// Collector
// Collector that stores a complete set of data structures.
pub struct Collector {
    pub definitions: Vec<(String, String)>,
    pub arguments: Vec<(String, String)>,
}

// Implementation of Collector
// Functions to read data into the collector.
impl Collector {
    // @name eval
    // @brief Evaluate a given term
    // @param &mut self, term: &str
    pub fn eval(&mut self, term: String) -> String {
        let editing_string: String = term.clone();

        // Turn into words

        // Rule 0: Replace definitions

        // Rule 1: Solve brackets
        let mut collect_bracket: bool = false;
        let mut bracket_term: String = String::from("");
        let mut resolved_bracket_term: String = String::from("");
        for character in editing_string.chars() {
            if character == '(' {
                collect_bracket = true;
                continue;
            }

            if character == ')' {
                if !collect_bracket {
                    panic!("Closing bracket without matching opening bracket!");
                } else {
                    resolved_bracket_term += self.eval(bracket_term).as_str();
                    bracket_term = String::from("");
                    collect_bracket = false;
                }
                continue;
            }

            if collect_bracket {
                bracket_term += character.to_string().as_str();
            } else {
                resolved_bracket_term += character.to_string().as_str();
            }
        }

        // Rule 2: Mul/Div

        // Rule 3: Add/Sub

        // Rule 4: Clean up from left to right

        println!("{}", resolved_bracket_term);
        return resolved_bracket_term;
    }
}