//
// imag - the personal information management suite for the commandline
// Copyright (C) 2015, 2016 Matthias Beyer <mail@beyermatthias.de> and contributors
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; version
// 2.1 of the License.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
//

use toml::Value;
use toml_query::read::TomlValueReadExt;

use libimagstore::store::Store;
use libimagstore::store::FileLockEntry;
use libimagstore::storeid::StoreIdIterator;

use error::Result;
use error::AnnotationErrorKind as AEK;
use error::AnnotationError as AE;
use error::ResultExt;

#[derive(Debug)]
pub struct AnnotationIter<'a>(StoreIdIterator, &'a Store);

impl<'a> AnnotationIter<'a> {

    pub fn new(iter: StoreIdIterator, store: &'a Store) -> AnnotationIter<'a> {
        AnnotationIter(iter, store)
    }

}

impl<'a> Iterator for AnnotationIter<'a> {
    type Item = Result<FileLockEntry<'a>>;

    fn next(&mut self) -> Option<Self::Item> {
        loop {
            match self.0.next().map(|id| self.1.get(id)) {
                Some(Ok(Some(entry))) => {
                    match entry.get_header().read("annotation.is_annotation") {
                        Ok(None) => continue, // not an annotation
                        Ok(Some(&Value::Boolean(true))) => return Some(Ok(entry)),
                        Ok(Some(_)) => return Some(Err(AE::from_kind(AEK::HeaderTypeError))),
                        Err(e) => return Some(Err(e).chain_err(|| AEK::HeaderReadError)),
                    }
                },
                Some(Ok(None)) => continue,
                Some(Err(e))   => return Some(Err(e).chain_err(|| AEK::StoreReadError)),
                None           => return None, // iterator consumed
            }
        }
    }

}