/*
 * Helpdesk Dialer patch — call-lifecycle webhook emitter.
 * Part of the com.android.dialer.helpdesk overlay (see components/dialer-patch).
 */
package com.android.dialer.helpdesk;

import android.telecom.DisconnectCause;
import android.telecom.TelecomManager;
import com.android.dialer.helpdesk.util.CzE164;
import com.android.incallui.call.CallList;
import com.android.incallui.call.DialerCall;
import com.android.incallui.call.state.DialerCallState;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
import org.json.JSONException;
import org.json.JSONObject;

/**
 * A {@link CallList.Listener} that emits the three device→backend call webhooks: mints the
 * {@code call_id} at RINGING and fires {@code /calls/incoming}; detects the ACTIVE edge in
 * {@code onCallListChange} and fires {@code /calls/answered}; fires {@code /calls/ended} on disconnect
 * with duration + {@link DisconnectCause}. All emission is enqueued on {@link HelpdeskDispatcher} — it
 * never blocks the Telecom callback thread. This is the single emitter (one webhook per event).
 */
public final class CallEventEmitter implements CallList.Listener {

  private final CallIdRegistry registry;
  private final HelpdeskDispatcher dispatcher;

  public CallEventEmitter(CallIdRegistry registry, HelpdeskDispatcher dispatcher) {
    this.registry = registry;
    this.dispatcher = dispatcher;
  }

  @Override
  public void onIncomingCall(DialerCall call) {
    CallIdRegistry.Entry e = registry.forCall(call.getId());
    e.startReported = true; // inbound start announced here; the outbound-edge loop must not double-fire
    JSONObject b = new JSONObject();
    try {
      b.put("call_id", e.callId);
      b.put("ts", isoNow());
      String num = CzE164.normalize(call.getNumber());
      b.put("number", num == null ? JSONObject.NULL : num);
      b.put("presentation", presentation(call.getNumberPresentation()));
      b.put("device_id", HelpdeskConfig.deviceId());
      // dialed_did (which of our DIDs was called) is not always available on inbound; the backend
      // tolerates its absence and resolves the operator server-side when present.
    } catch (JSONException ignored) {
      // JSONObject.put only throws on a NaN/Infinity double; none used here.
    }
    dispatcher.enqueuePost(e.callId + ":incoming", "/calls/incoming", b.toString());
  }

  @Override
  public void onCallListChange(CallList callList) {
    // Outbound start edge. CallList.Listener has no onOutgoingCall() — an operator-placed call only ever
    // surfaces here, in DIALING/CONNECTING. Mint the call_id and fire /calls/outgoing once, before it
    // goes ACTIVE, so the console screen-pops the callee (with history) exactly like an inbound call.
    // Recording, /calls/answered and /calls/ended already cover outbound unchanged (they don't look at
    // direction), so this webhook is the only outbound-specific emission.
    for (DialerCall call : callList.getAllCalls()) {
      int state = call.getState();
      if (state != DialerCallState.DIALING && state != DialerCallState.CONNECTING) {
        continue;
      }
      CallIdRegistry.Entry e = registry.forCall(call.getId());
      if (e.startReported) {
        continue;
      }
      e.startReported = true;
      JSONObject ob = new JSONObject();
      try {
        ob.put("call_id", e.callId);
        ob.put("ts", isoNow());
        String num = CzE164.normalize(call.getNumber());
        ob.put("number", num == null ? JSONObject.NULL : num);
        ob.put("device_id", HelpdeskConfig.deviceId());
      } catch (JSONException ignored) {
      }
      dispatcher.enqueuePost(e.callId + ":outgoing", "/calls/outgoing", ob.toString());
    }

    // Fire the ACTIVE edge PER CALL, not just for getActiveCall() (the FIRST active call). With a second
    // call answered from the PC while another is still ACTIVE, getActiveCall() returns the first and the
    // second call's /calls/answered would be silently dropped (leaving it 'ringing' until the watchdog).
    // The per-Entry answeredReported flag keeps each call's edge once-only.
    for (DialerCall call : callList.getAllCalls()) {
      if (call.getState() != DialerCallState.ACTIVE) {
        continue;
      }
      CallIdRegistry.Entry e = registry.forCall(call.getId());
      if (e.answeredReported) {
        continue;
      }
      e.answeredReported = true;
      JSONObject b = new JSONObject();
      try {
        b.put("call_id", e.callId);
        b.put("ts", isoNow());
      } catch (JSONException ignored) {
      }
      dispatcher.enqueuePost(e.callId + ":answered", "/calls/answered", b.toString());
    }
  }

  @Override
  public void onDisconnect(DialerCall call) {
    CallIdRegistry.Entry e = registry.forCall(call.getId());
    JSONObject b = new JSONObject();
    try {
      b.put("call_id", e.callId);
      b.put("ts", isoNow());
      long connect = call.getConnectTimeMillis();
      long durationS = connect > 0 ? Math.max(0, (System.currentTimeMillis() - connect) / 1000L) : 0L;
      b.put("duration_s", durationS);
      b.put("disconnect_cause", disconnectCause(call));
      b.put("recording_uuid", e.recordingUuid == null ? JSONObject.NULL : e.recordingUuid);
    } catch (JSONException ignored) {
    }
    dispatcher.enqueuePost(e.callId + ":ended", "/calls/ended", b.toString());
    registry.remove(call.getId());
  }

  // ---- presentation / disconnect mapping to the backend's enums ----

  private static String presentation(int p) {
    switch (p) {
      case TelecomManager.PRESENTATION_ALLOWED:
        return "allowed";
      case TelecomManager.PRESENTATION_RESTRICTED:
        return "restricted";
      case TelecomManager.PRESENTATION_PAYPHONE:
        return "payphone";
      default:
        return "unknown";
    }
  }

  private static String disconnectCause(DialerCall call) {
    DisconnectCause dc = call.getDisconnectCause();
    if (dc == null) {
      return "unknown";
    }
    switch (dc.getCode()) {
      case DisconnectCause.LOCAL:
        return "local";
      case DisconnectCause.REMOTE:
        return "remote";
      case DisconnectCause.MISSED:
        return "missed";
      case DisconnectCause.REJECTED:
        return "rejected";
      case DisconnectCause.ERROR:
        return "error";
      default:
        return "unknown";
    }
  }

  private static String isoNow() {
    SimpleDateFormat f = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.US);
    f.setTimeZone(TimeZone.getTimeZone("UTC"));
    return f.format(new Date());
  }

  // ---- unused CallList.Listener methods (no-ops) ----

  @Override
  public void onUpgradeToVideo(DialerCall call) {}

  @Override
  public void onSessionModificationStateChange(DialerCall call) {}

  @Override
  public void onWiFiToLteHandover(DialerCall call) {}

  @Override
  public void onHandoverToWifiFailed(DialerCall call) {}

  @Override
  public void onInternationalCallOnWifi(DialerCall call) {}
}