Summary of Changes

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This pull request addresses and resolves issues related to log rendering and scrolling within the TUI. By leveraging an unstable ratatui feature for accurate line counting and redefining the log_scroll mechanism, the log viewer now provides a more reliable and intuitive user experience, particularly when dealing with text wrapping and problematic log content. Additionally, it introduces a cleaning mechanism for log lines to prevent display glitches caused by special characters.

Highlights

• Improved Log Scrolling: The log_scroll variable now represents the line number of the last displayed line in the log buffer, rather than the first. This change, combined with the use of ratatui's unstable line_count feature, significantly enhances the accuracy of log scrolling, especially with text wrapping.
• Enhanced Log Rendering: A new clean_log_line function has been introduced to preprocess log entries, removing problematic characters like tab ( ) and ANSI clear screen codes (�[2J), which previously caused rendering issues in the TUI log panel.
• Ratatui Unstable Feature Enabled: The unstable-rendered-line-info feature has been enabled for the ratatui dependency, allowing the application to accurately determine the number of lines a Paragraph widget will render after text wrapping, which is crucial for correct scroll behavior.
• Refined Scroll Logic: Various log scrolling functions (e.g., toggle_log_follow, scroll_logs_down, scroll_logs_page_down, update_logs, and 'G' keybind) have been updated to align with the new log_scroll meaning, ensuring consistent and correct log navigation.

Greptile Summary

This PR refactors the TUI log rendering to fix scroll behavior by changing log_scroll semantics from "beginning of buffer" to "last displayed line number". It also adds log cleaning (removes tab chars and clear screen ANSI codes) and enables ratatui's unstable line counting feature.

Major changes:

• Enabled unstable-rendered-line-info feature in ratatui for accurate line counting after text wrapping
• Changed log_scroll to represent the last displayed line instead of buffer start position
• Added clean_log_line() function to sanitize log output
• Fixed fuzzy search sorting to properly order by descending score
• Introduced LOG_VIEWPORT_MAX_LINES constant (100 lines) for viewport management

Critical issues found:

• Integer underflow bug in scroll calculation that will cause panics in debug builds
• The 'g' key (scroll to top) sets log_scroll=0 which only displays 1 line instead of a full viewport due to the new semantics

Confidence Score: 1/5

• Critical bugs present that will cause runtime panics and incorrect behavior
• Two critical logic errors: (1) integer underflow in scroll calculation will panic in debug builds or produce incorrect behavior in release mode, and (2) scroll-to-top functionality is broken, showing only 1 line instead of a full viewport. These bugs significantly impact core functionality.
• Pay close attention to src/tui/ui.rs (line 914 underflow) and src/tui/event.rs (line 413 scroll behavior)

Important Files Changed

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    Start[Log Rendering] --> CheckFollow{log_follow enabled?}
    CheckFollow -->|Yes| SetToEnd[Set log_scroll = log_content.len]
    CheckFollow -->|No| CheckScroll[Use current log_scroll]
    
    SetToEnd --> CalcWindow[Calculate viewport window]
    CheckScroll --> CalcWindow
    
    CalcWindow --> Skip[log_skip = log_scroll - LOG_VIEWPORT_MAX_LINES]
    Skip --> Take[log_take = min log_scroll, LOG_VIEWPORT_MAX_LINES]
    Take --> GetLines[Get lines from buffer: skip log_skip, take log_take]
    
    GetLines --> Clean[Clean log lines: remove tabs, ANSI codes]
    Clean --> Highlight[Apply syntax highlighting and search matches]
    Highlight --> Pad{lines < LOG_VIEWPORT_MAX_LINES?}
    
    Pad -->|Yes| AddPadding[Add empty lines to reach LOG_VIEWPORT_MAX_LINES]
    Pad -->|No| CreateParagraph[Create Paragraph widget]
    AddPadding --> CreateParagraph
    
    CreateParagraph --> CountLines[Calculate line_count with text wrapping]
    CountLines --> CalcScroll[scroll_offset = line_count - area.height ⚠️ underflow risk]
    CalcScroll --> Render[Render widget with scroll offset]
    Render --> End[Display logs]

_{Last reviewed commit: ea29b5a}

@greptileai

log_scroll should have a minimum of 1, because otherwise it's possible for the top of the viewport to not be shown either for the same reason why the bottom was hidden in the previous implementation.