// Copyright 2019-2022 Tauri Programme within The Commons Conservancy
// SPDX-License-Identifier: Apache-2.0
// SPDX-License-Identifier: MIT

use std::{
    env::temp_dir,
    path::{Component, Path, PathBuf, MAIN_SEPARATOR},
};

use tauri::{
    plugin::{Builder, TauriPlugin},
    AppHandle, Manager, Runtime, State,
};

use serde_repr::{Deserialize_repr, Serialize_repr};

mod error;
pub use error::*;

#[cfg(desktop)]
mod desktop;
#[cfg(mobile)]
mod mobile;

#[cfg(desktop)]
use desktop::PathResolver;
#[cfg(mobile)]
use mobile::PathResolver;

/// A base directory to be used in [`resolve_directory`].
///
/// The base directory is the optional root of a file system operation.
/// If informed by the API call, all paths will be relative to the path of the given directory.
///
/// For more information, check the [`dirs_next` documentation](https://docs.rs/dirs_next/).
#[derive(Serialize_repr, Deserialize_repr, Clone, Copy, Debug)]
#[repr(u16)]
#[non_exhaustive]
pub enum BaseDirectory {
    /// The Audio directory.
    Audio = 1,
    /// The Cache directory.
    Cache,
    /// The Config directory.
    Config,
    /// The Data directory.
    Data,
    /// The LocalData directory.
    LocalData,
    /// The Document directory.
    Document,
    /// The Download directory.
    Download,
    /// The Picture directory.
    Picture,
    /// The Public directory.
    Public,
    /// The Video directory.
    Video,
    /// The Resource directory.
    Resource,
    /// A temporary directory.
    /// Resolves to [`temp_dir`].
    Temp,
    /// The default app config directory.
    /// Resolves to [`BaseDirectory::Config`]`/{bundle_identifier}`.
    AppConfig,
    /// The default app data directory.
    /// Resolves to [`BaseDirectory::Data`]`/{bundle_identifier}`.
    AppData,
    /// The default app local data directory.
    /// Resolves to [`BaseDirectory::LocalData`]`/{bundle_identifier}`.
    AppLocalData,
    /// The default app cache directory.
    /// Resolves to [`BaseDirectory::Cache`]`/{bundle_identifier}`.
    AppCache,
    /// The default app log directory.
    /// Resolves to [`BaseDirectory::Home`]`/Library/Logs/{bundle_identifier}` on macOS
    /// and [`BaseDirectory::Config`]`/{bundle_identifier}/logs` on linux and Windows.
    AppLog,

    /// The Desktop directory.
    #[cfg(desktop)]
    Desktop,
    /// The Executable directory.
    #[cfg(desktop)]
    Executable,
    /// The Font directory.
    #[cfg(desktop)]
    Font,
    /// The Home directory.
    #[cfg(desktop)]
    Home,
    /// The Runtime directory.
    #[cfg(desktop)]
    Runtime,
    /// The Template directory.
    #[cfg(desktop)]
    Template,
}

/// Extensions to [`tauri::App`], [`tauri::AppHandle`] and [`tauri::Window`] to access the camera APIs.
pub trait PathResolverExt<R: Runtime> {
    fn path_resolver(&self) -> &PathResolver<R>;
}

impl<R: Runtime, T: Manager<R>> PathResolverExt<R> for T {
    fn path_resolver(&self) -> &PathResolver<R> {
        self.state::<PathResolver<R>>().inner()
    }
}

/// Normalize a path, removing things like `.` and `..`, this snippet is taken from cargo's paths util.
/// https://github.com/rust-lang/cargo/blob/46fa867ff7043e3a0545bf3def7be904e1497afd/crates/cargo-util/src/paths.rs#L73-L106
fn normalize_path(path: &Path) -> PathBuf {
    let mut components = path.components().peekable();
    let mut ret = if let Some(c @ Component::Prefix(..)) = components.peek().cloned() {
        components.next();
        PathBuf::from(c.as_os_str())
    } else {
        PathBuf::new()
    };

    for component in components {
        match component {
            Component::Prefix(..) => unreachable!(),
            Component::RootDir => {
                ret.push(component.as_os_str());
            }
            Component::CurDir => {}
            Component::ParentDir => {
                ret.pop();
            }
            Component::Normal(c) => {
                ret.push(c);
            }
        }
    }
    ret
}

/// Normalize a path, removing things like `.` and `..`, this snippet is taken from cargo's paths util but
/// slightly modified to not resolve absolute paths.
/// https://github.com/rust-lang/cargo/blob/46fa867ff7043e3a0545bf3def7be904e1497afd/crates/cargo-util/src/paths.rs#L73-L106
fn normalize_path_no_absolute(path: &Path) -> PathBuf {
    let mut components = path.components().peekable();
    let mut ret = if let Some(c @ Component::Prefix(..)) = components.peek().cloned() {
        components.next();
        PathBuf::from(c.as_os_str())
    } else {
        PathBuf::new()
    };

    for component in components {
        match component {
            Component::Prefix(..) => unreachable!(),
            Component::RootDir => {
                ret.push(component.as_os_str());
            }
            Component::CurDir => {}
            Component::ParentDir => {
                ret.pop();
            }
            Component::Normal(c) => {
                // Using PathBuf::push here will replace the whole path if an absolute path is encountered
                // which is not the intended behavior, so instead of that, convert the current resolved path
                // to a string and do simple string concatenation with the current component then convert it
                // back to a PathBuf
                let mut p = ret.to_string_lossy().to_string();
                // Only add a separator if it doesn't have one already or if current normalized path is empty,
                // this ensures it won't have an unwanted leading separator
                if !p.is_empty() && !p.ends_with('/') && !p.ends_with('\\') {
                    p.push(MAIN_SEPARATOR);
                }
                if let Some(c) = c.to_str() {
                    p.push_str(c);
                }
                ret = PathBuf::from(p);
            }
        }
    }
    ret
}

#[tauri::command]
fn resolve_directory<R: Runtime>(
    _app: AppHandle<R>,
    resolver: State<'_, PathResolver<R>>,
    directory: BaseDirectory,
    path: Option<PathBuf>,
) -> Result<PathBuf> {
    let resolve_resource = matches!(directory, BaseDirectory::Resource);
    let mut base_dir_path = match directory {
        BaseDirectory::Audio => resolver.audio_dir(),
        BaseDirectory::Cache => resolver.cache_dir(),
        BaseDirectory::Config => resolver.config_dir(),
        BaseDirectory::Data => resolver.data_dir(),
        BaseDirectory::LocalData => resolver.local_data_dir(),
        BaseDirectory::Document => resolver.document_dir(),
        BaseDirectory::Download => resolver.download_dir(),
        BaseDirectory::Picture => resolver.picture_dir(),
        BaseDirectory::Public => resolver.public_dir(),
        BaseDirectory::Video => resolver.video_dir(),
        BaseDirectory::Resource => resolver.resource_dir(),
        BaseDirectory::Temp => Ok(temp_dir()),
        BaseDirectory::AppConfig => resolver.app_config_dir(),
        BaseDirectory::AppData => resolver.app_data_dir(),
        BaseDirectory::AppLocalData => resolver.app_local_data_dir(),
        BaseDirectory::AppCache => resolver.app_cache_dir(),
        BaseDirectory::AppLog => resolver.app_log_dir(),
        #[cfg(desktop)]
        BaseDirectory::Desktop => resolver.desktop_dir(),
        #[cfg(desktop)]
        BaseDirectory::Executable => resolver.executable_dir(),
        #[cfg(desktop)]
        BaseDirectory::Font => resolver.font_dir(),
        #[cfg(desktop)]
        BaseDirectory::Home => resolver.home_dir(),
        #[cfg(desktop)]
        BaseDirectory::Runtime => resolver.runtime_dir(),
        #[cfg(desktop)]
        BaseDirectory::Template => resolver.template_dir(),
    }?;

    if let Some(path) = path {
        // use the same path resolution mechanism as the bundler's resource injection algorithm
        if resolve_resource {
            let mut resource_path = PathBuf::new();
            for component in path.components() {
                match component {
                    Component::Prefix(_) => {}
                    Component::RootDir => resource_path.push("_root_"),
                    Component::CurDir => {}
                    Component::ParentDir => resource_path.push("_up_"),
                    Component::Normal(p) => resource_path.push(p),
                }
            }
            base_dir_path.push(resource_path);
        } else {
            base_dir_path.push(path);
        }
    }

    Ok(base_dir_path)
}

#[tauri::command]
fn resolve(paths: Vec<String>) -> Result<PathBuf> {
    // Start with current directory then start adding paths from the vector one by one using `PathBuf.push()` which
    // will ensure that if an absolute path is encountered in the iteration, it will be used as the current full path.
    //
    // examples:
    // 1. `vec!["."]` or `vec![]` will be equal to `std::env::current_dir()`
    // 2. `vec!["/foo/bar", "/tmp/file", "baz"]` will be equal to `PathBuf::from("/tmp/file/baz")`
    let mut path = std::env::current_dir().map_err(Error::CurrentDir)?;
    for p in paths {
        path.push(p);
    }
    Ok(normalize_path(&path))
}

#[tauri::command]
fn normalize(path: String) -> String {
    let mut p = normalize_path_no_absolute(Path::new(&path))
        .to_string_lossy()
        .to_string();

    // Node.js behavior is to return `".."` for `normalize("..")`
    // and `"."` for `normalize("")` or `normalize(".")`
    if p.is_empty() && path == ".." {
        "..".into()
    } else if p.is_empty() && path == "." {
        ".".into()
    } else {
        // Add a trailing separator if the path passed to this functions had a trailing separator. That's how Node.js behaves.
        if (path.ends_with('/') || path.ends_with('\\'))
            && (!p.ends_with('/') || !p.ends_with('\\'))
        {
            p.push(MAIN_SEPARATOR);
        }
        p
    }
}

#[tauri::command]
fn join(mut paths: Vec<String>) -> String {
    let path = PathBuf::from(
        paths
            .iter_mut()
            .map(|p| {
                // Add a `MAIN_SEPARATOR` if it doesn't already have one.
                // Doing this to ensure that the vector elements are separated in
                // the resulting string so path.components() can work correctly when called
                // in `normalize_path_no_absolute()` later on.
                if !p.ends_with('/') && !p.ends_with('\\') {
                    p.push(MAIN_SEPARATOR);
                }
                p.to_string()
            })
            .collect::<String>(),
    );

    let p = normalize_path_no_absolute(&path)
        .to_string_lossy()
        .to_string();
    if p.is_empty() {
        ".".into()
    } else {
        p
    }
}

#[tauri::command]
fn dirname(path: String) -> Result<PathBuf> {
    match Path::new(&path).parent() {
        Some(p) => Ok(p.to_path_buf()),
        None => Err(Error::NoParent),
    }
}

#[tauri::command]
fn extname(path: String) -> Result<String> {
    match Path::new(&path)
        .extension()
        .and_then(std::ffi::OsStr::to_str)
    {
        Some(p) => Ok(p.to_string()),
        None => Err(Error::NoExtension),
    }
}

#[tauri::command]
fn basename(path: String, ext: Option<String>) -> Result<String> {
    match Path::new(&path)
        .file_name()
        .and_then(std::ffi::OsStr::to_str)
    {
        Some(p) => Ok(if let Some(ext) = ext {
            p.replace(ext.as_str(), "")
        } else {
            p.to_string()
        }),
        None => Err(Error::NoBasename),
    }
}

#[tauri::command]
fn is_absolute(path: String) -> bool {
    Path::new(&path).is_absolute()
}

/// Initializes the plugin.
pub fn init<R: Runtime>() -> TauriPlugin<R> {
    Builder::new("path")
        .invoke_handler(tauri::generate_handler![
            resolve_directory,
            resolve,
            normalize,
            join,
            dirname,
            extname,
            basename,
            is_absolute
        ])
        .setup(|app, _api| {
            #[cfg(mobile)]
            {
                let handle =
                    _api.register_android_plugin(mobile::PLUGIN_IDENTIFIER, "PathPlugin")?;
                app.manage(PathResolver(handle));
            }

            #[cfg(desktop)]
            {
                app.manage(PathResolver(app.clone()));
            }

            Ok(())
        })
        .build()
}