import sqlalchemy as sa
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker, relationship

Base = declarative_base()


class Account(Base):
    __tablename__ = 'accounts'

    id = sa.Column(sa.Integer, primary_key=True)
    name = sa.Column(sa.String(100), nullable=False)
    account_type = sa.Column(sa.String(50), nullable=False)  # Asset, Liability, Equity, Revenue, Expense
    code = sa.Column(sa.String(20), unique=True, nullable=False)
    parent_id = sa.Column(sa.Integer, sa.ForeignKey('accounts.id'))
    balance = sa.Column(sa.Numeric(15, 2), default=0)

    parent = relationship('Account', remote_side=[id])
    entries = relationship('JournalEntryLine', back_populates='account')

    def __repr__(self):
        return f"<Account(code={self.code}, name={self.name}, type={self.account_type})>"


class JournalEntry(Base):
    __tablename__ = 'journal_entries'

    id = sa.Column(sa.Integer, primary_key=True)
    date = sa.Column(sa.Date, nullable=False)
    reference = sa.Column(sa.String(100))
    description = sa.Column(sa.String(200))
    created_at = sa.Column(sa.DateTime, server_default=sa.func.now())

    lines = relationship('JournalEntryLine', back_populates='journal_entry')


class JournalEntryLine(Base):
    __tablename__ = 'journal_entry_lines'

    id = sa.Column(sa.Integer, primary_key=True)
    journal_entry_id = sa.Column(sa.Integer, sa.ForeignKey('journal_entries.id'), nullable=False)
    account_id = sa.Column(sa.Integer, sa.ForeignKey('accounts.id'), nullable=False)
    amount = sa.Column(sa.Numeric(15, 2), nullable=False)
    is_debit = sa.Column(sa.Boolean, nullable=False)  # True for debit, False for credit

    journal_entry = relationship('JournalEntry', back_populates='lines')
    account = relationship('Account', back_populates='entries')


class BankAccount(Base):
    __tablename__ = 'bank_accounts'

    id = sa.Column(sa.Integer, primary_key=True)
    name = sa.Column(sa.String(100), nullable=False)
    account_number = sa.Column(sa.String(50))
    bank_name = sa.Column(sa.String(100))
    currency = sa.Column(sa.String(3), default='USD')
    ledger_account_id = sa.Column(sa.Integer, sa.ForeignKey('accounts.id'))

    ledger_account = relationship('Account')
    transactions = relationship('BankTransaction', back_populates='bank_account')


class BankTransaction(Base):
    __tablename__ = 'bank_transactions'

    id = sa.Column(sa.Integer, primary_key=True)
    bank_account_id = sa.Column(sa.Integer, sa.ForeignKey('bank_accounts.id'), nullable=False)
    date = sa.Column(sa.Date, nullable=False)
    amount = sa.Column(sa.Numeric(15, 2), nullable=False)
    description = sa.Column(sa.String(200))
    reference = sa.Column(sa.String(100))
    status = sa.Column(sa.String(20), default='unreconciled')  # unreconciled, reconciled
    journal_entry_id = sa.Column(sa.Integer, sa.ForeignKey('journal_entries.id'))

    bank_account = relationship('BankAccount', back_populates='transactions')
    journal_entry = relationship('JournalEntry')


class ReconciliationReport(Base):
    __tablename__ = 'reconciliation_reports'

    id = sa.Column(sa.Integer, primary_key=True)
    bank_account_id = sa.Column(sa.Integer, sa.ForeignKey('bank_accounts.id'), nullable=False)
    start_date = sa.Column(sa.Date, nullable=False)
    end_date = sa.Column(sa.Date, nullable=False)
    created_at = sa.Column(sa.DateTime, server_default=sa.func.now())
    status = sa.Column(sa.String(20), default='draft')  # draft, completed

    bank_account = relationship('BankAccount')
    matches = relationship('ReconciliationMatch', back_populates='report')


class ReconciliationMatch(Base):
    __tablename__ = 'reconciliation_matches'

    id = sa.Column(sa.Integer, primary_key=True)
    report_id = sa.Column(sa.Integer, sa.ForeignKey('reconciliation_reports.id'), nullable=False)
    transaction_id = sa.Column(sa.Integer, sa.ForeignKey('bank_transactions.id'), nullable=False)
    journal_entry_id = sa.Column(sa.Integer, sa.ForeignKey('journal_entries.id'), nullable=False)
    match_score = sa.Column(sa.Numeric(5, 2))  # 0-100 score for match quality
    notes = sa.Column(sa.String(200))

    report = relationship('ReconciliationReport', back_populates='matches')
    transaction = relationship('BankTransaction')
    journal_entry = relationship('JournalEntry')