"""Source-derived FeatureScript operation coverage inventory.

The registry records what the current source corpus actually contains.  It is
deliberately independent from conversion diagnostics: an old output directory
cannot make an operation appear supported, and a planned operation cannot be
reported as observed merely because its name is listed in the roadmap.
"""

from __future__ import annotations

from collections import Counter, defaultdict
from pathlib import Path
from typing import Any, Iterable

from .dataset import Sample
from .featurescript_parser import parse_featurescript


REGISTRY_SCHEMA = "cadfs_to_cdsl.operation_registry.v1"

# These are roadmap work items, not parser aliases or support declarations.
P3_OPERATION_WORK_ITEMS = (
    "draft",
    "thicken",
    "split",
    "moveFace",
    "deleteFace",
    "replaceFace",
    "transform",
    "derive",
    "import",
    "bend_add",
)


def build_operation_registry(samples: Iterable[Sample]) -> dict[str, Any]:
    """Parse every available FeatureScript source and inventory feature calls.

    Parse failures and missing FeatureScript modalities are recorded separately
    instead of being treated as a zero-count result.  Sample examples remain
    bounded only for report size; the count is computed from every feature.
    """
    counts: Counter[str] = Counter()
    sample_ids: dict[str, set[str]] = defaultdict(set)
    parse_failures: list[dict[str, str]] = []
    source_sample_count = 0

    for sample in samples:
        source_path = sample.files.get("featurescript")
        if not source_path:
            continue
        source_sample_count += 1
        try:
            model = parse_featurescript(Path(source_path).read_text(encoding="utf-8"), sample.sample_id)
        except Exception as error:
            parse_failures.append({"sample_id": sample.sample_id, "error": f"{type(error).__name__}: {error}"})
            continue
        for feature in model.features:
            counts[feature.operation] += 1
            sample_ids[feature.operation].add(sample.sample_id)

    operations: dict[str, dict[str, Any]] = {}
    for operation in sorted(counts):
        operations[operation] = {
            "state": "observed",
            "feature_count": counts[operation],
            "sample_count": len(sample_ids[operation]),
            "sample_ids": sorted(sample_ids[operation]),
        }
    for operation in P3_OPERATION_WORK_ITEMS:
        if operation in operations:
            operations[operation]["roadmap_work_item"] = True
        else:
            operations[operation] = {
                "state": "not_observed_in_current_source",
                "feature_count": 0,
                "sample_count": 0,
                "sample_ids": [],
                "roadmap_work_item": True,
            }

    return {
        "schema": REGISTRY_SCHEMA,
        "source_sample_count": source_sample_count,
        "parse_failure_count": len(parse_failures),
        "parse_failures": parse_failures,
        "operations": operations,
    }