use std::{io::Write, net::TcpStream, time::SystemTime};

use chrono::{DateTime, Utc};
use http::StatusCode;
use serde::{Deserialize, Serialize};

use crate::{
    text_template_result::TextTemplateResult,
    utils::{render_http500, STATIC_404_DEFAULT},
};

#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct HttpResponse {
    #[serde(skip, default = "StatusCode::default")]
    pub http_code: StatusCode,
    pub payload: Vec<u8>,
    pub content_type: Option<String>,
    pub last_modified: Option<SystemTime>,
    pub location: Option<String>,
    pub hsts: bool,
}

impl From<TextTemplateResult> for HttpResponse {
    fn from(buffer: TextTemplateResult) -> Self {
        HttpResponse::new(
            StatusCode::OK,
            buffer.text.as_bytes(),
            buffer.mime,
            buffer.time,
            None,
            false,
        )
    }
}

impl HttpResponse {
    pub fn new(
        http_code: StatusCode,
        payload: &[u8],
        content_type: Option<String>,
        last_modified: Option<SystemTime>,
        location: Option<String>,
        hsts: bool,
    ) -> Self {
        Self {
            http_code,
            payload: payload.to_vec(),
            content_type,
            last_modified,
            location,
            hsts,
        }
    }

    pub fn send_reply(&self, stream: &TcpStream) -> std::io::Result<()> {
        reply_http11_response(
            stream,
            &self.http_code,
            self.payload.as_slice(),
            self.content_type.as_ref(),
            self.last_modified.as_ref(),
            self.location.as_ref(),
            self.hsts,
        )
    }

    pub fn with_hsts(mut self, hsts: bool) -> Self {
        self.hsts = hsts;
        self
    }

    pub fn with_last_modified(mut self, last_modified: Option<&SystemTime>) -> Self {
        self.last_modified = last_modified.copied();
        self
    }

    pub fn generate_304(t: SystemTime) -> HttpResponse {
        HttpResponse::new(
            StatusCode::NOT_MODIFIED,
            Vec::<u8>::default().as_slice(),
            None,
            Some(t),
            None,
            false,
        )
    }

    pub fn generate_302<T: Into<String>>(s: T) -> HttpResponse {
        HttpResponse::new(
            StatusCode::FOUND,
            Vec::<u8>::default().as_slice(),
            None,
            None,
            Some(s.into()),
            false,
        )
    }

    pub fn generate_404() -> HttpResponse {
        HttpResponse::new(
            StatusCode::NOT_FOUND,
            STATIC_404_DEFAULT.as_bytes(),
            Some("text/html; charset=utf-8".to_string()),
            None,
            None,
            false,
        )
    }

    pub fn generate_500(reason: Option<&str>) -> HttpResponse {
        HttpResponse::new(
            StatusCode::INTERNAL_SERVER_ERROR,
            render_http500(reason).as_bytes(),
            Some("text/html; charset=utf-8".to_string()),
            None,
            None,
            false,
        )
    }
}

fn reply_http11_response(
    mut stream: &TcpStream,
    http_code: &StatusCode,
    payload: &[u8],
    content_type: Option<&String>,
    last_modified: Option<&SystemTime>,
    location: Option<&String>,
    hsts: bool,
) -> std::io::Result<()> {
    stream.write_all(
        format!(
            "HTTP/1.1 {} {}\r\n",
            http_code.as_u16(),
            http_code.canonical_reason().unwrap_or("Unknown")
        )
        .as_bytes(),
    )?;
    stream.write_all("Connection: close\r\n".as_bytes())?;
    stream.write_all(format!("Content-Length: {}\r\n", payload.len()).as_bytes())?;
    if let Some(x) = content_type {
        stream.write_all(format!("Content-Type: {}\r\n", x).as_bytes())?
    };
    if let Some(modified_date) = last_modified {
        let dt: DateTime<Utc> = (*modified_date).into();
        let date = dt.format("%a, %d %b %Y %H:%M:%S %z");
        stream.write_all(format!("Last-Modified: {}\r\n", date).as_bytes())?
    };
    if let Some(next_location) = location {
        stream.write_all(format!("Location: {}\r\n", next_location).as_bytes())?
    };
    if hsts {
        stream.write_all("Strict-Transport-Security: max-age=31536000\r\n".as_bytes())?
    }
    stream.write_all("\r\n".as_bytes())?;
    stream.write_all(payload)?;
    stream.flush()?;
    Ok(())
}