# backend/scripts/apply_trainer_schemas.py
from __future__ import annotations

import json
from pathlib import Path

REPO_ROOT = Path(__file__).resolve().parents[2]
TEMPLATES_DIR = REPO_ROOT / "backend" / "templates"
SCHEMAS_DIR = REPO_ROOT / "backend" / "trainer_schemas"

def main() -> None:
    if not SCHEMAS_DIR.exists():
        raise RuntimeError(f"Missing schemas dir: {SCHEMAS_DIR}")

    schema_files = sorted(SCHEMAS_DIR.glob("*.schema.json"))
    if not schema_files:
        raise RuntimeError(f"No schema files found in: {SCHEMAS_DIR}")

    applied = 0

    for sf in schema_files:
        template_id = sf.name.replace(".schema.json", "")
        template_path = TEMPLATES_DIR / f"{template_id}.json"

        if not template_path.exists():
            print(f"⚠️ skip (no template file): {template_path}")
            continue

        new_schema = json.loads(sf.read_text(encoding="utf-8"))
        if not isinstance(new_schema, dict):
            raise RuntimeError(f"Invalid schema json (not object): {sf}")
        if not isinstance(new_schema.get("fields"), list):
            raise RuntimeError(f"Invalid schema json (missing fields[]): {sf}")

        t = json.loads(template_path.read_text(encoding="utf-8"))
        t["schema"] = new_schema

        # Optional: bump template version when schema changes
        # t["version"] = int(t.get("version") or 0) + 1

        template_path.write_text(json.dumps(t, indent=2) + "\n", encoding="utf-8")
        print(f"✅ updated {template_path}  fields={len(new_schema['fields'])}")
        applied += 1

    print(f"done. applied={applied}")

if __name__ == "__main__":
    main()