use anyhow::{anyhow, Result};
use serde::{Deserialize, Serialize};
use tauri::{AppHandle, Manager};
use tokio::process::Command;
use std::{path::{Path, PathBuf}, sync::OnceLock};

use crate::model::misc::Game;

#[cfg(not(target_os = "windows"))]
static NAME: &str = "startliner";

#[cfg(target_os = "windows")]
static NAME: &str = "STARTLINER";

#[derive(Clone, Serialize, Deserialize)]
pub struct Dirs {
    config_dir: PathBuf,
    data_dir: PathBuf,
    cache_dir: PathBuf,
}

static DIRS: OnceLock<Dirs> = OnceLock::new();

pub fn init_dirs(apph: &AppHandle) {
    DIRS.get_or_init(|| {
        if cfg!(windows) {
            Dirs {
                config_dir: apph.path().data_dir().expect("Unable to set project directories").join(NAME),
                data_dir: apph.path().cache_dir().expect("Unable to set project directories").join(NAME).join("data"),
                cache_dir: apph.path().cache_dir().expect("Unable to set project directories").join(NAME).join("cache"),
            }
        } else {
            Dirs {
                config_dir: apph.path().config_dir().expect("Unable to set project directories").join(NAME),
                data_dir: apph.path().data_dir().expect("Unable to set project directories").join(NAME),
                cache_dir: apph.path().cache_dir().expect("Unable to set project directories").join(NAME),
            }
        }
    });
}

pub fn all_dirs() -> &'static Dirs {
    &DIRS.get().expect("Directories uninitialized")
}

pub fn config_dir() -> &'static Path {
    &DIRS.get().expect("Directories uninitialized").config_dir
}

pub fn profile_config_dir(game: Game, name: &str) -> PathBuf {
    config_dir().join(format!("profile-{}-{}", game, name))
}

pub fn data_dir() -> &'static Path {
    &DIRS.get().expect("Directories uninitialized").data_dir
}

pub fn cache_dir() -> &'static Path {
    &DIRS.get().expect("Directories uninitialized").cache_dir
}

pub fn pkg_dir() -> PathBuf {
    data_dir().join("pkg")
}

pub fn pkg_dir_of(namespace: &str, name: &str) -> PathBuf {
    pkg_dir().join(format!("{}-{}", namespace, name))
}

pub fn copy_directory(src: impl AsRef<Path>, dst: impl AsRef<Path>, recursive: bool) -> std::io::Result<()> {
    std::fs::create_dir_all(dst.as_ref()).unwrap();
    for entry in std::fs::read_dir(src.as_ref())? {
        let entry = entry?;
        let meta = entry.metadata()?;
        if meta.is_dir() {
            if recursive == true {
                copy_directory(&entry.path(), &dst.as_ref().join(entry.file_name()), true)?;
            } else {
                log::warn!("Skipping directory {:?}", meta);
            }
        } else {
            std::fs::copy(&entry.path(), &dst.as_ref().join(entry.file_name()))?;
        }
    }
    Ok(())
}

#[cfg(target_os = "linux")]
pub async fn symlink(src: impl AsRef<Path>, dst: impl AsRef<Path>) -> std::io::Result<()> {
    tokio::fs::symlink(src, dst).await
}

#[cfg(target_os = "windows")]
pub async fn symlink(src: impl AsRef<Path>, dst: impl AsRef<Path>) -> std::io::Result<()> {
    //std::os::windows::fs::junction_point(src, dst) // is unstable
    junction::create(src, dst)
}

#[cfg(target_os = "windows")]
pub static CREATE_NO_WINDOW: u32 = 0x08000000;

#[cfg(target_os = "windows")]
pub async fn pkill(process_name: &str) {
    _ = Command::new("taskkill.exe").arg("/f").arg("/im").arg(process_name)
        .creation_flags(CREATE_NO_WINDOW).output().await;
}

#[cfg(target_os = "linux")]
pub async fn pkill(process_name: &str) {
    _ = Command::new("pkill").arg(process_name)
        .output().await;
}

pub fn clean_up_opts(dir: impl AsRef<Path>) -> Result<()> {
    log::debug!("begin clean_up_opts");
    if dir.as_ref().is_dir() {
        for entry in std::fs::read_dir(dir)? {
            let entry = entry?;
            let path = entry.path();
            log::debug!("{:?}", path);
            if path.is_symlink() {
                #[cfg(target_os = "windows")]
                std::fs::remove_dir(path)?;
                #[cfg(not(target_os = "windows"))]
                std::fs::remove_file(path)?;
            } else {
                log::error!("Not a symlink: {:?}", path);
            }
        }
    }
    log::debug!("end clean_up_opts");
    Ok(())
}

pub trait PathStr {
    fn stringify(&self) -> Result<String>;
}

fn path_to_str(p: impl AsRef<Path>) -> Result<String> {
    Ok(p.as_ref().to_str().ok_or_else(|| anyhow!("Invalid path: {:?}", p.as_ref()))?.to_owned())
}

impl PathStr for Path {
    fn stringify(&self) -> Result<String> {
        path_to_str(self)
    }
}

impl PathStr for PathBuf {
    fn stringify(&self) -> Result<String> {
        path_to_str(&self)
    }
}

#[allow(dead_code)]
pub fn bool_to_01(val: bool) -> &'static str {
    return if val { "1" } else { "0" }
}

// rm -r with checks
pub async fn remove_dir_all(path: impl AsRef<Path>) -> Result<()> {
    let canon = path.as_ref().canonicalize()?;

    if canon.to_string_lossy().len() < 10 {
        return Err(anyhow!("invalid remove_dir_all target: too short"));
    }

    if canon.starts_with(data_dir().canonicalize()?)
    || canon.starts_with(config_dir().canonicalize()?)
    || canon.starts_with(cache_dir().canonicalize()?) {
        tokio::fs::remove_dir_all(path).await
            .map_err(|e| anyhow!("invalid remove_dir_all target: {:?}", e))?;
        Ok(())
    } else {
        Err(anyhow!("invalid remove_dir_all target: not in a data directory"))
    }
}

#[cfg(target_os = "windows")]
pub fn create_shortcut(
    apph: AppHandle,
    meta: &crate::profiles::ProfileMeta
) -> Result<()> {
    use winsafe::{co, prelude::{ole_IPersistFile, ole_IUnknown, shell_IShellLink}, CoCreateInstance, CoInitializeEx, IPersistFile};
    let _com_guard = CoInitializeEx(
        co::COINIT::APARTMENTTHREADED
        | co::COINIT::DISABLE_OLE1DDE,
    )?;
    let obj = CoCreateInstance::<winsafe::IShellLink>(
        &co::CLSID::ShellLink,
        None,
        co::CLSCTX::INPROC_SERVER,
    )?;

    let target_dir = apph.path().cache_dir()?.join(NAME);
    let target_path = target_dir.join("startliner.exe");
    let lnk_path = apph.path().desktop_dir()?.join(format!("{} {}.lnk", &meta.game.print(), &meta.name));

    obj.SetPath(target_path.to_str().ok_or_else(|| anyhow!("Illegal target path"))?)?;
    obj.SetDescription(&format!("{} – {} (STARTLINER)", &meta.game.print(), &meta.name))?;
    obj.SetArguments(&format!("--start --game {} --profile {}", &meta.game, &meta.name))?;
    obj.SetIconLocation(
        target_dir.join(format!("icon-{}.ico", &meta.game)).to_str().ok_or_else(|| anyhow!("Illegal icon path"))?,
        0
    )?;

    match meta.game {
        Game::Ongeki => std::fs::write(target_dir.join("icon-ongeki.ico"), include_bytes!("../../res/icon-ongeki.ico")),
        Game::Chunithm => std::fs::write(target_dir.join("icon-chunithm.ico"), include_bytes!("../../res/icon-chunithm.ico"))
    }?;

    let file = obj.QueryInterface::<IPersistFile>()?;

    file.Save(Some(lnk_path.to_str().ok_or_else(|| anyhow!("Illegal shortcut path"))?), true)?;

    Ok(())
}