ntune 0.0.51

// src/lib.rs
use std::{fs::File, io::Read};

#[derive(Debug)] // This allows us to print the structure easily with `dbg!`
pub struct Grammar {
    pub def: String,
    pub new: String,
}

///Process File with custom grammer and return the neit code
pub fn process_files(
    input_file: &str,
    user_grammar_file: Option<&str>,
    neit_file: Option<&str>,
) -> String {
    let mut nc = String::new();
    let defengine = gen_grm();
    let mut usrgrm: Vec<Grammar> = Vec::new();

    // Process the input grammar file
    if !input_file.is_empty() {
        process_grammar_file(input_file, &mut usrgrm);
    }

    // Process the user grammar file if provided
    if let Some(file) = user_grammar_file {
        process_grammar_file(file, &mut usrgrm);
    }

    // Process the neit file if provided
    if let Some(file) = neit_file {
        nc = process_neit_file(file, &usrgrm, &defengine);
    }
    nc
}

// Function to process grammar files
fn process_grammar_file(file_path: &str, usrgrm: &mut Vec<Grammar>) {
    match File::open(file_path) {
        Ok(mut file) => {
            let mut content = String::new();
            if let Err(e) = file.read_to_string(&mut content) {
                eprintln!(
                    "Error reading the source grammar file '{}': {}",
                    file_path, e
                );
                std::process::exit(1);
            }
            let mut index = 1;
            for ln in content.lines() {
                if ln.starts_with("#") {
                    continue; // Skip comments
                } else {
                    let pts: Vec<&str> = ln.split("~").collect();
                    if pts.len() != 2 {
                        eprintln!(
                            "Error on line({}) in the file '{}' : {}",
                            index, file_path, ln
                        );
                        std::process::exit(1);
                    }
                    let ogv = pts[0].trim(); // Original value
                    let nv = pts[1].trim(); // New value

                    usrgrm.push(Grammar {
                        def: ogv.to_string(),
                        new: nv.to_string(),
                    });
                }
                index += 1;
            }
        }
        Err(_) => {
            eprintln!(
                "Could not find the grammar file '{}'. Ensure it exists.",
                file_path
            );
            std::process::exit(1);
        }
    }
}

// Function to process the neit file
fn process_neit_file(file_path: &str, usrgrm: &[Grammar], defengine: &[Grammar]) -> String {
    let mut nc = String::new();
    match File::open(file_path) {
        Ok(mut file) => {
            let mut content = String::new();
            if let Err(e) = file.read_to_string(&mut content) {
                eprintln!("Error reading file '{}': {}", file_path, e);
                std::process::exit(1);
            }
            let mut modified_content = String::new();
            let mut current_word = String::new();
            let mut in_string_mode = false;

            for c in content.chars() {
                if c == '"' {
                    in_string_mode = !in_string_mode;
                    modified_content.push(c);
                    continue;
                }

                if in_string_mode {
                    modified_content.push(c);
                } else {
                    if c.is_whitespace() || c.is_ascii_punctuation() {
                        if !current_word.is_empty() {
                            let replaced_word = replace_word(&current_word, usrgrm, defengine);
                            modified_content.push_str(&replaced_word);
                            current_word.clear();
                        }
                        modified_content.push(c);
                    } else {
                        current_word.push(c);
                    }
                }
            }

            // Append any remaining word after the loop ends
            if !current_word.is_empty() {
                let replaced_word: String = replace_word(&current_word, usrgrm, defengine);
                modified_content.push_str(&replaced_word);
            }
            nc.push_str(&modified_content.as_str());
        }
        Err(_) => {
            eprintln!("Could not open neit file '{}'", file_path);
            std::process::exit(1);
        }
    }
    nc
}

// Helper function to replace a word if it matches grammar definitions
fn replace_word(word: &str, usrgrm: &[Grammar], defengine: &[Grammar]) -> String {
    for mapping in usrgrm.iter().chain(defengine.iter()) {
        if word == mapping.new {
            return mapping.def.clone();
        }
    }
    word.to_string()
}

// Function to generate default grammar mappings
fn gen_grm() -> Vec<Grammar> {
    vec![
        Grammar {
            def: "fn".to_string(),
            new: "fn".to_string(),
        },
        Grammar {
            def: "may".to_string(),
            new: "may".to_string(),
        },
        Grammar {
            def: "must".to_string(),
            new: "must".to_string(),
        },
        Grammar {
            def: "=".to_string(),
            new: "=".to_string(),
        },
        Grammar {
            def: "pub".to_string(),
            new: "pub".to_string(),
        },
        Grammar {
            def: "takein".to_string(),
            new: "takein".to_string(),
        },
        Grammar {
            def: "println".to_string(),
            new: "println".to_string(),
        },
        Grammar {
            def: "print".to_string(),
            new: "print".to_string(),
        },
    ]
}