from __future__ import annotations

import json
import math
from dataclasses import dataclass
from typing import Any


class RemoteApiError(ValueError):
    def __init__(self, message: str, *, status: int = 400) -> None:
        super().__init__(message)
        self.status = status


@dataclass(frozen=True, slots=True)
class RemoteResponse:
    status: int
    body: bytes
    content_type: str = "application/json"
    headers: dict[str, str] | None = None


def json_response(payload: dict[str, Any], *, status: int = 200) -> RemoteResponse:
    return RemoteResponse(
        status=status,
        body=json.dumps(payload, separators=(",", ":")).encode("utf-8"),
        content_type="application/json",
    )


def error_response(message: str, *, status: int = 400) -> RemoteResponse:
    return json_response({"ok": False, "error": message}, status=status)


def media_response(body: bytes, content_type: str, *, cache_seconds: int = 86400) -> RemoteResponse:
    return RemoteResponse(
        status=200,
        body=body,
        content_type=content_type,
        headers={"Cache-Control": f"private, max-age={max(0, int(cache_seconds))}"},
    )


def bounded_text(value: Any, *, max_length: int, label: str, required: bool = False) -> str:
    if value is None:
        value = ""
    if not isinstance(value, str):
        value = str(value)
    text = value.strip()
    if required and not text:
        raise RemoteApiError(f"{label} is required.")
    if len(text) > max_length:
        raise RemoteApiError(f"{label} must be {max_length} characters or shorter.")
    return text


def bounded_int(
    value: Any,
    *,
    minimum: int,
    maximum: int,
    default: int,
    label: str,
) -> int:
    if value in (None, ""):
        return default
    try:
        if isinstance(value, bool):
            raise ValueError
        number = int(value)
    except (TypeError, ValueError) as exc:
        raise RemoteApiError(f"{label} must be a whole number.") from exc
    if number < minimum or number > maximum:
        raise RemoteApiError(f"{label} must be between {minimum} and {maximum}.")
    return number


def bounded_float(
    value: Any,
    *,
    minimum: float,
    maximum: float,
    default: float,
    label: str,
) -> float:
    if value in (None, ""):
        return default
    try:
        if isinstance(value, bool):
            raise ValueError
        number = float(value)
    except (TypeError, ValueError) as exc:
        raise RemoteApiError(f"{label} must be a number.") from exc
    if not math.isfinite(number) or number < minimum or number > maximum:
        raise RemoteApiError(f"{label} must be between {minimum:g} and {maximum:g}.")
    return number


def parse_pagination(query: dict[str, list[str]], *, default_size: int = 24, max_size: int = 80) -> dict[str, int]:
    page = bounded_int(
        (query.get("page") or ["1"])[0],
        minimum=1,
        maximum=1_000_000,
        default=1,
        label="Page",
    )
    page_size = bounded_int(
        (query.get("page_size") or [str(default_size)])[0],
        minimum=1,
        maximum=max_size,
        default=default_size,
        label="Page size",
    )
    return {
        "page": page,
        "page_size": page_size,
        "offset": (page - 1) * page_size,
        "limit": page_size,
    }


def coerce_json_object(payload: Any) -> dict[str, Any]:
    if not isinstance(payload, dict):
        raise RemoteApiError("Send a JSON object.")
    return payload


def sanitized_arguments(arguments: dict[str, Any]) -> dict[str, Any]:
    """Return client-safe arguments without absolute filesystem paths."""
    hidden = {
        "dataset_dir",
        "output_dir",
        "model_path",
        "base_model",
        "base_model_path",
        "resume_from",
        "reference_image",
    }
    clean: dict[str, Any] = {}
    for key, value in arguments.items():
        if key in hidden:
            text = str(value or "")
            clean[f"{key}_name"] = text.replace("\\", "/").rstrip("/").rsplit("/", 1)[-1] if text else ""
            continue
        if isinstance(value, (str, int, float, bool)) or value is None:
            clean[key] = value
    return clean