from __future__ import annotations

import uuid
from datetime import datetime, timezone
from typing import Any

from sqlalchemy import Boolean, DateTime, ForeignKey, Index, Integer, JSON, String, Text, UniqueConstraint, text
from sqlalchemy.orm import Mapped, mapped_column, relationship

from govoplan_core.db.base import Base, TimestampMixin


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


class CalendarCollection(Base, TimestampMixin):
    __tablename__ = "calendar_collections"
    __table_args__ = (
        Index(
            "uq_calendar_collections_active_slug",
            "tenant_id",
            "slug",
            unique=True,
            sqlite_where=text("deleted_at IS NULL"),
            postgresql_where=text("deleted_at IS NULL"),
        ),
        Index("ix_calendar_collections_owner", "tenant_id", "owner_type", "owner_id"),
    )

    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)
    slug: Mapped[str] = mapped_column(String(100), nullable=False)
    name: Mapped[str] = mapped_column(String(255), nullable=False)
    description: Mapped[str | None] = mapped_column(Text)
    timezone: Mapped[str] = mapped_column(String(100), default="UTC", nullable=False)
    color: Mapped[str | None] = mapped_column(String(20))
    owner_type: Mapped[str] = mapped_column(String(20), default="tenant", nullable=False, index=True)
    owner_id: Mapped[str | None] = mapped_column(String(36), nullable=True, index=True)
    visibility: Mapped[str] = mapped_column(String(20), default="tenant", nullable=False, index=True)
    is_default: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False, index=True)
    created_by_user_id: Mapped[str | None] = mapped_column(ForeignKey("access_users.id", ondelete="SET NULL"), nullable=True, index=True)
    deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    metadata_: Mapped[dict[str, Any] | None] = mapped_column("metadata", JSON, nullable=True)

    events: Mapped[list["CalendarEvent"]] = relationship(back_populates="calendar", cascade="all, delete-orphan")


class CalendarEvent(Base, TimestampMixin):
    __tablename__ = "calendar_events"
    __table_args__ = (
        UniqueConstraint("calendar_id", "uid", "recurrence_id", name="uq_calendar_events_calendar_uid_recurrence"),
        Index("ix_calendar_events_range", "tenant_id", "calendar_id", "start_at", "end_at"),
        Index("ix_calendar_events_tenant_uid", "tenant_id", "uid"),
        Index(
            "ix_calendar_events_tenant_correlation",
            "tenant_id",
            "correlation_key",
        ),
        Index("ix_calendar_events_tenant_status", "tenant_id", "status"),
    )

    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)
    calendar_id: Mapped[str] = mapped_column(ForeignKey("calendar_collections.id", ondelete="CASCADE"), nullable=False, index=True)
    uid: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
    correlation_key: Mapped[str | None] = mapped_column(
        String(255), nullable=True, index=True
    )
    producer_module: Mapped[str | None] = mapped_column(
        String(100), nullable=True, index=True
    )
    producer_resource_type: Mapped[str | None] = mapped_column(
        String(100), nullable=True
    )
    producer_resource_id: Mapped[str | None] = mapped_column(
        String(255), nullable=True, index=True
    )
    recurrence_id: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)
    sequence: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    summary: Mapped[str] = mapped_column(String(500), nullable=False)
    description: Mapped[str | None] = mapped_column(Text)
    location: Mapped[str | None] = mapped_column(String(500))
    status: Mapped[str] = mapped_column(String(40), default="CONFIRMED", nullable=False, index=True)
    transparency: Mapped[str] = mapped_column(String(20), default="OPAQUE", nullable=False)
    classification: Mapped[str] = mapped_column(String(20), default="PUBLIC", nullable=False)
    start_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, index=True)
    end_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    duration_seconds: Mapped[int | None] = mapped_column(Integer)
    all_day: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False, index=True)
    timezone: Mapped[str | None] = mapped_column(String(100))
    organizer: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)
    attendees: Mapped[list[dict[str, Any]]] = mapped_column(JSON, default=list, nullable=False)
    categories: Mapped[list[str]] = mapped_column(JSON, default=list, nullable=False)
    rrule: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)
    rdate: Mapped[list[dict[str, Any]]] = mapped_column(JSON, default=list, nullable=False)
    exdate: Mapped[list[dict[str, Any]]] = mapped_column(JSON, default=list, nullable=False)
    reminders: Mapped[list[dict[str, Any]]] = mapped_column(JSON, default=list, nullable=False)
    attachments: Mapped[list[dict[str, Any]]] = mapped_column(JSON, default=list, nullable=False)
    related_to: Mapped[list[dict[str, Any]]] = mapped_column(JSON, default=list, nullable=False)
    source_kind: Mapped[str] = mapped_column(String(30), default="local", nullable=False, index=True)
    source_href: Mapped[str | None] = mapped_column(String(1000))
    etag: Mapped[str | None] = mapped_column(String(255), index=True)
    icalendar: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, nullable=False)
    raw_ics: Mapped[str | None] = mapped_column(Text)
    created_by_user_id: Mapped[str | None] = mapped_column(ForeignKey("access_users.id", ondelete="SET NULL"), nullable=True, index=True)
    updated_by_user_id: Mapped[str | None] = mapped_column(ForeignKey("access_users.id", ondelete="SET NULL"), nullable=True, index=True)
    deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    metadata_: Mapped[dict[str, Any] | None] = mapped_column("metadata", JSON, nullable=True)

    calendar: Mapped[CalendarCollection] = relationship(back_populates="events")


class CalendarViewPreference(Base, TimestampMixin):
    __tablename__ = "calendar_view_preferences"
    __table_args__ = (
        UniqueConstraint(
            "tenant_id",
            "user_id",
            name="uq_calendar_view_preferences_tenant_user",
        ),
    )

    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,
    )
    user_id: Mapped[str] = mapped_column(
        ForeignKey("access_users.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    dim_weekends: Mapped[bool | None] = mapped_column(Boolean, nullable=True)
    dim_off_hours: Mapped[bool | None] = mapped_column(Boolean, nullable=True)
    workday_start_hour: Mapped[int | None] = mapped_column(Integer, nullable=True)
    workday_end_hour: Mapped[int | None] = mapped_column(Integer, nullable=True)
    continuous_virtualization: Mapped[bool | None] = mapped_column(Boolean, nullable=True)
    continuous_overscan_weeks: Mapped[int | None] = mapped_column(Integer, nullable=True)
    alternate_continuous_months: Mapped[bool | None] = mapped_column(Boolean, nullable=True)


class CalendarSyncSource(Base, TimestampMixin):
    __tablename__ = "calendar_sync_sources"
    __table_args__ = (
        Index("ix_calendar_sync_sources_calendar", "tenant_id", "calendar_id", "source_kind"),
        Index(
            "uq_calendar_sync_sources_active_url",
            "tenant_id",
            "source_kind",
            "collection_url",
            unique=True,
            sqlite_where=text("deleted_at IS NULL"),
            postgresql_where=text("deleted_at IS NULL"),
        ),
    )

    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)
    calendar_id: Mapped[str] = mapped_column(ForeignKey("calendar_collections.id", ondelete="CASCADE"), nullable=False, index=True)
    source_kind: Mapped[str] = mapped_column(String(30), default="caldav", nullable=False, index=True)
    collection_url: Mapped[str] = mapped_column(String(1000), nullable=False)
    display_name: Mapped[str | None] = mapped_column(String(255))
    auth_type: Mapped[str] = mapped_column(String(30), default="none", nullable=False)
    username: Mapped[str | None] = mapped_column(String(255))
    credential_ref: Mapped[str | None] = mapped_column(String(255))
    sync_enabled: Mapped[bool] = mapped_column(Boolean, default=True, nullable=False, index=True)
    sync_interval_seconds: Mapped[int] = mapped_column(Integer, default=900, nullable=False)
    sync_direction: Mapped[str] = mapped_column(String(30), default="two_way", nullable=False)
    conflict_policy: Mapped[str] = mapped_column(String(30), default="etag", nullable=False)
    sync_token: Mapped[str | None] = mapped_column(Text)
    ctag: Mapped[str | None] = mapped_column(String(255))
    last_attempt_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    last_synced_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    next_sync_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    last_status: Mapped[str | None] = mapped_column(String(30))
    last_error: Mapped[str | None] = mapped_column(Text)
    deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    metadata_: Mapped[dict[str, Any] | None] = mapped_column("metadata", JSON, nullable=True)

    calendar: Mapped[CalendarCollection] = relationship()


class CalendarSyncCredential(Base, TimestampMixin):
    __tablename__ = "calendar_sync_credentials"
    __table_args__ = (
        Index("ix_calendar_sync_credentials_tenant_kind", "tenant_id", "credential_kind"),
    )

    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)
    credential_kind: Mapped[str] = mapped_column(String(30), nullable=False, index=True)
    label: Mapped[str | None] = mapped_column(String(255))
    secret_encrypted: Mapped[str | None] = mapped_column(Text)
    created_by_user_id: Mapped[str | None] = mapped_column(ForeignKey("access_users.id", ondelete="SET NULL"), nullable=True, index=True)
    deleted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    metadata_: Mapped[dict[str, Any] | None] = mapped_column("metadata", JSON, nullable=True)


class CalendarOutboxOperation(Base, TimestampMixin):
    """Durable desired state for one external CalDAV resource.

    Rows are inserted in the same transaction as the local event mutation.  A
    dispatcher leases and commits the row before performing network I/O, so a
    worker crash can be detected and reconciled without repeating a blind
    write.
    """

    __tablename__ = "calendar_outbox_operations"
    __table_args__ = (
        UniqueConstraint("idempotency_key", name="uq_calendar_outbox_operations_idempotency_key"),
        Index("ix_calendar_outbox_due", "status", "available_at", "created_at"),
        Index("ix_calendar_outbox_tenant_status", "tenant_id", "status"),
        Index("ix_calendar_outbox_resource", "source_id", "resource_href", "created_at"),
        Index("ix_calendar_outbox_lease", "status", "lease_expires_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)
    source_id: Mapped[str] = mapped_column(
        ForeignKey("calendar_sync_sources.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    event_id: Mapped[str | None] = mapped_column(
        ForeignKey("calendar_events.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )
    operation_kind: Mapped[str] = mapped_column(String(20), nullable=False, index=True)
    resource_href: Mapped[str] = mapped_column(String(1000), nullable=False)
    payload_ics: Mapped[str | None] = mapped_column(Text)
    payload_fingerprint: Mapped[str | None] = mapped_column(String(64), nullable=True, index=True)
    expected_etag: Mapped[str | None] = mapped_column(String(255))
    idempotency_key: Mapped[str] = mapped_column(String(64), nullable=False)
    status: Mapped[str] = mapped_column(String(30), default="pending", nullable=False, index=True)
    attempt_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    max_attempts: Mapped[int] = mapped_column(Integer, default=8, nullable=False)
    available_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(timezone.utc),
        nullable=False,
        index=True,
    )
    last_attempt_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    lease_token: Mapped[str | None] = mapped_column(String(36), nullable=True, index=True)
    lease_expires_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    completed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    reconciled_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    remote_etag: Mapped[str | None] = mapped_column(String(255))
    last_error: Mapped[str | None] = mapped_column(Text)
    metadata_: Mapped[dict[str, Any] | None] = mapped_column("metadata", JSON, nullable=True)

    source: Mapped[CalendarSyncSource] = relationship()
    event: Mapped[CalendarEvent | None] = relationship()


class CalendarMigrationBatch(Base, TimestampMixin):
    """Durable destructive remote-move saga and its authorization evidence."""

    __tablename__ = "calendar_migration_batches"
    __table_args__ = (
        Index("ix_calendar_migration_batches_tenant_status", "tenant_id", "status", "created_at"),
        Index("ix_calendar_migration_batches_calendars", "tenant_id", "source_calendar_id", "target_calendar_id"),
    )

    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)
    migration_kind: Mapped[str] = mapped_column(String(30), default="remote_move", nullable=False)
    status: Mapped[str] = mapped_column(String(30), default="active", nullable=False, index=True)
    phase: Mapped[str] = mapped_column(String(40), default="copying_destination", nullable=False, index=True)
    source_calendar_id: Mapped[str] = mapped_column(ForeignKey("calendar_collections.id", ondelete="RESTRICT"), nullable=False, index=True)
    target_calendar_id: Mapped[str] = mapped_column(ForeignKey("calendar_collections.id", ondelete="RESTRICT"), nullable=False, index=True)
    source_sync_source_id: Mapped[str] = mapped_column(ForeignKey("calendar_sync_sources.id", ondelete="RESTRICT"), nullable=False, index=True)
    target_sync_source_id: Mapped[str] = mapped_column(ForeignKey("calendar_sync_sources.id", ondelete="RESTRICT"), nullable=False, index=True)
    total_resources: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    total_events: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    created_by_user_id: Mapped[str | None] = mapped_column(ForeignKey("access_users.id", ondelete="SET NULL"), nullable=True, index=True)
    created_by_api_key_id: Mapped[str | None] = mapped_column(String(36), nullable=True, index=True)
    authorization_evidence: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, nullable=False)
    cancellation_evidence: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)
    last_error: Mapped[str | None] = mapped_column(Text)
    completed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)

    resources: Mapped[list["CalendarMigrationResource"]] = relationship(back_populates="batch", cascade="all, delete-orphan")


class CalendarMigrationResource(Base, TimestampMixin):
    __tablename__ = "calendar_migration_resources"
    __table_args__ = (
        UniqueConstraint("batch_id", "source_href", name="uq_calendar_migration_resources_batch_href"),
        Index("ix_calendar_migration_resources_batch_status", "batch_id", "status"),
    )

    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)
    batch_id: Mapped[str] = mapped_column(ForeignKey("calendar_migration_batches.id", ondelete="CASCADE"), nullable=False, index=True)
    source_href: Mapped[str] = mapped_column(String(1000), nullable=False)
    source_expected_etag: Mapped[str] = mapped_column(String(255), nullable=False)
    destination_href: Mapped[str] = mapped_column(String(1000), nullable=False)
    event_ids: Mapped[list[str]] = mapped_column(JSON, default=list, nullable=False)
    status: Mapped[str] = mapped_column(String(30), default="copy_pending", nullable=False, index=True)
    destination_operation_id: Mapped[str | None] = mapped_column(ForeignKey("calendar_outbox_operations.id", ondelete="SET NULL"), nullable=True, unique=True)
    source_delete_operation_id: Mapped[str | None] = mapped_column(ForeignKey("calendar_outbox_operations.id", ondelete="SET NULL"), nullable=True, unique=True)
    last_error: Mapped[str | None] = mapped_column(Text)

    batch: Mapped[CalendarMigrationBatch] = relationship(back_populates="resources")


__all__ = [
    "CalendarCollection",
    "CalendarEvent",
    "CalendarMigrationBatch",
    "CalendarMigrationResource",
    "CalendarOutboxOperation",
    "CalendarSyncCredential",
    "CalendarSyncSource",
    "CalendarViewPreference",
    "new_uuid",
]