#!/usr/bin/env python3
import json
import logging
from pathlib import Path

# ---------------------------------------------------------------------------
# Config
# ---------------------------------------------------------------------------

ROOT = Path(__file__).parent.parent.parent
SOURCE_DIR = ROOT / "source" / "motors" / "detail"
OUTPUT_FILE = ROOT / "data" / "motors.jsonl"
PREFIX = "motor"

logging.basicConfig(level=logging.INFO, format="%(message)s")
log = logging.getLogger(__name__)

# ---------------------------------------------------------------------------
# Mapper
# ---------------------------------------------------------------------------

def transform_motor(data: dict) -> dict:
    """Flatten motor JSON into a ChromaDB-ready format."""
    
    chroma_id = f"{PREFIX}:{int(data['id']):06d}"
    
    # Build searchable document text
    parts = []
    title = data.get('title') or data.get('designation')
    mfr = data.get('manufacturer')
    
    summary = f"Rocket Motor: {title}"
    if mfr: summary += f" manufactured by {mfr}"
    summary += "."
    parts.append(summary)
    
    perf = data.get("performance", {})
    phys = data.get("physical", {})
    
    stats = []
    if data.get("letter"): stats.append(f"Class: {data['letter']}")
    if perf.get("total_impulse_ns"): stats.append(f"Total Impulse: {perf['total_impulse_ns']} Ns")
    if perf.get("average_thrust_n"): stats.append(f"Average Thrust: {perf['average_thrust_n']} N")
    if phys.get("diameter_mm"): stats.append(f"Diameter: {phys['diameter_mm']} mm")
    if stats:
        parts.append("Performance: " + ", ".join(stats) + ".")
        
    if data.get("description"):
        parts.append(f"Description: {data['description']}")

    document = " ".join(parts)
    
    # Flatten metadata
    metadata = {
        "id": data["id"],
        "designation": data.get("designation"),
        "manufacturer": mfr,
        "letter": data.get("letter"),
        "diameter_mm": phys.get("diameter_mm"),
        "total_impulse_ns": perf.get("total_impulse_ns"),
        "average_thrust_n": perf.get("average_thrust_n"),
        "url": data.get("url")
    }
    
    metadata = {k: v for k, v in metadata.items() if v is not None}
    
    return {
        "id": chroma_id,
        "document": document,
        "metadata": metadata
    }

# ---------------------------------------------------------------------------
# Main
# ---------------------------------------------------------------------------

def main():
    if not SOURCE_DIR.exists():
        log.error(f"Source directory {SOURCE_DIR} not found.")
        return

    OUTPUT_FILE.parent.mkdir(parents=True, exist_ok=True)
    
    count = 0
    with OUTPUT_FILE.open("w", encoding="utf-8") as out:
        for shard_dir in sorted(SOURCE_DIR.iterdir()):
            if not shard_dir.is_dir(): continue
            for file_path in sorted(shard_dir.glob("*.json")):
                try:
                    with file_path.open("r", encoding="utf-8") as f:
                        raw_data = json.load(f)
                    processed = transform_motor(raw_data)
                    out.write(json.dumps(processed, ensure_ascii=False) + "\n")
                    count += 1
                except Exception as e:
                    log.error(f"Error processing {file_path}: {e}")

    log.info(f"Successfully built {count} records in {OUTPUT_FILE}")

if __name__ == "__main__":
    main()