/*
 * Helpdesk Dialer patch — build/provisioning config.
 * Part of the com.android.dialer.helpdesk overlay (see components/dialer-patch).
 */
package com.android.dialer.helpdesk;

/**
 * Backend endpoint + device credentials for the helpdesk integration.
 *
 * <p>Values resolve in precedence order: {@code persist.helpdesk.<key>} (runtime-settable, survives
 * reboot) → {@code ro.helpdesk.<key>} (baked at build/provisioning time) → dev default. The dev defaults
 * match the backend prototype (components/backend) so a userdebug build talks to a local server out of
 * the box.
 *
 * <p>The {@code persist.*} tier exists so a flashed device can be pointed at a different backend
 * <em>without a rebuild</em> — {@code ro.*} is write-once at init, so on a dev build you'd otherwise have
 * to re-flash to change the URL. So bring-up is just
 * {@code adb shell setprop persist.helpdesk.base_url https://<host>:8443/api/v1} and a reboot (this is
 * how the production phone is pointed at moje.al.army's device door).
 * NOTE: setting {@code persist.helpdesk.*} on-device also needs a property_contexts entry granting the
 * setter domain access (the sepolicy-patch handles this); reading is unrestricted. For a fully locked
 * production build, bake {@code ro.helpdesk.*} into product build.prop instead.
 * TODO(provisioning): move the secret to Keystore-wrapped storage before the device is locked.
 */
public final class HelpdeskConfig {

  private HelpdeskConfig() {}

  public static String baseUrl() {
    // Precedence: explicit override (persist.* runtime / ro.* build) → mDNS-discovered backend on the LAN
    // (no hardcoded IP — the phone finds it on whatever WiFi it's on) → dev default.
    String v = get("persist.helpdesk.base_url");
    if (v.isEmpty()) {
      v = get("ro.helpdesk.base_url");
    }
    if (!v.isEmpty()) {
      return v;
    }
    String discovered = HelpdeskDiscovery.get().baseUrl();
    if (discovered != null && !discovered.isEmpty()) {
      return discovered;
    }
    return "http://10.0.2.2:4000/api/v1";
  }

  public static String deviceToken() {
    return provisioned("device_token", "dev-device-token");
  }

  public static String deviceSecret() {
    return provisioned("device_secret", "dev-device-secret");
  }

  /** Fail-closed: on a production ("user") build, refuse the repo-public dev default — an unprovisioned
   *  device must NOT authenticate with a known credential. Dev builds keep the default for convenience. */
  private static String provisioned(String suffix, String devDefault) {
    String v = resolve(suffix, devDefault);
    if (v.equals(devDefault) && !isDevBuild()) {
      android.util.Log.e("HelpdeskConfig", "device " + suffix + " not provisioned on a production build — refusing the dev default");
      return ""; // empty → auth fails loudly instead of silently using the public dev credential
    }
    return v;
  }

  private static boolean isDevBuild() {
    String t = android.os.Build.TYPE; // "user" = production; "userdebug"/"eng" = dev
    return "userdebug".equals(t) || "eng".equals(t);
  }

  public static String deviceId() {
    return resolve("device_id", "stallion-dev");
  }

  // ---- call recording audio quality -------------------------------------------------------------
  // These exist as properties, not constants, because every one of them can only be judged by making a
  // real call and reading the transcript, and a rebuild-and-reflash per experiment is hours. With these
  // a single image can test the lot: `adb shell setprop persist.helpdesk.rec_bitrate 96000`, place a
  // call, score it with components/transcription-worker/bench/ab.rb.
  // Defaults reproduce the stock behaviour exactly, so an unset device records as it always has.

  /** Output format id: 0 = AAC/m4a (stock), 1 = AMR-WB, 2 = LPCM WAV (lossless, ~16x the bytes). */
  public static int recordingFormat() {
    return intProp("rec_format", -1); // -1 = "not set", caller keeps the user's own preference
  }

  /**
   * AAC bitrate in bits per second. Stock is 16000 for a 16 kHz stream, i.e. about ONE BIT PER SAMPLE,
   * which is aggressive enough to mangle ordinary words: production transcripts turn "balíček" into
   * "badíček" and "zmeškaný" into "myštěný", and both Whisper models make the same mistakes, which is
   * what points at the audio rather than the model. Ignored by the WAV and AMR-WB formats.
   */
  public static int recordingBitRate() {
    return intProp("rec_bitrate", 0); // 0 = "not set", keep the format's own value
  }

  /**
   * Log whether VOICE_UPLINK and VOICE_DOWNLINK can be captured on this device. Off by default; it
   * opens and immediately releases two AudioRecords, which is harmless but pointless in normal use.
   *
   * <p>This is a feasibility probe for per-speaker recording. Google Dialer captures uplink and
   * downlink as two separate AudioRecords and interleaves them into a 2-channel WAV, which makes
   * caller and callee exactly separable instead of leaving a diariser to guess. We cannot do that until
   * we know those sources are capturable here, and that is a property of the device's audio HAL and
   * sepolicy, not something the source can answer.
   */
  public static boolean recordingProbeSources() {
    return "1".equals(resolve("rec_probe_sources", "0"));
  }

  /**
   * Record the two call legs as separate channels instead of one pre-mixed stream: left = uplink
   * (operator), right = downlink (caller). Off by default.
   *
   * <p>This makes speaker attribution exact rather than something a diariser infers, which is the whole
   * problem with two similar voices on a narrowband line. It is opt-in because whether both sources can
   * be captured AT ONCE is a property of the device's audio HAL, not of the code; when they cannot,
   * {@link DualLegCapture#open} returns null and recording falls back to the ordinary mixed source with
   * nothing lost. Pair it with {@code rec_format=2} (WAV) - a stereo file is only useful if the two
   * channels survive to the backend intact.
   */
  public static boolean recordingDualLeg() {
    return "1".equals(resolve("rec_dual_leg", "0"));
  }

  private static int intProp(String suffix, int def) {
    try {
      String v = resolve(suffix, "");
      return v.isEmpty() ? def : Integer.parseInt(v.trim());
    } catch (NumberFormatException e) {
      android.util.Log.w("HelpdeskConfig", "bad numeric property helpdesk." + suffix + ", using default");
      return def;
    }
  }

  /** persist.helpdesk.<suffix> (runtime) → ro.helpdesk.<suffix> (build) → default. */
  private static String resolve(String suffix, String def) {
    String v = get("persist.helpdesk." + suffix);
    if (v.isEmpty()) {
      v = get("ro.helpdesk." + suffix);
    }
    return v.isEmpty() ? def : v;
  }

  private static String get(String key) {
    String v = android.os.SystemProperties.get(key, "");
    return v == null ? "" : v;
  }
}