Module TerminalProvider 

File: Mountain/Source/Environment/TerminalProvider.rs Role: Implements the TerminalProvider trait for the MountainEnvironment. Responsibilities:

• Core logic for managing integrated terminal instances.
• Creating native pseudo-terminals (PTYs) and handling their I/O.
• Spawning and managing the lifecycle of the underlying shell processes.
• Handle terminal show/hide UI state.
• Send text input to terminal processes.
• Manage terminal environment variables.
• Handle terminal resizing and dimension management. -Support terminal profiles and configuration.
• Handle terminal process exit detection.
• Manage terminal input/output channels.
• Support terminal color schemes and themes.
• Handle terminal bell/notification support.
• Implement terminal buffer management.
• Support terminal search and navigation.
• Handle terminal clipboard operations.
• Implement terminal tab support.
• Support custom shell integration.

TODOs:

• Implement terminal profile management
• Add terminal environment variable management
• Implement terminal resize handling (PtySize updates)
• Support terminal color scheme configuration
• Add terminal bell handling and visual notifications
• Implement terminal buffer scrolling and history
• Support terminal search within output
• Add terminal reconnection for crashed processes
• Implement terminal tab management
• Support terminal split view
• Add terminal decoration support (e.g., cwd indicator)
• Implement terminal command history
• Support terminal shell integration (e.g., fish, zsh, bash)
• Add terminal ANSI escape sequence handling
• Implement terminal clipboard operations
• Support terminal link detection and navigation
• Add terminal performance optimizations for large output
• Implement terminal process tree (parent/child processes)
• Support terminal environment injection
• Add terminal keyboard mapping customization
• Implement terminal logging for debugging
• Support terminal font size and font family
• Add terminal UTF-8 and Unicode support
• Implement terminal timeout and idle detection
• Support terminal command execution automation
• Add terminal multi-instance management

Inspired by VSCode’s integrated terminal which:

• Uses native PTY for process isolation
• Streams I/O to avoid blocking the main thread
• Supports multiple terminal instances
• Handles terminal show/hide state
• Manages terminal process lifecycle
• Supports terminal profiles and custom shells
• Provides shell integration features

TerminalProvider Implementation

Implements the TerminalProvider trait for the MountainEnvironment. This provider contains the core logic for managing integrated terminal instances, including creating native pseudo-terminals (PTYs) and handling their I/O.

Terminal Architecture

The terminal implementation uses the following architecture:

1. PTY Creation: Use portable-pty to create native PTY pairs
2. Process Spawning: Spawn shell process as child of PTY slave
3. I/O Streaming: Spawn async tasks for input and output streaming
4. IPC Communication: Forward output to Cocoon sidecar via IPC
5. State Management: Track terminal state in ApplicationState

Terminal Lifecycle

1. Create: Create PTY, spawn shell, start I/O tasks
2. SendText: Write user input to PTY master
3. ReceiveData: Read output from PTY and forward to sidecar
4. Show/Hide: Emit UI events to show/hide terminal
5. ProcessExit: Detect shell exit and notify sidecar
6. Dispose: Close PTY, kill process, cleanup state

Shell Detection

Default shell selection by platform:

• Windows: powershell.exe
• macOS/Linux: $SHELL environment variable, fallback to sh

Custom shell paths can be provided via terminal options.

I/O Streaming

Terminal I/O is handled by background tokio tasks:

• Input Task: Receives text from channel and writes to PTY master
• Output Task: Reads from PTY master and forwards to sidecar
• Exit Task: Waits for process exit and notifies sidecar

Each terminal gets its own I/O tasks to prevent blocking each other.