use crate::core::{ProfileExtra, ProfileResponse};
use std::{
  str::FromStr,
  time::{SystemTime, UNIX_EPOCH},
};

/// parse the string
fn parse_string<T: FromStr>(target: &str, key: &str) -> Option<T> {
  match target.find(key) {
    Some(idx) => {
      let idx = idx + key.len();
      let value = &target[idx..];
      match match value.split(';').nth(0) {
        Some(value) => value.trim().parse(),
        None => value.trim().parse(),
      } {
        Ok(r) => Some(r),
        Err(_) => None,
      }
    }
    None => None,
  }
}

/// fetch and parse the profile url
/// maybe it contains some Subscription infomations, maybe not
pub async fn fetch_profile(url: &str, with_proxy: bool) -> Result<ProfileResponse, String> {
  let builder = reqwest::ClientBuilder::new();
  let client = match with_proxy {
    true => builder.build(),
    false => builder.no_proxy().build(),
  };

  let resp = match client.unwrap().get(url).send().await {
    Ok(res) => res,
    Err(_) => return Err("failed to create https client".into()),
  };

  let header = resp.headers();

  // parse the Subscription Userinfo
  let extra = match header.get("Subscription-Userinfo") {
    Some(value) => {
      let sub_info = value.to_str().unwrap_or("");

      Some(ProfileExtra {
        upload: parse_string(sub_info, "upload=").unwrap_or(0),
        download: parse_string(sub_info, "download=").unwrap_or(0),
        total: parse_string(sub_info, "total=").unwrap_or(0),
        expire: parse_string(sub_info, "expire=").unwrap_or(0),
      })
    }
    None => None,
  };

  let file = {
    let now = SystemTime::now()
      .duration_since(UNIX_EPOCH)
      .unwrap()
      .as_secs();
    format!("{}.yaml", now)
  };

  let name = match header.get("Content-Disposition") {
    Some(name) => {
      let name = name.to_str().unwrap();
      parse_string::<String>(name, "filename=").unwrap_or(file.clone())
    }
    None => file.clone(),
  };

  // get the data
  match resp.text_with_charset("utf-8").await {
    Ok(data) => Ok(ProfileResponse {
      file,
      name,
      data,
      extra,
    }),
    Err(_) => Err("failed to parse the response data".into()),
  }
}

#[test]
fn test_parse_value() {
  let test_1 = "upload=111; download=2222; total=3333; expire=444";
  let test_2 = "attachment; filename=Clash.yaml";

  assert_eq!(parse_string::<usize>(test_1, "upload=").unwrap(), 111);
  assert_eq!(parse_string::<usize>(test_1, "download=").unwrap(), 2222);
  assert_eq!(parse_string::<usize>(test_1, "total=").unwrap(), 3333);
  assert_eq!(parse_string::<usize>(test_1, "expire=").unwrap(), 444);
  assert_eq!(
    parse_string::<String>(test_2, "filename=").unwrap(),
    format!("Clash.yaml")
  );

  assert_eq!(parse_string::<usize>(test_1, "aaa="), None);
  assert_eq!(parse_string::<usize>(test_1, "upload1="), None);
  assert_eq!(parse_string::<usize>(test_1, "expire1="), None);
  assert_eq!(parse_string::<usize>(test_2, "attachment="), None);
}