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//! Depth path matcher

use super::MatchMaker;

/// Based on actual path depth
///
/// Path is matched when path depth is higher or equal min and lower or equal max (optional)
#[derive(Default, Debug, Clone)]
pub struct Depth {
    min: usize,
    max: Option<usize>,
}

impl Depth {
    /// Creates new depth matcher
    ///
    /// # Arguments
    /// * `min` - minimal depth (lower won't be matched)
    /// * `max` - maximal depth - optional (higher won't be matched)
    pub fn new(min: usize, max: Option<usize>) -> Self {
        Self { min, max }
    }

    /// Returns depth of a given path
    pub fn get_depth(path: &str) -> usize {
        let mut escaped: bool = false;
        let mut depth: usize = 0;
        for chr in path.chars() {
            if escaped {
                escaped = false;
            } else if chr == '\\' {
                escaped = true;
            } else if chr == '}' || chr == ']' {
                depth += 1;
            }
        }
        depth
    }
}

impl MatchMaker for Depth {
    fn match_path(&self, path: &str) -> bool {
        let depth = Depth::get_depth(path);
        if let Some(max) = self.max {
            self.min <= depth && max >= depth
        } else {
            self.min <= depth
        }
    }
}

#[cfg(test)]
mod tests {
    use super::{Depth, MatchMaker};

    #[test]
    fn get_depth() {
        assert_eq!(Depth::get_depth(""), 0);
        assert_eq!(Depth::get_depth("[1]"), 1);
        assert_eq!(Depth::get_depth(r#"{"first"}"#), 1);
        assert_eq!(Depth::get_depth(r#"[1]{"first"}"#), 2);
        assert_eq!(Depth::get_depth(r#"{"first"}[1]"#), 2);
        assert_eq!(Depth::get_depth(r#"{"escaped \] \}"}"#), 1);
    }

    #[test]
    fn match_path() {
        let depth = Depth::new(2, None);

        assert!(!depth.match_path(r#"{"People"}"#));
        assert!(depth.match_path(r#"{"People"}[0]"#));
        assert!(depth.match_path(r#"{"People"}[0]{"Age"}"#));
        assert!(depth.match_path(r#"{"People"}[0]{"Height"}"#));
        assert!(depth.match_path(r#"{"People"}[1]"#));
        assert!(depth.match_path(r#"{"People"}[1]{"Age"}"#));
        assert!(depth.match_path(r#"{"People"}[1]{"Height"}"#));

        let depth = Depth::new(2, Some(2));
        assert!(!depth.match_path(r#"{"People"}"#));
        assert!(depth.match_path(r#"{"People"}[0]"#));
        assert!(!depth.match_path(r#"{"People"}[0]{"Age"}"#));
        assert!(!depth.match_path(r#"{"People"}[0]{"Height"}"#));
        assert!(depth.match_path(r#"{"People"}[1]"#));
        assert!(!depth.match_path(r#"{"People"}[1]{"Age"}"#));
        assert!(!depth.match_path(r#"{"People"}[1]{"Height"}"#));
    }
}