#!/usr/bin/env python3
from __future__ import annotations

import json
from datetime import datetime, timezone
from pathlib import Path
from typing import Any

ROOT = Path(__file__).resolve().parents[1]
BUILD_DIR = ROOT / "build" / "system"
USER_GOVERNANCE_PATH = BUILD_DIR / "user_governance.json"
OUTPUT_PATH = BUILD_DIR / "product_candidate_registry.json"


def utc_now() -> str:
    return datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")


def load_json(path: Path) -> dict[str, Any]:
    return json.loads(path.read_text(encoding="utf-8"))


def delivery_stage(status: str) -> str:
    return {
        "implemented": "live_candidate",
        "partial": "prototype",
        "requested": "discovery",
    }.get(status, "unknown")


def default_lane(primitive: str) -> str:
    if primitive in {"auto_reuse_prior_tools", "prior_artifact_recall", "history_navigation_surface"}:
        return "memory"
    if primitive in {"thin_intent_shell", "route_by_purpose"}:
        return "tooling"
    if primitive in {"intent_to_packet"}:
        return "audit"
    return "memory"


def build_candidate(move: dict[str, Any]) -> dict[str, Any]:
    primitive = move["primitive"]
    return {
        "candidate_id": primitive,
        "title": primitive.replace("_", " "),
        "primitive": primitive,
        "lane": default_lane(primitive),
        "priority_score": move["score"],
        "status": move["status"],
        "delivery_stage": delivery_stage(move["status"]),
        "trigger": move.get("trigger", ""),
        "why": move.get("why", ""),
        "first_surface": move.get("first_surface", ""),
        "expected_artifact": move.get("expected_artifact", ""),
        "benchmark_gate": "benchmarks/run_standalone_control_bench.sh",
        "promotion_gate": "receipts + benchmark pass",
    }


def main() -> int:
    if not USER_GOVERNANCE_PATH.exists():
        raise SystemExit(f"user governance surface missing: {USER_GOVERNANCE_PATH}")

    governance = load_json(USER_GOVERNANCE_PATH)
    candidates = [build_candidate(move) for move in governance.get("next_moves", [])]
    candidates.sort(key=lambda item: (-item["priority_score"], item["candidate_id"]))

    registry = {
        "compiled_at": utc_now(),
        "source": str(USER_GOVERNANCE_PATH),
        "one_liner": "Product candidates are reduced delivery slices discovered from user data and ranked for bounded shipping work.",
        "rules": governance.get("governing_rules", []),
        "motif_rule": governance.get("motif_rule"),
        "candidate_count": len(candidates),
        "top_candidate_id": candidates[0]["candidate_id"] if candidates else None,
        "candidates": candidates,
    }

    BUILD_DIR.mkdir(parents=True, exist_ok=True)
    OUTPUT_PATH.write_text(json.dumps(registry, indent=2, sort_keys=True) + "\n", encoding="utf-8")
    print(OUTPUT_PATH)
    return 0


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