from __future__ import annotations

from datetime import datetime, timezone

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

from app.core.db.common import CommonBase


class AccountingPurchasePostingAttempt(CommonBase):
    """Controlled posting state for one reviewed GSTR-2B purchase.

    Phase 10 intentionally keeps posting separate from the purchase review record so
    accounting review history is never overwritten by workstation/Tally execution state.
    """

    __tablename__ = "accounting_purchase_posting_attempts"
    __table_args__ = (
        UniqueConstraint(
            "tenant_id", "client_id", "purchase_id",
            name="uq_accounting_purchase_posting_purchase",
        ),
    )

    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)
    purchase_id: Mapped[int] = mapped_column(
        ForeignKey("accounting_gstr2b_purchases.id", ondelete="CASCADE"), nullable=False, index=True
    )

    workstation_agent_id: Mapped[int | None] = mapped_column(
        ForeignKey("erp_workstation_agents.id", ondelete="SET NULL"), nullable=True, index=True
    )
    tally_guid: Mapped[str] = mapped_column(String(120), nullable=False, default="", index=True)
    tally_company_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")

    status: Mapped[str] = mapped_column(String(40), nullable=False, default="not_started", index=True)
    preflight_job_id: Mapped[int | None] = mapped_column(
        ForeignKey("erp_agent_jobs.id", ondelete="SET NULL"), nullable=True, index=True
    )
    posting_job_id: Mapped[int | None] = mapped_column(
        ForeignKey("erp_agent_jobs.id", ondelete="SET NULL"), nullable=True, index=True
    )

    preflight_result_json: Mapped[str | None] = mapped_column(Text, nullable=True)
    posting_result_json: Mapped[str | None] = mapped_column(Text, nullable=True)
    last_error: Mapped[str | None] = mapped_column(Text, nullable=True)

    party_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
    purchase_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
    input_igst_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
    input_cgst_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
    input_sgst_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")
    input_cess_ledger_name: Mapped[str] = mapped_column(String(240), nullable=False, default="")

    tally_voucher_id: Mapped[str] = mapped_column(String(120), nullable=False, default="")
    tally_voucher_number: Mapped[str] = mapped_column(String(160), nullable=False, default="")
    tally_reference: Mapped[str] = mapped_column(String(160), nullable=False, default="")
    idempotency_key: Mapped[str] = mapped_column(String(200), nullable=False, default="", index=True)

    requested_by_user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
    posted_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), default=lambda: datetime.now(timezone.utc), nullable=False, index=True
    )
    updated_at_utc: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
        nullable=False,
    )
    preflight_completed_at_utc: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    posting_requested_at_utc: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    posted_at_utc: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)