1jehuang--jcode/crates/jcode-base/src/login_qr.rs

use qrcode::{Color, QrCode, types::QrError};

const QUIET_ZONE_WIDTH: usize = 2;

fn env_truthy(key: &str) -> bool {
    std::env::var(key)
        .ok()
        .map(|value| {
            let trimmed = value.trim();
            !trimmed.is_empty() && trimmed != "0" && !trimmed.eq_ignore_ascii_case("false")
        })
        .unwrap_or(false)
}

fn qr_rendering_enabled() -> bool {
    env_truthy("JCODE_SHOW_LOGIN_QR") || env_truthy("JCODE_LOGIN_QR")
}

fn tui_qr_rendering_enabled() -> bool {
    env_truthy("JCODE_SHOW_TUI_LOGIN_QR") || env_truthy("JCODE_TUI_LOGIN_QR")
}

pub fn render_unicode_qr(data: &str) -> Result<String, QrError> {
    let code = QrCode::new(data.as_bytes())?;
    let code_size = code.width();
    let size = code_size + QUIET_ZONE_WIDTH * 2;
    let mut out = String::new();

    for row in (0..size).step_by(2) {
        for col in 0..size {
            let top = qr_color_at(&code, code_size, col, row);
            let bottom = if row + 1 < size {
                qr_color_at(&code, code_size, col, row + 1)
            } else {
                Color::Light
            };

            let ch = match (top, bottom) {
                (Color::Dark, Color::Dark) => '█',
                (Color::Dark, Color::Light) => '▀',
                (Color::Light, Color::Dark) => '▄',
                (Color::Light, Color::Light) => ' ',
            };
            out.push(ch);
        }
        if row + 2 < size {
            out.push('\n');
        }
    }

    Ok(out)
}

fn qr_color_at(code: &QrCode, code_size: usize, col: usize, row: usize) -> Color {
    if col < QUIET_ZONE_WIDTH
        || row < QUIET_ZONE_WIDTH
        || col >= code_size + QUIET_ZONE_WIDTH
        || row >= code_size + QUIET_ZONE_WIDTH
    {
        return Color::Light;
    }
    code[(col - QUIET_ZONE_WIDTH, row - QUIET_ZONE_WIDTH)]
}

pub fn markdown_section(data: &str, heading: &str) -> Option<String> {
    if !qr_rendering_enabled() {
        return None;
    }
    let qr = render_unicode_qr(data).ok()?;
    Some(format!("{heading}\n\n```text\n{qr}\n```"))
}

pub fn markdown_section_for_tui(data: &str, heading: &str) -> Option<String> {
    if !tui_qr_rendering_enabled() {
        return None;
    }
    let qr = render_unicode_qr(data).ok()?;
    Some(format!("{heading}\n\n```text\n{qr}\n```"))
}

pub fn indented_section(data: &str, heading: &str, indent: &str) -> Option<String> {
    if !qr_rendering_enabled() {
        return None;
    }
    let qr = render_unicode_qr(data).ok()?;
    let mut out = String::new();
    out.push_str(heading);
    out.push_str("\n\n");
    for line in qr.lines() {
        out.push_str(indent);
        out.push_str(line);
        out.push('\n');
    }
    Some(out.trim_end_matches('\n').to_string())
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::storage::lock_test_env;

    #[test]
    fn render_unicode_qr_uses_block_glyphs_without_ansi() {
        let qr = render_unicode_qr("https://example.com/login").unwrap();
        assert!(qr.contains('█') || qr.contains('▀') || qr.contains('▄'));
        assert!(qr.contains('\n'));
        assert!(!qr.contains("\u{1b}["));
    }

    #[test]
    fn markdown_section_wraps_qr_in_code_block() {
        let _guard = lock_test_env();
        crate::env::set_var("JCODE_SHOW_LOGIN_QR", "1");
        let section =
            markdown_section("https://example.com/login", "Scan this on another device:").unwrap();
        assert!(section.starts_with("Scan this on another device:\n\n```text\n"));
        assert!(section.ends_with("\n```"));
        crate::env::remove_var("JCODE_SHOW_LOGIN_QR");
    }

    #[test]
    fn tui_markdown_section_is_opt_in_even_when_general_qr_is_enabled() {
        let _guard = lock_test_env();
        crate::env::set_var("JCODE_SHOW_LOGIN_QR", "1");
        crate::env::remove_var("JCODE_SHOW_TUI_LOGIN_QR");
        crate::env::remove_var("JCODE_TUI_LOGIN_QR");
        assert!(markdown_section_for_tui("https://example.com/login", "Scan:").is_none());
        crate::env::remove_var("JCODE_SHOW_LOGIN_QR");
    }

    #[test]
    fn tui_markdown_section_uses_dedicated_env_flag() {
        let _guard = lock_test_env();
        crate::env::set_var("JCODE_SHOW_TUI_LOGIN_QR", "1");
        let section = markdown_section_for_tui("https://example.com/login", "Scan:")
            .expect("tui qr should be enabled");
        assert!(section.starts_with("Scan:\n\n```text\n"));
        assert!(section.ends_with("\n```"));
        crate::env::remove_var("JCODE_SHOW_TUI_LOGIN_QR");
    }

    #[test]
    fn indented_section_prefixes_each_line() {
        let _guard = lock_test_env();
        crate::env::set_var("JCODE_SHOW_LOGIN_QR", "1");
        let section = indented_section("https://example.com/login", "Scan:", "    ").unwrap();
        assert!(section.starts_with("Scan:\n\n    "));
        assert!(
            section
                .lines()
                .skip(2)
                .all(|line| line.is_empty() || line.starts_with("    "))
        );
        crate::env::remove_var("JCODE_SHOW_LOGIN_QR");
    }

    #[test]
    fn qr_sections_are_disabled_by_default() {
        let _guard = lock_test_env();
        crate::env::remove_var("JCODE_SHOW_LOGIN_QR");
        crate::env::remove_var("JCODE_LOGIN_QR");
        assert!(markdown_section("https://example.com/login", "Scan:").is_none());
        assert!(indented_section("https://example.com/login", "Scan:", "    ").is_none());
    }
}