//! This example shows how to use a file as input to a lexer, rather than a hardcoded string.
//!
//! This lexer simply captures as many standard identifiers as it can, and ignores everything else.

#![allow(missing_docs)]

use std::{
    fs,
    io::{stdin, stdout, BufRead, Write},
    path::Path,
};

use alkale::{span::Spanned, token::Token, LexerResult, SourceCodeScanner};

pub fn main() {
    // Buffer for the input path
    let mut str_path = String::new();

    println!(
        "Current path: {:?}",
        std::env::current_dir().expect("No current dir exists.")
    );
    println!("Leave input blank to use default path.");
    print!("Input path to file: ");

    stdout().lock().flush().expect("Could not flush stdout.");

    // Read path input
    stdin()
        .lock()
        .read_line(&mut str_path)
        .expect("Could not read stdin.");

    let trimmed = str_path.trim();

    // Get path from string.
    let path = if trimmed.is_empty() {
        Path::new("./examples/file/file.txt")
    } else {
        Path::new(trimmed)
    };

    println!();
    println!("Path: {path:?}");

    let source = fs::read_to_string(path).expect("Could not read file");

    // Create a context from the BufReader. The closure dictates
    // how we want to handle any read failures— in this case just panic.
    let context = SourceCodeScanner::new(&source);
    let mut result = LexerResult::<&str, ()>::new();

    // Lexer logic
    while context.has_next() {
        if let Some(Spanned { data, span }) = context.try_consume_standard_identifier() {
            result.push_token(Token::new(data, span));
        } else {
            context.skip();
        }
    }

    // Print result
    println!();
    println!("{:#?}", result.finalize());
}