from __future__ import annotations

from datetime import datetime, timezone

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

from app.core.db.common import CommonBase


class AccountingPurchaseEnrichmentBatch(CommonBase):
    __tablename__ = "accounting_purchase_enrichment_batches"

    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, default="", index=True)

    source_type: Mapped[str] = mapped_column(String(30), nullable=False, index=True)
    original_filename: Mapped[str] = mapped_column(String(260), nullable=False, default="")
    file_sha256: Mapped[str] = mapped_column(String(64), nullable=False, index=True)
    source_period: Mapped[str] = mapped_column(String(20), nullable=False, default="", index=True)
    status: Mapped[str] = mapped_column(String(30), nullable=False, default="imported", index=True)

    records_read: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    records_imported: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    records_duplicate: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    records_linked: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    records_unmatched: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    records_ambiguous: Mapped[int] = mapped_column(Integer, nullable=False, default=0)

    imported_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
    )
    completed_at_utc: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)


class AccountingPurchaseEnrichmentRecord(CommonBase):
    __tablename__ = "accounting_purchase_enrichment_records"
    __table_args__ = (
        UniqueConstraint(
            "tenant_id", "client_id", "source_type", "source_document_key",
            name="uq_accounting_purchase_enrichment_source_document",
        ),
    )

    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)
    batch_id: Mapped[int] = mapped_column(
        ForeignKey("accounting_purchase_enrichment_batches.id", ondelete="CASCADE"), nullable=False, index=True
    )
    tally_guid: Mapped[str] = mapped_column(String(120), nullable=False, default="", index=True)

    source_type: Mapped[str] = mapped_column(String(30), nullable=False, index=True)
    source_document_key: Mapped[str] = mapped_column(String(500), nullable=False, index=True)
    external_reference: Mapped[str] = mapped_column(String(180), nullable=False, default="", index=True)

    supplier_gstin: Mapped[str] = mapped_column(String(20), nullable=False, default="", index=True)
    supplier_name: Mapped[str] = mapped_column(String(260), nullable=False, default="", index=True)
    recipient_gstin: Mapped[str] = mapped_column(String(20), nullable=False, default="", index=True)

    document_number: Mapped[str] = mapped_column(String(160), nullable=False, default="", index=True)
    document_date: Mapped[str] = mapped_column(String(20), nullable=False, default="", index=True)
    document_type: Mapped[str] = mapped_column(String(40), nullable=False, default="invoice", index=True)

    taxable_value: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    igst: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    cgst: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    sgst: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    cess: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    invoice_value: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)

    place_of_supply: Mapped[str] = mapped_column(String(120), nullable=False, default="")
    transport_mode: Mapped[str] = mapped_column(String(80), nullable=False, default="")
    vehicle_number: Mapped[str] = mapped_column(String(40), nullable=False, default="")
    transporter_id: Mapped[str] = mapped_column(String(40), nullable=False, default="")

    raw_summary_json: Mapped[str | None] = mapped_column(Text, nullable=True)
    source_row_hash: Mapped[str] = mapped_column(String(64), nullable=False, default="", index=True)

    gstr2b_purchase_id: Mapped[int | None] = mapped_column(
        ForeignKey("accounting_gstr2b_purchases.id", ondelete="SET NULL"), nullable=True, index=True
    )
    match_status: Mapped[str] = mapped_column(String(30), nullable=False, default="unmatched", index=True)
    match_method: Mapped[str] = mapped_column(String(80), nullable=False, default="")
    match_confidence: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    manually_linked: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)

    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,
    )


class AccountingPurchaseEnrichmentItem(CommonBase):
    __tablename__ = "accounting_purchase_enrichment_items"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    record_id: Mapped[int] = mapped_column(
        ForeignKey("accounting_purchase_enrichment_records.id", ondelete="CASCADE"), nullable=False, index=True
    )
    line_number: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    product_name: Mapped[str] = mapped_column(String(500), nullable=False, default="")
    description_text: Mapped[str | None] = mapped_column(Text, nullable=True)
    hsn_code: Mapped[str] = mapped_column(String(20), nullable=False, default="", index=True)
    quantity: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    unit: Mapped[str] = mapped_column(String(30), nullable=False, default="")
    unit_price: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    taxable_value: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    gst_rate: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    igst: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    cgst: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    sgst: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
    cess: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)