import type { OctopusConfig, ConsumptionParams, ConsumptionResponse } from "./types.js";
const OCTOPUS_API_BASE = "https://api.octopus.energy/v1";
const FETCH_TIMEOUT_MS = 30000;
export async function fetchConsumption(
config: OctopusConfig,
type: "electricity" | "gas",
params: ConsumptionParams
): Promise<ConsumptionResponse> {
if (!config.apiKey) {
throw new Error("OCTOPUS_API_KEY environment variable is not set");
}
// Use provided values or fall back to config
const identifier = type === "electricity"
? (params.mpan || config.electricityMpan)
: (params.mprn || config.gasMprn);
const serialNumber = params.serialNumber ||
(type === "electricity" ? config.electricitySerialNumber : config.gasSerialNumber);
if (!identifier) {
throw new Error(
`${type === "electricity" ? "MPAN" : "MPRN"} is required for ${type} consumption. ` +
`Provide it as a parameter or set ${type === "electricity" ? "ELECTRICITY_MPAN" : "GAS_MPRN"} in your .env file.`
);
}
if (!serialNumber) {
throw new Error(
`Serial number is required for ${type} consumption. ` +
`Provide it as a parameter or set ${type === "electricity" ? "ELECTRICITY_SERIAL_NUMBER" : "GAS_SERIAL_NUMBER"} in your .env file.`
);
}
const endpoint =
type === "electricity"
? `${OCTOPUS_API_BASE}/electricity-meter-points/${identifier}/meters/${serialNumber}/consumption/`
: `${OCTOPUS_API_BASE}/gas-meter-points/${identifier}/meters/${serialNumber}/consumption/`;
// Build query parameters
const queryParams = new URLSearchParams();
if (params.periodFrom) queryParams.append("period_from", params.periodFrom);
if (params.periodTo) queryParams.append("period_to", params.periodTo);
if (params.pageSize) queryParams.append("page_size", params.pageSize.toString());
if (params.orderBy) queryParams.append("order_by", params.orderBy);
if (params.groupBy) queryParams.append("group_by", params.groupBy);
const url = `${endpoint}${queryParams.toString() ? `?${queryParams.toString()}` : ""}`;
// Use Basic Auth with API key as username
const auth = Buffer.from(`${config.apiKey}:`).toString("base64");
let response: Response;
try {
response = await fetch(url, {
headers: {
Authorization: `Basic ${auth}`,
"Content-Type": "application/json",
},
signal: AbortSignal.timeout(FETCH_TIMEOUT_MS),
});
} catch (error) {
if (error instanceof DOMException && error.name === "TimeoutError") {
throw new Error(
`Request timed out after ${FETCH_TIMEOUT_MS / 1000} seconds querying ${type} meter ${identifier}`
);
}
throw error;
}
if (!response.ok) {
const errorText = await response.text();
throw new Error(
`Octopus Energy API error (${response.status}) querying ${type} meter ${identifier}: ${errorText}`
);
}
return await response.json();
}
