ag-session 0.14.7

//! Pure focused-review parsing helpers shared across session frontends.

use std::fmt;
use std::str::FromStr;

/// Durable state of one focused-review generation attempt.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum FocusedReviewStatus {
    /// Review generation is still running.
    Pending,
    /// Review generation completed and persisted its markdown.
    Ready,
    /// Review generation completed without usable markdown.
    Failed,
}

impl fmt::Display for FocusedReviewStatus {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        formatter.write_str(match self {
            Self::Pending => "Pending",
            Self::Ready => "Ready",
            Self::Failed => "Failed",
        })
    }
}

impl FromStr for FocusedReviewStatus {
    type Err = String;

    fn from_str(value: &str) -> Result<Self, Self::Err> {
        match value {
            "Pending" => Ok(Self::Pending),
            "Ready" => Ok(Self::Ready),
            "Failed" => Ok(Self::Failed),
            _ => Err(format!("Unknown focused review status: {value}")),
        }
    }
}

/// Extracts actionable suggestion content from focused-review markdown.
///
/// Returns `None` when the `### Suggestions` section is missing, empty, or
/// reports `- None` with optional trailing punctuation.
#[must_use]
pub fn review_suggestions(review_text: &str) -> Option<String> {
    let suggestions_header = "### Suggestions";
    let header_start = review_text.find(suggestions_header)?;
    let content_start = header_start + suggestions_header.len();
    let content = &review_text[content_start..];
    let section_end = content.find("\n### ").unwrap_or(content.len());
    let suggestions = content[..section_end].trim();

    if suggestions.is_empty() || is_no_suggestions_sentinel(suggestions) {
        return None;
    }

    Some(suggestions.to_string())
}

/// Returns whether a suggestions section contains only the required `None`
/// sentinel plus optional trailing punctuation.
fn is_no_suggestions_sentinel(suggestions: &str) -> bool {
    suggestions.strip_prefix("- None").is_some_and(|suffix| {
        suffix
            .chars()
            .all(|character| character.is_ascii_punctuation())
    })
}

/// Returns whether focused-review markdown contains suggestions that `/apply`
/// can act on.
#[must_use]
pub fn has_actionable_review_suggestions(review_text: Option<&str>) -> bool {
    review_text.and_then(review_suggestions).is_some()
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn focused_review_status_round_trips_persisted_values() {
        // Arrange
        let statuses = [
            FocusedReviewStatus::Pending,
            FocusedReviewStatus::Ready,
            FocusedReviewStatus::Failed,
        ];

        // Act / Assert
        for status in statuses {
            assert_eq!(status.to_string().parse(), Ok(status));
        }
        assert!("Unknown".parse::<FocusedReviewStatus>().is_err());
    }

    #[test]
    fn test_review_suggestions_returns_suggestions_content() {
        // Arrange
        let review_text = "\
### Summary

- Good shape.

### Suggestions

- Fix the typo in `README.md:10`.";

        // Act
        let suggestions = review_suggestions(review_text);

        // Assert
        assert_eq!(
            suggestions,
            Some("- Fix the typo in `README.md:10`.".to_string())
        );
    }

    #[test]
    fn test_review_suggestions_returns_none_for_no_suggestions() {
        // Arrange
        let review_text = "\
### Summary

- Good shape.

### Suggestions

- None";

        // Act
        let suggestions = review_suggestions(review_text);

        // Assert
        assert_eq!(suggestions, None);
    }

    #[test]
    fn test_review_suggestions_returns_none_for_punctuated_no_suggestions() {
        // Arrange
        let review_text = "## Review\n\n### Suggestions\n\n- None.";

        // Act
        let suggestions = review_suggestions(review_text);

        // Assert
        assert_eq!(suggestions, None);
    }

    #[test]
    fn test_review_suggestions_returns_none_when_section_missing() {
        // Arrange
        let review_text = "\
### Summary

- Good shape overall.";

        // Act
        let suggestions = review_suggestions(review_text);

        // Assert
        assert_eq!(suggestions, None);
    }

    #[test]
    fn test_review_suggestions_stops_at_next_heading() {
        // Arrange
        let review_text = "\
### Summary

- Good shape.

### Suggestions

- Fix the typo in `README.md:10`.

### Project Impact

- Great work overall.";

        // Act
        let suggestions = review_suggestions(review_text);

        // Assert
        assert_eq!(
            suggestions,
            Some("- Fix the typo in `README.md:10`.".to_string())
        );
    }

    #[test]
    fn test_review_suggestions_returns_none_for_empty_section() {
        // Arrange
        let review_text = "\
### Suggestions

### Project Impact

- None";

        // Act
        let suggestions = review_suggestions(review_text);

        // Assert
        assert_eq!(suggestions, None);
    }

    #[test]
    fn test_has_actionable_review_suggestions_detects_suggestions_section() {
        // Arrange
        let review_with_suggestions = "## Review\n### Suggestions\n- Fix typo\n### Notes";
        let review_without_suggestions = "## Review\n### Suggestions\n- None\n### Notes";

        // Act
        let with_suggestions = has_actionable_review_suggestions(Some(review_with_suggestions));
        let without_suggestions =
            has_actionable_review_suggestions(Some(review_without_suggestions));
        let missing_header = has_actionable_review_suggestions(Some("## Review"));

        // Assert
        assert!(with_suggestions);
        assert!(!without_suggestions);
        assert!(!missing_header);
    }
}