"""
Copyright 2024-2026 ReplyPier

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""

import uuid

from sqlalchemy import Boolean, Column, DateTime, ForeignKey, Index, Integer, String, Text
from sqlalchemy.dialects.postgresql import JSON, UUID
from sqlalchemy.orm import relationship
from sqlalchemy.sql import expression, func

from app.database import Base
from app.models.ticket import _ValueStrEnum


class DBConnectorEngine(_ValueStrEnum):
    POSTGRESQL = "postgresql"
    MYSQL = "mysql"


# Which value of the ticket's customer is matched against the scope column.
# Email is the default because it is the identifier a support database is most
# likely to share with ReplyPier; phone suits channel-first businesses.
ROW_SCOPE_KEYS = ("email", "phone")


class TicketDBConnector(Base):
    """A guardrailed, read-only database connection the ticket investigation
    agent may query. Guardrails are structural, enforced outside the model:
    SELECT-only AST validation against allowed_tables, forced row limits,
    column masking, read-only transaction + statement timeout, full audit.
    """
    __tablename__ = "ticket_db_connectors"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    organization_id = Column(
        UUID(as_uuid=True),
        ForeignKey("organizations.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    name = Column(String(200), nullable=False)
    engine = Column(String, nullable=False, default=DBConnectorEngine.POSTGRESQL)
    host = Column(String(500), nullable=False)
    port = Column(Integer, nullable=False, default=5432)
    database = Column(String(200), nullable=False)
    username = Column(String(200), nullable=False)
    # Encrypted with app.core.security.encrypt_api_key — never stored plain.
    encrypted_password = Column(Text, nullable=False)

    enabled = Column(Boolean, nullable=False, default=True, server_default=expression.true())

    # SSH tunnel (bastion / jump host). Production databases are rarely
    # directly reachable — the connection is forwarded through an SSH host.
    # host/port above are then resolved from the SSH host's perspective.
    ssh_enabled = Column(Boolean, nullable=False, default=False, server_default=expression.false())
    ssh_host = Column(String(500), nullable=True)
    ssh_port = Column(Integer, nullable=False, default=22, server_default="22")
    ssh_username = Column(String(200), nullable=True)
    # Exactly one auth method is used: private key preferred, else password.
    # All encrypted with app.core.security.encrypt_api_key.
    encrypted_ssh_password = Column(Text, nullable=True)
    encrypted_ssh_private_key = Column(Text, nullable=True)
    encrypted_ssh_key_passphrase = Column(Text, nullable=True)

    # ["schema.table", ...] — nothing is queryable unless listed here.
    allowed_tables = Column(JSON, nullable=True)
    # ["email", "phone", ...] — masked before the AI ever sees them; the AST
    # validator also rejects any query referencing them.
    masked_columns = Column(JSON, nullable=True)
    # {"schema.table": "customer_email", ...} — row-level scoping. A listed
    # table is rewritten into a subquery pre-filtered to the ticket customer's
    # own rows, so the agent cannot read across customers even with a query
    # that tries to. Tables left out are unscoped: reference data (products,
    # error codes) that belongs to nobody in particular.
    row_scope = Column(JSON, nullable=True)
    # Which customer value fills the predicate — see ROW_SCOPE_KEYS.
    row_scope_key = Column(
        String(20), nullable=False, default="email", server_default="email"
    )
    max_rows = Column(Integer, nullable=False, default=100, server_default="100")
    statement_timeout_ms = Column(Integer, nullable=False, default=5000, server_default="5000")

    last_test_at = Column(DateTime(timezone=True), nullable=True)
    last_test_ok = Column(Boolean, nullable=True)

    created_at = Column(DateTime(timezone=True), server_default=func.now())
    updated_at = Column(DateTime(timezone=True), onupdate=func.now())

    organization = relationship("Organization")


class DBConnectorAuditOutcome(_ValueStrEnum):
    ALLOWED = "allowed"
    BLOCKED = "blocked"
    ERROR = "error"


class DBConnectorAuditLog(Base):
    """Append-only audit of every query the AI attempted against a
    connector: the raw model SQL, what actually executed (canonical form),
    and the outcome. Result rows are never stored."""
    __tablename__ = "db_connector_audit_logs"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    connector_id = Column(
        UUID(as_uuid=True),
        ForeignKey("ticket_db_connectors.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    organization_id = Column(
        UUID(as_uuid=True),
        ForeignKey("organizations.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    ticket_id = Column(
        UUID(as_uuid=True), ForeignKey("tickets.id", ondelete="SET NULL"), nullable=True
    )
    run_id = Column(
        UUID(as_uuid=True),
        ForeignKey("investigation_runs.id", ondelete="SET NULL"),
        nullable=True,
    )
    raw_sql = Column(Text, nullable=False)
    validated_sql = Column(Text, nullable=True)
    outcome = Column(String, nullable=False)
    block_reason = Column(Text, nullable=True)
    row_count = Column(Integer, nullable=True)
    duration_ms = Column(Integer, nullable=True)
    created_at = Column(DateTime(timezone=True), server_default=func.now())

    __table_args__ = (
        Index("ix_db_connector_audit_logs_created", "organization_id", "created_at"),
    )