Mobile Workflows

1. Offline Model Download

sequenceDiagram
    participant User
    participant Start as StartScreen (Flutter)
    participant Channel as LlmPlatformChannel
    participant Native as MainActivity (Kotlin)
    participant Net as HuggingFace URL
    participant FS as App filesDir

    User->>Start: Tap "Download Offline Model"
    Start->>Channel: downloadModel()
    Channel->>Native: MethodChannel.invoke("downloadModel")
    Native->>Net: Open URL connection
    loop file chunks
        Net-->>Native: bytes
        Native-->>Channel: downloadProgress(downloaded,total)
        Channel-->>Start: progress stream event
    end
    Native->>FS: write qwen.task
    Native->>Native: save model_path in SharedPreferences
    Native-->>Channel: success=true
    Channel-->>Start: Future<bool> completed
    Start-->>User: Navigate to chat on success

2. Inference Invocation Path

This is the current low-level execution path implemented in code.
Note: the active ChatScreen is currently scripted; wiring chat input to this path is pending.

sequenceDiagram
    participant UI as Flutter Caller
    participant Dart as LlmPlatformChannel.generateResponse
    participant Native as MainActivity
    participant Engine as InferenceModel
    participant MP as MediaPipe LlmInferenceSession
    participant Metrics as MetricsRecorder

    UI->>Dart: generateResponse(prompt)
    Dart->>Dart: start stopwatch + read memory
    Dart->>Native: invokeMethod("generateResponse")
    Native->>Engine: getInstance() if needed
    Engine->>MP: addQueryChunk(prompt)
    Engine->>MP: generateResponseAsync(...)
    MP-->>Native: final response text
    Native-->>Dart: result.success(response)
    Dart->>Dart: stop stopwatch + compute metrics
    Dart->>Metrics: recordEntry(...)
    Dart-->>UI: response text

3. Help Request Form Flow

flowchart TD
    A[Open Help Request Screen] --> B[Fill disaster type + details]
    B --> C[Optional photo via image_picker]
    C --> D[Get location permission]
    D --> E{Location captured?}
    E -- No --> F[Show validation snackbar]
    E -- Yes --> G[Tap Send Request]
    G --> H[Local simulated submit]
    H --> I[Show success snackbar]
    I --> J[Navigate back]

4. Metrics Storage and Export

flowchart LR
    A[generateResponse called] --> B[Collect latency + memory + text metrics]
    B --> C[Append MetricEntry in memory]
    C --> D[Persist llm_metrics.json in app-docs]
    D --> E{User exports CSV?}
    E -- Yes --> F[Ask Android for public Downloads path]
    F --> G[Write llm_metrics.csv]
    E -- No --> H[Keep JSON history only]