package com.ruoyi.shadow.startup;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.ruoyi.shadow.config.ShadowProperties;
import com.ruoyi.shadow.kernel.ShadowDispatchSnapshotAssembler;
import com.ruoyi.shadow.evidence.ShadowInputPayloadCodec;
import org.springframework.core.env.Environment;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.util.Collections;
import java.util.Locale;
import java.util.Map;
import java.util.TreeMap;

/** Identifies this source revision and the nonsecret dispatch/storage settings, not a built artifact. */
public final class ShadowRuntimeIdentity {
    public static final String BUILD_ID = "ft546-shadow-20260910-source-recovery-v1";
    private ShadowRuntimeIdentity() { }

    public static Map<String, Object> describe(ShadowProperties properties, Environment env) {
        Map<String, Object> settings = new TreeMap<String, Object>();
        settings.put("enabled", properties.isEnabled());
        settings.put("cycleDeadlineMillis", env.getProperty("shadow.cycle.deadline-ms", Long.class, 10000L));
        settings.put("pollDelayMillis", env.getProperty("shadow.poll.fixed-delay-ms", Long.class, 5000L));
        settings.put("initialDelayMillis", env.getProperty("shadow.poll.initial-delay-ms", Long.class, 5000L));
        settings.put("maximumDatabaseBytes", properties.getEvidence().getMaximumDatabaseBytes());
        settings.put("maximumBatchPayloadBytes", properties.getEvidence().getMaximumBatchPayloadBytes());
        settings.put("minimumFreeBytes", properties.getEvidence().getMinimumFreeBytes());
        settings.put("statusAddress", env.getProperty("server.address", "127.0.0.1"));
        settings.put("statusPort", env.getProperty("server.port", Integer.class, 18091));
        settings.put("safeWaitSites", ShadowDispatchSnapshotAssembler.safeSites(properties.getTraffic().getSafeWaitSites()));
        settings.put("safeYieldSites", ShadowDispatchSnapshotAssembler.safeSites(properties.getTraffic().getSafeYieldSites()));
        settings.put("inputStorageFormat", ShadowInputPayloadCodec.GZIP);
        Map<String, Object> result = new TreeMap<String, Object>();
        result.put("buildId", BUILD_ID);
        result.put("effectiveSettings", Collections.unmodifiableMap(settings));
        result.put("effectiveSettingsSha256", digest(settings));
        result.put("identityScope", "SOURCE_BUILD_LABEL_AND_NONSECRET_DISPATCH_STORAGE_SETTINGS");
        result.put("operatorArtifactSha256", properties.getEvidence().getRun().getArtifactSha256());
        result.put("operatorConfigurationSha256", properties.getEvidence().getRun().getConfigurationSha256());
        result.put("safePointConfiguration", properties.getTraffic().getSafeWaitSites().isEmpty()
                && properties.getTraffic().getSafeYieldSites().isEmpty() ? "UNCONFIGURED" : "CONFIGURED_REQUIRES_TOPOLOGY_VALIDATION");
        return Collections.unmodifiableMap(result);
    }

    private static String digest(Map<String, Object> settings) {
        try {
            byte[] bytes = new ObjectMapper().writeValueAsString(settings).getBytes(StandardCharsets.UTF_8);
            StringBuilder result = new StringBuilder();
            for (byte b : MessageDigest.getInstance("SHA-256").digest(bytes))
                result.append(String.format(Locale.ROOT, "%02x", b & 255));
            return result.toString();
        } catch (Exception impossible) { throw new IllegalStateException("RUNTIME_IDENTITY_FAILED", impossible); }
    }
}