"""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
    # Saldo, wie ihn die Bank fuehrt – nur bei angebundenen Konten gesetzt. Er
    # ersetzt die eigene Rechnung nicht, er prueft sie.
    bank_balance_cents: int | None = None
    bank_balance_at: datetime | None = None
    # Nur ein GEBUCHTER Saldo ist mit Certains Rechnung vergleichbar. Ein
    # verfuegbarer enthaelt Vorgemerktes, das hier bewusst nicht gebucht wird.
    bank_balance_vergleichbar: bool = False


# --- 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
    # Budget-Monat (YYYY-MM). Leer heisst: aus dem Datum ableiten.
    budget_period: str | None = Field(default=None, pattern=r"^\d{4}-\d{2}$")
    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
    # Budget-Monat (YYYY-MM). Leer heisst: aus dem Datum ableiten.
    budget_period: str | None = Field(default=None, pattern=r"^\d{4}-\d{2}$")
    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
    # Der Budget-Monat, in dem die Buchung zaehlt – immer gesetzt. Ob er von
    # Hand gewaehlt wurde oder aus dem Datum stammt, sagt das zweite Feld.
    budget_period: str
    budget_period_manuell: bool = False
    # Woher die Buchung stammt, fuer die Arbeitsliste: Ist sie gesetzt,
    # kam die Buchung aus einem Datei-Import.
    import_batch_id: int | None = None
    # Woher die Buchung stammt: bank, mail, shortcut, transfer, csv, manuell.
    herkunft: str = "manuell"
    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
    # Das jeweils ANDERE Konto, wenn die Buchung ein Kontoübertrag ist. Ohne
    # das kann die Oberfläche einen Übertrag nicht von einer Ausgabe
    # unterscheiden und fragt weiter nach einer Kategorie.
    transfer_account_id: int | None = None
    # Was die Bank ueber die Umrechnung mitteilt – ihr Kurs schlaegt die EZB.
    fx_rate: float | None = None
    counter_amount_cents: int | None = None
    counter_currency: str | None = 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


# --- Postfächer für den Mail-Abruf -------------------------------------------


class MailSourceIn(BaseModel):
    name: str = Field(default="", max_length=80)
    host: str = Field(min_length=1, max_length=255)
    port: int = 993
    security: Literal["ssl", "starttls", "none"] = "ssl"
    username: str = Field(min_length=1, max_length=255)
    # Beim Ändern weglassen, um das gespeicherte Passwort zu behalten.
    password: str | None = None
    folder: str = "INBOX"
    done_folder: str | None = None
    mark_seen: bool = True
    is_active: bool = True
    poll_minutes: int = Field(default=15, ge=5, le=1440)


class MailSourceOut(BaseModel):
    id: int
    name: str
    host: str
    port: int
    security: str
    username: str
    folder: str
    done_folder: str | None
    mark_seen: bool
    is_active: bool
    poll_minutes: int
    last_poll_at: datetime | None
    last_error: str | None
    # Das Passwort verlässt den Server nie – nur die Tatsache, dass eines da ist.
    password_set: bool = True

    model_config = ConfigDict(from_attributes=True)


class MailSenderIn(BaseModel):
    name: str = Field(default="", max_length=80)
    from_contains: str | None = Field(default=None, max_length=255)
    subject_contains: str | None = Field(default=None, max_length=255)
    currency: str | None = Field(default=None, max_length=3)
    account_id: int | None = None


class MailSenderOut(MailSenderIn):
    id: int
    source_id: int

    model_config = ConfigDict(from_attributes=True)


# --- Bankanbindung (PSD2) ----------------------------------------------------


class BankAppIn(BaseModel):
    application_id: str = Field(min_length=1, max_length=64)
    # Inhalt der .pem-Datei aus dem Control Panel.
    private_key: str = Field(min_length=1)
    # Öffentliche Adresse dieser Installation; die Bank leitet dorthin zurück.
    base_url: str = Field(min_length=1, max_length=255)

    @field_validator("base_url")
    @classmethod
    def nur_https(cls, v: str) -> str:
        """Ohne HTTPS lehnt die Bank die Rückleitung ab.

        Bewusst eingetragen statt erkannt: Hinter einem Proxy sieht der Dienst
        selbst „http", obwohl der Browser HTTPS spricht – automatisches Raten
        würde hier zuverlässig das Falsche liefern.
        """
        v = v.strip().rstrip("/")
        if not v.lower().startswith("https://"):
            raise ValueError(
                "Die Adresse muss mit https:// beginnen. Banken leiten nicht "
                "auf eine unverschlüsselte Adresse zurück."
            )
        return v


class BankAppOut(BaseModel):
    id: int
    application_id: str
    base_url: str
    created_at: datetime | None
    # Der Schlüssel verlässt den Server nie – nur die Tatsache, dass einer da ist.
    key_set: bool = True

    model_config = ConfigDict(from_attributes=True)


class BankConnectionOut(BaseModel):
    id: int
    aspsp_name: str
    aspsp_country: str
    valid_until: datetime | None
    last_sync_at: datetime | None
    # Takt des automatischen Abrufs in Minuten, 0 = aus.
    poll_minutes: int = 0
    last_error: str | None
    expires_soon: bool = False

    model_config = ConfigDict(from_attributes=True)


class BankAccountLinkOut(BaseModel):
    id: int
    connection_id: int
    remote_uid: str
    iban: str | None
    remote_name: str | None
    product: str | None = None
    other_id: str | None = None
    bank_felder: dict = {}
    currency: str
    balance_cents: int | None = None
    balance_type: str | None = None
    balance_vergleichbar: bool = False
    balance_at: datetime | None = None
    last_sync_at: datetime | None = None
    account_id: int | None

    model_config = ConfigDict(from_attributes=True)


class BankConnectStart(BaseModel):
    aspsp_name: str = Field(min_length=1, max_length=120)
    country: str = Field(min_length=2, max_length=2)
    psu_type: Literal["personal", "business"] = "personal"