from __future__ import annotations

from typing import Any

from .auth import find_project_config, resolve_project_token
from .http_client import request_json
from .protocols import MODBUS_SPEC
from .protocols.modbus import MODBUS_POINT_TYPE_ALIASES, MODBUS_REGISTER_TYPE_ALIASES


def _merge_defaults(defaults: dict[str, Any], payload: dict[str, Any]) -> dict[str, Any]:
    merged = dict(defaults)
    merged.update(payload)
    return merged


def _require_non_empty_text(payload: dict[str, Any], field_name: str) -> str:
    value = str(payload.get(field_name) or "").strip()
    if not value:
        raise ValueError(f"payload.{field_name} is required")
    return value


def _require_present(payload: dict[str, Any], field_name: str) -> Any:
    if field_name not in payload or payload.get(field_name) is None:
        raise ValueError(f"payload.{field_name} is required")
    return payload[field_name]


def _normalize_modbus_device_payload(payload: dict[str, Any]) -> dict[str, Any]:
    normalized = dict(payload)

    normalized["name"] = _require_non_empty_text(normalized, "name")
    normalized["ip"] = _require_non_empty_text(normalized, "ip")
    _require_present(normalized, "device_type")
    _require_present(normalized, "port")
    _require_present(normalized, "slave_id")
    _require_present(normalized, "word_order")
    _require_present(normalized, "byte_order")
    address_base = _require_present(normalized, "address_base")
    normalized["address_offset"] = address_base
    normalized.pop("address_base", None)

    return normalized


def _normalize_modbus_point_payload(payload: dict[str, Any]) -> dict[str, Any]:
    normalized = dict(payload)

    normalized["name"] = _require_non_empty_text(normalized, "name")
    _require_present(normalized, "address")

    raw_type = _require_non_empty_text(normalized, "type")
    normalized_type = MODBUS_POINT_TYPE_ALIASES.get(raw_type)
    if normalized_type is None:
        normalized_type = MODBUS_POINT_TYPE_ALIASES.get(raw_type.lower())
    if normalized_type is None:
        raise ValueError(
            "payload.type is invalid; use one of bool, int16, uint16, int32, "
            "uint32, int64, uint64, float32, float64, or a documented alias "
            "such as SHORT, WORD, LONG, DWORD, FLOAT, DOUBLE"
        )
    normalized["type"] = normalized_type

    if normalized.get("func_code") is None:
        register_type = _require_non_empty_text(normalized, "register_type")
        func_code = MODBUS_REGISTER_TYPE_ALIASES.get(register_type)
        if func_code is None:
            func_code = MODBUS_REGISTER_TYPE_ALIASES.get(register_type.lower())
        if func_code is None:
            raise ValueError(
                "payload.register_type is invalid; use coil, discrete_input, "
                "holding_register, input_register, or func_code 1/2/3/4"
            )
        normalized["func_code"] = func_code
    else:
        try:
            normalized["func_code"] = int(str(normalized["func_code"]).strip())
        except Exception as exc:
            raise ValueError("payload.func_code must be one of 1, 2, 3, 4") from exc
        if normalized["func_code"] not in {1, 2, 3, 4}:
            raise ValueError("payload.func_code must be one of 1, 2, 3, 4")

    if "register_type" in normalized:
        normalized.pop("register_type")

    return normalized


def _request_collector(
    project_key: str,
    method: str,
    path: str,
    *,
    json_payload: dict[str, Any] | None = None,
) -> dict[str, Any]:
    project = find_project_config(project_key)
    authorization = resolve_project_token(project)
    response_payload = request_json(
        method,
        f"{project['data_collector_base_url']}{path}",
        authorization,
        json_payload=json_payload,
    )
    if not isinstance(response_payload, dict):
        raise ValueError(f"collector API returned invalid payload for {path}: {response_payload}")
    return response_payload


def create_modbus_device(project_key: str, payload: dict[str, Any]) -> dict[str, Any]:
    return _request_collector(
        project_key,
        "POST",
        MODBUS_SPEC.create_device_path,
        json_payload=_merge_defaults(
            MODBUS_SPEC.device_defaults,
            _normalize_modbus_device_payload(payload),
        ),
    )


def create_modbus_point(project_key: str, payload: dict[str, Any]) -> dict[str, Any]:
    return _request_collector(
        project_key,
        "POST",
        MODBUS_SPEC.create_point_path,
        json_payload=_merge_defaults(
            MODBUS_SPEC.point_defaults,
            _normalize_modbus_point_payload(payload),
        ),
    )


def list_devices(project_key: str, num_points: bool = False) -> dict[str, Any]:
    num_points_text = "true" if num_points else "false"
    return _request_collector(
        project_key,
        "GET",
        f"/api/collector/device?num_points={num_points_text}",
    )