export default function distanceQuery(
    table: string,
    column1: string,
    column2: string,
    newColumn: string,
    options: {
        unit?: "m" | "km"
        method?: "srs" | "spheroid" | "haversine"
        decimals?: number
    } = {}
) {
    options.method = options.method ?? "srs"

    if (options.method === "srs" && typeof options.unit === "string") {
        throw new Error(
            "Using the SRS unit. You can't specify options.unit unless you set options.method to 'spheroid' or 'haversine'."
        )
    } else if (["spheroid", "haversine"].includes(options.method)) {
        options.unit = options.unit ?? "m"
        if (!["m", "km"].includes(options.unit)) {
            throw new Error(
                `Unknown unit ${options.unit}. Choose between 'm' and 'km'.`
            )
        }
    }

    let query = `ALTER TABLE ${table} ADD ${newColumn} DOUBLE; UPDATE ${table} SET ${newColumn} = `

    if (options.method === "srs") {
        if (typeof options.decimals === "number") {
            query += `ROUND(ST_Distance(${column1}, ${column2}), ${options.decimals})`
        } else {
            query += `ST_Distance(${column1}, ${column2})`
        }
    } else if (options.method === "haversine") {
        if (typeof options.decimals === "number") {
            query += `ROUND(ST_Distance_Sphere(${column1}, ${column2}) ${options.unit === "km" ? "/ 1000" : ""}, ${options.decimals});`
        } else {
            query += `ST_Distance_Sphere(${column1}, ${column2}) ${options.unit === "km" ? "/ 1000" : ""};`
        }
    } else if (options.method === "spheroid") {
        if (typeof options.decimals === "number") {
            query += `ROUND(ST_Distance_Spheroid(${column1}, ${column2}) ${options.unit === "km" ? "/ 1000" : ""}, ${options.decimals});`
        } else {
            query += `ST_Distance_Spheroid(${column1}, ${column2}) ${options.unit === "km" ? "/ 1000" : ""};`
        }
    } else {
        throw new Error(
            `Uknown method ${options.method}. Choose between 'srs', 'haversine' and 'spheroid'.`
        )
    }

    return query
}