"""SQLAlchemy models for the QUOTATION & PROCUREMENT domain — mirrors migration.sql exactly."""
import uuid
from datetime import date, datetime
from decimal import Decimal

from sqlalchemy import (
    Boolean,
    Column,
    Date,
    DateTime,
    Enum,
    ForeignKey,
    Numeric,
    SmallInteger,
    Table,
    Text,
    Uuid,
    UniqueConstraint,
    func,
    text,
)
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.db.base import Base
from app.models.catalog import Material, Unit, _timestamptz, _uuid_pk

user_role_enum = Enum(
    "pm", "procurement_manager", "admin",
    name="user_role", native_enum=True,
)
quote_status_enum = Enum(
    "offered", "accepted", "arrived", "rejected", "expired",
    name="quote_status", native_enum=True,
)
termsheet_status_enum = Enum(
    "offered", "accepted", "rejected",
    name="termsheet_status", native_enum=True,
)
discount_type_enum = Enum(
    "none", "percent", "fixed",
    name="discount_type", native_enum=True,
)
item_decision_status_enum = Enum(
    "pending", "chosen", "rejected",
    name="item_decision_status", native_enum=True,
)
quote_event_type_enum = Enum(
    "offered", "accepted", "rejected", "arrived", "note", "edited", "expired",
    name="quote_event_type", native_enum=True,
)


class User(Base):
    """users — Casdoor-backed identity. role is OUR authorization source."""

    __tablename__ = "users"

    id: Mapped[uuid.UUID] = _uuid_pk()
    casdoor_id: Mapped[str] = mapped_column(Text, nullable=False, unique=True)
    first_name: Mapped[str] = mapped_column(Text, nullable=False)
    last_name: Mapped[str] = mapped_column(Text, nullable=False)
    phone: Mapped[str | None] = mapped_column(Text)
    role: Mapped[str | None] = mapped_column(user_role_enum)
    created_at: Mapped[datetime] = _timestamptz()


class Supplier(Base):
    __tablename__ = "suppliers"

    id: Mapped[uuid.UUID] = _uuid_pk()
    name: Mapped[str] = mapped_column(Text, nullable=False)
    # v2.6: 1 supplier → exactly 1 category (one of the 8 fixed topic
    # categories). The old runtime JSONB `categories` column is dropped.
    category_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("material_categories.id", ondelete="RESTRICT"), nullable=False
    )
    location: Mapped[str | None] = mapped_column(Text)
    phone: Mapped[str | None] = mapped_column(Text)
    contact_person: Mapped[str | None] = mapped_column(Text)
    tax_id: Mapped[str | None] = mapped_column(Text)
    created_at: Mapped[datetime] = _timestamptz()

    category: Mapped["MaterialCategory"] = relationship(lazy="raise")


class SupplierMaterial(Base):
    """supplier_materials — catalog-layer M:N supplier ↔ material link (v2.5).

    Auto-created whenever a quote line item is saved; also managed via
    /suppliers/{id}/materials. Inserting a row derives materials.category_id
    (first-link-wins) via service + DB trigger.
    """

    __tablename__ = "supplier_materials"
    __table_args__ = (UniqueConstraint("supplier_id", "material_id", name="uq_supplier_material"),)
    __mapper_args__ = {"eager_defaults": True}

    id: Mapped[uuid.UUID] = _uuid_pk()
    supplier_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("suppliers.id", ondelete="CASCADE"), nullable=False
    )
    material_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("materials.id", ondelete="CASCADE"), nullable=False
    )
    is_active: Mapped[bool] = mapped_column(Boolean, nullable=False, server_default=text("true"))
    last_quoted_price: Mapped[Decimal | None] = mapped_column(Numeric(18, 4))
    last_quoted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    created_at: Mapped[datetime] = _timestamptz()

    supplier: Mapped["Supplier"] = relationship(lazy="raise")
    material: Mapped["Material"] = relationship(lazy="raise")


class QuoteProjects(Base):
    """M:N quotes ↔ projects junction (a quote can be about several projects)."""

    __tablename__ = "quote_projects"

    quote_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("quotes.id", ondelete="CASCADE"), primary_key=True
    )
    project_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("projects.id", ondelete="CASCADE"), primary_key=True
    )

    project: Mapped["Project"] = relationship(lazy="raise")


class LineItemProjects(Base):
    """M:N line_items ↔ projects junction — which projects each material is allocated to."""

    __tablename__ = "line_item_projects"

    line_item_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("line_items.id", ondelete="CASCADE"), primary_key=True
    )
    project_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("projects.id", ondelete="CASCADE"), primary_key=True
    )

    project: Mapped["Project"] = relationship(lazy="raise")


class Project(Base):
    __tablename__ = "projects"

    id: Mapped[uuid.UUID] = _uuid_pk()
    name: Mapped[str] = mapped_column(Text, nullable=False)
    description: Mapped[str | None] = mapped_column(Text)
    start_date: Mapped[date | None] = mapped_column(Date)
    # v2.6: the single PM responsible for this project (confirms arrivals).
    pm_user_id: Mapped[uuid.UUID | None] = mapped_column(
        ForeignKey("users.id", ondelete="SET NULL")
    )
    created_at: Mapped[datetime] = _timestamptz()


class Quote(Base):
    __tablename__ = "quotes"
    __mapper_args__ = {"eager_defaults": True}  # fetch onupdate=func.now() via RETURNING

    id: Mapped[uuid.UUID] = _uuid_pk()
    supplier_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("suppliers.id", ondelete="RESTRICT"), nullable=False
    )
    project_id: Mapped[uuid.UUID | None] = mapped_column(
        ForeignKey("projects.id", ondelete="SET NULL")
    )
    quote_date: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())
    expiry_date: Mapped[date | None] = mapped_column(Date)
    accepted_date: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    arrived_date: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    status: Mapped[str] = mapped_column(quote_status_enum, nullable=False, server_default=text("'offered'"))
    is_official: Mapped[bool] = mapped_column(Boolean, nullable=False, server_default=text("true"))
    notes: Mapped[str | None] = mapped_column(Text)
    created_at: Mapped[datetime] = _timestamptz()
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
    )

    supplier: Mapped["Supplier"] = relationship(foreign_keys=[supplier_id], lazy="raise")
    project: Mapped["Project | None"] = relationship(foreign_keys=[project_id], lazy="raise")
    line_items: Mapped[list["LineItem"]] = relationship(
        back_populates="quote", lazy="raise", passive_deletes=True, order_by="LineItem.created_at"
    )
    termsheets: Mapped[list["Termsheet"]] = relationship(
        back_populates="quote", lazy="raise", passive_deletes=True, order_by="Termsheet.created_at"
    )
    events: Mapped[list["QuoteEvent"]] = relationship(
        back_populates="quote", lazy="raise", passive_deletes=True, order_by="QuoteEvent.occurred_at"
    )


class QuoteEvent(Base):
    __tablename__ = "quote_events"

    id: Mapped[uuid.UUID] = _uuid_pk()
    quote_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("quotes.id", ondelete="CASCADE"), nullable=False)
    event_type: Mapped[str] = mapped_column(quote_event_type_enum, nullable=False)
    payload: Mapped[dict] = mapped_column(JSONB, nullable=False, server_default=text("'{}'::jsonb"))
    occurred_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())
    actor: Mapped[str | None] = mapped_column(Text)

    quote: Mapped["Quote"] = relationship(back_populates="events", lazy="raise")


class LineItem(Base):
    __tablename__ = "line_items"

    id: Mapped[uuid.UUID] = _uuid_pk()
    quote_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("quotes.id", ondelete="CASCADE"), nullable=False)
    material_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("materials.id", ondelete="RESTRICT"), nullable=False)
    brand_material_id: Mapped[uuid.UUID | None] = mapped_column(
        ForeignKey("brand_materials.id", ondelete="SET NULL")
    )  # optional; app-layer check ensures it belongs to material_id
    unit_id: Mapped[int] = mapped_column(ForeignKey("units.id", ondelete="RESTRICT"), nullable=False)
    quantity: Mapped[Decimal] = mapped_column(Numeric(18, 4), nullable=False)
    notes: Mapped[str | None] = mapped_column(Text)
    created_at: Mapped[datetime] = _timestamptz()

    quote: Mapped["Quote"] = relationship(back_populates="line_items", lazy="raise")
    material: Mapped["Material"] = relationship(lazy="raise")
    unit: Mapped["Unit"] = relationship(lazy="raise")
    specs: Mapped[list["LineItemSpec"]] = relationship(
        back_populates="line_item", lazy="raise", passive_deletes=True
    )
    decision: Mapped["ItemDecision | None"] = relationship(
        back_populates="line_item", uselist=False, lazy="raise", passive_deletes=True
    )
    item_termsheets: Mapped[list["ItemTermsheet"]] = relationship(
        back_populates="line_item", lazy="raise", passive_deletes=True
    )


class LineItemSpec(Base):
    """Historical snapshot — freezes material specs at quote generation time."""

    __tablename__ = "line_item_specs"
    __table_args__ = (UniqueConstraint("line_item_id", "attribute_definition_id", name="uq_lineitem_spec"),)

    id: Mapped[uuid.UUID] = _uuid_pk()
    line_item_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("line_items.id", ondelete="CASCADE"), nullable=False)
    attribute_definition_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("attribute_definitions.id", ondelete="RESTRICT"), nullable=False
    )
    value_number: Mapped[Decimal | None] = mapped_column(Numeric(18, 6))
    value_string: Mapped[str | None] = mapped_column(Text)
    value_boolean: Mapped[bool | None] = mapped_column(Boolean)
    value_date: Mapped[date | None] = mapped_column(Date)
    unit_id_at_time: Mapped[int | None] = mapped_column(ForeignKey("units.id", ondelete="SET NULL"))

    line_item: Mapped["LineItem"] = relationship(back_populates="specs", lazy="raise")


class Termsheet(Base):
    __tablename__ = "termsheets"

    id: Mapped[uuid.UUID] = _uuid_pk()
    quote_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("quotes.id", ondelete="CASCADE"), nullable=False)
    label: Mapped[str] = mapped_column(Text, nullable=False)
    status: Mapped[str] = mapped_column(termsheet_status_enum, nullable=False, server_default=text("'offered'"))
    discount_type: Mapped[str] = mapped_column(discount_type_enum, nullable=False, server_default=text("'none'"))
    discount_value: Mapped[Decimal] = mapped_column(Numeric(18, 4), nullable=False, server_default=text("0"))
    created_at: Mapped[datetime] = _timestamptz()

    quote: Mapped["Quote"] = relationship(back_populates="termsheets", lazy="raise")
    schedule_steps: Mapped[list["TermsheetScheduleStep"]] = relationship(
        back_populates="termsheet", lazy="raise", passive_deletes=True, order_by="TermsheetScheduleStep.step_no"
    )
    item_termsheets: Mapped[list["ItemTermsheet"]] = relationship(
        back_populates="termsheet", lazy="raise", passive_deletes=True
    )


class TermsheetScheduleStep(Base):
    __tablename__ = "termsheet_schedule_steps"
    __table_args__ = (UniqueConstraint("termsheet_id", "step_no", name="uq_termsheet_step"),)

    id: Mapped[uuid.UUID] = _uuid_pk()
    termsheet_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("termsheets.id", ondelete="CASCADE"), nullable=False)
    step_no: Mapped[int] = mapped_column(SmallInteger, nullable=False)
    due_date: Mapped[date] = mapped_column(Date, nullable=False)
    amount: Mapped[Decimal] = mapped_column(Numeric(18, 2), nullable=False)
    note: Mapped[str | None] = mapped_column(Text)

    termsheet: Mapped["Termsheet"] = relationship(back_populates="schedule_steps", lazy="raise")


class ItemTermsheet(Base):
    """Line-item pricing inside a termsheet."""

    __tablename__ = "item_termsheets"
    __table_args__ = (UniqueConstraint("line_item_id", "termsheet_id", name="uq_item_termsheet"),)

    id: Mapped[uuid.UUID] = _uuid_pk()
    line_item_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("line_items.id", ondelete="CASCADE"), nullable=False)
    termsheet_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("termsheets.id", ondelete="CASCADE"), nullable=False)
    unit_price: Mapped[Decimal] = mapped_column(Numeric(18, 4), nullable=False)
    min_order_qty: Mapped[Decimal | None] = mapped_column(Numeric(18, 4))

    line_item: Mapped["LineItem"] = relationship(back_populates="item_termsheets", lazy="raise")
    termsheet: Mapped["Termsheet"] = relationship(back_populates="item_termsheets", lazy="raise")


class ItemTermsheetsWithTotal(Base):
    """Read-only mapping of the VIEW item_termsheets_with_total.

    total_price is NEVER stored — it is computed by the view as
    unit_price × line_items.quantity.
    """

    __table__ = Table(
        "item_termsheets_with_total",
        Base.metadata,
        Column("id", Uuid(as_uuid=True), primary_key=True),
        Column("line_item_id", Uuid(as_uuid=True)),
        Column("termsheet_id", Uuid(as_uuid=True)),
        Column("unit_price", Numeric(18, 4)),
        Column("min_order_qty", Numeric(18, 4)),
        Column("total_price", Numeric(18, 2)),
    )


class ItemDecision(Base):
    """1:1 with line_items (UNIQUE on line_item_id).

    project_id: the SINGLE purchased project, picked by the procurement
    manager at purchase (auto-filled when the offer had one project;
    validated against line_item_projects). Warehouses of this project are
    the only valid arrival destinations.
    """

    __tablename__ = "item_decisions"

    id: Mapped[uuid.UUID] = _uuid_pk()
    line_item_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("line_items.id", ondelete="CASCADE"), nullable=False, unique=True
    )
    chosen_item_termsheet_id: Mapped[uuid.UUID | None] = mapped_column(
        ForeignKey("item_termsheets.id", ondelete="SET NULL")
    )
    status: Mapped[str] = mapped_column(item_decision_status_enum, nullable=False, server_default=text("'pending'"))
    project_id: Mapped[uuid.UUID | None] = mapped_column(
        ForeignKey("projects.id", ondelete="SET NULL")
    )
    adjusted_unit_price: Mapped[Decimal | None] = mapped_column(Numeric(18, 4))
    adjusted_notes: Mapped[str | None] = mapped_column(Text)
    decided_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))

    line_item: Mapped["LineItem"] = relationship(back_populates="decision", lazy="raise")
    project: Mapped["Project | None"] = relationship(lazy="raise")
    receipt: Mapped["ItemReceipt | None"] = relationship(
        back_populates="decision", uselist=False, lazy="raise", passive_deletes=True
    )


class ItemReceipt(Base):
    """1 item : N receipts (PARTIAL DELIVERIES — no UNIQUE on item_decision_id).

    A receipt means "the PM confirmed this delivery". received_qty is in the
    line item's unit; inventory posting converts to the inventory row's unit.
    """

    __tablename__ = "item_receipts"

    id: Mapped[uuid.UUID] = _uuid_pk()
    item_decision_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("item_decisions.id", ondelete="CASCADE"), nullable=False
    )
    confirmed_by: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("users.id", ondelete="RESTRICT"), nullable=False
    )
    received_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())
    received_qty: Mapped[Decimal] = mapped_column(Numeric(18, 4), nullable=False)
    on_time: Mapped[bool | None] = mapped_column(Boolean)
    quality_note: Mapped[str | None] = mapped_column(Text)

    decision: Mapped["ItemDecision"] = relationship(back_populates="receipt", lazy="raise")
    allocations: Mapped[list["ItemReceiptAllocation"]] = relationship(
        back_populates="receipt", lazy="raise", passive_deletes=True
    )


class ItemReceiptAllocation(Base):
    """item_receipt_allocations — the PM's split of one receipt across
    warehouses (typically 3). SUM(quantity) must equal the receipt's
    received_qty; every warehouse belongs to the decision's project.
    """

    __tablename__ = "item_receipt_allocations"
    __table_args__ = (UniqueConstraint("receipt_id", "warehouse_id", name="uq_receipt_warehouse"),)

    id: Mapped[uuid.UUID] = _uuid_pk()
    receipt_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("item_receipts.id", ondelete="CASCADE"), nullable=False
    )
    warehouse_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("warehouses.id", ondelete="RESTRICT"), nullable=False
    )
    quantity: Mapped[Decimal] = mapped_column(Numeric(18, 6), nullable=False)

    receipt: Mapped["ItemReceipt"] = relationship(back_populates="allocations", lazy="raise")
    warehouse: Mapped["Warehouse"] = relationship(lazy="raise")