# FILE: src/apps/sales/models/proposal.py
from __future__ import annotations

from datetime import datetime
from decimal import Decimal
from typing import List, Optional
from uuid import UUID

from sqlalchemy import DateTime, ForeignKey, Integer, Numeric, String, Text, UniqueConstraint
from sqlalchemy.dialects.postgresql import UUID as PG_UUID
from sqlalchemy.orm import Mapped, mapped_column, relationship

from src.database.base import BaseModel, TenantSoftDeleteModel


class Proposal(TenantSoftDeleteModel):
    __tablename__ = "proposals"

    __table_args__ = (
        UniqueConstraint("tenant_id", "quote_number", name="uq_proposals_tenant_quote_number"),
    )

    # Override tenant_id with explicit FK
    tenant_id: Mapped[UUID] = mapped_column(
        PG_UUID(as_uuid=True),
        ForeignKey("accounts.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )

    opportunity_id: Mapped[Optional[UUID]] = mapped_column(
        PG_UUID(as_uuid=True),
        ForeignKey("opportunities.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )
    sales_owner_id: Mapped[Optional[UUID]] = mapped_column(
        PG_UUID(as_uuid=True),
        ForeignKey("users.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )

    quote_number: Mapped[str] = mapped_column(String(50), nullable=False)
    to_email: Mapped[str] = mapped_column(String(255), nullable=False)
    cc_email: Mapped[Optional[str]] = mapped_column(String(255), nullable=True)
    subject: Mapped[str] = mapped_column(String(500), nullable=False)
    cover_note: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    valid_days: Mapped[int] = mapped_column(Integer, nullable=False, default=30)
    status: Mapped[str] = mapped_column(String(50), nullable=False, default="draft")

    subtotal: Mapped[Decimal] = mapped_column(Numeric(12, 2), nullable=False, default=Decimal("0"))
    tax_rate: Mapped[Decimal] = mapped_column(Numeric(5, 4), nullable=False, default=Decimal("0.13"))
    tax_amount: Mapped[Decimal] = mapped_column(Numeric(12, 2), nullable=False, default=Decimal("0"))
    total_amount: Mapped[Decimal] = mapped_column(Numeric(12, 2), nullable=False, default=Decimal("0"))

    sent_at: Mapped[Optional[datetime]] = mapped_column(DateTime(timezone=True), nullable=True)
    accepted_at: Mapped[Optional[datetime]] = mapped_column(DateTime(timezone=True), nullable=True)
    pdf_s3_key: Mapped[Optional[str]] = mapped_column(Text, nullable=True)

    # Relationships
    line_items: Mapped[List["ProposalLineItem"]] = relationship(
        "ProposalLineItem",
        back_populates="proposal",
        order_by="ProposalLineItem.sort_order",
    )


class ProposalLineItem(BaseModel):
    __tablename__ = "proposal_line_items"

    proposal_id: Mapped[UUID] = mapped_column(
        PG_UUID(as_uuid=True),
        ForeignKey("proposals.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    tenant_id: Mapped[UUID] = mapped_column(
        PG_UUID(as_uuid=True),
        ForeignKey("accounts.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )

    sort_order: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    description: Mapped[str] = mapped_column(Text, nullable=False)
    quantity: Mapped[Decimal] = mapped_column(Numeric(10, 2), nullable=False, default=Decimal("1"))
    unit_price: Mapped[Decimal] = mapped_column(Numeric(12, 2), nullable=False)
    line_total: Mapped[Decimal] = mapped_column(Numeric(12, 2), nullable=False, default=Decimal("0"))

    # Relationships
    proposal: Mapped["Proposal"] = relationship("Proposal", back_populates="line_items")