use base64::{engine::general_purpose, Engine};
use reqwest::StatusCode;
use std::fmt;

use crate::{config, bots::approved_bot::modules::download::DownloadQueryData};

use self::types::{CachedMessage, DownloadFile};

pub mod types;

#[derive(Debug, Clone)]
struct DownloadError {
    status_code: StatusCode,
}

impl fmt::Display for DownloadError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "Status code is {0}", self.status_code)
    }
}

impl std::error::Error for DownloadError {}

pub async fn get_cached_message(
    download_data: &DownloadQueryData,
) -> Result<CachedMessage, Box<dyn std::error::Error + Send + Sync>> {
    let DownloadQueryData::DownloadData { book_id: id, file_type: format } = download_data;

    let client = reqwest::Client::new();
    let response = client
        .get(format!(
            "{}/api/v1/{id}/{format}",
            &config::CONFIG.cache_server_url
        ))
        .header("Authorization", &config::CONFIG.cache_server_api_key)
        .send()
        .await?
        .error_for_status()?;

    if response.status() != StatusCode::OK {
        return Err(Box::new(DownloadError {
            status_code: response.status(),
        }));
    };

    Ok(response.json::<CachedMessage>().await?)
}

pub async fn download_file(
    download_data: &DownloadQueryData,
) -> Result<DownloadFile, Box<dyn std::error::Error + Send + Sync>> {
    let DownloadQueryData::DownloadData { book_id: id, file_type: format } = download_data;

    let response = reqwest::Client::new()
        .get(format!(
            "{}/api/v1/download/{id}/{format}",
            &config::CONFIG.cache_server_url
        ))
        .header("Authorization", &config::CONFIG.cache_server_api_key)
        .send()
        .await?
        .error_for_status()?;

    if response.status() != StatusCode::OK {
        return Err(Box::new(DownloadError {
            status_code: response.status(),
        }));
    };

    let headers = response.headers();

    let base64_encoder = general_purpose::STANDARD;

    let filename = std::str::from_utf8(
        &base64_encoder
            .decode(headers.get("x-filename-b64").unwrap())
            .unwrap(),
    )
    .unwrap()
    .to_string();

    let caption = std::str::from_utf8(
        &base64_encoder
            .decode(headers.get("x-caption-b64").unwrap())
            .unwrap(),
    )
    .unwrap()
    .to_string();

    Ok(DownloadFile {
        response,
        filename,
        caption,
    })
}