import { ValidationError } from "../errors";
import { validate as uuidlibValidate, version as uuidlibVersion } from 'uuid'

export function validatePisCode(code: unknown): boolean {
    if (typeof code == "number") {
        code = code.toString();
    }
    if (typeof code !== "string") {
        throw new ValidationError("Invalid input: code must be a four digit number or string")
    }
    const codeRegex = /^\d{4}$/;
    if (!codeRegex.test(code)) {
        throw new ValidationError("Invalid input: code must be a four-character string consisting of only numerals");
    }
    return true;
}

export function validateTiploc(tiploc: unknown): boolean {
    if (typeof tiploc !== "string") {
        throw new ValidationError("Invalid input: TIPLOC must be a string");
    }
    const tiplocRegex = /[a-zA-Z0-9]{4,7}/;
    if (!tiplocRegex.test(tiploc)) {
        throw new ValidationError("Invalid input: TIPLOC must be between four and seven characters");
    }
    return true;
}

export function validateCrs(crs: unknown): boolean {
    if (typeof crs !== "string") {
        throw new ValidationError("Invalid input: CRS/3ALPHA must be a string")
    }

    const crsRegex = /^[a-zA-Z]{3}$/;
    if (!crsRegex.test(crs)) {
        throw new ValidationError("Invalid input: CRS/3ALPHA must be exactly three letters")
    }
    return true;
}

export function validateNlc(nlc: unknown): boolean {
    if (typeof nlc === "string") {
        if (!/^\d{6}$/.test(nlc)) {
            throw new ValidationError("Invalid input: NLC must be a 6 digit number (or a string representation)");
        }
        return true;
    }
    if (typeof nlc === "number") {
        if (!Number.isInteger(nlc) || nlc < 100000 || nlc > 999999) {
            throw new ValidationError("Invalid input: NLC must be a 6 digit number (or a string representation)");
        }
        return true;
    }
    
    // If not a string or number, throw ValidationError
    throw new ValidationError("Invalid input: NLC must be a 6 digit number (or string representation");
}

export function validateStanox(stanox: unknown): boolean {
    if (typeof stanox === "string") {
        if (!/^\d{5}$/.test(stanox)) {
            throw new ValidationError("Invalid input: STANOX must be a 5 digit number (or a string representation)");
        }
        return true;
    }
    if (typeof stanox === "number") {
        if (!Number.isInteger(stanox) || stanox < 10000 || stanox > 99999) {
            throw new ValidationError("Invalid input: STANOX must be a 5 digit number (or a string representation");
        }
        return true;
    }

    // If not a string or number, throw ValidationError
    throw new ValidationError("Invalid input: STANOX must be a 5 digit numer (or a string representation)");
}

export function validateUuid(uuid: unknown): boolean {
    if (typeof uuid !== "string") {
        throw new ValidationError("Invalid input: The UUID/api_key should be a string");
    }
    if (!uuidlibValidate(uuid)) {
        throw new ValidationError("Invalid input: The UUID/api_key is the expexted value")
    }
    return true;
}

export function validateStation(station: unknown): boolean {
    if (typeof station !== "string") {
        throw new ValidationError("Invalid input: The station name should be a string");
    }
    if (!/^[A-Za-z0-9\s&'()-]+$/.test(station)) {
        throw new ValidationError("Invalid input: Station name should include letters, spaces, ', '/', '-', '&' only");
    }
    return true;
}

export function validateReasonCode(code: unknown): boolean {
    if (typeof code === "number") {
        // Ensure it's a 3-digit number (100-999)
        if (!Number.isInteger(code) || code < 100 || code > 999) {
            throw new ValidationError("Invalid input: Reason code must be a three-digit number (100-999).");
        }
        return true;
    }

    if (typeof code === "string") {
        // Ensure it consists of exactly 3 numeric characters
        if (!/^\d{3}$/.test(code)) {
            throw new ValidationError("Invalid input: Reason code must be a string of three digits.");
        }
        return true;
    }

    // If it's neither a number nor a string, throw an error
    throw new ValidationError("Invalid input: Reason code must be a number or a string of three digits.");
}

export function validateHeadcode(headcode: unknown): boolean {
    if (typeof headcode !== "string") {
        throw new ValidationError("Invalid input: Headcode must be a string");
    }

    if (!/^\d[A-Za-z]\d{2}$/.test(headcode)) {
        throw new ValidationError("Invalid input: Headcode must be in the format dLdd where d=digit and L=letter");
    }
    return true;
}