import uuid
from datetime import date
from typing import Any

from sqlalchemy import (
    JSON,
    BigInteger,
    Boolean,
    CheckConstraint,
    Date,
    ForeignKey,
    ForeignKeyConstraint,
    Integer,
    LargeBinary,
    String,
    UniqueConstraint,
    Uuid,
)
from sqlalchemy.orm import Mapped, mapped_column

from app.db.base import Base, PkMixin, TimestampMixin

DOCUMENT_STATUSES = (
    "uploaded",
    "queued",
    "processing",
    "ready",
    "review_required",
    "confirmed",
    "failed",
    "deleted",
)
RUN_STATUSES = ("pending", "running", "succeeded", "failed")
CANDIDATE_KINDS = ("duplicate", "transfer")
CANDIDATE_CONFIDENCES = ("unique", "possible")
CANDIDATE_RESOLUTIONS = ("pending", "is_duplicate", "is_new")


class StatementDocument(Base, PkMixin, TimestampMixin):
    __tablename__ = "statement_documents"
    __table_args__ = (
        ForeignKeyConstraint(
            ["space_id", "account_id"],
            ["accounts.space_id", "accounts.id"],
            name="fk_documents_account_tenant",
        ),
        UniqueConstraint("space_id", "content_sha256", name="uq_documents_space_sha"),
        UniqueConstraint("space_id", "id", name="uq_documents_space_id"),
    )

    space_id: Mapped[uuid.UUID] = mapped_column(
        Uuid, ForeignKey("financial_spaces.id", ondelete="CASCADE"), nullable=False, index=True
    )
    account_id: Mapped[uuid.UUID | None] = mapped_column(Uuid, nullable=True, index=True)
    original_filename: Mapped[str] = mapped_column(String(300), nullable=False)
    size_bytes: Mapped[int] = mapped_column(BigInteger, nullable=False)
    content_sha256: Mapped[str] = mapped_column(String(64), nullable=False, index=True)
    object_key: Mapped[str] = mapped_column(String(64), nullable=False, unique=True)
    dek_wrapped: Mapped[bytes | None] = mapped_column(LargeBinary, nullable=True)
    dek_wrap_nonce: Mapped[bytes | None] = mapped_column(LargeBinary, nullable=True)
    content_nonce: Mapped[bytes | None] = mapped_column(LargeBinary, nullable=True)
    adapter_id: Mapped[str | None] = mapped_column(String(48), nullable=True)
    account_fingerprint: Mapped[str | None] = mapped_column(String(128), nullable=True)
    status: Mapped[str] = mapped_column(String(20), nullable=False, default="uploaded", index=True)
    error_code: Mapped[str | None] = mapped_column(String(64), nullable=True)
    reconciliation: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)
    needs_account_mapping: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
    active_parse_run_id: Mapped[uuid.UUID | None] = mapped_column(Uuid, nullable=True)
    uploaded_by_user_id: Mapped[uuid.UUID | None] = mapped_column(
        Uuid, ForeignKey("users.id", ondelete="SET NULL"), nullable=True
    )


class ParseRun(Base, PkMixin, TimestampMixin):
    __tablename__ = "parse_runs"
    __table_args__ = (
        ForeignKeyConstraint(
            ["space_id", "document_id"],
            ["statement_documents.space_id", "statement_documents.id"],
            ondelete="CASCADE",
            name="fk_parse_runs_document_tenant",
        ),
        UniqueConstraint("space_id", "id", name="uq_parse_runs_space_id"),
    )

    space_id: Mapped[uuid.UUID] = mapped_column(
        Uuid, ForeignKey("financial_spaces.id", ondelete="CASCADE"), nullable=False, index=True
    )
    document_id: Mapped[uuid.UUID] = mapped_column(Uuid, nullable=False, index=True)
    adapter_id: Mapped[str | None] = mapped_column(String(48), nullable=True)
    parser_version: Mapped[str] = mapped_column(String(16), nullable=False, default="1")
    status: Mapped[str] = mapped_column(String(16), nullable=False, default="pending")
    error_code: Mapped[str | None] = mapped_column(String(64), nullable=True)
    draft: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)


class SourceRecord(Base, PkMixin, TimestampMixin):
    """Immutable extracted bank fact with document origin coordinates."""

    __tablename__ = "source_records"
    __table_args__ = (
        ForeignKeyConstraint(
            ["space_id", "document_id"],
            ["statement_documents.space_id", "statement_documents.id"],
            name="fk_source_records_document_tenant",
        ),
        ForeignKeyConstraint(
            ["space_id", "parse_run_id"],
            ["parse_runs.space_id", "parse_runs.id"],
            ondelete="CASCADE",
            name="fk_source_records_run_tenant",
        ),
        ForeignKeyConstraint(
            ["space_id", "duplicate_operation_id"],
            ["operations.space_id", "operations.id"],
            name="fk_source_records_duplicate_tenant",
        ),
        UniqueConstraint("space_id", "id", name="uq_source_records_space_id"),
    )

    space_id: Mapped[uuid.UUID] = mapped_column(
        Uuid, ForeignKey("financial_spaces.id", ondelete="CASCADE"), nullable=False, index=True
    )
    document_id: Mapped[uuid.UUID | None] = mapped_column(Uuid, nullable=True, index=True)
    parse_run_id: Mapped[uuid.UUID] = mapped_column(Uuid, nullable=False, index=True)
    external_id: Mapped[str | None] = mapped_column(String(120), nullable=True)
    occurred_on: Mapped[date | None] = mapped_column(Date, nullable=True)
    posted_on: Mapped[date | None] = mapped_column(Date, nullable=True)
    amount_kopecks: Mapped[int] = mapped_column(BigInteger, nullable=False)
    direction: Mapped[str] = mapped_column(String(8), nullable=False)
    description: Mapped[str | None] = mapped_column(String(500), nullable=True)
    mcc: Mapped[int | None] = mapped_column(Integer, nullable=True)
    bank_category: Mapped[str | None] = mapped_column(String(100), nullable=True)
    location: Mapped[str | None] = mapped_column(String(200), nullable=True)
    row_ref: Mapped[str] = mapped_column(String(120), nullable=False)
    field_warnings: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)
    critical: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
    record_fp: Mapped[str] = mapped_column(String(64), nullable=False, index=True)
    review_decision: Mapped[str] = mapped_column(String(16), nullable=False, default="create")
    duplicate_operation_id: Mapped[uuid.UUID | None] = mapped_column(Uuid, nullable=True)


class SourceRecordLink(Base, PkMixin, TimestampMixin):
    __tablename__ = "source_record_links"
    __table_args__ = (
        ForeignKeyConstraint(
            ["space_id", "source_record_id"],
            ["source_records.space_id", "source_records.id"],
            ondelete="CASCADE",
            name="fk_links_source_record_tenant",
        ),
        ForeignKeyConstraint(
            ["space_id", "operation_id"],
            ["operations.space_id", "operations.id"],
            name="fk_links_operation_tenant",
        ),
        UniqueConstraint("source_record_id", name="uq_links_source_record"),
        UniqueConstraint("space_id", "id", name="uq_links_space_id"),
    )

    space_id: Mapped[uuid.UUID] = mapped_column(
        Uuid, ForeignKey("financial_spaces.id", ondelete="CASCADE"), nullable=False, index=True
    )
    source_record_id: Mapped[uuid.UUID] = mapped_column(Uuid, nullable=False)
    operation_id: Mapped[uuid.UUID] = mapped_column(Uuid, nullable=False, index=True)
    kind: Mapped[str] = mapped_column(String(16), nullable=False)


class DedupCandidate(Base, PkMixin, TimestampMixin):
    __tablename__ = "dedup_candidates"
    __table_args__ = (
        CheckConstraint("candidate_kind IN ('duplicate', 'transfer')", name="kind_valid"),
        CheckConstraint(
            "resolution IN ('pending', 'is_duplicate', 'is_new', 'accepted_transfer')",
            name="resolution_valid",
        ),
        ForeignKeyConstraint(
            ["space_id", "source_record_id"],
            ["source_records.space_id", "source_records.id"],
            ondelete="CASCADE",
            name="fk_candidates_source_tenant",
        ),
        ForeignKeyConstraint(
            ["space_id", "existing_operation_id"],
            ["operations.space_id", "operations.id"],
            name="fk_candidates_operation_tenant",
        ),
        ForeignKeyConstraint(
            ["space_id", "existing_source_record_id"],
            ["source_records.space_id", "source_records.id"],
            ondelete="CASCADE",
            name="fk_candidates_existing_source_tenant",
        ),
        UniqueConstraint("space_id", "id", name="uq_candidates_space_id"),
    )

    space_id: Mapped[uuid.UUID] = mapped_column(
        Uuid, ForeignKey("financial_spaces.id", ondelete="CASCADE"), nullable=False, index=True
    )
    source_record_id: Mapped[uuid.UUID] = mapped_column(Uuid, nullable=False, index=True)
    candidate_kind: Mapped[str] = mapped_column(String(16), nullable=False, default="duplicate")
    existing_operation_id: Mapped[uuid.UUID | None] = mapped_column(Uuid, nullable=True, index=True)
    existing_source_record_id: Mapped[uuid.UUID | None] = mapped_column(
        Uuid, nullable=True, index=True
    )
    confidence: Mapped[str] = mapped_column(String(16), nullable=False, default="possible")
    resolution: Mapped[str] = mapped_column(String(16), nullable=False, default="pending")
    replacement_snapshot: Mapped[dict | None] = mapped_column(JSON, nullable=True)
    decided_by_user_id: Mapped[uuid.UUID | None] = mapped_column(
        Uuid, ForeignKey("users.id", ondelete="SET NULL"), nullable=True
    )