from __future__ import annotations

from datetime import datetime, timezone

from sqlalchemy import DateTime, Float, ForeignKey, Integer, String, Text, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column

from app.core.db.common import CommonBase


def _utcnow():
    return datetime.now(timezone.utc)


class BankReconciliationRun(CommonBase):
    __tablename__ = "accounting_bank_reconciliation_runs"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    tenant_id: Mapped[int] = mapped_column(ForeignKey("tenants.id", ondelete="CASCADE"), nullable=False, index=True)
    client_id: Mapped[int] = mapped_column(ForeignKey("clients.id", ondelete="CASCADE"), nullable=False, index=True)
    source_job_id: Mapped[str] = mapped_column(ForeignKey("bank_statement_analysis_jobs.id", ondelete="CASCADE"), nullable=False, index=True)
    tally_guid: Mapped[str] = mapped_column(String(120), nullable=False, index=True)
    company_name: Mapped[str] = mapped_column(String(255), nullable=False, default="")
    bank_ledger_name: Mapped[str] = mapped_column(String(255), nullable=False)
    account_number: Mapped[str] = mapped_column(String(100), nullable=False, default="", index=True)
    date_from: Mapped[str] = mapped_column(String(10), nullable=False)
    date_to: Mapped[str] = mapped_column(String(10), nullable=False)
    date_tolerance_days: Mapped[int] = mapped_column(Integer, nullable=False, default=15)

    workstation_agent_id: Mapped[int] = mapped_column(ForeignKey("erp_workstation_agents.id", ondelete="RESTRICT"), nullable=False, index=True)
    agent_job_id: Mapped[int | None] = mapped_column(ForeignKey("erp_agent_jobs.id", ondelete="SET NULL"), nullable=True, index=True)

    status: Mapped[str] = mapped_column(String(30), nullable=False, default="queued", index=True)
    summary_json: Mapped[str] = mapped_column(Text, nullable=False, default="{}")
    last_error: Mapped[str] = mapped_column(Text, nullable=False, default="")

    created_by_user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
    created_at_utc: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, default=_utcnow, index=True)
    completed_at_utc: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)


class BankReconciliationItem(CommonBase):
    __tablename__ = "accounting_bank_reconciliation_items"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    run_id: Mapped[int] = mapped_column(ForeignKey("accounting_bank_reconciliation_runs.id", ondelete="CASCADE"), nullable=False, index=True)
    bank_transaction_id: Mapped[int | None] = mapped_column(ForeignKey("accounting_bank_transactions.id", ondelete="SET NULL"), nullable=True, index=True)

    match_status: Mapped[str] = mapped_column(String(30), nullable=False, index=True)
    confidence: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    match_reason: Mapped[str] = mapped_column(Text, nullable=False, default="")

    bank_date: Mapped[str] = mapped_column(String(10), nullable=False, default="")
    bank_direction: Mapped[str] = mapped_column(String(10), nullable=False, default="")
    bank_amount: Mapped[float] = mapped_column(Float, nullable=False, default=0)
    bank_reference: Mapped[str] = mapped_column(String(180), nullable=False, default="")
    bank_narration: Mapped[str] = mapped_column(Text, nullable=False, default="")

    tally_guid: Mapped[str] = mapped_column(String(120), nullable=False, default="")
    tally_voucher_number: Mapped[str] = mapped_column(String(160), nullable=False, default="")
    tally_voucher_type: Mapped[str] = mapped_column(String(60), nullable=False, default="")
    tally_date: Mapped[str] = mapped_column(String(10), nullable=False, default="")
    tally_reference: Mapped[str] = mapped_column(String(180), nullable=False, default="")
    tally_narration: Mapped[str] = mapped_column(Text, nullable=False, default="")
    tally_amount: Mapped[float] = mapped_column(Float, nullable=False, default=0)
    tally_direction: Mapped[str] = mapped_column(String(10), nullable=False, default="")

    resolution_status: Mapped[str] = mapped_column(String(30), nullable=False, default="unresolved", index=True)
    resolution_note: Mapped[str] = mapped_column(Text, nullable=False, default="")
    resolved_by_user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
    resolved_at_utc: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)


class AccountingBankLedgerMapping(CommonBase):
    __tablename__ = "accounting_bank_ledger_mappings"
    __table_args__ = (
        UniqueConstraint(
            "tenant_id",
            "client_id",
            "account_number",
            "tally_guid",
            name="uq_accounting_bank_ledger_mapping",
        ),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    tenant_id: Mapped[int] = mapped_column(ForeignKey("tenants.id", ondelete="CASCADE"), nullable=False, index=True)
    client_id: Mapped[int] = mapped_column(ForeignKey("clients.id", ondelete="CASCADE"), nullable=False, index=True)
    account_number: Mapped[str] = mapped_column(String(100), nullable=False, index=True)
    bank_name: Mapped[str] = mapped_column(String(160), nullable=False, default="")
    tally_guid: Mapped[str] = mapped_column(String(120), nullable=False, index=True)
    company_name: Mapped[str] = mapped_column(String(255), nullable=False, default="")
    bank_ledger_name: Mapped[str] = mapped_column(String(255), nullable=False)
    created_by_user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
    updated_by_user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
    created_at_utc: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, default=_utcnow)
    updated_at_utc: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, default=_utcnow)