-- =====================================================
-- LLM SCHEMA - EMBEDDINGS TABLE
-- =====================================================
-- Description: Vector embeddings for RAG and semantic search
-- Schema: llm
-- Author: Database Agent
-- Date: 2025-12-06
-- =====================================================

-- NOTA: Requiere extensión pgvector
-- CREATE EXTENSION IF NOT EXISTS vector;

CREATE TABLE llm.embeddings (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),

  -- Tipo de contenido
  content_type VARCHAR(50) NOT NULL, -- message, document, faq, tutorial, article

  -- Referencia al contenido original
  content_id UUID, -- ID del mensaje, documento, etc.

  -- Contenido
  content TEXT NOT NULL,
  content_hash VARCHAR(64), -- SHA-256 para deduplicación

  -- Metadata del contenido
  title VARCHAR(500),
  description TEXT,

  -- Vector embedding (dimensión depende del modelo)
  -- OpenAI text-embedding-3-small: 1536 dims
  -- OpenAI text-embedding-3-large: 3072 dims
  -- Voyage AI: 1024 dims
  embedding vector(1536), -- Ajustar según modelo usado

  -- Modelo usado para generar embedding
  embedding_model VARCHAR(100) NOT NULL, -- text-embedding-3-small, voyage-2, etc.

  -- Metadata para filtrado
  user_id UUID REFERENCES auth.users(id) ON DELETE CASCADE, -- Si es contenido específico de usuario
  is_public BOOLEAN DEFAULT true,

  -- Categorización
  category VARCHAR(100), -- education, trading, market_news, platform_help
  subcategory VARCHAR(100),
  tags TEXT[] DEFAULT '{}',

  -- Relevancia
  importance_score DECIMAL(3,2) DEFAULT 0.50,

  -- Contexto adicional
  context_metadata JSONB, -- Metadata adicional para mejorar recuperación

  -- Fuente
  source_url VARCHAR(500),
  source_type VARCHAR(50), -- internal, external, generated

  -- Validez
  is_active BOOLEAN DEFAULT true,
  expires_at TIMESTAMPTZ,

  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Índices
CREATE INDEX idx_embeddings_type ON llm.embeddings(content_type);
CREATE INDEX idx_embeddings_user ON llm.embeddings(user_id) WHERE user_id IS NOT NULL;
CREATE INDEX idx_embeddings_category ON llm.embeddings(category);
CREATE INDEX idx_embeddings_tags ON llm.embeddings USING GIN(tags);
CREATE INDEX idx_embeddings_active ON llm.embeddings(is_active) WHERE is_active = true;
CREATE INDEX idx_embeddings_hash ON llm.embeddings(content_hash);

-- Índice para búsqueda vectorial (HNSW para mejor performance)
-- Requiere pgvector
CREATE INDEX idx_embeddings_vector_hnsw ON llm.embeddings
  USING hnsw (embedding vector_cosine_ops);

-- Índice alternativo: IVFFlat (más rápido de construir, menos preciso)
-- CREATE INDEX idx_embeddings_vector_ivfflat ON llm.embeddings
--   USING ivfflat (embedding vector_cosine_ops) WITH (lists = 100);

-- Comentarios
COMMENT ON TABLE llm.embeddings IS 'Vector embeddings for RAG and semantic search using pgvector';
COMMENT ON COLUMN llm.embeddings.content_type IS 'Type of content: message, document, faq, tutorial, article';
COMMENT ON COLUMN llm.embeddings.content_id IS 'Reference to original content (e.g., message ID)';
COMMENT ON COLUMN llm.embeddings.content IS 'Text content that was embedded';
COMMENT ON COLUMN llm.embeddings.content_hash IS 'SHA-256 hash for deduplication';
COMMENT ON COLUMN llm.embeddings.embedding IS 'Vector embedding (dimension depends on model)';
COMMENT ON COLUMN llm.embeddings.embedding_model IS 'Model used to generate embedding';
COMMENT ON COLUMN llm.embeddings.is_public IS 'Whether embedding is accessible to all users or user-specific';
COMMENT ON COLUMN llm.embeddings.importance_score IS 'Relevance score for retrieval prioritization';

-- Ejemplo de uso para búsqueda semántica:
COMMENT ON TABLE llm.embeddings IS
'Vector search example:
SELECT
  content,
  title,
  1 - (embedding <=> query_embedding) AS similarity
FROM llm.embeddings
WHERE is_active = true
  AND category = ''education''
ORDER BY embedding <=> query_embedding
LIMIT 5;

Operators:
- <-> : L2 distance
- <#> : inner product
- <=> : cosine distance (recommended)';

-- Ejemplo de context_metadata JSONB:
COMMENT ON COLUMN llm.embeddings.context_metadata IS
'Example: {
  "language": "es",
  "difficulty_level": "beginner",
  "reading_time_minutes": 5,
  "author": "system",
  "last_updated": "2025-12-01",
  "related_symbols": ["BTCUSDT"],
  "related_topics": ["technical_analysis", "rsi"]
}';