# Requirements Document

## Introduction

SIGPLAY is a terminal-based music player application built with Python's Textual framework. The application provides a retro-modern aesthetic with a warm orange color scheme reminiscent of vintage computing systems, while maintaining contemporary usability. Users can navigate through different views to manage their music library, view currently playing tracks, and visualize audio playback.

## Glossary

- **SIGPLAY**: The terminal-based music player application
- **TUI**: Text User Interface - the visual interface rendered in the terminal
- **Library View**: The interface page displaying the user's music collection
- **Now Playing View**: The interface page showing currently playing track information
- **Visualizer View**: The interface page displaying audio visualization
- **Tab Navigation**: The mechanism for switching between different views using the Tab key
- **Header**: The top section of the TUI displaying ASCII art branding
- **Footer**: The bottom section of the TUI displaying navigation commands and help text

## Requirements

### Requirement 1

**User Story:** As a user, I want to see distinctive ASCII art branding when I launch SIGPLAY, so that I have a visually appealing and recognizable interface.

#### Acceptance Criteria

1. WHEN the SIGPLAY application launches, THE TUI SHALL display ASCII art of "SIGPLAY" in the Header
2. THE Header SHALL remain visible across all views
3. THE ASCII art SHALL use the retro-modern orange color scheme
4. THE Footer SHALL display a command helper line showing available keyboard shortcuts

### Requirement 2

**User Story:** As a user, I want to navigate between different functional areas of the application using vim-style keybindings, so that I can access library management, playback information, and visualizations efficiently.

#### Acceptance Criteria

1. THE SIGPLAY SHALL provide three distinct views: Library View, Now Playing View, and Visualizer View
2. WHEN the user presses the Tab key, THE SIGPLAY SHALL cycle to the next view in sequence
3. THE SIGPLAY SHALL support vim motion keys (h, j, k, l) for navigation within views
4. THE Footer SHALL indicate which view is currently active
5. THE SIGPLAY SHALL maintain the current view state until the user navigates to a different view

### Requirement 3

**User Story:** As a user, I want to exit the application cleanly, so that I can return to my terminal prompt without errors.

#### Acceptance Criteria

1. WHEN the user presses the 'q' key, THE SIGPLAY SHALL terminate the application
2. THE SIGPLAY SHALL perform cleanup operations before termination
3. THE SIGPLAY SHALL return control to the terminal shell after termination

### Requirement 4

**User Story:** As a user, I want the application to have a cohesive retro-modern aesthetic, so that the interface is visually appealing and evokes nostalgia while remaining functional.

#### Acceptance Criteria

1. THE SIGPLAY SHALL use a warm orange color palette as the primary theme color
2. THE color scheme SHALL evoke vintage computing systems while maintaining modern readability
3. THE TUI SHALL apply consistent styling across all views
4. THE SIGPLAY SHALL use the Textual framework's theming capabilities for color management

### Requirement 5

**User Story:** As a user, I want to view my music library and navigate through it using vim motions, so that I can browse and select tracks to play efficiently.

#### Acceptance Criteria

1. WHEN the Library View is active, THE SIGPLAY SHALL display a list of available music tracks
2. WHEN the user presses 'j' or 'k' keys, THE SIGPLAY SHALL move the selection down or up respectively
3. THE Library View SHALL show relevant metadata for each track
4. THE Library View SHALL provide visual feedback for the currently selected track
5. WHERE placeholder content is used, THE Library View SHALL display sample track entries

### Requirement 6

**User Story:** As a user, I want to see information about the currently playing track, so that I know what is playing at any time.

#### Acceptance Criteria

1. WHEN the Now Playing View is active, THE SIGPLAY SHALL display the current track title
2. THE Now Playing View SHALL show playback progress information
3. THE Now Playing View SHALL display relevant track metadata
4. WHERE placeholder content is used, THE Now Playing View SHALL display sample track information

### Requirement 7

**User Story:** As a user, I want to see a visual representation of the audio, so that I have an engaging visual experience while listening to music.

#### Acceptance Criteria

1. WHEN the Visualizer View is active, THE SIGPLAY SHALL display an audio visualization
2. THE visualization SHALL update in response to audio playback
3. THE visualization SHALL use the retro-modern color scheme
4. WHERE placeholder content is used, THE Visualizer View SHALL display a sample visualization pattern
