package vn.sis.appointment;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

final class TokenJsonParser {
    private static final Pattern ACCESS_TOKEN = Pattern.compile(
            "\\\"access_token\\\"\\s*:\\s*\\\"([^\\\"]+)\\\"");
    private static final Pattern TOKEN_TYPE = Pattern.compile(
            "\\\"token_type\\\"\\s*:\\s*\\\"([^\\\"]*)\\\"");
    private static final Pattern EXPIRES_IN = Pattern.compile(
            "\\\"expires_in\\\"\\s*:\\s*(\\d+)");

    private TokenJsonParser() {
    }

    static ParsedToken parse(String json) {
        String accessToken = group(ACCESS_TOKEN, json);
        if (accessToken == null || accessToken.isBlank()) {
            throw new IllegalArgumentException("API token khong tra ve access_token hop le.");
        }
        String tokenType = group(TOKEN_TYPE, json);
        String expiresText = group(EXPIRES_IN, json);
        long expiresIn = expiresText == null ? 3600 : Long.parseLong(expiresText);
        return new ParsedToken(accessToken, tokenType == null ? "Bearer" : tokenType, expiresIn);
    }

    private static String group(Pattern pattern, String text) {
        Matcher matcher = pattern.matcher(text == null ? "" : text);
        return matcher.find() ? matcher.group(1) : null;
    }

    record ParsedToken(String accessToken, String tokenType, long expiresIn) {
    }
}