use std::path::{Path, PathBuf};
use std::sync::Mutex;

use crate::consts::*;

static LAST_SETTING_ID: Mutex<u128> = Mutex::new(0);

pub fn filename(id: u128, ext: &str) -> String {
    format!("{}.{}", id, ext)
}

pub fn setting_path_by_id(root: impl AsRef<Path>, id: u128, ext: &str) -> PathBuf {
    root.as_ref()
        .join(SETTING_FOLDER)
        .join(ID_FOLDER)
        .join(filename(id, ext))
}

pub fn setting_folder_by_app_id(root: impl AsRef<Path>, steam_app_id: u32) -> PathBuf {
    root.as_ref()
        .join(SETTING_FOLDER)
        .join(APP_ID_FOLDER)
        .join(steam_app_id.to_string())
}

pub fn setting_tag_folder_by_app_id(root: impl AsRef<Path>, steam_app_id: u32) -> PathBuf {
    root.as_ref()
        .join(SETTING_FOLDER)
        .join(APP_ID_FOLDER)
        .join(steam_app_id.to_string())
        .join(TAG_FOLDER)
}

pub fn setting_folder_by_app_id_tag(root: impl AsRef<Path>, steam_app_id: u32, tag: &str) -> PathBuf {
    root.as_ref()
        .join(SETTING_FOLDER)
        .join(APP_ID_FOLDER)
        .join(steam_app_id.to_string())
        .join(TAG_FOLDER)
        .join(tag)
}

pub fn setting_folder_by_user_id(root: impl AsRef<Path>, steam_user_id: u64) -> PathBuf {
    root.as_ref()
        .join(SETTING_FOLDER)
        .join(USER_ID_FOLDER)
        .join(steam_user_id.to_string())
}

pub fn setting_tag_folder_by_user_id(root: impl AsRef<Path>, steam_user_id: u64) -> PathBuf {
    root.as_ref()
        .join(SETTING_FOLDER)
        .join(USER_ID_FOLDER)
        .join(steam_user_id.to_string())
        .join(TAG_FOLDER)
}

pub fn setting_folder_by_user_id_tag(root: impl AsRef<Path>, steam_user_id: u64, tag: &str) -> PathBuf {
    root.as_ref()
        .join(SETTING_FOLDER)
        .join(USER_ID_FOLDER)
        .join(steam_user_id.to_string())
        .join(TAG_FOLDER)
        .join(tag)
}

pub fn setting_folder_by_tag(root: impl AsRef<Path>, tag: &str) -> PathBuf {
    root.as_ref()
        .join(SETTING_FOLDER)
        .join(TAG_FOLDER)
        .join(tag)
}

pub fn next_setting_id(root: impl AsRef<Path>) -> u128 {
    let mut lock = LAST_SETTING_ID.lock().unwrap();
    let mut last_id = *lock;
    if last_id == 0 {
        // needs init
        last_id = 1;
        let mut path = setting_path_by_id(root.as_ref(), last_id, RON_EXTENSION);
        while path.exists() {
            last_id += 1;
            path = setting_path_by_id(root.as_ref(), last_id, RON_EXTENSION);
        }
        *lock = last_id - 1;
        log::info!("setting id initialized to {}", last_id);
    }
    *lock += 1;
    *lock
}

pub struct ToSymlink {
    pub ron: Vec<PathBuf>,
    pub json: Vec<PathBuf>,
}

pub fn symlinks(root: impl AsRef<Path>, meta: &community_settings_core::v1::Metadata) -> std::io::Result<ToSymlink> {
    let mut symlink_locations = ToSymlink { ron: Vec::new(), json: Vec::new() };
    let filename_ron = filename(meta.get_id(), crate::consts::RON_EXTENSION);
    let filename_json = filename(meta.get_id(), crate::consts::JSON_EXTENSION);
    // build symlinks to app id folder
    let app_id_folder = setting_folder_by_app_id(&root, meta.steam_app_id);
    log::debug!("App id folder {}", app_id_folder.display());
    if !app_id_folder.exists() {
        std::fs::create_dir(&app_id_folder)?;
        std::fs::create_dir(setting_tag_folder_by_app_id(&root, meta.steam_app_id))?;
    }
    symlink_locations.ron.push(app_id_folder.join(&filename_ron));
    symlink_locations.json.push(app_id_folder.join(&filename_json));

    // create symlinks for user id folder
    let user_id_folder = setting_folder_by_user_id(&root, meta.steam_user_id);
    if !user_id_folder.exists() {
        std::fs::create_dir(&user_id_folder)?;
        std::fs::create_dir(setting_tag_folder_by_user_id(&root, meta.steam_user_id))?;
    }
    symlink_locations.ron.push(user_id_folder.join(&filename_ron));
    symlink_locations.json.push(user_id_folder.join(&filename_json));

    // create symlinks for each tag
    for tag in meta.tags.iter() {
        if !str_is_alphanumeric_or_space(&tag){
            continue;
        }
        // create symlinks for general tag folder
        let tag_folder = setting_folder_by_tag(&root, tag);
        if !tag_folder.exists() {
            std::fs::create_dir(&tag_folder)?;
        }
        symlink_locations.ron.push(tag_folder.join(&filename_ron));
        symlink_locations.json.push(tag_folder.join(&filename_json));

        // create symlinks for app id tag folder
        let app_tag_folder = setting_folder_by_app_id_tag(&root, meta.steam_app_id, tag);
        if !app_tag_folder.exists() {
            std::fs::create_dir(&app_tag_folder)?;
        }
        symlink_locations.ron.push(app_tag_folder.join(&filename_ron));
        symlink_locations.json.push(app_tag_folder.join(&filename_json));

        // create symlinks for user id tag folder
        let user_tag_folder = setting_folder_by_user_id_tag(&root, meta.steam_user_id, tag);
        if !user_tag_folder.exists() {
            std::fs::create_dir(&user_tag_folder)?;
        }
        symlink_locations.ron.push(user_tag_folder.join(&filename_ron));
        symlink_locations.json.push(user_tag_folder.join(&filename_json));
    }
    Ok(symlink_locations)
}

fn str_is_alphanumeric_or_space(s: &str) -> bool {
    let mut result = true;
    for ch in s.chars() {
        result &= ch.is_ascii_alphanumeric() || ch == ' ';
    }
    result
}