"""Result envelope and JSON/human output writer."""

from __future__ import annotations

import json
import sys
from dataclasses import dataclass, field
from typing import Any


@dataclass
class Result:
    """Structured result for a CLI command."""

    command: str
    ok: bool = True
    status: str = "ok"
    version: str | None = None
    data: dict[str, Any] = field(default_factory=dict)
    error_code: str | None = None
    error_message: str | None = None

    def to_envelope(self) -> dict[str, Any]:
        env: dict[str, Any] = {
            "ok": self.ok,
            "command": self.command,
        }
        if self.version is not None:
            env["version"] = self.version
        env["status"] = self.status
        if self.ok:
            for k, v in self.data.items():
                env[k] = v
        else:
            env["error"] = {
                "code": self.error_code or "error",
                "message": self.error_message or "",
            }
        return env


def write_result(result: Result, *, json_mode: bool, human_summary: str | None = None) -> None:
    """Emit the result.

    When json_mode is True: only JSON on stdout.
    When json_mode is False: human summary on stderr, JSON on stdout.
    """
    envelope = result.to_envelope()
    if not json_mode and human_summary:
        print(human_summary, file=sys.stderr)
    json.dump(envelope, sys.stdout, indent=2, sort_keys=False)
    sys.stdout.write("\n")
    sys.stdout.flush()