use anyhow::{bail, Result};
use bp7::Bundle;
use log::{debug, error, info};
use sanitize_filename_reader_friendly::sanitize;
use std::path::{Path, PathBuf};
use std::{convert::TryInto, fs};
use walkdir::{DirEntry, WalkDir};

use crate::db::BundleEntry;

#[derive(Debug, Clone)]
pub struct D7sFs {
    base: String,
}

impl D7sFs {
    pub fn open(base: &str) -> Result<Self> {
        let me = Self { base: base.into() };
        me.setup()?;
        Ok(me)
    }
    fn setup(&self) -> Result<()> {
        let basepath = Path::new(&self.base);
        fs::create_dir_all(basepath)?;

        fs::create_dir_all(self.path_single())?;
        fs::create_dir_all(self.path_administrative())?;
        fs::create_dir_all(self.path_group())?;

        let version_file = basepath.join("version.txt");
        if version_file.exists() {
            let version: u32 = fs::read_to_string(version_file)?.parse()?;
            if version < crate::D7S_VERSION {
                info!("old filesystem structure detected, upgrade needed");
                unimplemented!();
            } else if version > crate::D7S_VERSION {
                error!("filesystem structure is newer, upgrade program to newest version");
                bail!("outdated program version");
            }
        }
        let version_file = basepath.join("version.txt");
        fs::write(version_file, format!("{}", crate::D7S_VERSION))?;

        Ok(())
    }
    pub fn path_single(&self) -> PathBuf {
        let basepath = Path::new(&self.base);
        basepath.join("single")
    }
    pub fn path_administrative(&self) -> PathBuf {
        let basepath = Path::new(&self.base);
        basepath.join("adm")
    }
    pub fn path_group(&self) -> PathBuf {
        let basepath = Path::new(&self.base);
        basepath.join("group")
    }
    pub fn path_for_bundle(&self, bndl: &Bundle) -> PathBuf {
        let dst = sanitize(
            &bndl
                .primary
                .destination
                .node()
                .unwrap_or_else(|| "none".to_owned()),
        );
        if bndl.is_administrative_record() {
            self.path_administrative().join(&dst)
        } else {
            match &bndl.primary.destination {
                bp7::EndpointID::Dtn(_, addr) => {
                    if addr.is_non_singleton() {
                        self.path_group().join(&dst)
                    } else {
                        self.path_single().join(&dst)
                    }
                }
                bp7::EndpointID::DtnNone(_, _) => {
                    unimplemented!()
                }
                bp7::EndpointID::Ipn(_, _addr) => {
                    unimplemented!()
                }
            }
        }
    }

    pub fn path_for_bundle_with_filename(&self, bndl: &Bundle) -> PathBuf {
        let filename = format!("{}.bundle", sanitize(&bndl.id()));
        self.path_for_bundle(bndl).join(&filename)
    }
    pub fn exists(&self, bndl: &Bundle) -> bool {
        self.path_for_bundle_with_filename(bndl).exists()
    }
    pub fn save_bundle(&self, bndl: &mut Bundle) -> Result<(u64, String)> {
        let bid = bndl.id();
        let filename = format!("{}.bundle", sanitize(&bid));
        let dest_path = self.path_for_bundle(bndl);

        fs::create_dir_all(&dest_path)?;
        let dest_path = dest_path.join(&filename);
        if dest_path.exists() {
            debug!("File {} already exists, skipping", filename);
        } else {
            fs::write(&dest_path, bndl.to_cbor())?;
            debug!("saved {} to {}", bid, dest_path.to_string_lossy());
        }
        //info!("filename {}", filename);
        Ok((
            fs::metadata(&dest_path)?.len(),
            dest_path.to_string_lossy().into(),
        ))
    }
    pub fn remove_bundle(&self, bid: &str) -> Result<()> {
        if let Some(filename) = self.find_file_by_bid(bid) {
            fs::remove_file(filename)?;
        } else {
            bail!("bundle ID not found");
        }
        Ok(())
    }
    pub fn find_file_by_bid(&self, bid: &str) -> Option<PathBuf> {
        let target = format!("{}.bundle", sanitize(bid));
        for entry in WalkDir::new(&self.base)
            .into_iter()
            .filter_map(|e| e.ok())
            .filter(|f| f.file_name().to_str().unwrap_or_default() == target)
        {
            //let filename = entry.file_name().to_str()?;
            //if filename == format!("{}.bundle", sanitize(bid)) {
            return Some(entry.into_path());
            //}
        }
        None
    }
    pub fn all_bids(&self) -> Vec<String> {
        let mut bids = Vec::new();
        for entry in WalkDir::new(&self.base)
            .into_iter()
            .filter_map(|e| e.ok())
            .filter(|f| {
                f.file_name()
                    .to_str()
                    .unwrap_or_default()
                    .ends_with(".bundle")
            })
        {
            let filename = entry
                .file_name()
                .to_str()
                .unwrap()
                .rsplit('.')
                .collect::<Vec<&str>>()[1]
                .to_string();
            if filename.starts_with("dtn_") {
                let bid = if filename.starts_with("dtn_none") {
                    filename.replacen('_', ":", 1)
                } else {
                    filename.replacen('_', "://", 1)
                };
                let bid = bid.replacen('_', "/", 1);
                bids.push(bid);
            } else {
                unimplemented!("only dtn bundle scheme support at the moment!");
            }
        }
        bids
    }
    pub fn get_bundle(&self, bid: &str) -> Result<Bundle> {
        if let Some(filename) = self.find_file_by_bid(bid) {
            let buffer = fs::read(filename)?;
            let bndl: Bundle = buffer.try_into()?;
            Ok(bndl)
        } else {
            bail!("bundle ID not found");
        }
    }
    fn check_file_from_store(
        &self,
        entry: DirEntry,
        db: &crate::D7DB,
    ) -> Result<Option<(String, BundleEntry)>> {
        let (filebase, _extension) = entry
            .file_name()
            .to_str()
            .unwrap()
            .rsplit_once('.')
            .unwrap();
        let res = if filebase.starts_with("dtn") {
            let bid = filebase.replace('_', "/").replacen("dtn", "dtn:/", 1);
            let is_in_db = db.exists(&bid);
            debug!("{} in db: {}", entry.path().display(), is_in_db);
            if !is_in_db {
                let buf = std::fs::read(entry.path())?;
                let bundle_size = buf.len();

                let bndl: Bundle = buf.try_into()?;
                let mut be = BundleEntry::from(&bndl);
                be.size = bundle_size as u64;
                info!("adding {} to db", bndl.id());
                Some((bndl.id(), be))
            } else {
                debug!("{} already in store", &bid);
                None
            }
        } else {
            None
        };
        Ok(res)
    }
    pub fn sync_to_db(&self, db: &crate::D7DB) -> Result<()> {
        info!("syncing fs to db");
        let mut bes = Vec::new();
        for entry in WalkDir::new(&self.base)
            .into_iter()
            .filter_map(|e| e.ok())
            .filter(|f| {
                f.file_name()
                    .to_str()
                    .unwrap_or_default()
                    .ends_with(".bundle")
            })
        {
            let file_path = entry.path().to_string_lossy().to_string();
            if let Ok(Some((bid, be))) = self.check_file_from_store(entry, db) {
                bes.push((bid, be, Some(file_path)));
            }
        }
        db.insert_bulk(&bes)?;
        Ok(())
    }
    pub fn import_hex(&self, hexstr: &str) -> Result<(Bundle, u64, String)> {
        let mut bndl: Bundle = bp7::helpers::unhexify(hexstr)?.try_into()?;

        let (bundle_size, path) = self.save_bundle(&mut bndl)?;
        Ok((bndl, bundle_size, path))
    }

    pub fn import_vec(&self, buf: Vec<u8>) -> Result<(Bundle, u64, String)> {
        let mut bndl: Bundle = buf.try_into()?;

        let (bundle_size, path) = self.save_bundle(&mut bndl)?;
        Ok((bndl, bundle_size, path))
    }
}