# RAG System Validator

let rag_schema = import "../schemas/rag.ncl" in
let constraints = import "../constraints/constraints.toml" in

{
  validate_rag_config | rag_schema.RagConfig -> Array String = fun config =>
    let errors = [] in

    # If RAG is disabled, skip subsystem validation
    let errors = if config.rag.enabled != true
                 then [] # No validation needed for disabled RAG
                 else
                   let errors = [] in

                   # Embeddings validation
                   let errors = if config.embeddings != null
                                then
                                  let e = [] in
                                  let e = if std.array.length config.embeddings.model == 0
                                           then e @ ["Embeddings model cannot be empty"]
                                           else e in
                                  let e = if config.embeddings.dimension < 1
                                           then e @ ["Embeddings dimension must be positive"]
                                           else e in
                                  let e = if config.embeddings.provider == "openai" || config.embeddings.provider == "anthropic"
                                           then if std.is_null config.embeddings.api_key
                                                then e @ ["API key required for #{config.embeddings.provider} embeddings"]
                                                else e
                                           else e in
                                  errors @ e
                                else errors in

                   # Vector DB validation
                   let errors = if config.vector_db != null
                                then
                                  let e = [] in
                                  let e = if config.vector_db.db_type == "surrealdb" || config.vector_db.db_type == "qdrant" || config.vector_db.db_type == "milvus"
                                           then if std.is_null config.vector_db.url || config.vector_db.url == ""
                                                then e @ ["Database URL required for #{config.vector_db.db_type}"]
                                                else e
                                           else e in
                                  let e = if std.array.length config.vector_db.namespace == 0
                                           then e @ ["Namespace cannot be empty"]
                                           else e in
                                  errors @ e
                                else errors in

                   # LLM validation
                   let errors = if config.llm != null
                                then
                                  let e = [] in
                                  let e = if std.array.length config.llm.model == 0
                                           then e @ ["LLM model cannot be empty"]
                                           else e in
                                  let e = if config.llm.provider == "anthropic" || config.llm.provider == "openai"
                                           then if std.is_null config.llm.api_key
                                                then e @ ["API key required for #{config.llm.provider} LLM"]
                                                else e
                                           else e in
                                  let e = if config.llm.temperature < 0.0 || config.llm.temperature > 1.0
                                           then e @ ["Temperature must be between 0.0 and 1.0"]
                                           else e in
                                  let e = if config.llm.max_tokens < 1
                                           then e @ ["Max tokens must be positive"]
                                           else e in
                                  errors @ e
                                else errors in

                   # Retrieval validation
                   let errors = if config.retrieval != null
                                then
                                  let e = [] in
                                  let e = if config.retrieval.top_k < 1
                                           then e @ ["Top K must be at least 1"]
                                           else e in
                                  let e = if config.retrieval.similarity_threshold < 0.0 || config.retrieval.similarity_threshold > 1.0
                                           then e @ ["Similarity threshold must be between 0.0 and 1.0"]
                                           else e in
                                  errors @ e
                                else errors in

                   # Ingestion validation
                   let errors = if config.ingestion != null
                                then
                                  let e = [] in
                                  let e = if config.ingestion.chunk_size < 1
                                           then e @ ["Chunk size must be positive"]
                                           else e in
                                  let e = if config.ingestion.overlap >= config.ingestion.chunk_size
                                           then e @ ["Overlap must be less than chunk size"]
                                           else e in
                                  let e = if std.array.length config.ingestion.doc_types == 0
                                           then e @ ["At least one document type must be specified"]
                                           else e in
                                  errors @ e
                                else errors in

                   errors in

    errors,
}