from peewee import *
from playhouse.fields import CompressedField
from playhouse.hybrid import *

import datetime

from .prefixes import query_pseudo_prefix
 
db = SqliteDatabase('test.db', pragmas=[('foreign_keys', 'ON')])

__tables__ = []
__all__ = ['create_tables', 'drop_tables']

def table(cls):
    __tables__.append(cls)
    __all__.append(cls.__name__)
    return cls

def create_tables():
    db.create_tables(__tables__, True)

def drop_tables():
    db.drop_tables(__tables__, True)

class BaseModel(Model):
    class Meta:
        database = db

@table
class Document(BaseModel):
    content = CompressedField()
    created = DateField(default=datetime.datetime.now)
    description = CharField(null=True)
    direction = BooleanField(null=True)
    original_path = CharField(null=True)
    inserted = DateTimeField(default=datetime.datetime.now)

    @classmethod
    def matches(cls, prefix, value):
        return query_pseudo_prefix(prefix, value) or Document.id << (
                DocumentTag.select(DocumentTag.document)
                .join(Tag, on=Tag.matches(prefix, value)))

@table
class Prefix(BaseModel):
    name = CharField(primary_key = True)
    builtin = BooleanField(default = False)
    pseudo = BooleanField(default = False)
    description = CharField(null=True)

    def __str__ (self):
        return self.name

@table
class Tag(BaseModel):
    name = CharField()
    prefix = ForeignKeyField(Prefix, null=True, related_name = 'tag', db_column = 'prefix')
    description = CharField(null=True)

    @hybrid_method
    def matches(self, prefix, name):
        return (self.prefix == prefix) & (self.name == name)

    class Meta:
        indexes = [
            (('name', 'prefix'), True)
        ]

    def __str__(self):
        prefix = self.prefix.name + ':' if self.prefix else ''
        description = ' -- ' + self.description if self.description else ''

        return prefix + self.name + description

@table
class DocumentTag(BaseModel):
    document = ForeignKeyField(Document, related_name = 'tags')
    tag = ForeignKeyField(Tag)

    class Meta:
        primary_key = CompositeKey('document', 'tag')

@table
class TagImplications(BaseModel):
    tag = ForeignKeyField(Tag)
    implies_tag = ForeignKeyField(Tag, related_name = 'implications')
    
    class Meta:
        primary_key = CompositeKey('tag', 'implies_tag')