"""Versioned journey registry and mandatory collected-test coverage validation."""

import json
from pathlib import Path

ROOT = Path(__file__).resolve().parents[2]
REGISTRY = ROOT / "docs/usecases/registry.json"


def load_cases():
    data = json.loads(REGISTRY.read_text(encoding="utf-8"))
    if data.get("schema_version") != 1 or not isinstance(data.get("cases"), list):
        raise ValueError("Unsupported use-case registry schema")
    cases = data["cases"]
    if not cases:
        raise ValueError("The use-case registry cannot be empty")
    ids = set()
    for case in cases:
        uid = case["id"]
        if uid in ids:
            raise ValueError(f"Duplicate use-case id: {uid}")
        ids.add(uid)
        if case["confirmation"] not in {"inferred", "observed", "user-confirmed"}:
            raise ValueError(f"Unknown confirmation for {uid}")
        if case["transfer_status"] not in {"pending-user-review", "accepted", "deferred"}:
            raise ValueError(f"Unknown transfer status for {uid}")
        if case["transfer_status"] == "accepted" and not case.get("acceptance_ref"):
            raise ValueError(f"Accepted case {uid} needs a user acceptance reference")
        for field in ("narrative", "fixture"):
            path = (ROOT / case[field]).resolve()
            if not path.is_relative_to(ROOT) or not path.is_file():
                raise ValueError(f"Missing or outside-repo {field} for {uid}")
        fixture = json.loads((ROOT / case["fixture"]).read_text(encoding="utf-8"))
        if fixture.get("synthetic") is not True or fixture.get("usecase_id") != uid:
            raise ValueError(f"Fixture must be synthetic and linked to {uid}")
        if not isinstance(case["established"], bool):
            raise ValueError(f"established must be a boolean for {uid}")
        if set(case["tests"]) != {"fast", "browser"}:
            raise ValueError(f"Expected fast and browser test layers for {uid}")
        if case["established"]:
            if case["confirmation"] != "user-confirmed" or not case["contract"]:
                raise ValueError(f"Established case {uid} needs user confirmation and contract")
            for layer in ("fast", "browser"):
                if not case["tests"].get(layer):
                    raise ValueError(f"Established case {uid} missing {layer} coverage")
    return cases


def validate_coverage(cases, collected):
    """Require exact node IDs, UC marker, and correct fast/browser layer."""
    ids = {case["id"] for case in cases}
    for nodeid, markers in collected.items():
        if markers["usecases"] - ids:
            raise ValueError(f"Use-case test has an unregistered ID: {nodeid}")
    for case in cases:
        if not case["established"]:
            continue
        for layer, nodeids in case["tests"].items():
            for nodeid in nodeids:
                markers = collected.get(nodeid)
                if markers is None:
                    raise ValueError(f"{case['id']} missing collected {layer} test: {nodeid}")
                if case["id"] not in markers["usecases"]:
                    raise ValueError(f"{nodeid} is not marked for {case['id']}")
                if markers.get("disabled"):
                    raise ValueError(f"Protected use-case test cannot skip/xfail: {nodeid}")
                if markers["browser"] != (layer == "browser"):
                    raise ValueError(f"Wrong regression layer for {nodeid}")