mod finder;
mod matcher;
mod sorter;

use std::collections::HashMap;
use std::ffi::CStr;
use std::ffi::CString;
use std::os::raw::{c_char, c_int};
use std::sync::Mutex;
use std::sync::OnceLock;

struct Ivy {
    pub file_cache: HashMap<String, Vec<String>>,
}

static INSTANCE: OnceLock<Mutex<Ivy>> = OnceLock::new();

impl Ivy {
    pub fn new() -> Self {
        Self {
            file_cache: HashMap::new(),
        }
    }

    pub fn global() -> &'static Mutex<Ivy> {
        INSTANCE.get_or_init(|| Mutex::new(Ivy::new()))
    }
}

fn to_string(input: *const c_char) -> String {
    unsafe { CStr::from_ptr(input) }
        .to_str()
        .unwrap()
        .to_string()
}

fn get_files(directory: &String) -> Vec<String> {
    let mut ivy = Ivy::global().lock().unwrap();
    if !ivy.file_cache.contains_key(directory) {
        let finder_options = finder::Options {
            directory: directory.clone(),
        };

        ivy.file_cache
            .insert(directory.clone(), finder::find_files(finder_options));
    }

    return ivy.file_cache.get(directory).unwrap().to_vec();
}

#[no_mangle]
pub extern "C" fn ivy_init(c_base_dir: *const c_char) {
    let directory = to_string(c_base_dir);
    get_files(&directory);
}

#[no_mangle]
pub extern "C" fn ivy_cwd() -> *const c_char {
    return CString::new(std::env::current_dir().unwrap().to_str().unwrap())
        .unwrap()
        .into_raw();
}

#[no_mangle]
pub extern "C" fn ivy_match(c_pattern: *const c_char, c_text: *const c_char) -> c_int {
    let pattern = to_string(c_pattern);
    let text = to_string(c_text);

    inner_match(pattern, text)
}

pub fn inner_match(pattern: String, text: String) -> i32 {
    let m = matcher::Matcher::new(pattern);

    m.score(text.as_str()) as i32
}

#[no_mangle]
pub extern "C" fn ivy_files(c_pattern: *const c_char, c_base_dir: *const c_char) -> *const c_char {
    let pattern = to_string(c_pattern);
    let directory = to_string(c_base_dir);

    let output = inner_files(pattern, directory);

    CString::new(output).unwrap().into_raw()
}

pub fn inner_files(pattern: String, base_dir: String) -> String {
    let mut output = String::new();

    // Bail out early if the pattern is empty; it's never going to find anything
    if pattern.is_empty() {
        return output;
    }

    let files = get_files(&base_dir);

    let sorter_options = sorter::Options::new(pattern);

    let files = sorter::sort_strings(sorter_options, files);
    for file in files.iter() {
        output.push_str(&file.content);
        output.push('\n');
    }

    output
}