from app.extensions import db
from datetime import datetime


class Investment(db.Model):
    __tablename__ = 'investments'

    id = db.Column(db.Integer, primary_key=True)
    # Optional link to a PFM account (e.g. Schwab Individual, Schwab Roth IRA).
    # NULL means the holding is not tied to a specific account.
    account_id = db.Column(db.Integer, db.ForeignKey('accounts.id'), nullable=True, index=True)
    asset_name = db.Column(db.String(100), nullable=False)
    ticker = db.Column(db.String(20), nullable=True)
    asset_type = db.Column(
        db.Enum('stock', 'etf', 'crypto', 'real_estate', 'bond', 'cash', 'other'),
        nullable=False,
        default='stock'
    )
    shares = db.Column(db.Numeric(18, 8), nullable=False, default=0)
    avg_cost_basis = db.Column(db.Numeric(15, 4), nullable=False, default=0)
    current_price = db.Column(db.Numeric(15, 4), nullable=True)
    last_price_update = db.Column(db.DateTime, nullable=True)
    notes = db.Column(db.Text, nullable=True)
    is_active = db.Column(db.Boolean, default=True)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)

    account = db.relationship('Account', foreign_keys=[account_id])
    inv_transactions = db.relationship('InvestmentTransaction', back_populates='investment',
                                       lazy='dynamic', cascade='all, delete-orphan')

    @property
    def total_cost(self):
        return float(self.shares) * float(self.avg_cost_basis)

    @property
    def current_value(self):
        if self.current_price:
            return float(self.shares) * float(self.current_price)
        return self.total_cost

    @property
    def unrealized_gain(self):
        return self.current_value - self.total_cost

    @property
    def unrealized_gain_pct(self):
        if self.total_cost == 0:
            return 0
        return round((self.unrealized_gain / self.total_cost) * 100, 2)

    def __repr__(self):
        return f'<Investment {self.asset_name}>'


class InvestmentTransaction(db.Model):
    __tablename__ = 'investment_transactions'

    id = db.Column(db.Integer, primary_key=True)
    investment_id = db.Column(db.Integer, db.ForeignKey('investments.id'), nullable=False)
    transaction_type = db.Column(db.Enum('buy', 'sell', 'dividend', 'split'), nullable=False)
    shares = db.Column(db.Numeric(18, 8), nullable=False)
    price_per_share = db.Column(db.Numeric(15, 4), nullable=False)
    total_amount = db.Column(db.Numeric(15, 2), nullable=False)
    fees = db.Column(db.Numeric(10, 2), default=0.00)
    date = db.Column(db.Date, nullable=False, index=True)
    notes = db.Column(db.String(255), nullable=True)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)

    investment = db.relationship('Investment', back_populates='inv_transactions')

    def __repr__(self):
        return f'<InvTransaction {self.transaction_type} {self.shares}@{self.price_per_share}>'