# FocusModeService

- File ID: file:1953stk:focusmodeservice-cs
- Path: NexusReader.UI.Shared/Services/FocusModeService.cs
- Role: service
- Layer: frontend

## Purpose

Provides a UI-scoped service that tracks and persists a 'focus mode' flag using IJSRuntime (localStorage) and notifies subscribers when the mode changes.

## Key Details

Reads/writes browser localStorage via IJSRuntime with try/catch to tolerate SSR/pre-render; exposes an event to notify UI components when mode changes.

## Symbols

- FocusModeService: Provides a UI-scoped service that tracks and persists a 'focus mode' flag using IJSRuntime (localStorage) and notifies subscribers when the mode changes.
- FocusModeService(): Constructs the service and captures an IJSRuntime instance for JS interop.
- InitializeAsync(): Reads persisted focus-mode flag from localStorage and activates focus mode if stored as true, notifying subscribers; ignores JS errors (e.g., during pre-render).
- ToggleAsync(): Toggles the in-memory focus-mode flag, notifies subscribers, and persists the new value to localStorage; ignores JS write errors.
- FocusModeService: Service to manage a user-selectable 'focus mode' state, persistence, and notifications.

## Dependencies

- No resolved dependencies.

## Calls

- No resolved calls.

## Unresolved References

- dependency-target: Microsoft.JSInterop (IJSRuntime)
- dependency-target: IFocusModeService (consumer interface)
- call-target: unknown
- call-target: self
- call-target: self
- call-target: unknown

## Coverage

- Symbols: 5
- Executable symbols: 3
- Executable symbols with control flow: 3
- Grounded edges: 5
- Unresolved references: 6
- Control-flow fragments: 3
- Unresolved jumps: 4
- Unsupported constructs: 0
- Control-flow coverage: 100%
- Required diagrams: 2
- Generated diagrams: 4

## Control Flow Fragments

- FocusModeService: 3 nodes, 2 edges, 0 jumps, 0 unsupported constructs
- InitializeAsync: 22 nodes, 24 edges, 2 jumps, 0 unsupported constructs
- ToggleAsync: 15 nodes, 15 edges, 2 jumps, 0 unsupported constructs

## Diagrams

### FocusModeService Neighborhood

```mermaid
flowchart LR
    class_oyj9xs_focusmodeservice("FocusModeService")
    file_1953stk_focusmodeservice_cs("FocusModeService")
    method_1094u9_initializeasync[["InitializeAsync()"]]
    method_439s8m_toggleasync[["ToggleAsync()"]]
    method_wn38ys_focusmodeservice[["FocusModeService()"]]
    type_1af3t0x_focusmodeservice[/"FocusModeService"/]
```

### FocusModeService Execution Overview

```mermaid
flowchart TD
    class_oyj9xs_focusmodeservice("FocusModeService")
    method_1094u9_initializeasync[["InitializeAsync()"]]
    method_439s8m_toggleasync[["ToggleAsync()"]]
    method_wn38ys_focusmodeservice[["FocusModeService()"]]
    unresolved_unresolved_12ho2u8_call_target{"Unresolved: IJSRuntime.InvokeAsync"}
    unresolved_unresolved_147cark_call_target{"Unresolved: OnFocusModeChanged"}
    unresolved_unresolved_1i0mp08_call_target{"Unresolved: IJSRuntime.InvokeVoidAsync"}
    unresolved_unresolved_1yx28bi_call_target{"Unresolved: OnFocusModeChanged"}
    class_oyj9xs_focusmodeservice -->|contains| method_1094u9_initializeasync
    class_oyj9xs_focusmodeservice -->|contains| method_439s8m_toggleasync
    class_oyj9xs_focusmodeservice -->|contains| method_wn38ys_focusmodeservice
    method_1094u9_initializeasync -->|unresolved call| unresolved_unresolved_12ho2u8_call_target
    method_1094u9_initializeasync -->|unresolved call| unresolved_unresolved_1yx28bi_call_target
    method_439s8m_toggleasync -->|unresolved call| unresolved_unresolved_147cark_call_target
    method_439s8m_toggleasync -->|unresolved call| unresolved_unresolved_1i0mp08_call_target
```

### InitializeAsync() Control Flow

_Warnings: diagram method_1094u9_initializeasync__fragment_diagram exceeds preferred complexity thresholds (22 nodes, 24 edges)._

```mermaid
---
config:
  flowchart:
    defaultRenderer: "elk"
---
flowchart TD
    method_1094u9_initializeasync__call_20_IJSRuntime_InvokeAsync[["IJSRuntime.InvokeAsync"]]
    method_1094u9_initializeasync__call_24_OnFocusModeChanged[["OnFocusModeChanged"]]
    method_1094u9_initializeasync__action_18_initializeasync_try_18_0__try("Begins protected execution")
    method_1094u9_initializeasync__action_18_try_catch_18__linear("Wrap JS interop in try/catch")
    method_1094u9_initializeasync__action_20_initializeasync_await_20_1__await[["Waits for async work"]]
    method_1094u9_initializeasync__action_21_guard_clause_21__condition{"value == \\"true\\" && !IsFocusModeActive"}
    method_1094u9_initializeasync__action_21_guard_clause_21__false("no-op")
    method_1094u9_initializeasync__action_21_guard_clause_21__merge("merge")
    method_1094u9_initializeasync__action_21_guard_clause_21__true("set active & notify")
    method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__condition{"value == \\"true\\" && !IsFocusModeActive"}
    method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__false("false")
    method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__merge("merge")
    method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__true("true")
    method_1094u9_initializeasync__action_24_event_invocation_24__linear("Notify subscribers of mode change")
    method_1094u9_initializeasync__action_24_initializeasync_await_24_4__await[["Waits for async work"]]
    method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__condition{"OnFocusModeChanged != null) await OnFocusModeChanged("}
    method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__false("false")
    method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__merge("merge")
    method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__true("true")
    method_1094u9_initializeasync__action_27_initializeasync_catch_27_5__catch("Handles exception path")
    method_1094u9_initializeasync__entry(["InitializeAsync entry"])
    method_1094u9_initializeasync__implicit_return(["return"])
    method_1094u9_initializeasync__action_18_initializeasync_try_18_0__try -->|next| method_1094u9_initializeasync__action_20_initializeasync_await_20_1__await
    method_1094u9_initializeasync__action_18_try_catch_18__linear -->|next| method_1094u9_initializeasync__action_18_initializeasync_try_18_0__try
    method_1094u9_initializeasync__action_20_initializeasync_await_20_1__await -->|calls| method_1094u9_initializeasync__call_20_IJSRuntime_InvokeAsync
    method_1094u9_initializeasync__action_21_guard_clause_21__condition -->|no-op| method_1094u9_initializeasync__action_21_guard_clause_21__false
    method_1094u9_initializeasync__action_21_guard_clause_21__condition -->|transforms input| method_1094u9_initializeasync__action_21_guard_clause_21__true
    method_1094u9_initializeasync__action_21_guard_clause_21__false -->|next| method_1094u9_initializeasync__action_21_guard_clause_21__merge
    method_1094u9_initializeasync__action_21_guard_clause_21__merge -->|next| method_1094u9_initializeasync__action_24_initializeasync_await_24_4__await
    method_1094u9_initializeasync__action_21_guard_clause_21__true -->|next| method_1094u9_initializeasync__action_21_guard_clause_21__merge
    method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__condition -->|false| method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__false
    method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__condition -->|true| method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__true
    method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__false -->|next| method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__merge
    method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__merge -->|next| method_1094u9_initializeasync__action_21_guard_clause_21__condition
    method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__true -->|next| method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__merge
    method_1094u9_initializeasync__action_24_event_invocation_24__linear -->|next| method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__condition
    method_1094u9_initializeasync__action_24_initializeasync_await_24_4__await -->|next| method_1094u9_initializeasync__action_24_event_invocation_24__linear
    method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__condition -->|false| method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__false
    method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__condition -->|true| method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__true
    method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__false -->|next| method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__merge
    method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__merge -->|no args, invokes subscribers asynchronously| method_1094u9_initializeasync__call_24_OnFocusModeChanged
    method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__true -->|next| method_1094u9_initializeasync__action_24_initializeasync_branch_24_3__merge
    method_1094u9_initializeasync__action_27_initializeasync_catch_27_5__catch -->|return| method_1094u9_initializeasync__implicit_return
    method_1094u9_initializeasync__call_20_IJSRuntime_InvokeAsync -->|next| method_1094u9_initializeasync__action_21_initializeasync_branch_21_2__condition
    method_1094u9_initializeasync__call_24_OnFocusModeChanged -->|exception| method_1094u9_initializeasync__action_27_initializeasync_catch_27_5__catch
    method_1094u9_initializeasync__entry -->|next| method_1094u9_initializeasync__action_18_try_catch_18__linear
```

### ToggleAsync() Control Flow

```mermaid
flowchart TD
    method_439s8m_toggleasync__call_36_OnFocusModeChanged[["OnFocusModeChanged"]]
    method_439s8m_toggleasync__call_40_IJSRuntime_InvokeVoidAsync[["IJSRuntime.InvokeVoidAsync"]]
    method_439s8m_toggleasync__action_35_state_change_35__linear("Toggle in-memory flag")
    method_439s8m_toggleasync__action_36_event_invocation_36__linear("Notify subscribers after toggle")
    method_439s8m_toggleasync__action_36_toggleasync_await_36_1__await[["Waits for async work"]]
    method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__condition{"OnFocusModeChanged != null) await OnFocusModeChanged("}
    method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__false("false")
    method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__merge("merge")
    method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__true("true")
    method_439s8m_toggleasync__action_38_toggleasync_try_38_2__try("Begins protected execution")
    method_439s8m_toggleasync__action_38_try_catch_38__linear("Persist new value to localStorage, ignore errors")
    method_439s8m_toggleasync__action_40_toggleasync_await_40_3__await[["Waits for async work"]]
    method_439s8m_toggleasync__action_42_toggleasync_catch_42_4__catch("Handles exception path")
    method_439s8m_toggleasync__entry(["ToggleAsync entry"])
    method_439s8m_toggleasync__implicit_return(["return"])
    method_439s8m_toggleasync__action_35_state_change_35__linear -->|next| method_439s8m_toggleasync__action_36_toggleasync_await_36_1__await
    method_439s8m_toggleasync__action_36_event_invocation_36__linear -->|next| method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__condition
    method_439s8m_toggleasync__action_36_toggleasync_await_36_1__await -->|next| method_439s8m_toggleasync__action_36_event_invocation_36__linear
    method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__condition -->|false| method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__false
    method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__condition -->|true| method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__true
    method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__false -->|next| method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__merge
    method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__merge -->|no args, invokes subscribers asynchronously| method_439s8m_toggleasync__call_36_OnFocusModeChanged
    method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__true -->|next| method_439s8m_toggleasync__action_36_toggleasync_branch_36_0__merge
    method_439s8m_toggleasync__action_38_toggleasync_try_38_2__try -->|next| method_439s8m_toggleasync__action_40_toggleasync_await_40_3__await
    method_439s8m_toggleasync__action_38_try_catch_38__linear -->|next| method_439s8m_toggleasync__action_38_toggleasync_try_38_2__try
    method_439s8m_toggleasync__action_40_toggleasync_await_40_3__await -->|calls| method_439s8m_toggleasync__call_40_IJSRuntime_InvokeVoidAsync
    method_439s8m_toggleasync__action_42_toggleasync_catch_42_4__catch -->|return| method_439s8m_toggleasync__implicit_return
    method_439s8m_toggleasync__call_36_OnFocusModeChanged -->|next| method_439s8m_toggleasync__action_38_try_catch_38__linear
    method_439s8m_toggleasync__call_40_IJSRuntime_InvokeVoidAsync -->|exception| method_439s8m_toggleasync__action_42_toggleasync_catch_42_4__catch
    method_439s8m_toggleasync__entry -->|next| method_439s8m_toggleasync__action_35_state_change_35__linear
```

## Diagram Validation

- Status: warn
- Warning: Control-flow extraction left 4 unresolved jumps.
- Warning: control-flow: diagram method_1094u9_initializeasync__fragment_diagram exceeds preferred complexity thresholds (22 nodes, 24 edges).
