use log::debug;
use mime_guess::{Mime, mime};
use std::path::Path;
use std::str::FromStr;
use tokio::fs;

pub async fn read_response_body(body_path: impl AsRef<Path>, content_type: &str) -> Option<String> {
    let body = fs::read(body_path).await.ok()?;
    let body_charset = parse_charset(content_type).unwrap_or("utf-8".to_string());
    debug!("body_charset: {}", body_charset);
    if let Some(decoder) = charset::Charset::for_label(body_charset.as_bytes()) {
        debug!("Using decoder for charset: {}", body_charset);
        let (cow, real_encoding, exist_replace) = decoder.decode(&body);
        debug!(
            "Decoded body with charset: {}, real_encoding: {:?}, exist_replace: {}",
            body_charset, real_encoding, exist_replace
        );
        return cow.into_owned().into();
    }

    Some(String::from_utf8_lossy(&body).to_string())
}

fn parse_charset(content_type: &str) -> Option<String> {
    let mime: Mime = Mime::from_str(content_type).ok()?;
    mime.get_param(mime::CHARSET).map(|v| v.to_string())
}