"""Workflow model.

A workflow fires an action (set relay ON/OFF/TOGGLE) on a *target* board
whenever a specific input on a *trigger* board changes state.
"""
from datetime import datetime
from app import db


class Workflow(db.Model):
    __tablename__ = "workflows"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(128), nullable=False)
    is_enabled = db.Column(db.Boolean, default=True, nullable=False)

    # ── trigger ──────────────────────────────────────────────────────
    trigger_board_id = db.Column(
        db.Integer, db.ForeignKey("boards.id", ondelete="CASCADE"), nullable=False
    )
    trigger_input = db.Column(db.Integer, nullable=False)   # 1-based
    # "press" (rising edge), "release" (falling), "both"
    trigger_event = db.Column(db.String(16), nullable=False, default="press")

    # ── action ───────────────────────────────────────────────────────
    action_board_id = db.Column(
        db.Integer, db.ForeignKey("boards.id"), nullable=False
    )
    action_relay = db.Column(db.Integer, nullable=False)    # 1-based
    # "on", "off", "toggle"
    action_type = db.Column(db.String(16), nullable=False, default="toggle")

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

    # ── relationships ────────────────────────────────────────────────
    trigger_board = db.relationship(
        "Board", foreign_keys=[trigger_board_id],
        back_populates="workflows_trigger"
    )
    action_board = db.relationship(
        "Board", foreign_keys=[action_board_id],
        back_populates="workflows_target"
    )

    def __repr__(self) -> str:
        return (
            f"<Workflow '{self.name}' "
            f"Board#{self.trigger_board_id}.in{self.trigger_input} "
            f"→ Board#{self.action_board_id}.relay{self.action_relay} [{self.action_type}]>"
        )