import json
import uuid

from datetime import date, datetime
from decimal import Decimal
from typing import List, Optional

from brewman.schemas import to_camel
from brewman.schemas.master import AccountLink, CostCentreLink
from brewman.schemas.voucher import (
    EmployeeBenefit,
    Incentive,
    Inventory,
    Journal,
    VoucherIn,
)
from fastapi import Form
from pydantic import BaseModel, Field, validator
from sqlalchemy.orm import Session


class JournalIn(VoucherIn):
    journals: List[Journal]

    class Config:
        anystr_strip_whitespace = True
        alias_generator = to_camel
        json_encoders = {
            date: lambda v: v.strftime("%d-%b-%Y"),
            datetime: lambda v: v.strftime("%d-%b-%Y %H:%I"),
        }

    @validator("date_", pre=True)
    def parse_date(cls, value):
        if isinstance(value, date):
            return value
        return datetime.strptime(value, "%d-%b-%Y").date()

    @validator("journals")
    def validate_signed_amount(cls, value: List[Journal]):
        if sum(x.debit * x.amount for x in value) != 0:
            raise ValueError("Journal amounts do no match")
        return value

    @validator("journals")
    def is_distinct(cls, value: List[Journal]):
        journal_set = set(
            hash(x.account.id_)
            ^ hash(None if x.cost_centre is None else x.cost_centre.id_)
            for x in value
        )
        if len(value) != len(journal_set):
            raise ValueError("Duplicate journals")
        return value

    @classmethod
    def load_form(cls, data: str = Form(...)):
        json_data = json.loads(data)
        return cls.parse_obj(json_data)


class PurchaseIn(VoucherIn):
    vendor: AccountLink
    inventories: List[Inventory]

    class Config:
        anystr_strip_whitespace = True
        alias_generator = to_camel
        json_encoders = {
            date: lambda v: v.strftime("%d-%b-%Y"),
            datetime: lambda v: v.strftime("%d-%b-%Y %H:%I"),
        }

    @validator("date_", pre=True)
    def parse_date(cls, value):
        if isinstance(value, date):
            return value
        return datetime.strptime(value, "%d-%b-%Y").date()

    @validator("inventories")  #  For Purchase, Issue and Return Vouchers
    def validate_enough_inventories(cls, value: List[Inventory]):
        if len(value) < 1:
            raise ValueError("Not enough inventories")
        return value

    @validator("inventories")  #  For Purchase, Issue and Return Vouchers
    def validate_inventories_unique(cls, value: List[Inventory]):
        if len(set(x.product.id_ for x in value)) != len(value):
            raise ValueError("Duplicate products")
        return value

    @classmethod
    def load_form(cls, data: str = Form(...)):
        json_data = json.loads(data)
        return cls.parse_obj(json_data)


class IssueIn(VoucherIn):
    source: CostCentreLink
    destination: CostCentreLink
    inventories: List[Inventory]

    class Config:
        anystr_strip_whitespace = True
        alias_generator = to_camel
        json_encoders = {
            date: lambda v: v.strftime("%d-%b-%Y"),
            datetime: lambda v: v.strftime("%d-%b-%Y %H:%I"),
        }

    @validator("date_", pre=True)
    def parse_date(cls, value):
        if isinstance(value, date):
            return value
        return datetime.strptime(value, "%d-%b-%Y").date()

    @validator("inventories")  #  For Purchase, Issue and Return Vouchers
    def validate_enough_inventories(cls, value: List[Inventory]):
        if len(value) < 1:
            raise ValueError("Not enough inventories")
        return value

    @validator("inventories")  #  For Purchase, Issue and Return Vouchers
    def validate_inventories_unique(cls, value: List[Inventory]):
        if len(set(x.product.id_ for x in value)) != len(value):
            raise ValueError("Duplicate products")
        return value

    @validator("destination")  #  For Purchase, Issue and Return Vouchers
    def source_destination_unique(cls, value: CostCentreLink, values):
        if value.id_ == values["source"].id_:
            raise ValueError("Source and destination cannot be the same")
        return value

    @classmethod
    def load_form(cls, data: str = Form(...)):
        json_data = json.loads(data)
        return cls.parse_obj(json_data)


class EmployeeBenefitIn(VoucherIn):
    employee_benefits: List[EmployeeBenefit]

    class Config:
        anystr_strip_whitespace = True
        alias_generator = to_camel
        json_encoders = {
            date: lambda v: v.strftime("%d-%b-%Y"),
            datetime: lambda v: v.strftime("%d-%b-%Y %H:%I"),
        }

    @validator("date_", pre=True)
    def parse_date(cls, value):
        if isinstance(value, date):
            return value
        return datetime.strptime(value, "%d-%b-%Y").date()

    @classmethod
    def load_form(cls, data: str = Form(...)):
        json_data = json.loads(data)
        return cls.parse_obj(json_data)


class IncentiveIn(VoucherIn):
    incentives: List[Incentive]

    class Config:
        anystr_strip_whitespace = True
        alias_generator = to_camel
        json_encoders = {
            date: lambda v: v.strftime("%d-%b-%Y"),
            datetime: lambda v: v.strftime("%d-%b-%Y %H:%I"),
        }

    @validator("date_", pre=True)
    def parse_date(cls, value):
        if isinstance(value, date):
            return value
        return datetime.strptime(value, "%d-%b-%Y").date()

    @classmethod
    def load_form(cls, data: str = Form(...)):
        json_data = json.loads(data)
        return cls.parse_obj(json_data)


class IncentiveEmployee(BaseModel):
    id_: Optional[uuid.UUID]
    employee_id: uuid.UUID
    cost_centre_id: uuid.UUID
    journal: Optional[Journal]
    days_worked: Decimal = Field(ge=0, multiple_of=0.5)
    points: Decimal = Field(ge=0, multiple_of=0.01)