"""Atomically hand generated data to the next process."""

import hashlib
import json
import os
import tempfile
from pathlib import Path


def write_contract(path, payload):
    path = Path(path)
    data = json.dumps(payload, ensure_ascii=False, indent=2).encode("utf-8")
    expected = {"bytes": len(data), "sha256": hashlib.sha256(data).hexdigest()}
    try:
        fd, temporary = tempfile.mkstemp(
            prefix=path.name + ".", suffix=".tmp", dir=path.parent
        )
    except OSError as exc:
        raise ValueError(f"contract write incomplete: {path}: {exc}") from exc
    temporary = Path(temporary)
    try:
        try:
            with os.fdopen(fd, "wb") as stream:
                written = stream.write(data)
                if written != len(data):
                    raise ValueError(
                        f"contract write incomplete: {path}: "
                        f"expected {expected}, write returned {written}"
                    )
        except OSError as exc:
            raise ValueError(
                f"contract write incomplete: {path}: expected {expected}: "
                f"{exc}"
            ) from exc
        try:
            saved = temporary.read_bytes()
            if saved != data:
                actual = {
                    "bytes": len(saved),
                    "sha256": hashlib.sha256(saved).hexdigest(),
                }
                raise ValueError(
                    f"contract saved content mismatch: {path}: "
                    f"expected {expected}, actual {actual}"
                )
            os.replace(temporary, path)
        except OSError as exc:
            raise ValueError(
                f"contract saved content mismatch: {path}: {exc}"
            ) from exc
    finally:
        temporary.unlink(missing_ok=True)
    return expected


def verify_contract(path, expected):
    path = Path(path)
    try:
        data = path.read_bytes()
    except OSError as exc:
        raise ValueError(
            f"contract changed before consumer: {path}: {exc}"
        ) from exc
    actual = {"bytes": len(data), "sha256": hashlib.sha256(data).hexdigest()}
    if actual != expected:
        raise ValueError(
            f"contract changed before consumer: {path}: "
            f"expected {expected}, actual {actual}"
        )
    return data


def alphabet_report(result):
    """Record an already generated result without font/catalog access.
    """
    from copy import deepcopy

    return deepcopy(result)