"""Pydantic-Schemas für Anfragen/Antworten (Phase 0: Auth, Benutzer, Einstellungen)."""

from datetime import date as date_t, datetime, time as time_t
from decimal import Decimal
from typing import Literal

from pydantic import BaseModel, ConfigDict, Field, field_validator

from .models import (
    AccountType,
    AmountMode,
    BudgetTreatment,
    CategoryKind,
    IdentifierKind,
    ImportStatus,
    Role,
    TxnType,
)

ALLOWED_CURRENCIES = {"EUR", "CHF"}


def _check_currency(v: str) -> str:
    v = v.upper()
    if v not in ALLOWED_CURRENCIES:
        raise ValueError("Währung muss EUR oder CHF sein")
    return v


class UserOut(BaseModel):
    model_config = ConfigDict(from_attributes=True)

    id: int
    username: str
    role: Role
    display_name: str | None = None
    is_active: bool
    must_change_password: bool
    must_change_password_reason: str | None = None
    totp_enabled: bool = False
    created_at: datetime
    # Kein Datenbankfeld: „Richtlinie verlangt MFA und dieser Benutzer hat
    # keins". Wird beim Ausliefern gesetzt (siehe deps.user_out), damit das
    # Frontend ohne zweite Abfrage weiss, wohin es umleiten muss.
    mfa_setup_required: bool = False


class UserCreate(BaseModel):
    username: str = Field(min_length=1, max_length=64)
    password: str = Field(min_length=1, max_length=1024)
    role: Role = Role.user
    display_name: str | None = Field(default=None, max_length=120)


class UserUpdate(BaseModel):
    password: str | None = Field(default=None, min_length=1, max_length=1024)
    role: Role | None = None
    display_name: str | None = Field(default=None, max_length=120)
    is_active: bool | None = None


class PasswordChange(BaseModel):
    current_password: str = Field(min_length=1, max_length=1024)
    new_password: str = Field(min_length=1, max_length=1024)


class SettingOut(BaseModel):
    key: str
    value: str | None = None


# --- Passwortrichtlinie -----------------------------------------------------


class PolicyOut(BaseModel):
    min_length: int
    require_upper: bool
    require_lower: bool
    require_digit: bool
    require_special: bool
    mfa_required: bool


class PolicyIn(BaseModel):
    min_length: int = Field(ge=8, le=128)
    require_upper: bool = False
    require_lower: bool = False
    require_digit: bool = False
    require_special: bool = False
    mfa_required: bool = False


# --- Anmeldung / Zwei-Faktor ------------------------------------------------


class LoginOut(BaseModel):
    """Antwort auf ``POST /auth/login``.

    ``status`` ist ``"ok"`` (angemeldet, ``user`` gesetzt) oder ``"2fa_required"``
    (Passwort stimmt, es fehlt noch der Code – ``user`` bleibt leer)."""

    status: str = "ok"
    user: UserOut | None = None


class TwoFactorVerify(BaseModel):
    code: str = Field(min_length=1, max_length=64)
    recovery: bool = False


class TwoFactorSetupOut(BaseModel):
    secret: str
    otpauth_uri: str
    qr_png: str  # data:-URI, direkt in <img src=...> verwendbar


class TwoFactorActivate(BaseModel):
    code: str = Field(min_length=1, max_length=16)


class TwoFactorPassword(BaseModel):
    password: str = Field(min_length=1, max_length=1024)


class RecoveryCodesOut(BaseModel):
    codes: list[str]


class TwoFactorStatusOut(BaseModel):
    enabled: bool
    recovery_codes_left: int


# --- Konten ----------------------------------------------------------------


class AccountIdentifierIn(BaseModel):
    kind: IdentifierKind = IdentifierKind.iban
    value: str = Field(min_length=1, max_length=64)


class AccountIdentifierOut(BaseModel):
    id: int
    kind: IdentifierKind
    value: str


class AccountCreate(BaseModel):
    name: str = Field(min_length=1, max_length=120)
    type: AccountType = AccountType.girokonto
    currency: str = "EUR"
    icon: str = "wallet"
    color: str = "#3f51b5"
    opening_balance_cents: int = 0
    opening_date: date_t | None = None
    identifiers: list[AccountIdentifierIn] = Field(default_factory=list)

    @field_validator("currency")
    @classmethod
    def _cur(cls, v: str) -> str:
        return _check_currency(v)


class AccountOrder(BaseModel):
    """Konto-IDs in der gewünschten Reihenfolge."""

    ids: list[int]


class AccountUpdate(BaseModel):
    name: str | None = Field(default=None, min_length=1, max_length=120)
    type: AccountType | None = None
    currency: str | None = None
    icon: str | None = None
    color: str | None = None
    opening_balance_cents: int | None = None
    opening_date: date_t | None = None
    is_archived: bool | None = None
    position: int | None = None
    # Wenn gesetzt, ersetzt die komplette Identifikator-Liste.
    identifiers: list[AccountIdentifierIn] | None = None

    @field_validator("currency")
    @classmethod
    def _cur(cls, v: str | None) -> str | None:
        return _check_currency(v) if v is not None else None


class AccountOut(BaseModel):
    id: int
    name: str
    type: AccountType
    currency: str
    icon: str
    color: str
    opening_balance_cents: int
    opening_date: date_t | None
    is_archived: bool
    position: int
    identifiers: list[AccountIdentifierOut]
    balance_cents: int
    balance_base_cents: int


# --- Kategorien ------------------------------------------------------------


class CategoryOut(BaseModel):
    model_config = ConfigDict(from_attributes=True)

    id: int
    group_id: int
    name: str
    type: CategoryKind
    icon: str
    color: str
    position: int
    is_builtin: bool
    is_archived: bool
    excluded_from_stats: bool = False
    # Anzahl hinterlegter Schlagwörter. Nur in der Liste gefüllt, damit die
    # Übersicht ohne einen Abruf je Kategorie auskommt.
    keyword_count: int = 0


class CategoryGroupOut(BaseModel):
    id: int
    name: str
    kind: CategoryKind
    icon: str
    color: str
    position: int
    is_builtin: bool
    categories: list[CategoryOut]


class CategoryGroupCreate(BaseModel):
    name: str = Field(min_length=1, max_length=120)
    kind: CategoryKind = CategoryKind.expense
    icon: str = "list"
    color: str = "#6b7480"


class CategoryGroupUpdate(BaseModel):
    name: str | None = Field(default=None, min_length=1, max_length=120)
    icon: str | None = None
    color: str | None = None
    position: int | None = None


class CategoryCreate(BaseModel):
    group_id: int
    name: str = Field(min_length=1, max_length=120)
    icon: str = "more-horizontal"
    color: str = "#6b7480"
    excluded_from_stats: bool = False


class CategoryUpdate(BaseModel):
    name: str | None = Field(default=None, min_length=1, max_length=120)
    group_id: int | None = None
    icon: str | None = None
    color: str | None = None
    position: int | None = None
    is_archived: bool | None = None
    excluded_from_stats: bool | None = None


# --- Transaktionen ---------------------------------------------------------


class TransactionCreate(BaseModel):
    type: TxnType
    date: date_t
    time: time_t | None = None
    account_id: int
    to_account_id: int | None = None
    amount_cents: int = Field(gt=0)
    to_amount_cents: int | None = Field(default=None, gt=0)
    fx_rate: float | None = Field(default=None, gt=0)
    category_id: int | None = None
    budget_treatment: BudgetTreatment | None = None
    budget_category_id: int | None = None
    payee: str | None = Field(default=None, max_length=255)
    description: str | None = Field(default=None, max_length=255)
    notes: str | None = None


class TransactionUpdate(BaseModel):
    type: TxnType | None = None
    date: date_t | None = None
    time: time_t | None = None
    account_id: int | None = None
    to_account_id: int | None = None
    amount_cents: int | None = Field(default=None, gt=0)
    to_amount_cents: int | None = Field(default=None, gt=0)
    fx_rate: float | None = Field(default=None, gt=0)
    category_id: int | None = None
    budget_treatment: BudgetTreatment | None = None
    budget_category_id: int | None = None
    payee: str | None = Field(default=None, max_length=255)
    description: str | None = Field(default=None, max_length=255)
    notes: str | None = None


class TransactionOut(BaseModel):
    id: int
    type: TxnType
    date: date_t
    time: time_t | None
    account_id: int
    to_account_id: int | None
    account_currency: str
    amount_cents: int
    to_amount_cents: int | None
    fx_rate: float | None
    amount_eur_cents: int
    amount_base_cents: int
    category_id: int | None
    budget_treatment: BudgetTreatment | None
    budget_category_id: int | None
    payee: str | None
    description: str | None
    notes: str | None


class RateStatus(BaseModel):
    currency: str
    count: int
    min_date: date_t | None
    max_date: date_t | None
    latest_rate: float | None


class ConversionOut(BaseModel):
    amount_cents: int
    from_currency: str
    to_currency: str
    date: date_t
    converted_cents: int | None
    rate: float | None


# --- Budget: geplante Einnahmen --------------------------------------------


class PlannedIncomeCreate(BaseModel):
    label: str = Field(min_length=1, max_length=120)
    category_id: int | None = None
    target_account_id: int | None = None
    planned_cents: int = Field(ge=0)


class PlannedIncomeUpdate(BaseModel):
    label: str | None = Field(default=None, min_length=1, max_length=120)
    category_id: int | None = None
    target_account_id: int | None = None
    planned_cents: int | None = Field(default=None, ge=0)


class PlannedIncomeOut(BaseModel):
    model_config = ConfigDict(from_attributes=True)

    id: int
    label: str
    category_id: int | None
    target_account_id: int | None
    planned_cents: int
    position: int


# --- CSV-Import ------------------------------------------------------------


class ImportTemplateCreate(BaseModel):
    name: str = Field(min_length=1, max_length=120)
    delimiter: str = ";"
    decimal_sep: str = ","
    date_format: str = "%d.%m.%Y"
    encoding: str = "utf-8"
    has_header: bool = True
    skip_rows: int = 0
    amount_mode: AmountMode = AmountMode.signed
    column_map: dict[str, int | None] = Field(default_factory=dict)
    filter_column: int | None = None
    filter_value: str | None = None


class ImportTemplateUpdate(BaseModel):
    name: str | None = Field(default=None, min_length=1, max_length=120)
    delimiter: str | None = None
    decimal_sep: str | None = None
    date_format: str | None = None
    encoding: str | None = None
    has_header: bool | None = None
    skip_rows: int | None = None
    amount_mode: AmountMode | None = None
    column_map: dict[str, int | None] | None = None
    filter_column: int | None = None
    filter_value: str | None = None


class ImportTemplateOut(BaseModel):
    id: int
    name: str
    delimiter: str
    decimal_sep: str
    date_format: str
    encoding: str
    has_header: bool
    skip_rows: int
    amount_mode: AmountMode
    column_map: dict[str, int | None]
    filter_column: int | None = None
    filter_value: str | None = None


class ImportBatchOut(BaseModel):
    model_config = ConfigDict(from_attributes=True)

    id: int
    account_id: int
    template_id: int | None
    preset: str | None
    filename: str
    row_count: int
    imported_count: int
    status: ImportStatus
    created_at: datetime


class ImportCommitIn(BaseModel):
    account_id: int
    template_id: int | None = None
    preset: str | None = None
    filename: str = ""
    rows: list[dict] = Field(default_factory=list)


# --- Schlagwörter (manuelle Kategorisierungs-Regeln) -----------------------


class KeywordCreate(BaseModel):
    word: str = Field(min_length=1, max_length=255)
    amount_cents: int | None = Field(default=None, gt=0)


class KeywordUpdate(BaseModel):
    word: str = Field(min_length=1, max_length=255)
    amount_cents: int | None = Field(default=None, gt=0)


class KeywordOut(BaseModel):
    id: int
    category_id: int
    word: str
    amount_cents: int | None = None


class TransferKeywordCreate(BaseModel):
    word: str = Field(min_length=1, max_length=255)
    amount_cents: int | None = Field(default=None, gt=0)
    target_account_id: int | None = None


class TransferKeywordOut(BaseModel):
    id: int
    word: str
    amount_cents: int | None = None
    target_account_id: int | None = None


class FlaggedKeywordOut(BaseModel):
    id: int
    category_id: int | None = None
    category_name: str
    word: str
    applied_count: int
    overridden_count: int


# --- Gerätemarken und Eingang ------------------------------------------------


class ApiTokenCreate(BaseModel):
    name: str = Field(min_length=1, max_length=80)
    default_account_id: int | None = None


class ApiTokenOut(BaseModel):
    id: int
    name: str
    default_account_id: int | None
    last_used_at: datetime | None
    created_at: datetime | None

    model_config = ConfigDict(from_attributes=True)


class ApiTokenCreated(ApiTokenOut):
    """Antwort beim Anlegen – der Klartext ist hier das einzige Mal zu sehen."""

    token: str


class QuickBookingIn(BaseModel):
    """Was ein Kurzbefehl schickt. Bewusst genügsam: Betrag reicht."""

    amount: Decimal
    payee: str | None = Field(default=None, max_length=255)
    date: date_t | None = None
    account_id: int | None = None
    note: str | None = None
    # Kennung des Kurzbefehls, damit ein doppelt ausgelöster Aufruf nicht
    # zweimal bucht (schlechtes Netz, versehentlicher Doppeltipp).
    external_id: str | None = Field(default=None, max_length=255)
    kind: Literal["expense", "income"] = "expense"


class InboxItemOut(BaseModel):
    id: int
    source: str
    status: str
    account_id: int | None
    date: date_t
    amount_cents: int
    currency: str
    payee: str | None
    note: str | None
    category_id: int | None
    transaction_id: int | None
    created_at: datetime | None

    model_config = ConfigDict(from_attributes=True)


class QuickBookingOut(BaseModel):
    """Kurze Rückmeldung – der Kurzbefehl zeigt sie als Mitteilung an."""

    ok: bool = True
    message: str
    item: InboxItemOut