"""User-defined device abstraction.

A Device is a human-friendly alias for a board relay (controllable output) or
a board digital input (sensor/trigger) that the user wants to expose as a named
entity — e.g. "Outdoor Light 1 (Courtyard)" mapped to Board "Garage" / Relay 4.

Devices provide an intermediate, named layer so they can later be placed on
Layout pages as interactive widgets without the UI needing raw board/relay IDs.
"""
from datetime import datetime
from app import db


class Device(db.Model):
    __tablename__ = "devices"

    id           = db.Column(db.Integer, primary_key=True)
    name         = db.Column(db.String(128), nullable=False)
    description  = db.Column(db.String(256), nullable=True)
    area         = db.Column(db.String(64),  nullable=True)   # e.g. "Courtyard", "Living Room"

    # Device category — drives default icon and state labels
    device_class = db.Column(db.String(32),  nullable=False, default="switch")

    # Bootstrap-Icons class override; None → use type default
    icon         = db.Column(db.String(64),  nullable=True)

    # ── Source entity on a board ─────────────────────────────────────────────
    board_id     = db.Column(
        db.Integer, db.ForeignKey("boards.id", ondelete="SET NULL"), nullable=True
    )
    entity_type  = db.Column(db.String(16), nullable=True)   # "relay" | "input"
    entity_num   = db.Column(db.Integer,    nullable=True)    # 1-based relay/input index

    created_at   = db.Column(db.DateTime, default=datetime.utcnow)

    # ── relationships ────────────────────────────────────────────────────────
    board = db.relationship("Board", back_populates="devices")

    # ── helpers ──────────────────────────────────────────────────────────────
    @property
    def is_controllable(self) -> bool:
        """True when the source entity is a relay (can be toggled ON/OFF)."""
        return self.entity_type == "relay"

    @property
    def effective_icon(self) -> str:
        """Icon class to use in the UI (custom override or type default)."""
        from app.models.entity_types import RELAY_ENTITY_TYPES, INPUT_ENTITY_TYPES
        if self.icon:
            return self.icon
        if self.entity_type == "relay":
            return RELAY_ENTITY_TYPES.get(
                self.device_class, RELAY_ENTITY_TYPES["switch"]
            )["icon"]
        if self.entity_type == "input":
            return INPUT_ENTITY_TYPES.get(
                self.device_class, INPUT_ENTITY_TYPES["generic"]
            )["icon"]
        return "bi-cpu"

    @property
    def current_state(self):
        """Returns the current boolean state or None if unavailable."""
        if not self.board or not self.entity_type or not self.entity_num:
            return None
        if self.entity_type == "relay":
            return self.board.relay_states.get(f"relay_{self.entity_num}", False)
        if self.entity_type == "input":
            raw = self.board.input_states.get(f"input_{self.entity_num}", True)
            return not raw   # NC contact: raw True = resting → False = idle
        return None

    @property
    def state_label(self) -> str:
        """Human-readable state string."""
        from app.models.entity_types import RELAY_ENTITY_TYPES, INPUT_ENTITY_TYPES
        state = self.current_state
        if state is None:
            return "Unknown"
        if self.entity_type == "relay":
            tdef = RELAY_ENTITY_TYPES.get(self.device_class, RELAY_ENTITY_TYPES["switch"])
            return tdef["on"][1] if state else tdef["off"][1]
        if self.entity_type == "input":
            tdef = INPUT_ENTITY_TYPES.get(self.device_class, INPUT_ENTITY_TYPES["generic"])
            return tdef["active"][1] if state else tdef["idle"][1]
        return "Unknown"

    @property
    def state_color(self) -> str:
        """Bootstrap color name for current state badge."""
        from app.models.entity_types import RELAY_ENTITY_TYPES, INPUT_ENTITY_TYPES
        state = self.current_state
        if state is None:
            return "secondary"
        if self.entity_type == "relay":
            tdef = RELAY_ENTITY_TYPES.get(self.device_class, RELAY_ENTITY_TYPES["switch"])
            return tdef["on"][0] if state else tdef["off"][0]
        if self.entity_type == "input":
            tdef = INPUT_ENTITY_TYPES.get(self.device_class, INPUT_ENTITY_TYPES["generic"])
            return tdef["active"][0] if state else tdef["idle"][0]
        return "secondary"

    def __repr__(self):
        return f"<Device {self.name!r} id={self.id}>"