import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;

public class FundOverlap {
    public static void main(String[] args) throws Exception {
        // Read both funds' files; each has the date of its own issuer's file
        var http = HttpClient.newHttpClient();
        Map<String, JsonObject> funds = new LinkedHashMap<>();
        for (String ticker : List.of("VOO", "QQQ")) {
            var request = HttpRequest.newBuilder(URI.create(
                    "https://tickerinside.com/api/v1/fund/"
                    + ticker.toLowerCase(Locale.ROOT) + ".json"))
                .header("User-Agent", "MyProject/1.0 (+https://example.com)")
                .build();
            var response = http.send(request,
                HttpResponse.BodyHandlers.ofString());
            if (response.statusCode() != 200) {
                throw new RuntimeException("HTTP " + response.statusCode());
            }
            JsonObject fund = JsonParser.parseString(response.body())
                .getAsJsonObject();
            funds.put(ticker, fund);
            System.out.println(ticker + " holdings_as_of "
                + fund.get("holdings_as_of").getAsString());
        }

        // Overlap by weight, as the site computes it: for every ticker both
        // funds hold, add the smaller of its two weights
        JsonObject a = funds.get("VOO").getAsJsonObject("holdings");
        JsonObject b = funds.get("QQQ").getAsJsonObject("holdings");
        double overlap = 0;
        int shared = 0;
        for (String t : a.keySet()) {
            if (b.has(t)) {
                overlap += Math.min(a.get(t).getAsDouble(),
                                    b.get(t).getAsDouble());
                shared++;
            }
        }
        System.out.println(String.format(Locale.ROOT,
            "overlap by weight %.1f%%, %d companies in both", overlap, shared));

        // The lines to print under the figure, one per fund file
        for (JsonObject fund : funds.values()) {
            System.out.println(fund.get("cite_as").getAsString());
        }
    }
}