use std::str::FromStr;
use crate::{status::{Status, self}, version::Version, header::{HeaderMap, Header}, parse::TryParse, error::HTTPError};

pub struct Response<T: ToString + FromStr> {
    version: Version,
    status: Status,
    headers: HeaderMap,
    body: Option<T>    
}

impl<T: ToString + FromStr> Response<T> {
    pub fn new() -> Self {
        Self {
            version: Version::HTTP11,
            status: status::SUCCESS,
            headers: HeaderMap::new(),
            body: None
        }
    }

    pub fn set_version(mut self, version: impl Into<Version>) -> Self {
        self.version = version.into();
        self
    }

    pub fn set_status(mut self, status: impl Into<Status>) -> Self {
        self.status = status.into();
        self
    }

    pub fn add_header(mut self, header: impl Into<Header>) -> Self {
        self.headers.insert(header.into());
        self
    }

    pub fn set_body(mut self, body: T) -> Self {
        self.body = Some(body);
        self
    }
}

impl<T: ToString + FromStr> TryParse for Response<T> {
    fn try_parse(s: impl Into<String>) -> Result<Self, HTTPError> {
        let s = s.into();
        let mut lines = s.lines();

        let Some(header_str) = lines.next() else {
            return Err(HTTPError::MissingHeader) 
        };

        let mut header_parts = header_str.split(" ");
        let Some(version_str) = header_parts.next() else {
            return Err(HTTPError::InvalidHeader(header_str.into()))
        };
        let version = version_str.into();

        let status_str: String = header_parts.collect();
        let status = status_str.try_into()?;

        let mut headers = HeaderMap::new();

        loop {
            let Some(next) = lines.next() else {
                return Err(HTTPError::MissingHeaderBreak)
            };

            if next.len() < 1 { break }

            let header = Header::try_parse(next)?;
            headers.insert(header);
        }

        let rest: String = lines.collect();
        let body;
        if rest.len() < 1 {
            body = None
        } else {
            body = match T::from_str(&rest) {
                Ok(body) => Some(body),
                Err(_) => return Err(HTTPError::InvalidBody)
            }
        }

        Ok(Self { version, status, headers, body })
    }
}

impl<T: ToString + FromStr> ToString for Response<T> {
    fn to_string(&self) -> String {
        let mut s = String::new();
        s.push_str(self.version.as_str());
        s.push(' ');
        s.push_str(&self.status.to_string());
        s.push_str("\r\n");
        let iter = self.headers.iter();
        for headers in iter {
            for header in headers {
                s.push_str(header.name.as_str());
                s.push_str(": ");
                s.push_str(header.value.as_str());
                s.push_str("\r\n");
            }
        }
        s.push_str("\r\n");
        if let Some(body) = &self.body {
            s.push_str(&body.to_string());
        }
        s
    }
}