/*
 * Helpdesk Dialer patch — per-call correlation registry.
 * Part of the com.android.dialer.helpdesk overlay (see components/dialer-patch).
 */
package com.android.dialer.helpdesk;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.UUID;

/**
 * Maps a live {@code DialerCall} (by its Dialer id) to our correlation {@code call_id} (UUIDv4),
 * minted the first time the call is seen (at RINGING), plus per-call flags. The {@code call_id} is
 * the single key that stitches the webhooks, the recording upload, the transcript and the reverse
 * commands together. Thread-safe (touched from the Telecom/InCall callback thread).
 */
public final class CallIdRegistry {

  public static final class Entry {
    public final String callId = UUID.randomUUID().toString();
    // Helpdesk: the call's start edge was announced (/calls/incoming for inbound, /calls/outgoing for
    // outbound). Prevents re-firing the once-only start webhook on every onCallListChange tick.
    public volatile boolean startReported;
    public volatile boolean answeredReported;
    public volatile String recordingUuid;
  }

  private final ConcurrentHashMap<String, Entry> byDialerId = new ConcurrentHashMap<>();

  // Process-wide singleton. Shared by the in-call CallEventEmitter/RecordingBridge AND the always-on
  // HelpdeskCommandService poller, so a reverse command that arrives between calls (e.g. `dial`) and one
  // that arrives during a call (answer/mute/hold) both resolve against the same call_id <-> DialerCall map.
  private static final CallIdRegistry INSTANCE = new CallIdRegistry();

  public static CallIdRegistry get() {
    return INSTANCE;
  }

  /** Get-or-create the entry, minting the call_id on first sight. */
  public Entry forCall(String dialerId) {
    return byDialerId.computeIfAbsent(dialerId, k -> new Entry());
  }

  public Entry peek(String dialerId) {
    return byDialerId.get(dialerId);
  }

  public void remove(String dialerId) {
    byDialerId.remove(dialerId);
  }

  /** Reverse lookup: the DialerCall id for our correlation call_id (used to apply reverse commands). */
  public String dialerIdForCallId(String callId) {
    if (callId == null) {
      return null;
    }
    for (Map.Entry<String, Entry> e : byDialerId.entrySet()) {
      if (callId.equals(e.getValue().callId)) {
        return e.getKey();
      }
    }
    return null;
  }
}