"""Bound diagnostic payloads without changing live message processing."""

from __future__ import annotations

import json
import os
from typing import Any


TRUNCATION_MARKER = "\n...[日志内容过长，已截断]"
_MESSAGE_FIELDS = (
    "type",
    "url",
    "uri",
    "text",
    "name",
    "width",
    "height",
    "duration",
    "sticker_id",
    "mime_type",
)


def _env_limit(name: str, default: int, minimum: int, maximum: int) -> int:
    try:
        value = int(os.getenv(name, str(default)) or default)
    except (TypeError, ValueError):
        value = default
    return max(minimum, min(maximum, value))


def truncate_text(value: Any, limit: int) -> str:
    text = "" if value is None else str(value)
    if len(text) <= limit:
        return text
    keep = max(0, limit - len(TRUNCATION_MARKER))
    return text[:keep] + TRUNCATION_MARKER


def bound_system_log_detail(value: Any) -> str:
    return truncate_text(
        value,
        _env_limit("KEFU_SYSTEM_LOG_MAX_CHARS", 4096, 512, 65536),
    )


def _compact_media_message(value: Any) -> Any:
    if not isinstance(value, dict):
        return truncate_text(value, 2048)
    compact: dict[str, Any] = {}
    for key in _MESSAGE_FIELDS:
        if key not in value:
            continue
        item = value[key]
        compact[key] = truncate_text(item, 2048) if isinstance(item, str) else item
    compact["_log_truncated"] = True
    return compact


def bound_message_log_content(value: Any) -> str:
    """Keep a valid compact media JSON payload when a log entry is oversized."""
    limit = _env_limit("KEFU_MESSAGE_LOG_MAX_CHARS", 16384, 2048, 262144)
    text = "" if value is None else str(value)
    if len(text) <= limit:
        return text

    try:
        parsed = json.loads(text)
    except (TypeError, ValueError, json.JSONDecodeError):
        return truncate_text(text, limit)

    if isinstance(parsed, dict) and parsed.get("type"):
        compact = _compact_media_message(parsed)
    elif isinstance(parsed, dict) and isinstance(parsed.get("messages"), list):
        compact = {
            "messages": [
                _compact_media_message(item)
                for item in parsed["messages"][:20]
            ],
            "_log_truncated": True,
        }
    else:
        return truncate_text(text, limit)

    encoded = json.dumps(compact, ensure_ascii=False, separators=(",", ":"))
    return encoded if len(encoded) <= limit else truncate_text(encoded, limit)


def bound_raw_message_log_content(value: Any) -> str:
    return truncate_text(
        value,
        _env_limit("KEFU_RAW_MESSAGE_LOG_MAX_CHARS", 32768, 4096, 262144),
    )


def bound_error_log_content(value: Any) -> str:
    return truncate_text(
        value,
        _env_limit("KEFU_ERROR_LOG_MAX_CHARS", 4096, 512, 65536),
    )