#[must_use]
#[derive(Debug, Clone)]
pub struct Summary {
    // Encountered e.g. an IO error.
    has_operational_errors: bool,

    // Failed to reformat code because of parsing errors.
    has_parsing_errors: bool,

    // Code is valid, but it is impossible to format it properly.
    has_formatting_errors: bool,

    // Formatted code differs from existing code (write-mode diff only).
    pub has_diff: bool,
}

impl Summary {
    pub fn new() -> Summary {
        Summary {
            has_operational_errors: false,
            has_parsing_errors: false,
            has_formatting_errors: false,
            has_diff: false,
        }
    }

    pub fn has_operational_errors(&self) -> bool {
        self.has_operational_errors
    }

    pub fn has_parsing_errors(&self) -> bool {
        self.has_parsing_errors
    }

    pub fn has_formatting_errors(&self) -> bool {
        self.has_formatting_errors
    }

    pub fn add_operational_error(&mut self) {
        self.has_operational_errors = true;
    }

    pub fn add_parsing_error(&mut self) {
        self.has_parsing_errors = true;
    }

    pub fn add_formatting_error(&mut self) {
        self.has_formatting_errors = true;
    }

    pub fn add_diff(&mut self) {
        self.has_diff = true;
    }

    pub fn has_no_errors(&self) -> bool {
        !(self.has_operational_errors || self.has_parsing_errors || self.has_formatting_errors ||
          self.has_diff)
    }

    pub fn add(&mut self, other: Summary) {
        self.has_operational_errors |= other.has_operational_errors;
        self.has_formatting_errors |= other.has_formatting_errors;
        self.has_parsing_errors |= other.has_parsing_errors;
        self.has_diff |= other.has_diff;
    }

    pub fn print_exit_codes() {
        let exit_codes = r#"Exit Codes:
    0 = No errors
    1 = Encountered operational errors e.g. an IO error
    2 = Failed to reformat code because of parsing errors
    3 = Code is valid, but it is impossible to format it properly
    4 = Formatted code differs from existing code (write-mode diff only)"#;
        println!("{}", exit_codes);
    }
}