"""
data_factory/config.py
======================
Central configuration for the NL2SQL Synthetic Data Factory.

Design philosophy:
  - SQL ALWAYS comes from human-verified templates  → zero SQL errors
  - LLM ONLY generates natural language paraphrases → no SQL hallucination
  - Every SQL is execution-validated before saving   → guaranteed correctness
"""

from __future__ import annotations
from pathlib import Path

# ── Paths ────────────────────────────────────────────────────────────────
ROOT_DIR        = Path(__file__).parent.parent
DATA_DIR        = ROOT_DIR / "generated_data"
CHECKPOINT_DIR  = DATA_DIR / "checkpoints"
OUTPUT_DIR      = DATA_DIR / "output"

# ── vLLM / Model ─────────────────────────────────────────────────────────
# For H100 with 80GB VRAM — run Llama-3-70B or Qwen-72B at full bf16
GENERATOR_MODEL  = "meta-llama/Meta-Llama-3-70B-Instruct"   # change to your preferred model
TENSOR_PARALLEL  = 4          # Number of GPUs for tensor parallelism (H100 cluster)
MAX_MODEL_LEN    = 4096       # Max context length
GPU_MEMORY_UTIL  = 0.90       # Leave 10% headroom

# ── Generation settings ──────────────────────────────────────────────────
PERSONAS = ["ceo", "chatty", "lazy_typist", "non_techie", "analyst"]
NL_VARIANTS_PER_TEMPLATE = 5   # One per persona
AUGMENTATIONS_PER_NL     = 3   # Rule-based variations per NL string
TEMPERATURE              = 0.85  # Slightly high for diversity
MAX_NEW_TOKENS           = 150   # NL questions are short

# ── Scale targets ────────────────────────────────────────────────────────
# 56 base SQL templates × 5 personas × 3 augmentations = 840 "original" records
# With vLLM generating more NL variants, target: ~500K-1M clean records
VLLM_EXTRA_VARIANTS = 10   # Additional vLLM NL variants per template beyond personas

# ── Validation ───────────────────────────────────────────────────────────
RANDOM_SEED = 42

# ── Domains ──────────────────────────────────────────────────────────────
DOMAINS = ["ecommerce", "healthcare", "finance", "hr"]

DIFFICULTY_LABELS = {
    "easy":   "Single-table SELECT with basic WHERE/ORDER/LIMIT.",
    "medium": "Multi-table JOIN with GROUP BY/HAVING/aggregates.",
    "hard":   "CTEs, window functions, subqueries.",
}