"""
ContextSnippet model for storing reusable context snippets.

Stores small, highly compressed pieces of information like technical decisions,
configurations, patterns, and lessons learned for quick retrieval.
"""

from typing import TYPE_CHECKING, Optional

from sqlalchemy import Float, ForeignKey, Index, Integer, String, Text
from sqlalchemy.orm import Mapped, mapped_column, relationship

from .base import Base, TimestampMixin, UUIDMixin

if TYPE_CHECKING:
    from .client import Client
    from .project import Project


class ContextSnippet(Base, UUIDMixin, TimestampMixin):
    """
    ContextSnippet model for storing reusable context snippets.

    Stores small, highly compressed pieces of information like technical
    decisions, configurations, patterns, and lessons learned. These snippets
    are designed for quick retrieval and reuse across conversations.

    Attributes:
        category: Category of snippet (tech_decision, configuration, pattern, lesson_learned)
        title: Brief title describing the snippet
        dense_content: Highly compressed information content
        structured_data: JSON object for optional structured representation
        tags: JSON array of tags for retrieval and categorization
        project_id: Foreign key to projects (optional)
        client_id: Foreign key to clients (optional)
        relevance_score: Float score for ranking relevance (default 1.0)
        usage_count: Integer count of how many times this snippet was retrieved (default 0)
        project: Relationship to Project model
        client: Relationship to Client model
    """

    __tablename__ = "context_snippets"

    # Foreign keys
    project_id: Mapped[Optional[str]] = mapped_column(
        String(36),
        ForeignKey("projects.id", ondelete="SET NULL"),
        doc="Foreign key to projects (optional)"
    )

    client_id: Mapped[Optional[str]] = mapped_column(
        String(36),
        ForeignKey("clients.id", ondelete="SET NULL"),
        doc="Foreign key to clients (optional)"
    )

    # Snippet metadata
    category: Mapped[str] = mapped_column(
        String(100),
        nullable=False,
        doc="Category: tech_decision, configuration, pattern, lesson_learned"
    )

    title: Mapped[str] = mapped_column(
        String(200),
        nullable=False,
        doc="Brief title describing the snippet"
    )

    # Content
    dense_content: Mapped[str] = mapped_column(
        Text,
        nullable=False,
        doc="Highly compressed information content"
    )

    structured_data: Mapped[Optional[str]] = mapped_column(
        Text,
        doc="JSON object for optional structured representation"
    )

    # Retrieval metadata
    tags: Mapped[Optional[str]] = mapped_column(
        Text,
        doc="JSON array of tags for retrieval and categorization"
    )

    relevance_score: Mapped[float] = mapped_column(
        Float,
        default=1.0,
        server_default="1.0",
        doc="Float score for ranking relevance (default 1.0)"
    )

    usage_count: Mapped[int] = mapped_column(
        Integer,
        default=0,
        server_default="0",
        doc="Integer count of how many times this snippet was retrieved"
    )

    # Relationships
    project: Mapped[Optional["Project"]] = relationship(
        "Project",
        doc="Relationship to Project model"
    )

    client: Mapped[Optional["Client"]] = relationship(
        "Client",
        doc="Relationship to Client model"
    )

    # Indexes
    __table_args__ = (
        Index("idx_context_snippets_project", "project_id"),
        Index("idx_context_snippets_client", "client_id"),
        Index("idx_context_snippets_category", "category"),
        Index("idx_context_snippets_relevance", "relevance_score"),
        Index("idx_context_snippets_usage", "usage_count"),
    )

    def __repr__(self) -> str:
        """String representation of the context snippet."""
        return f"<ContextSnippet(title='{self.title}', category='{self.category}', usage={self.usage_count})>"