"""Read a single session digest from the local store (AGENTIC-WP-0011 T03).

Thin read path for ``kaizen-agentic metrics correlate`` and other consumers.
Does not run ingest.

Usage:
    python -m session_memory.digest_lookup <session_uid> [--json]
    HELIX_STORE_DB=/abs/path/to/mem.db python -m session_memory.digest_lookup <uid>
"""

from __future__ import annotations

import argparse
import json
import os
import sys

from .core.store import Store
from .ingest import _expand, load_config


def resolve_store_paths(*, config_path: str | None = None) -> tuple[str, str]:
    """Resolve db + blob paths from HELIX_STORE_DB or config.toml [store]."""
    env_db = os.environ.get("HELIX_STORE_DB")
    if env_db:
        db_path = _expand(env_db)
        blob_dir = os.path.join(os.path.dirname(db_path), "blobs")
        return db_path, blob_dir

    here = os.path.dirname(os.path.abspath(__file__))
    cfg_path = config_path or os.path.join(here, "config.toml")
    store_cfg = load_config(cfg_path).get("store", {})
    return _expand(store_cfg.get("db_path", "session_memory/.store/mem.db")), _expand(
        store_cfg.get("blob_dir", "session_memory/.store/blobs")
    )


def lookup_digest(session_uid: str, *, config_path: str | None = None) -> dict | None:
    db_path, blob_dir = resolve_store_paths(config_path=config_path)
    store = Store(db_path, blob_dir)
    try:
        return store.get_digest(session_uid)
    finally:
        store.close()


def main(argv: list[str] | None = None) -> int:
    here = os.path.dirname(os.path.abspath(__file__))
    ap = argparse.ArgumentParser(
        description="Read one session digest from the Helix Forge store (no ingest)."
    )
    ap.add_argument("session_uid", help="Normalized session uid, e.g. claude:abc-123")
    ap.add_argument("--config", default=os.path.join(here, "config.toml"),
                    help="config.toml when HELIX_STORE_DB is unset")
    ap.add_argument("--json", action="store_true", help="print digest JSON to stdout")
    args = ap.parse_args(argv)

    digest = lookup_digest(args.session_uid, config_path=args.config)
    if digest is None:
        print(f"digest not found: {args.session_uid}", file=sys.stderr)
        return 1

    if args.json:
        print(json.dumps(digest, indent=2, sort_keys=True))
    else:
        cost = digest.get("cost") or {}
        tokens = cost.get("input_tokens", 0) + cost.get("output_tokens", 0)
        print(f"session_uid: {digest.get('session_uid')}")
        print(f"repo: {digest.get('repo')}  flavor: {digest.get('flavor')}")
        print(f"outcome: {digest.get('outcome')}  tokens: {tokens}")
        print(f"started_at: {digest.get('started_at')}  ended_at: {digest.get('ended_at')}")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())