bible 0.3.0

use std::io::Read;
use std::time::Duration;

use crate::bible::Bible;
use crate::error::{Error, Result};
use crate::storage;

const RAW_URL_BASE: &str =
    "https://raw.githubusercontent.com/Beblia/Holy-Bible-XML-Format/master/";

// Largest Beblia XML files we expect. KJV is ~4MB; concordance variants and
// some Asian-language texts can run larger. We cap at 32MB to bound memory
// without rejecting any sane translation.
const MAX_BODY_BYTES: u64 = 32 * 1024 * 1024;

/// Callback signature: `progress(bytes_so_far, total_bytes_if_known)`.
pub type Progress<'a> = &'a mut dyn FnMut(u64, Option<u64>);

pub fn install(id: &str, mut progress: Option<Progress<'_>>) -> Result<Bible> {
    let url = format!("{RAW_URL_BASE}{id}.xml");
    let config = ureq::Agent::config_builder()
        .timeout_global(Some(Duration::from_secs(60)))
        .user_agent(concat!("bible-tui/", env!("CARGO_PKG_VERSION")))
        .build();
    let agent: ureq::Agent = config.into();

    let mut resp = agent
        .get(&url)
        .call()
        .map_err(|e| Error::Http(e.to_string()))?;

    let total = resp.body().content_length();
    let mut reader = resp
        .body_mut()
        .with_config()
        .limit(MAX_BODY_BYTES)
        .reader();

    let mut buf = Vec::with_capacity(total.unwrap_or(2 * 1024 * 1024) as usize);
    let mut chunk = [0u8; 16 * 1024];
    let mut bytes: u64 = 0;
    loop {
        let n = reader
            .read(&mut chunk)
            .map_err(|e| Error::Http(e.to_string()))?;
        if n == 0 {
            break;
        }
        buf.extend_from_slice(&chunk[..n]);
        bytes += n as u64;
        if let Some(p) = progress.as_deref_mut() {
            p(bytes, total);
        }
    }

    let xml = String::from_utf8(buf).map_err(|e| Error::Xml(format!("not utf-8: {e}")))?;
    let bible = crate::parser::parse_xml(&xml, id)?;
    storage::save_bible(&bible)?;
    Ok(bible)
}