gemini-engine 1.2.1

use crate::core::Vec2D;
use std::{fmt, sync::OnceLock};
use terminal_size::terminal_size;

static TERMINAL_PREPARED: OnceLock<bool> = OnceLock::new();

/// Returns the size of the terminal as a `Vec2D`, using [`terminal_size::terminal_size()`]
#[must_use]
pub fn get_terminal_size_as_vec2d() -> Option<Vec2D> {
    let (width, height) = terminal_size()?;
    Some(Vec2D::new(i64::from(width.0), i64::from(height.0)))
}

/// Blocks the process until the console window is resized to fit `view_size`
pub fn block_until_resized(view_size: Vec2D) {
    if let Some(term_size) = get_terminal_size_as_vec2d() {
        if term_size.cmplt(view_size).any() {
            println!("Please resize your console window to fit the render\r");
            loop {
                let term_size = get_terminal_size_as_vec2d().unwrap_or_else(|| unreachable!());
                if term_size.cmpge(view_size).all() {
                    break;
                }
            }
        }
    }
}

/// Prepares the console. This is only done the first time this function is called, after which it does nothing. Operations
/// - Prints blank lines to move previous console lines out of the way
/// - If on Windows, Calls [`enable_ansi_support()`](https://crates.io/crates/enable-ansi-support) to enable Windows support
///
/// Returns an error if [`terminal_size`] returns `None`, or if it fails to write to the formatter
pub fn prepare_terminal(f: &mut fmt::Formatter<'_>) -> Result<(), String> {
    // If the console hasn't been prepared before
    if TERMINAL_PREPARED.get().is_none() {
        // Prevent the console from being prepared again
        TERMINAL_PREPARED.get_or_init(|| true);

        let Some((_, height)) = terminal_size() else {
            return Err(String::from("Couldn't get terminal size"));
        };

        write!(f, "{}", "\n".repeat(height.0 as usize)).map_err(|e| e.to_string())?;

        // If using Windows, call a function to enable full ANSI escape code support.
        #[cfg(windows)]
        if enable_ansi_support::enable_ansi_support().is_err() {
            return Err(String::from("Failed to enable Windows ANSI support."));
        }
    }

    Ok(())
}