Add preview APK update channel

app/build.gradle.kts

@@ -14,6 +14,8 @@ val defaultGithubUpdateUrl = providers.gradleProperty("defaultGithubUpdateUrl")
     .orElse("https://github.com/${repoSlug.get()}/releases/latest/download/latest.json")
 val defaultGiteaUpdateUrl = providers.gradleProperty("defaultGiteaUpdateUrl")
     .orElse("https://gitea.neatcn.com/api/v1/repos/tmux/tmux-browser-android/releases/latest")
+val defaultPreviewUpdateUrl = providers.gradleProperty("defaultPreviewUpdateUrl")
+    .orElse("https://gitea.neatcn.com/tmux/tmux-browser-android/releases/download/preview/latest.json")
 val defaultApkUrl = providers.gradleProperty("defaultApkUrl")
     .orElse("https://github.com/${repoSlug.get()}/releases/latest/download/tmux-android.apk")
 val defaultReleasePageUrl = providers.gradleProperty("defaultReleasePageUrl")
@@ -40,6 +42,7 @@ android {
         buildConfigField("String", "DEFAULT_UPDATE_URL", "\"${defaultUpdateUrl.get()}\"")
         buildConfigField("String", "DEFAULT_GITHUB_UPDATE_URL", "\"${defaultGithubUpdateUrl.get()}\"")
         buildConfigField("String", "DEFAULT_GITEA_UPDATE_URL", "\"${defaultGiteaUpdateUrl.get()}\"")
+        buildConfigField("String", "DEFAULT_PREVIEW_UPDATE_URL", "\"${defaultPreviewUpdateUrl.get()}\"")
         buildConfigField("String", "DEFAULT_APK_URL", "\"${defaultApkUrl.get()}\"")
         buildConfigField("String", "DEFAULT_RELEASE_PAGE_URL", "\"${defaultReleasePageUrl.get()}\"")
     }

app/src/main/java/com/neatstudio/tmuxandroid/MainActivity.java

@@ -19,6 +19,7 @@ import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
 import android.provider.Settings;
+import android.text.TextUtils;
 import android.text.InputType;
 import android.view.Gravity;
 import android.view.HapticFeedbackConstants;
@@ -113,12 +114,16 @@ public final class MainActivity extends Activity {
     private TextView sessionSummaryText;
     private LinearLayout projectList;
     private TextView terminalText;
+    private TextView terminalMetaText;
     private ScrollView terminalScroll;
     private EditText inputField;
     private Button terminalKeyPageButton;
     private View terminalComposerBar;
     private LinearLayout terminalGroupRow;
     private String activeSessionName;
+    private String terminalPathStatus = "";
+    private String terminalSocketStatus = "";
+    private String terminalEventStatus = "";
     private String activeMainPage = PAGE_SERVERS;
     private String pendingImageUploadSession;
     private TerminalScreenBuffer terminalScreen = new TerminalScreenBuffer(DEFAULT_TERMINAL_COLS, DEFAULT_TERMINAL_ROWS);
@@ -505,6 +510,7 @@ public final class MainActivity extends Activity {
                 actionButton("Auto check", view -> updateManager.check(true)),
                 actionButton("Gitea", view -> updateManager.checkGitea(true)),
                 actionButton("GitHub", view -> updateManager.checkGithub(true)),
+                actionButton("Preview", view -> updateManager.checkPreview(true)),
                 actionButton("Selected", view -> updateManager.checkSelected(true)),
                 actionButton("Source", view -> showUpdateSourcePicker()),
                 actionButton("APK", view -> updateManager.openApkDownload())
@@ -1116,6 +1122,9 @@ public final class MainActivity extends Activity {
         terminalSelectionEnabled = false;
         terminalFollowOutput = true;
         terminalKeyPage = 0;
+        terminalPathStatus = "path loading";
+        terminalSocketStatus = "terminal idle";
+        terminalEventStatus = "events listening";
         lastTerminalRenderMs = 0L;
         terminalCols = DEFAULT_TERMINAL_COLS;
         terminalRows = DEFAULT_TERMINAL_ROWS;
@@ -1166,6 +1175,7 @@ public final class MainActivity extends Activity {
             resizeTerminalToViewport(false);
             connectTerminal(sessionName);
             refreshTerminalGroupSessions(sessionName);
+            refreshTerminalSessionMeta(sessionName);
         });
         inputField.post(() -> {
             inputField.requestFocus();
@@ -1177,17 +1187,41 @@ public final class MainActivity extends Activity {
         LinearLayout bar = new LinearLayout(this);
         bar.setOrientation(LinearLayout.HORIZONTAL);
         bar.setGravity(Gravity.CENTER_VERTICAL);
-        bar.setPadding(dp(5), dp(5), dp(5), dp(5));
+        bar.setPadding(dp(5), dp(3), dp(5), dp(3));
         bar.setBackgroundColor(COLOR_BAR);
         bar.addView(terminalToolButton("‹", view -> openSessionPage()));
+
+        LinearLayout titleBlock = new LinearLayout(this);
+        titleBlock.setOrientation(LinearLayout.VERTICAL);
+        titleBlock.setGravity(Gravity.CENTER_VERTICAL);
+        titleBlock.setPadding(dp(8), 0, dp(8), 0);
+
         TextView title = new TextView(this);
         title.setText(sessionName);
         title.setTextColor(COLOR_TEXT);
-        title.setTextSize(15);
+        title.setTextSize(14);
         title.setTypeface(Typeface.DEFAULT_BOLD);
         title.setSingleLine(true);
-        title.setPadding(dp(8), 0, dp(8), 0);
+        title.setEllipsize(TextUtils.TruncateAt.END);
-        bar.addView(title, new LinearLayout.LayoutParams(0, dp(36), 1));
+        title.setIncludeFontPadding(false);
+
+        terminalMetaText = new TextView(this);
+        terminalMetaText.setTextColor(COLOR_TEXT_DIM);
+        terminalMetaText.setTextSize(10);
+        terminalMetaText.setSingleLine(true);
+        terminalMetaText.setEllipsize(TextUtils.TruncateAt.MIDDLE);
+        terminalMetaText.setIncludeFontPadding(false);
+        updateTerminalMeta();
+
+        titleBlock.addView(title, new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                dp(18)
+        ));
+        titleBlock.addView(terminalMetaText, new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                dp(14)
+        ));
+        bar.addView(titleBlock, new LinearLayout.LayoutParams(0, dp(34), 1));
         bar.addView(terminalToolButton("↻", view -> connectTerminal(sessionName)));
         bar.addView(terminalToolButton("⋯", view -> showTerminalActions(sessionName)));
         return bar;
@@ -1227,6 +1261,56 @@ public final class MainActivity extends Activity {
         });
     }
 
+    private void refreshTerminalSessionMeta(String sessionName) {
+        executor.execute(() -> {
+            try {
+                List<SessionSummary> sessions = api.getSessions();
+                String path = "";
+                String command = "";
+                for (SessionSummary session : sessions) {
+                    if (sessionName.equals(session.name)) {
+                        path = defaultValue(session.currentPath, "");
+                        command = defaultValue(session.currentCommand, "");
+                        break;
+                    }
+                }
+                String meta = path.isEmpty() ? "path unavailable" : path;
+                if (!command.isEmpty()) {
+                    meta = meta + "  ·  " + command;
+                }
+                String finalMeta = meta;
+                runOnUiThread(() -> {
+                    if (sessionName.equals(activeSessionName)) {
+                        terminalPathStatus = finalMeta;
+                        updateTerminalMeta();
+                    }
+                });
+            } catch (Exception error) {
+                runOnUiThread(() -> {
+                    if (sessionName.equals(activeSessionName)) {
+                        terminalPathStatus = "path unavailable";
+                        updateTerminalMeta();
+                    }
+                });
+            }
+        });
+    }
+
+    private void updateTerminalMeta() {
+        if (terminalMetaText == null) {
+            return;
+        }
+        StringBuilder meta = new StringBuilder();
+        meta.append(defaultValue(terminalPathStatus, "path loading"));
+        if (!terminalSocketStatus.isEmpty()) {
+            meta.append("  ·  ").append(terminalSocketStatus);
+        }
+        if (!terminalEventStatus.isEmpty()) {
+            meta.append("  ·  ").append(terminalEventStatus);
+        }
+        terminalMetaText.setText(meta.toString());
+    }
+
     private void renderTerminalGroupSessions(String sessionName, String text) {
         if (!sessionName.equals(activeSessionName) || terminalGroupRow == null) {
             return;
@@ -1497,6 +1581,10 @@ public final class MainActivity extends Activity {
             return false;
         });
         row.addView(inputField, new LinearLayout.LayoutParams(0, ViewGroup.LayoutParams.WRAP_CONTENT, 1));
+        row.addView(toolbarButton("Type", view -> sendTypedText()), new LinearLayout.LayoutParams(
+                ViewGroup.LayoutParams.WRAP_CONTENT,
+                dp(48)
+        ));
         row.addView(toolbarButton("Send", view -> sendLine()), new LinearLayout.LayoutParams(
                 ViewGroup.LayoutParams.WRAP_CONTENT,
                 dp(48)
@@ -1749,7 +1837,7 @@ public final class MainActivity extends Activity {
         text.append("Tap Release on the About page. The app resolves the page from the selected update source.\n");
         text.append('\n');
         text.append("In-app update:\n");
-        text.append("Tap Auto check on the Update page to try Gitea first and GitHub only if Gitea cannot be reached. Use Gitea, GitHub, or Selected to force one source. Each source retries transient network failures before failing. The app downloads one APK per version, verifies SHA-256, then opens Android's installer.\n");
+        text.append("Tap Auto check on the Update page to try Gitea first and GitHub only if Gitea cannot be reached. Use Gitea, GitHub, Preview, or Selected to force one source. Preview resolves the mutable Gitea preview attachment for fast UI testing. Each source retries transient network failures before failing. The app downloads one APK per version, verifies SHA-256, then opens Android's installer.\n");
         text.append("Selected manifest: ")
                 .append(updateSourceHost())
                 .append('\n')
@@ -1758,6 +1846,7 @@ public final class MainActivity extends Activity {
         text.append("Available sources:\n");
         text.append("Gitea default: ").append(BuildConfig.DEFAULT_GITEA_UPDATE_URL).append('\n');
         text.append("GitHub optional: ").append(BuildConfig.DEFAULT_GITHUB_UPDATE_URL).append('\n');
+        text.append("Preview manual: ").append(BuildConfig.DEFAULT_PREVIEW_UPDATE_URL).append('\n');
         text.append('\n');
         text.append(permissionSummary());
 
@@ -1796,6 +1885,7 @@ public final class MainActivity extends Activity {
         String[] items = {
                 "Gitea default: " + BuildConfig.DEFAULT_GITEA_UPDATE_URL,
                 "GitHub optional: " + BuildConfig.DEFAULT_GITHUB_UPDATE_URL,
+                "Preview manual: " + BuildConfig.DEFAULT_PREVIEW_UPDATE_URL,
                 "Custom URL"
         };
         new AlertDialog.Builder(this)
@@ -1805,6 +1895,8 @@ public final class MainActivity extends Activity {
                         setUpdateUrl(BuildConfig.DEFAULT_GITEA_UPDATE_URL);
                     } else if (which == 1) {
                         setUpdateUrl(BuildConfig.DEFAULT_GITHUB_UPDATE_URL);
+                    } else if (which == 2) {
+                        setUpdateUrl(BuildConfig.DEFAULT_PREVIEW_UPDATE_URL);
                     } else {
                         promptText("Custom update manifest", "https://.../latest.json", prefs.getString("update_url", BuildConfig.DEFAULT_UPDATE_URL), this::setUpdateUrl);
                     }
@@ -2138,7 +2230,8 @@ public final class MainActivity extends Activity {
                 addComposerButton(topRow, "→", () -> moveComposerCursor(1));
                 addSoftKey(topRow, "↑", "\u001b[A");
                 addSoftKey(topRow, "↓", "\u001b[B");
-                addSoftKey(topRow, "↵", TERMINAL_ENTER);
+                addSoftKey(topRow, "Enter", TERMINAL_ENTER);
+                addSoftKey(topRow, "Tab", "\t");
                 addAccessoryButton(topRow, "NL", view -> insertComposerText("\n"));
                 addSoftButton(bottomRow, "Pst", view -> pasteClipboard());
                 addAccessoryButton(bottomRow, "⌫", view -> backspaceComposerText());
@@ -2168,6 +2261,8 @@ public final class MainActivity extends Activity {
         closeTerminalSocket();
         queuedTerminalInput.setLength(0);
         terminalConnected = false;
+        terminalSocketStatus = "terminal connecting";
+        updateTerminalMeta();
         setStatus("Connecting " + sessionName);
         resizeTerminalToViewport(false);
         appendTerminal("[connecting]\r\n");
@@ -2176,6 +2271,8 @@ public final class MainActivity extends Activity {
             public void onConnected() {
                 runOnUiThread(() -> {
                     terminalConnected = true;
+                    terminalSocketStatus = "terminal connected";
+                    updateTerminalMeta();
                     setStatus("Connected " + sessionName);
                     resizeTerminalToViewport(true);
                     flushQueuedTerminalInput();
@@ -2191,6 +2288,8 @@ public final class MainActivity extends Activity {
             public void onError(String message) {
                 runOnUiThread(() -> {
                     appendTerminal("\r\n[error] " + message + "\r\n");
+                    terminalSocketStatus = "terminal error";
+                    updateTerminalMeta();
                     setStatus("Terminal error: " + message);
                 });
             }
@@ -2199,6 +2298,8 @@ public final class MainActivity extends Activity {
             public void onClosed() {
                 runOnUiThread(() -> {
                     terminalConnected = false;
+                    terminalSocketStatus = "terminal disconnected";
+                    updateTerminalMeta();
                     setStatus("Disconnected " + sessionName);
                 });
             }
@@ -2259,6 +2360,21 @@ public final class MainActivity extends Activity {
         setStatus("Sent " + text.length() + " chars");
     }
 
+    private void sendTypedText() {
+        if (inputField == null) {
+            return;
+        }
+        String text = inputField.getText().toString();
+        if (text.isEmpty()) {
+            return;
+        }
+        String normalized = text.replace("\r\n", "\n").replace('\r', '\n');
+        terminalFollowOutput = true;
+        sendTerminalInput(normalized);
+        inputField.setText("");
+        setStatus("Typed " + text.length() + " chars");
+    }
+
     private void sendTerminalInput(String data) {
         if (activeSessionName == null) {
             return;
@@ -2820,7 +2936,11 @@ public final class MainActivity extends Activity {
 
             @Override
             public void onClosed() {
-                runOnUiThread(() -> setStatus("Event stream disconnected"));
+                runOnUiThread(() -> {
+                    terminalEventStatus = "events disconnected";
+                    updateTerminalMeta();
+                    setStatus("Event stream disconnected");
+                });
             }
         });
         eventSocket.connect(api.getBaseUrl());
@@ -2831,10 +2951,17 @@ public final class MainActivity extends Activity {
             JSONObject event = new JSONObject(text);
             String type = event.optString("type", "");
             if ("hello".equals(type)) {
+                terminalEventStatus = "events connected";
+                updateTerminalMeta();
                 setStatus("Event stream connected");
                 return;
             }
             if ("sessions-invalidated".equals(type)) {
+                terminalEventStatus = "sessions changed";
+                updateTerminalMeta();
+                if (activeSessionName != null) {
+                    refreshTerminalSessionMeta(activeSessionName);
+                }
                 setStatus("Sessions changed: " + event.optString("reason", "update"));
                 if (activeSessionName == null) {
                     refreshSessions();
@@ -2842,11 +2969,17 @@ public final class MainActivity extends Activity {
                 return;
             }
             if ("hook-event".equals(type)) {
+                terminalEventStatus = "hook event";
+                updateTerminalMeta();
                 showMessage(event.optString("title", "Hook event"));
                 return;
             }
+            terminalEventStatus = type.isEmpty() ? "event received" : type;
+            updateTerminalMeta();
             setStatus(type.isEmpty() ? "Event received" : type);
         } catch (Exception error) {
+            terminalEventStatus = "event received";
+            updateTerminalMeta();
             setStatus("Event received");
         }
     }

app/src/main/java/com/neatstudio/tmuxandroid/UpdateManager.java

@@ -80,6 +80,14 @@ final class UpdateManager {
         );
     }
 
+    void checkPreview(boolean userInitiated) {
+        startUpdateCheck(
+                userInitiated,
+                "Preview",
+                new String[]{BuildConfig.DEFAULT_PREVIEW_UPDATE_URL}
+        );
+    }
+
     void checkWithFallback(boolean userInitiated) {
         startUpdateCheck(
                 userInitiated,

docs/preview-build.md

@@ -0,0 +1,41 @@
+# Preview APK workflow
+
+Use this path for fast UI testing before a formal tag/release.
+
+The preview build is a debug APK with package id `com.neatstudio.tmuxandroid.debug`.
+It can be installed next to the formal release app, so preview version codes do not
+block future formal releases.
+
+## Build locally
+
+```bash
+scripts/setup-android-local.sh
+scripts/build-preview-apk.sh
+```
+
+Output:
+
+- `release/preview/tmux-android-preview.apk`
+- `release/preview/latest.json`
+
+## Upload to Gitea preview release
+
+```bash
+scripts/upload-gitea-preview.sh
+```
+
+The script reads `TMUX_GITEA_TOKEN` or prompts for a hidden token.
+Before uploading, it deletes existing assets with the same names, so the preview
+release keeps only one current APK and one current manifest.
+
+Fixed preview URLs:
+
+- Manifest: `https://gitea.neatcn.com/tmux/tmux-browser-android/releases/download/preview/latest.json`
+- APK: `https://gitea.neatcn.com/tmux/tmux-browser-android/releases/download/preview/tmux-android-preview.apk`
+
+## Notes
+
+- Preview APKs are not formal releases and should not be tagged as `v*`.
+- Preview uses debug signing unless a separate debug signing setup is added.
+- The installed preview app is separate from the release app because Gradle applies
+  `applicationIdSuffix = ".debug"` for debug builds.

scripts/build-preview-apk.sh

@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+CI_DIR="${ROOT_DIR}/.ci"
+GRADLE_VERSION="${GRADLE_VERSION:-8.10.2}"
+GRADLE_HOME="${CI_DIR}/gradle-${GRADLE_VERSION}"
+ANDROID_HOME="${ANDROID_HOME:-${CI_DIR}/android-sdk}"
+CMDLINE_TOOLS="${ANDROID_HOME}/cmdline-tools/latest"
+BUILD_NUMBER="${BUILD_NUMBER:-$(date -u +%m%d%H%M)}"
+VERSION_CODE="${VERSION_CODE:-$((900000000 + 10#${BUILD_NUMBER}))}"
+VERSION_NAME="${VERSION_NAME:-preview-${BUILD_NUMBER}}"
+
+if [ ! -x "${GRADLE_HOME}/bin/gradle" ] || [ ! -x "${CMDLINE_TOOLS}/bin/sdkmanager" ]; then
+  "${ROOT_DIR}/scripts/setup-android-local.sh"
+fi
+
+export ANDROID_HOME
+export ANDROID_SDK_ROOT="${ANDROID_HOME}"
+export PATH="${GRADLE_HOME}/bin:${CMDLINE_TOOLS}/bin:${ANDROID_HOME}/platform-tools:${PATH}"
+
+cd "${ROOT_DIR}"
+gradle :app:assembleDebug \
+  -PversionCode="${VERSION_CODE}" \
+  -PversionName="${VERSION_NAME}" \
+  -PrepoSlug="neatstudio/tmux-browser-android"
+
+OUT_DIR="${ROOT_DIR}/release/preview"
+mkdir -p "${OUT_DIR}"
+APK_PATH="$(find app/build/outputs/apk/debug -name '*.apk' | sort | tail -n 1)"
+cp "${APK_PATH}" "${OUT_DIR}/tmux-android-preview.apk"
+SHA256="$(sha256sum "${OUT_DIR}/tmux-android-preview.apk" | cut -d " " -f 1)"
+
+cat > "${OUT_DIR}/latest.json" <<JSON
+{
+  "versionCode": ${VERSION_CODE},
+  "versionName": "${VERSION_NAME}",
+  "apkUrl": "https://gitea.neatcn.com/tmux/tmux-browser-android/releases/download/preview/tmux-android-preview.apk",
+  "sha256": "${SHA256}",
+  "releasePageUrl": "https://gitea.neatcn.com/tmux/tmux-browser-android/releases/tag/preview",
+  "minSdk": 26
+}
+JSON
+
+ls -lh "${OUT_DIR}/tmux-android-preview.apk" "${OUT_DIR}/latest.json"
+sha256sum "${OUT_DIR}/tmux-android-preview.apk"

scripts/setup-android-local.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+CI_DIR="${ROOT_DIR}/.ci"
+GRADLE_VERSION="${GRADLE_VERSION:-8.10.2}"
+ANDROID_TOOLS_ZIP="${ANDROID_TOOLS_ZIP:-commandlinetools-linux-11076708_latest.zip}"
+GRADLE_HOME="${CI_DIR}/gradle-${GRADLE_VERSION}"
+ANDROID_HOME="${ANDROID_HOME:-${CI_DIR}/android-sdk}"
+CMDLINE_TOOLS="${ANDROID_HOME}/cmdline-tools/latest"
+
+mkdir -p "${CI_DIR}"
+
+if [ ! -x "${GRADLE_HOME}/bin/gradle" ]; then
+  curl -fSL --connect-timeout 20 --retry 3 --retry-delay 2 --max-time 600 \
+    -o "${CI_DIR}/gradle.zip" \
+    "https://services.gradle.org/distributions/gradle-${GRADLE_VERSION}-bin.zip"
+  unzip -q "${CI_DIR}/gradle.zip" -d "${CI_DIR}"
+fi
+
+if [ ! -x "${CMDLINE_TOOLS}/bin/sdkmanager" ]; then
+  mkdir -p "${ANDROID_HOME}/cmdline-tools"
+  curl -fSL --connect-timeout 20 --retry 3 --retry-delay 2 --max-time 600 \
+    -o "${CI_DIR}/android-tools.zip" \
+    "https://dl.google.com/android/repository/${ANDROID_TOOLS_ZIP}"
+  unzip -q "${CI_DIR}/android-tools.zip" -d "${ANDROID_HOME}/cmdline-tools"
+  rm -rf "${CMDLINE_TOOLS}"
+  mv "${ANDROID_HOME}/cmdline-tools/cmdline-tools" "${CMDLINE_TOOLS}"
+fi
+
+export ANDROID_HOME
+export ANDROID_SDK_ROOT="${ANDROID_HOME}"
+export PATH="${GRADLE_HOME}/bin:${CMDLINE_TOOLS}/bin:${ANDROID_HOME}/platform-tools:${PATH}"
+
+yes | sdkmanager --licenses >/dev/null || true
+sdkmanager "platforms;android-35" "build-tools;35.0.0" "platform-tools"
+
+echo "ANDROID_HOME=${ANDROID_HOME}"
+echo "GRADLE_HOME=${GRADLE_HOME}"

scripts/upload-gitea-preview.sh

@@ -0,0 +1,93 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+APK_PATH="${1:-${ROOT_DIR}/release/preview/tmux-android-preview.apk}"
+LATEST_JSON="${2:-${ROOT_DIR}/release/preview/latest.json}"
+TAG="preview"
+API_ROOT="https://gitea.neatcn.com/api/v1/repos/tmux/tmux-browser-android"
+
+if [ ! -f "${APK_PATH}" ]; then
+  echo "APK not found: ${APK_PATH}" >&2
+  exit 1
+fi
+if [ ! -f "${LATEST_JSON}" ]; then
+  echo "latest.json not found: ${LATEST_JSON}" >&2
+  exit 1
+fi
+
+TOKEN="${TMUX_GITEA_TOKEN:-}"
+if [ -z "${TOKEN}" ]; then
+  printf "Gitea token: " >&2
+  IFS= read -rs TOKEN
+  printf "\n" >&2
+fi
+if [ -z "${TOKEN}" ]; then
+  echo "Missing Gitea token." >&2
+  exit 1
+fi
+
+WORK_DIR="$(mktemp -d)"
+trap 'rm -rf "${WORK_DIR}"' EXIT
+
+RELEASE_JSON="${WORK_DIR}/release.json"
+BODY='{"tag_name":"preview","target_commitish":"main","name":"tmux Android Preview","body":"Mutable preview APK for fast UI testing. This is not a formal release.","draft":false,"prerelease":true}'
+
+if ! curl -fsSL \
+  -X POST \
+  -H "Authorization: token ${TOKEN}" \
+  -H "Content-Type: application/json" \
+  -d "${BODY}" \
+  "${API_ROOT}/releases" \
+  -o "${RELEASE_JSON}"; then
+  curl -fsSL \
+    -H "Authorization: token ${TOKEN}" \
+    "${API_ROOT}/releases/tags/${TAG}" \
+    -o "${RELEASE_JSON}"
+fi
+
+RELEASE_ID="$(sed -n 's/^{"id":\([0-9][0-9]*\),.*/\1/p' "${RELEASE_JSON}" | head -1)"
+if [ -z "${RELEASE_ID}" ]; then
+  echo "Cannot resolve Gitea release id for preview." >&2
+  exit 1
+fi
+
+upload_asset() {
+  local file="$1"
+  local name="$2"
+  local type="$3"
+  local assets_json old_ids old_id
+  assets_json="${WORK_DIR}/assets-${name}.json"
+  curl -fsSL -H "Authorization: token ${TOKEN}" \
+    "${API_ROOT}/releases/${RELEASE_ID}/assets" \
+    -o "${assets_json}"
+  old_ids="$(python3 - "${assets_json}" "${name}" <<'PY'
+import json
+import sys
+
+with open(sys.argv[1], "r", encoding="utf-8") as handle:
+    assets = json.load(handle)
+for asset in assets:
+    if asset.get("name") == sys.argv[2]:
+        print(asset.get("id"))
+PY
+)"
+  for old_id in ${old_ids}; do
+    curl -fsSL -X DELETE -H "Authorization: token ${TOKEN}" \
+      "${API_ROOT}/releases/${RELEASE_ID}/assets/${old_id}" \
+      -o /dev/null
+  done
+  curl -fsSL \
+    -X POST \
+    -H "Authorization: token ${TOKEN}" \
+    -F "attachment=@${file};type=${type}" \
+    "${API_ROOT}/releases/${RELEASE_ID}/assets?name=${name}" \
+    -o "${WORK_DIR}/${name}.asset.json"
+}
+
+upload_asset "${APK_PATH}" "tmux-android-preview.apk" "application/vnd.android.package-archive"
+upload_asset "${LATEST_JSON}" "latest.json" "application/json"
+
+echo "Uploaded preview release ${RELEASE_ID}"
+echo "Manifest: https://gitea.neatcn.com/tmux/tmux-browser-android/releases/download/preview/latest.json"
+echo "APK: https://gitea.neatcn.com/tmux/tmux-browser-android/releases/download/preview/tmux-android-preview.apk"