# ------------------------------------------------------------
# Central place for all data‑model definitions.
# ------------------------------------------------------------

from __future__ import annotations

from dataclasses import dataclass, asdict, fields
from datetime import date, datetime
from typing import Any, Dict, Tuple, Type, TypeVar, Union

# ----------------------------------------------------------------------
# Helper types – what sqlite3.Row returns (either a tuple‑like or a dict‑like)
# ----------------------------------------------------------------------
Row = Tuple[Any, ...] | Dict[str, Any]

T = TypeVar("T", bound="BaseModel")


# ----------------------------------------------------------------------
# BaseModel – common conversion helpers for every model
# ----------------------------------------------------------------------
class BaseModel:
    """
    Minimal base class that knows how to:

    * Build an instance from a SQLite row (or any mapping with column names).
    * Export itself as a plain ``dict`` suitable for INSERT/UPDATE statements.
    * Render a readable ``repr`` for debugging.
    """

    @classmethod
    def from_row(cls: Type[T], row: Row) -> T:
        """
        Convert a ``sqlite3.Row`` (or a dict‑like mapping) into a dataclass
        instance.  Field names are matched to column names; ``None`` values are
        preserved verbatim.  ``datetime`` and ``date`` columns are parsed from
        ISO‑8601 strings when necessary.
        """
        # ``row`` may already be a dict – otherwise turn the Row into one.
        data = dict(row) if not isinstance(row, dict) else row

        converted: Dict[str, Any] = {}
        for f in fields(cls):
            raw = data.get(f.name)

            # Preserve ``None`` exactly as‑is.
            if raw is None:
                converted[f.name] = None
                continue

            # ------------------------------------------------------------------
            # 1️⃣ datetime handling
            # ------------------------------------------------------------------
            if f.type is datetime:
                # SQLite stores datetimes as ISO strings.
                if isinstance(raw, str):
                    converted[f.name] = datetime.fromisoformat(raw)
                else:
                    converted[f.name] = raw

            # ------------------------------------------------------------------
            # 2️⃣ date handling
            # ------------------------------------------------------------------
            elif f.type is date:
                if isinstance(raw, str):
                    converted[f.name] = date.fromisoformat(raw)
                else:
                    converted[f.name] = raw

            # ------------------------------------------------------------------
            # 3️⃣ fallback – keep whatever we received
            # ------------------------------------------------------------------
            else:
                converted[f.name] = raw

        # Instantiate the concrete dataclass.
        return cls(**converted)  # type: ignore[arg-type]

    # ------------------------------------------------------------------
    # Convenience helpers
    # ------------------------------------------------------------------
    def to_dict(self) -> Dict[str, Any]:
        """Return a plain ``dict`` of the dataclass fields (good for INSERTs)."""
        return asdict(self)

    def __repr__(self) -> str:
        """Readable representation useful during debugging."""
        parts = ", ".join(f"{f.name}={getattr(self, f.name)!r}" for f in fields(self))
        return f"{self.__class__.__name__}({parts})"


# ----------------------------------------------------------------------
# Concrete models – each one is a thin dataclass inheriting from BaseModel.
# ----------------------------------------------------------------------


# ---------- Logging tables ----------
@dataclass
class AcceptedLog(BaseModel):
    LogId: int
    MemberId: int
    ServiceId: int
    AcceptedAt: datetime


@dataclass
class DeclineLog(BaseModel):
    DeclineId: int
    MemberId: int
    ServiceId: int
    DeclinedAt: datetime
    DeclineDate: date          # the service day that was declined
    Reason: Union[str, None] = None


@dataclass
class ScheduledLog(BaseModel):
    LogId: int
    MemberId: int
    ServiceId: int
    ScheduledAt: datetime
    ExpiresAt: datetime


# ---------- Core reference data ----------
@dataclass
class Classification(BaseModel):
    ClassificationId: int
    ClassificationName: str


@dataclass
class ServiceType(BaseModel):
    ServiceTypeId: int
    TypeName: str


# ---------- Primary domain entities ----------
@dataclass
class Member(BaseModel):
    MemberId: int
    FirstName: str
    LastName: str
    Email: Union[str, None] = None
    PhoneNumber: Union[str, None] = None
    ClassificationId: Union[int, None] = None
    Notes: Union[str, None] = None
    IsActive: int = 1
    LastScheduledAt: Union[datetime, None] = None
    LastAcceptedAt: Union[datetime, None] = None
    LastDeclinedAt: Union[datetime, None] = None
    DeclineStreak: int = 0


@dataclass
class Service(BaseModel):
    ServiceId: int
    ServiceTypeId: int
    ServiceDate: date


@dataclass
class ServiceAvailability(BaseModel):
    ServiceAvailabilityId: int
    MemberId: int
    ServiceTypeId: int


@dataclass
class Schedule(BaseModel):
    ScheduleId: int
    ServiceId: int
    MemberId: int
    Status: str                     # 'pending' | 'accepted' | 'declined'
    ScheduledAt: datetime
    AcceptedAt: Union[datetime, None] = None
    DeclinedAt: Union[datetime, None] = None
    ExpiresAt: Union[datetime, None] = None
    DeclineReason: Union[str, None] = None