from datetime import datetime
from app.extensions import db
from app.utils.crypto import EncryptedText


class PlaidItem(db.Model):
    """One Plaid Item = one bank connection (may contain multiple accounts)."""
    __tablename__ = 'plaid_items'

    id               = db.Column(db.Integer, primary_key=True)
    item_id          = db.Column(db.String(100), unique=True, nullable=False, index=True)
    access_token     = db.Column(EncryptedText, nullable=False)
    institution_id   = db.Column(db.String(50),  nullable=True)
    institution_name = db.Column(db.String(100), nullable=True)
    cursor           = db.Column(db.String(500), nullable=True)   # /transactions/sync cursor
    is_active        = db.Column(db.Boolean, default=True)
    created_at       = db.Column(db.DateTime, default=datetime.utcnow)
    last_synced_at   = db.Column(db.DateTime, nullable=True)

    accounts = db.relationship('PlaidAccount', back_populates='item',
                               cascade='all, delete-orphan', lazy='dynamic')

    def __repr__(self):
        return f'<PlaidItem {self.institution_name} ({self.item_id[:12]}…)>'


class PlaidAccount(db.Model):
    """Maps one Plaid account inside an item to a PFM account."""
    __tablename__ = 'plaid_accounts'

    id               = db.Column(db.Integer, primary_key=True)
    item_id          = db.Column(db.Integer, db.ForeignKey('plaid_items.id'), nullable=False)
    plaid_account_id = db.Column(db.String(100), unique=True, nullable=False, index=True)
    pfm_account_id   = db.Column(db.Integer, db.ForeignKey('accounts.id'), nullable=True)

    account_name     = db.Column(db.String(100), nullable=True)
    account_type     = db.Column(db.String(50),  nullable=True)   # depository / credit / investment
    account_subtype  = db.Column(db.String(50),  nullable=True)   # checking / savings / credit card
    mask             = db.Column(db.String(10),  nullable=True)   # last 4 digits

    last_sync_date   = db.Column(db.Date, nullable=True)

    # Credit card billing info (populated from /liabilities/get)
    cc_due_date              = db.Column(db.Date,          nullable=True)
    cc_minimum_payment       = db.Column(db.Numeric(12, 2), nullable=True)
    cc_last_statement_balance = db.Column(db.Numeric(12, 2), nullable=True)
    cc_is_overdue            = db.Column(db.Boolean, default=False)
    cc_updated_at            = db.Column(db.DateTime, nullable=True)

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

    item        = db.relationship('PlaidItem', back_populates='accounts')
    pfm_account = db.relationship('Account')

    @property
    def display_name(self):
        suffix = f' ••••{self.mask}' if self.mask else ''
        return f'{self.account_name}{suffix}'

    def __repr__(self):
        return f'<PlaidAccount {self.account_name} → PFM #{self.pfm_account_id}>'


class PlaidSyncPreview(db.Model):
    """Temporary server-side storage for Plaid sync preview data (per item)."""
    __tablename__ = 'plaid_sync_previews'

    id          = db.Column(db.Integer, primary_key=True)
    item_id     = db.Column(db.Integer, db.ForeignKey('plaid_items.id'),
                            nullable=False, unique=True, index=True)
    data_json   = db.Column(db.Text, nullable=False)     # JSON array of parsed transactions
    next_cursor = db.Column(db.String(500), nullable=True)  # advance item cursor on confirm
    created_at  = db.Column(db.DateTime, default=datetime.utcnow)

    def __repr__(self):
        return f'<PlaidSyncPreview item_id={self.item_id}>'