"""Shared helpers: project root, settings, logging, run ledger, output manifest."""
from __future__ import annotations
import hashlib, json, logging, os, sqlite3, sys, time, pathlib
import yaml

ROOT = pathlib.Path(__file__).resolve().parents[1]
SETTINGS = yaml.safe_load((ROOT / "config" / "settings.yaml").read_text())
SEED = int(SETTINGS["seed"])
REGIONS = list(SETTINGS["regions"])
LABEL = os.environ.get("WP38_LABEL", "rule")          # "rule" (platform keyword labels) or "model" (A-002 classifier labels)
SUFFIX = "" if LABEL == "rule" else f"_{LABEL}"
P = {k: ROOT / v for k, v in SETTINGS["paths"].items()}
P["processed"] = ROOT / f"data/processed{SUFFIX}"; P["experiments"] = ROOT / f"experiments{SUFFIX}"
P["figures"] = ROOT / f"paper/figures{SUFFIX}"; P["tables"] = ROOT / f"paper/tables{SUFFIX}"
for _p in P.values():
    _p.mkdir(parents=True, exist_ok=True)
PROC_DIR, EXP_DIR = P["processed"], P["experiments"]
BASE_PROC, BASE_EXP = ROOT / "data/processed", ROOT / "experiments"   # label-independent artefacts (cleaning, audits, matching)
BASE_PROC.mkdir(parents=True, exist_ok=True); BASE_EXP.mkdir(parents=True, exist_ok=True)


def get_logger(name: str) -> logging.Logger:
    log = logging.getLogger(name)
    if not log.handlers:
        log.setLevel(logging.INFO)
        fmt = logging.Formatter("%(asctime)s %(name)s %(levelname)s %(message)s", "%H:%M:%S")
        h = logging.StreamHandler(sys.stdout); h.setFormatter(fmt); log.addHandler(h)
        fh = logging.FileHandler(P["logs"] / "pipeline.log"); fh.setFormatter(fmt); log.addHandler(fh)
    return log


def snapshot_conn() -> sqlite3.Connection:
    path = ROOT / SETTINGS["snapshot"]["path"]
    return sqlite3.connect(f"file:{path}?mode=ro", uri=True)


def sha256_file(path: pathlib.Path) -> str:
    h = hashlib.sha256()
    with open(path, "rb") as f:
        for chunk in iter(lambda: f.read(1 << 22), b""):
            h.update(chunk)
    return h.hexdigest()


def ledger(step: str, **kw) -> None:
    """Append one JSON line to logs/run_ledger.jsonl (what ran, when, with which inputs/outputs)."""
    rec = {"ts": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()), "step": step, **kw}
    with open(P["logs"] / "run_ledger.jsonl", "a") as f:
        f.write(json.dumps(rec, ensure_ascii=False, default=str) + "\n")


def register_output(path: pathlib.Path, step: str) -> None:
    """Record sha256 of a produced file in logs/manifest.json."""
    mf = P["logs"] / "manifest.json"
    d = json.loads(mf.read_text()) if mf.exists() else {}
    d[str(path.relative_to(ROOT))] = {"sha256": sha256_file(path), "bytes": path.stat().st_size, "step": step,
                                      "ts": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())}
    mf.write_text(json.dumps(d, indent=1, sort_keys=True))


def write_json(obj, path: pathlib.Path, step: str = "") -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(json.dumps(obj, indent=1, ensure_ascii=False, default=str))
    if step:
        register_output(path, step)