from __future__ import annotations

from datetime import datetime
from typing import Any
import uuid

from sqlalchemy import BigInteger, DateTime, ForeignKey, Index, JSON, String, Text, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column

from govoplan_core.db.base import Base, TimestampMixin


def new_uuid() -> str:
    return str(uuid.uuid4())


class PaymentObligation(Base, TimestampMixin):
    __tablename__ = "payment_obligations"
    __table_args__ = (
        UniqueConstraint("tenant_id", "payment_id", name="uq_payment_obligation"),
        UniqueConstraint(
            "tenant_id",
            "source_module",
            "idempotency_key",
            name="uq_payment_request_idempotency",
        ),
        UniqueConstraint(
            "tenant_id", "payment_reference", name="uq_payment_reference"
        ),
        Index(
            "ix_payment_obligation_source",
            "tenant_id",
            "source_module",
            "source_resource_type",
            "source_resource_id",
        ),
        Index(
            "ix_payment_obligation_state",
            "tenant_id",
            "status",
            "requested_at",
        ),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    payment_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    payment_reference: Mapped[str] = mapped_column(
        String(32), nullable=False, index=True
    )
    source_module: Mapped[str] = mapped_column(String(120), nullable=False, index=True)
    source_resource_type: Mapped[str] = mapped_column(
        String(120), nullable=False, index=True
    )
    source_resource_id: Mapped[str] = mapped_column(
        String(255), nullable=False, index=True
    )
    amount_minor: Mapped[int] = mapped_column(BigInteger, nullable=False)
    currency: Mapped[str] = mapped_column(String(3), nullable=False, index=True)
    subject: Mapped[str] = mapped_column(Text, nullable=False)
    status: Mapped[str] = mapped_column(String(30), nullable=False, index=True)
    idempotency_key: Mapped[str] = mapped_column(String(255), nullable=False)
    request_sha256: Mapped[str] = mapped_column(String(64), nullable=False)
    requested_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, index=True
    )
    requested_by_ref: Mapped[str] = mapped_column(
        String(255), nullable=False, index=True
    )
    due_at: Mapped[datetime | None] = mapped_column(
        DateTime(timezone=True), nullable=True, index=True
    )
    settled_at: Mapped[datetime | None] = mapped_column(
        DateTime(timezone=True), nullable=True, index=True
    )
    context_refs: Mapped[dict[str, str]] = mapped_column(
        JSON, default=dict, nullable=False
    )
    details: Mapped[dict[str, Any]] = mapped_column(
        "metadata", JSON, default=dict, nullable=False
    )


class PaymentReconciliation(Base, TimestampMixin):
    __tablename__ = "payment_reconciliations"
    __table_args__ = (
        UniqueConstraint(
            "tenant_id", "reconciliation_id", name="uq_payment_reconciliation"
        ),
        UniqueConstraint(
            "tenant_id",
            "payment_row_id",
            "idempotency_key",
            name="uq_payment_reconciliation_idempotency",
        ),
        Index(
            "ix_payment_reconciliation_payment",
            "tenant_id",
            "payment_row_id",
            "recorded_at",
        ),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    reconciliation_id: Mapped[str] = mapped_column(
        String(36), nullable=False, index=True
    )
    payment_row_id: Mapped[str] = mapped_column(
        ForeignKey("payment_obligations.id", ondelete="RESTRICT"),
        nullable=False,
        index=True,
    )
    mode: Mapped[str] = mapped_column(String(30), nullable=False, index=True)
    amount_minor: Mapped[int] = mapped_column(BigInteger, nullable=False)
    currency: Mapped[str] = mapped_column(String(3), nullable=False)
    transaction_reference: Mapped[str] = mapped_column(
        String(255), nullable=False, index=True
    )
    evidence_ref: Mapped[dict[str, Any]] = mapped_column(JSON, nullable=False)
    idempotency_key: Mapped[str] = mapped_column(String(255), nullable=False)
    request_sha256: Mapped[str] = mapped_column(String(64), nullable=False)
    received_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, index=True
    )
    recorded_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, index=True
    )
    recorded_by_ref: Mapped[str] = mapped_column(
        String(255), nullable=False, index=True
    )
    details: Mapped[dict[str, Any]] = mapped_column(
        "metadata", JSON, default=dict, nullable=False
    )


class PaymentEvent(Base, TimestampMixin):
    __tablename__ = "payment_events"
    __table_args__ = (
        UniqueConstraint("tenant_id", "event_id", name="uq_payment_event"),
        Index(
            "ix_payment_event_stream",
            "tenant_id",
            "payment_row_id",
            "occurred_at",
        ),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=new_uuid)
    tenant_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    event_id: Mapped[str] = mapped_column(String(36), nullable=False, index=True)
    payment_row_id: Mapped[str] = mapped_column(
        ForeignKey("payment_obligations.id", ondelete="RESTRICT"),
        nullable=False,
        index=True,
    )
    event_type: Mapped[str] = mapped_column(String(120), nullable=False, index=True)
    status: Mapped[str] = mapped_column(String(30), nullable=False, index=True)
    occurred_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, index=True
    )
    actor_ref: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    payload: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, nullable=False)


__all__ = ["PaymentEvent", "PaymentObligation", "PaymentReconciliation"]