot filter predicate
        @return: List of slot definitions
        """
        if filtr is None:
            filtr = lambda x: True

        rval = []
        cls = self.schema.classes[cn]
        cls_slots = self.all_slots(cls, cls_slots_first=True)
        for slot in cls_slots:
            if (all_slots or slot.range in self.schema.classes) and filtr(slot):
                rval.append(slot)

        return rval

    def prop_modifier(self, cls: ClassDefinition, slot: SlotDefinition) -> str:
        """ Return the modifiers for the slot:
            (i) - inherited
            (m) - inherited through mixin
            (a) - injected
            (pk) - primary ckey

        @param cls:
        @param slot:
        @return:
        """
        pk = '(pk)' if slot.key else ''
        inherited = slot.name not in self.own_slot_names(cls)
        mixin = inherited and slot.name in \
                [mslot.name for mslot in [self.schema.classes[m] for m in cls.mixins]]
        injected = cls.name in self.synopsis.applytos.classrefs and \
                   slot.name in [aslot.name for aslot in
                                 [self.schema.classes[a] for a in sorted(self.synopsis.applytorefs[cls.name].classrefs)]]
        return pk + ('(a)' if injected else '(m)' if mixin else '(i)' if inherited else '')


@shared_arguments(YumlGenerator)
@click.command()
@click.option("--classes", "-c", multiple=True, help="Class(es) to emit")
@click.option("--directory", "-d", help="Output directory - if supplied, YUML rendering will be saved in file")
def cli(yamlfile, **args):
    """ Generate a UML representation of a LinkML model """
    print(YumlGenerator(yamlfile, **args).serialize(**args), end="")


if __name__ == '__main__':
    cli()
