use serde::{Deserialize, Serialize};
use std::{
    convert::TryFrom,
    ops::Deref,
    path::{Path, PathBuf},
};
use thiserror::Error;
use uuid::Uuid;

mod file;
mod fileinfo;
mod thumbnail;
pub mod utils;

pub use file::File;
pub use fileinfo::FileInfo;
pub use thumbnail::Thumbnail;

#[derive(Debug, Error)]
pub enum WriteFileError {
    #[error("root file path does not exist")]
    RootNotFound,

    #[error("permission denied")]
    PermissionDenied,

    #[error("invalid path")]
    InvalidPath,

    #[error("image conversion failed")]
    ImageError(#[from] image::ImageError),

    #[error("JSON error")]
    JSONError(#[from] serde_json::error::Error),

    #[error("IO error")]
    IOError(#[from] std::io::Error),
}

#[derive(Debug, Error)]
pub enum ReadFileError {
    #[error("file not found")]
    FileNotFound(PathBuf),

    #[error("path is not a file")]
    NotAFile,

    #[error("permission denied")]
    PermissionDenied,

    #[error("invalid path")]
    InvalidPath,

    #[error("JSON error")]
    JSONError(#[from] serde_json::error::Error),

    #[error("IO error")]
    IOError(#[from] std::io::Error),
}

#[derive(Debug, Error)]
pub enum PathError {
    #[error("path cannot be derived from input")]
    InvalidPath,
}

#[derive(Clone, Debug)]
pub struct PathResolver {
    base: PathBuf,
    id: String,
    extension: String,
}

impl PathResolver {
    fn new(base: &Path, id: &str, extension: &str) -> Self {
        Self {
            base: base.to_owned(),
            id: id.to_owned(),
            extension: extension.to_owned(),
        }
    }

    fn file_path(&self) -> PathBuf {
        let mut path = self.base.clone();
        path.push(self.id.clone());
        path.set_extension(self.extension.clone());
        path
    }

    fn metadata_path(&self) -> PathBuf {
        let mut path = self.base.clone();
        path.push(self.id.clone());
        path.set_extension("json");
        path
    }

    fn thumbnail_path(&self) -> PathBuf {
        let mut path = self.base.clone();
        path.push(self.id.clone());
        path.set_extension(format!("tn.{}", self.extension));
        path
    }
}

impl TryFrom<String> for PathResolver {
    type Error = PathError;
    fn try_from(s: String) -> Result<Self, Self::Error> {
        PathResolver::try_from(s.as_str())
    }
}

impl TryFrom<&str> for PathResolver {
    type Error = PathError;
    fn try_from(s: &str) -> Result<Self, Self::Error> {
        let path = Path::new(s);
        PathResolver::try_from(Path::new(s))
    }
}

impl TryFrom<PathBuf> for PathResolver {
    type Error = PathError;
    fn try_from(path: PathBuf) -> Result<Self, Self::Error> {
        PathResolver::try_from(path.as_path())
    }
}

impl TryFrom<&Path> for PathResolver {
    type Error = PathError;
    fn try_from(path: &Path) -> Result<Self, Self::Error> {
        Ok(Self {
            base: path
                .parent()
                .map(|s| s.to_owned())
                .ok_or(PathError::InvalidPath)?,
            id: path
                .file_stem()
                .and_then(|s| s.to_str().map(|s| s.to_owned()))
                .ok_or(PathError::InvalidPath)?,
            extension: path
                .extension()
                .and_then(|s| s.to_str().map(|s| s.to_owned()))
                .ok_or(PathError::InvalidPath)?,
        })
    }
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct FileId(String);

impl From<String> for FileId {
    fn from(s: String) -> Self {
        Self(s)
    }
}

impl From<&str> for FileId {
    fn from(s: &str) -> Self {
        Self(s.to_owned())
    }
}

impl Deref for FileId {
    type Target = String;
    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

pub trait FileRoot {
    fn root(&self) -> PathBuf;
}

pub struct Context(PathBuf);

impl FileRoot for Context {
    fn root(&self) -> PathBuf {
        self.0.clone()
    }
}

pub struct Store {
    files_root: PathBuf,
}

impl Store {
    pub fn new(files_root: PathBuf) -> Self {
        Self { files_root }
    }

    pub fn list_files(&self) -> Vec<Result<File, ReadFileError>> {
        unimplemented!()
    }

    pub fn add_file(&mut self, filename: String, content: Vec<u8>) -> Result<File, WriteFileError> {
        let context = Context(self.files_root.clone());
        let mut file = File::new(filename, context)?;
        file.set_content(content)?;
        Ok(file)
    }

    pub fn delete_file(&mut self, id: FileId) -> Result<(), WriteFileError> {
        /*
        let f = File::open(&id, &self.files_root)?;
        f.delete()
        */
        unimplemented!()
    }

    pub fn get_metadata(&self, id: FileId) -> Result<FileInfo, ReadFileError> {
        let mut path = self.files_root.clone();
        path.push(PathBuf::from((*id).clone()));
        path.set_extension("json");
        FileInfo::load(path)
    }

    pub fn get_file(&self, id: FileId) -> Result<(FileInfo, File), ReadFileError> {
        let info = self.get_metadata(id.clone())?;

        let resolver = PathResolver {
            base: self.files_root.clone(),
            id: (*id).clone(),
            extension: info.extension.clone(),
        };

        let f = File::load(resolver)?;
        Ok((info, f))
    }

    pub fn get_thumbnail(&self, id: FileId) -> Result<(FileInfo, File), ReadFileError> {
        unimplemented!()
    }
}

#[cfg(test)]
mod test {
    use super::*;
    use crate::store::utils::FileCleanup;
    use cool_asserts::assert_matches;
    use std::io::Read;

    #[test]
    fn paths() {
        let resolver = PathResolver::try_from("path/82420255-d3c8-4d90-a582-f94be588c70c.png")
            .expect("to have a valid path");
        assert_eq!(
            resolver.file_path(),
            PathBuf::from("path/82420255-d3c8-4d90-a582-f94be588c70c.png")
        );
        assert_eq!(
            resolver.metadata_path(),
            PathBuf::from("path/82420255-d3c8-4d90-a582-f94be588c70c.json")
        );
        assert_eq!(
            resolver.thumbnail_path(),
            PathBuf::from("path/82420255-d3c8-4d90-a582-f94be588c70c.tn.png")
        );
    }

    #[test]
    fn adds_files() {
        let mut buf = Vec::new();
        let mut file = std::fs::File::open("fixtures/rawr.png").unwrap();
        file.read_to_end(&mut buf).unwrap();

        let mut store = Store::new(PathBuf::from("var/"));
        let file_record = store.add_file("rawr.png".to_owned(), buf).unwrap();

        let _file = FileCleanup(PathBuf::from(format!("var/{}.png", *file_record.id)));
        let _md = FileCleanup(PathBuf::from(format!("var/{}.json", *file_record.id)));
        let _tn = FileCleanup(PathBuf::from(format!("var/{}.tn", *file_record.id)));

        store
            .get_file(file_record.id.clone())
            .expect("to retrieve the file");

        assert!(PathBuf::from(format!("var/{}.png", *file_record.id)).exists());
        assert!(PathBuf::from(format!("var/{}.json", *file_record.id)).exists());
        assert!(PathBuf::from(format!("var/{}.tn.png", *file_record.id)).exists());
    }

    #[test]
    fn sets_up_metadata_for_file() {
        let mut buf = Vec::new();
        let mut file = std::fs::File::open("fixtures/rawr.png").unwrap();
        file.read_to_end(&mut buf).unwrap();

        let mut store = Store::new(PathBuf::from("var/"));
        let file_record = store.add_file("rawr.png".to_owned(), buf).unwrap();

        let _file = FileCleanup(PathBuf::from(format!("var/{}.png", *file_record.id)));
        let _md = FileCleanup(PathBuf::from(format!("var/{}.json", *file_record.id)));
        let _tn = FileCleanup(PathBuf::from(format!("var/{}.tn", *file_record.id)));

        let info = store
            .get_metadata(file_record.id.clone())
            .expect("to retrieve the file");

        assert_matches!(info, FileInfo { size, file_type, hash, extension, .. } => {
            assert_eq!(size, 23777);
            assert_eq!(file_type, "image/png");
            assert_eq!(hash, "".to_owned());
            assert_eq!(extension, "png".to_owned());
        });

        assert!(PathBuf::from(format!("var/{}.png", *file_record.id)).exists());
        assert!(PathBuf::from(format!("var/{}.json", *file_record.id)).exists());
        assert!(PathBuf::from(format!("var/{}.tn.png", *file_record.id)).exists());
    }

    #[test]
    fn sets_up_thumbnail_for_file() {}

    #[test]
    fn deletes_associated_files() {}

    #[test]
    fn lists_files_in_the_db() {}
}