# -*- coding: utf-8 -*-
from __future__ import unicode_literals

from decimal import Decimal

from django.db import models, connection
from django.utils import timezone


class Category(models.Model):
    cat_name = models.CharField("Category", max_length=50)
    cat_type = models.CharField(
        "Type", max_length=1, choices=(("I", "Income"), ("E", "Expence"))
    )
    user = models.ForeignKey("auth.user", null=True, blank=True)
    budget_type = models.CharField(
        "Type",
        max_length=1,
        choices=(("W", "Weekly"), ("M", "Monthly"), ("Y", "Yearly")),
        default="M",
    )
    budget_amount = models.DecimalField(
        "Amount", max_digits=10, decimal_places=2, default=0
    )

    def natural_key(self):
        return self.cat_name

    def __unicode__(self):
        return self.cat_name

    def cat_sum(self):
        from django.db.models import Sum

        data = Transaction.objects.filter(
            tr_cat=self.id,
            tr_date__gte=timezone.now().replace(
                day=1, hour=0, minute=0, second=0, microsecond=0
            ),
        ).aggregate(Sum("tr_amount"))
        return float(data["tr_amount__sum"]) if data["tr_amount__sum"] else 0

    def minus_sum(self):
        return self.cat_sum() * (-1)

    def balance(self):
        return -self.budget()

    def ratio(self):
        if self.budget_amount == 0:
            return 100
        return min(100, int(Decimal(self.cat_sum()) / self.budget_amount * 100))

    class Meta:
        verbose_name_plural = "Categories"


class Account(models.Model):
    acc_name = models.CharField("Account", max_length=50)
    acc_balance = models.DecimalField("Balance", max_digits=10, decimal_places=2)
    acc_currency = models.CharField("Currency", max_length=3)
    user = models.ForeignKey("auth.user", null=True, blank=True)

    def natural_key(self):
        return self.acc_name

    def __unicode__(self):
        return self.acc_name

    SQL_exp = """SELECT SUM(tr_amount) from pfm_transaction as t JOIN pfm_account as a 
                 ON t.tr_acc_id = a.id WHERE tr_type='E' AND tr_acc_id=%s"""

    SQL_inc = """SELECT SUM(tr_amount) from pfm_transaction as t JOIN pfm_account as a 
                  ON t.tr_acc_id = a.id WHERE tr_type='I' AND tr_acc_id=%s"""

    def count(self, SQL):
        cur = connection.cursor()
        cur.execute(SQL, (self.id,))
        try:
            return float(cur.fetchone()[0])
        except TypeError:
            return 0
        cur.close()

    def exp(self):
        return self.count(Account.SQL_exp)

    def inc(self):
        return self.count(Account.SQL_inc)

    def tr_in(self):
        cur = connection.cursor()
        cur.execute(
            """SELECT SUM(tr_amount) from pfm_transfer as t JOIN pfm_account as a
                    ON t.to_acc_id = a.id WHERE to_acc_id=%s""",
            (self.id,),
        )
        try:
            return float(cur.fetchone()[0])
        except TypeError:
            return 0
        cur.close()

    def tr_out(self):
        cur = connection.cursor()
        cur.execute(
            """SELECT SUM(tr_amount) from pfm_transfer as t JOIN pfm_account as a
                    ON t.from_acc_id = a.id WHERE from_acc_id=%s""",
            (self.id,),
        )
        try:
            return float(cur.fetchone()[0])
        except TypeError:
            return 0
        cur.close()

    def rest(self):
        return (
            float(self.acc_balance)
            - self.count(Account.SQL_exp)
            - self.tr_out()
            + self.count(Account.SQL_inc)
            + self.tr_in()
        )


class Transaction(models.Model):
    tr_acc = models.ForeignKey(Account)
    tr_cat = models.ForeignKey(Category)
    tr_type = models.CharField(
        "Type", max_length=1, choices=(("I", "Income"), ("E", "Expence")), default="E"
    )
    tr_amount = models.DecimalField(
        "Amount", max_digits=10, decimal_places=2, default="0.00"
    )
    tr_note = models.CharField(max_length=100, null=True, blank=True)
    tr_date = models.DateField(default=timezone.now)
    pub_date = models.DateTimeField(blank=True, null=True)
    user = models.ForeignKey("auth.user", blank=True, null=True)

    def publish(self):
        self.pub_date = timezone.now()
        self.save()

    def __unicode__(self):
        return "%s,%s,%s,%s" % (
            self.tr_cat,
            self.tr_acc,
            self.tr_amount,
            self.tr_date.strftime("%d.%m.%Y"),
        )


class Transfer(models.Model):
    from_acc = models.ForeignKey(Account, related_name="to_acc")
    to_acc = models.ForeignKey(Account, related_name="from_acc")
    tr_amount = models.DecimalField("Amount", max_digits=10, decimal_places=2)
    tr_date = models.DateTimeField(default=timezone.now)
    user = models.ForeignKey("auth.user", blank=True, null=True)

    def publish(self):
        self.save()

    def __unicode__(self):
        return "%s >>> %s, %s" % (self.from_acc, self.to_acc, self.tr_amount)