pub mod header {
    pub struct Header {
        key: &'static str,
        value: &'static str,
    }

    impl Header {
        pub fn to_string(&self) -> String {
            format!("{}: {}", &self.key, &self.value)
        }

        pub fn new(key: &'static str, value: &'static str) -> Header {
            Header {
                key: key.trim(),
                value: value.trim(),
            }
        }
    }

    pub struct Headers {
        headers: Vec<Header>,
    }

    impl Headers {

        pub fn new() -> Headers {
            Headers { headers: vec![] }
        }

        pub fn append(&mut self, header: Header) {
            self.headers.push(header);
        }

        pub fn has(&self, key: &'static str) -> bool {
            for header in &self.headers {
                if key.trim().to_lowercase().eq(&header.key.to_lowercase()) {
                    return true;
                }
            }

            false
        }

        pub fn get(&self, key: &'static str) -> Option<&Header> {
            for header in &self.headers {
                if key.trim().to_lowercase().eq(&header.key.to_lowercase()) {
                    return Some(header);
                }
            }

            None
        }

        pub fn finalize(&self) -> String {
            let mut final_string = String::new();

            for header in &self.headers {
                final_string += &header.to_string();
                final_string += "\r\n\r\n";
            }

            final_string
        }
    }
}


#[cfg(test)]
mod tests {

    #[test]
    fn to_string() {
        use super::header::Header;

        let header = Header::new("Content-Type", "application/json");

        assert_eq!(header.to_string(), String::from("Content-Type: application/json"));
    }

    #[test]
    fn has() {
        use super::header::Header;
        use super::header::Headers;

        let mut headers = Headers::new();
        headers.append(Header::new("Content-Type", "Application/Json"));
        headers.append(Header::new("Content-Type", "Application/Json"));

        assert_eq!(true, headers.has("content-type"));
    }
}