from __future__ import annotations

from datetime import datetime, timezone

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

from app.core.db.common import CommonBase


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


class AccountingVoucherDraft(CommonBase):
    __tablename__ = "accounting_voucher_drafts"

    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)

    tally_guid: Mapped[str] = mapped_column(String(120), nullable=False, index=True)
    company_name: Mapped[str] = mapped_column(String(255), nullable=False, default="")
    voucher_type: Mapped[str] = mapped_column(String(30), nullable=False, index=True)
    business_nature: Mapped[str] = mapped_column(String(60), nullable=False, default="", index=True)
    voucher_date: Mapped[str] = mapped_column(String(10), nullable=False, index=True)
    reference: Mapped[str] = mapped_column(String(180), nullable=False, default="", index=True)
    narration: Mapped[str] = mapped_column(Text, nullable=False, default="")

    source_type: Mapped[str] = mapped_column(String(60), nullable=False, default="manual", index=True)
    source_record_type: Mapped[str] = mapped_column(String(80), nullable=False, default="")
    source_record_id: Mapped[str] = mapped_column(String(120), nullable=False, default="")
    source_evidence_json: Mapped[str] = mapped_column(Text, nullable=False, default="{}")

    audit_area: Mapped[str] = mapped_column(String(120), nullable=False, default="", index=True)
    audit_flags_json: Mapped[str] = mapped_column(Text, nullable=False, default="[]")

    total_debit: Mapped[float] = mapped_column(Float, nullable=False, default=0)
    total_credit: Mapped[float] = mapped_column(Float, nullable=False, default=0)

    status: Mapped[str] = mapped_column(String(30), nullable=False, default="draft", index=True)
    review_note: Mapped[str] = mapped_column(Text, nullable=False, default="")
    reviewed_by_user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
    reviewed_at_utc: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    approved_by_user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
    approved_at_utc: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)

    workstation_agent_id: Mapped[int | None] = mapped_column(ForeignKey("erp_workstation_agents.id", ondelete="SET NULL"), nullable=True, 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] = mapped_column(Text, nullable=False, default="{}")
    posting_result_json: Mapped[str] = mapped_column(Text, 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="")
    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)
    updated_at_utc: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, default=_utcnow)

    lines: Mapped[list["AccountingVoucherLine"]] = relationship(
        "AccountingVoucherLine",
        back_populates="draft",
        cascade="all, delete-orphan",
        order_by="AccountingVoucherLine.line_no",
    )

    items: Mapped[list["AccountingVoucherItemLine"]] = relationship(
        "AccountingVoucherItemLine",
        back_populates="draft",
        cascade="all, delete-orphan",
        order_by="AccountingVoucherItemLine.line_no",
    )


class AccountingVoucherLine(CommonBase):
    __tablename__ = "accounting_voucher_lines"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    draft_id: Mapped[int] = mapped_column(ForeignKey("accounting_voucher_drafts.id", ondelete="CASCADE"), nullable=False, index=True)
    line_no: Mapped[int] = mapped_column(Integer, nullable=False, default=1)
    ledger_name: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    ledger_role_code: Mapped[str] = mapped_column(String(50), nullable=False, default="", index=True)
    dr_cr: Mapped[str] = mapped_column(String(2), nullable=False)
    amount: Mapped[float] = mapped_column(Float, nullable=False, default=0)
    line_note: Mapped[str] = mapped_column(Text, nullable=False, default="")

    draft: Mapped[AccountingVoucherDraft] = relationship("AccountingVoucherDraft", back_populates="lines")


class AccountingVoucherItemLine(CommonBase):
    __tablename__ = "accounting_voucher_item_lines"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    draft_id: Mapped[int] = mapped_column(
        ForeignKey("accounting_voucher_drafts.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    line_no: Mapped[int] = mapped_column(Integer, nullable=False, default=1)
    stock_item_name: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    hsn_sac: Mapped[str] = mapped_column(String(30), nullable=False, default="", index=True)
    quantity: Mapped[float] = mapped_column(Float, nullable=False, default=0)
    unit: Mapped[str] = mapped_column(String(40), nullable=False, default="")
    rate: Mapped[float] = mapped_column(Float, nullable=False, default=0)
    amount: Mapped[float] = mapped_column(Float, nullable=False, default=0)
    dr_cr: Mapped[str] = mapped_column(String(2), nullable=False)
    accounting_ledger_name: Mapped[str] = mapped_column(String(255), nullable=False, default="")
    godown_name: Mapped[str] = mapped_column(String(255), nullable=False, default="")
    source_item_json: Mapped[str] = mapped_column(Text, nullable=False, default="{}")

    draft: Mapped[AccountingVoucherDraft] = relationship(
        "AccountingVoucherDraft",
        back_populates="items",
    )