use crate::utils::{self, ProjectDirError};
use log::{debug, info, trace, warn};
use save_sync::db::{establish_connection, query::GameSaveQuery, Database};
use save_sync::game::{GameFile, GameSaveLocation};
use std::path::{Path, PathBuf};
use thiserror::Error;
use walkdir::WalkDir;

#[derive(Debug, Clone)]
pub struct Archive {
    tracked_games: Vec<GameSaveLocation>,
    data_root: PathBuf,
    config_root: PathBuf,
}

impl Archive {
    /// Returns a Result, potentially containing a new instance of Archive
    ///
    /// This method infers the proper config and data user directories,
    /// so having `$HOME` unset will cause the method to fail.
    ///
    /// # Examples
    /// ```
    /// # use client::archive::Archive;
    /// let archive_res = Archive::try_default();
    /// ```
    pub fn try_default() -> Result<Self, ProjectDirError> {
        let user = utils::get_project_dirs()?;
        let data = user.data_dir().to_path_buf();
        let config = user.config_dir().to_path_buf();

        debug!("Created default Archive with: {:?} and {:?}", data, config);

        Ok(Self {
            tracked_games: Vec::new(),
            data_root: data,
            config_root: config,
        })
    }

    /// Creates a new instance of Archive
    ///
    /// # Arguments
    /// * `data_root` - Path to the user application data folder
    /// * `config_root` -  Path to the user configuration data folder.
    ///
    /// # Examples
    /// ```
    /// # use client::archive::Archive;
    /// let archive = Archive::new("/home/user/.local/share/save-sync", "/home/user/.config/save-sync");
    /// ```
    pub fn new<P: AsRef<Path>>(data_root: P, config_root: P) -> Self {
        let data_root = data_root.as_ref();
        let config_root = config_root.as_ref();

        debug!(
            "Created new Archive with: {:?} and {:?}",
            data_root, config_root
        );

        Self {
            tracked_games: Vec::new(),
            data_root: data_root.to_path_buf(),
            config_root: config_root.to_path_buf(),
        }
    }
}

impl Archive {
    /// Adds a path and its contents to the list of tracked game files
    ///
    /// TODO: Add note here about how GameSaveLocation, GameFile and tracking individual files rather than directories work
    ///
    /// # Arguments
    /// * `path` - The path which will be tracked along with any children it may have
    ///
    /// # Examples
    /// ```
    /// # use client::archive::Archive;
    /// let mut archive = Archive::try_default().expect("Failed to create an Archive");
    /// let save_path = "/home/user/Documents/generic_company/generic_game/save_folder";
    /// match archive.track_game(save_path) {
    ///     Ok(_) => println!("Save Sync is now tracking {}", save_path),
    ///     Err(err) => eprintln!("Failed to track {}: {:?}", save_path, err)
    /// };
    /// ```
    pub fn track_game<P: AsRef<Path>>(&mut self, path: P) -> Result<(), GameTrackError> {
        let game_save_loc = self.get_game_save_files(path, None)?;

        Self::write_game_save(&game_save_loc);

        self.tracked_games.push(game_save_loc);
        Ok(())
    }

    /// Adds a path and its contents to the list of tracked game files
    ///
    /// TODO: Add similar note to the one in [`track_game`]
    ///
    /// # Arguments
    /// * `path` - The path which will be tracked along with any children it may have
    ///
    /// # Examples
    /// ```
    /// # use client::archive::Archive;
    /// let mut archive = Archive::try_default().expect("Failed to create an Archive");
    /// let save_path = "/home/user/Documents/generic_company/generic_game/save_folder";
    /// let friendly_name = "Generic Game";
    /// match archive.track_game_with_friendly(save_path, friendly_name) {
    ///     Ok(_) => println!("Save Sync is now tracking {}", friendly_name),
    ///     Err(err) => eprintln!("Save Sync failed to start tracking {}", friendly_name)
    /// };
    pub fn track_game_with_friendly<P>(&mut self, path: P, name: &str) -> Result<(), GameTrackError>
    where
        P: AsRef<Path>,
    {
        let game_save_loc = self.get_game_save_files(path, Some(name))?;

        Self::write_game_save(&game_save_loc);

        self.tracked_games.push(game_save_loc);
        Ok(())
    }

    fn get_game_save_files<P>(
        &mut self,
        path: P,
        friendly_name: Option<&str>,
    ) -> Result<GameSaveLocation, GameTrackError>
    where
        P: AsRef<Path>,
    {
        use GameTrackError::*;

        let path = path.as_ref();
        let mut game_files: Vec<GameFile> = Vec::new();

        if path.is_dir() {
            for maybe_entry in WalkDir::new(path) {
                match maybe_entry {
                    Ok(entry) => {
                        if entry.path().is_file() {
                            let game_file = GameFile::new(entry.path())?;
                            game_files.push(game_file);
                        }

                        // FIXME: WalkDir will also return the paths of files. DO we want to track these?
                        // if so, how will be do that?
                    }
                    Err(err) => {
                        let io_err: std::io::Error = err.into();
                        return Err(io_err.into());
                    }
                }
            }
        } else if path.is_file() {
            // We've been requested to track an individual file.
            todo!("Implement the ability to track a single file instead of a directory")
        } else {
            return Err(UnknownFileSystemObject(path.to_path_buf()));
        }

        // FIXME: There most likely is a function that does this (check clippy)
        let friendly_name = friendly_name.map(|s| s.to_owned());
        Ok(GameSaveLocation::new(path, game_files, friendly_name))
    }
}

impl Archive {
    pub fn drop_game<P: AsRef<Path>>(path: P) -> Result<Option<()>, GameDropError> {
        let conn = establish_connection();
        let query = GameSaveQuery::Path(path.as_ref());
        Ok(Database::drop_game_save(&conn, query)?)
    }

    pub fn drop_game_with_friendly(name: &str) -> Result<Option<()>, GameDropError> {
        let conn = establish_connection();
        let query = GameSaveQuery::FriendlyName(name);
        Ok(Database::drop_game_save(&conn, query)?)
    }
}

impl Archive {
    pub fn get_game<P>(path: P) -> Result<Option<GameSaveLocation>, GameGetError>
    where
        P: AsRef<Path>,
    {
        let conn = establish_connection();
        let query = GameSaveQuery::Path(path.as_ref());
        Ok(Database::get_game_save(&conn, query)?)
    }

    pub fn get_game_with_friendly(name: &str) -> Result<Option<GameSaveLocation>, GameGetError> {
        let conn = establish_connection();
        let query = GameSaveQuery::FriendlyName(name);
        Ok(Database::get_game_save(&conn, query)?)
    }
}

impl Archive {
    pub fn get_all_games() -> Result<Option<Vec<GameSaveLocation>>, GameGetError> {
        let conn = establish_connection();
        Ok(Database::get_all_game_saves(&conn)?)
    }
}

impl Archive {
    fn write_game_save(game_save_loc: &GameSaveLocation) -> Result<(), GameTrackError> {
        let conn = establish_connection();
        Ok(Database::write_game_save(&conn, &game_save_loc)?)
    }
}

#[derive(Error, Debug)]
pub enum GameTrackError {
    #[error(transparent)]
    IoError(#[from] std::io::Error),
    #[error("{0:?} is not a supported inode type (File System Object)")]
    UnknownFileSystemObject(PathBuf), // FIXME: Is there a better name for this?
    #[error(transparent)]
    DatabaseError(#[from] save_sync::db::DatabaseError),
}

#[derive(Error, Debug)]
pub enum GameDropError {
    #[error("Unable to find Game with the name {0}")]
    UnknownFriendlyName(String),
    #[error("Unable to find game with the path {0:?}")]
    UnknownPath(PathBuf),
    #[error(transparent)]
    DatabaseError(#[from] save_sync::db::DatabaseError),
}

#[derive(Error, Debug)]
pub enum GameGetError {
    #[error(transparent)]
    DatabaseError(#[from] save_sync::db::DatabaseError),
}