use super::*;


#[derive(Debug, Serialize, Deserialize, PartialEq, Eq)]
pub struct Freeze
{
    metadata: StoreMetadata,
    data: Vec<Entry>,
}

impl Freeze
{
    pub(super) fn new_ref(from: &Store) -> Self
    {
	Self {
	    metadata: from.metadata.clone(),
	    data: from.data.iter().map(Entry::clone).collect(),
	}
    }
    pub(super) fn new_moved(from: Store) -> Self
    {
	Self {
	    metadata: from.metadata,
	    data: from.data.into_iter().map(Entry::with_no_cache).collect(),
	}
    }

    pub(super) fn create_new(&self) -> Store
    {
	let mut new = Store::with_capacity(self.metadata.clone(), self.data.len());
	
	for entry in self.data.iter()
	{
	    let hash = entry.hash().clone();
	    let hash_idx = new.data_hashes.insert(hash);
	    
	    // insert the tags
	    for tag in entry.tags.iter()
	    {
		if let Some(&ti) = new.tags.get(tag) {
		    // This tag has an entry already, append to it
		    new.tag_mappings.get_mut(ti).unwrap().insert(hash_idx);
		} else {
		    // This tag has no entry, create it
		    let ti = new.tag_mappings.insert(iter![hash_idx].collect());
		    new.tags.insert(tag.clone(), ti);
		}
	    }
	    
	    new.data.insert(entry.clone());
	}
	new

    }
    pub(super) fn into_new(self) -> Store
    {
	let Freeze { data, metadata } = self;
	
	let mut new = Store::with_capacity(metadata, data.len());
	for entry in data.into_iter()
	{
	    let hash = entry.hash().clone();
	    let hash_idx = new.data_hashes.insert(hash);
	    
	    // insert the tags
	    for tag in entry.tags.iter()
	    {
		if let Some(&ti) = new.tags.get(tag) {
		    // This tag has an entry already, append to it
		    new.tag_mappings.get_mut(ti).unwrap().insert(hash_idx);
		} else {
		    // This tag has no entry, create it
		    let ti = new.tag_mappings.insert(iter![hash_idx].collect());
		    new.tags.insert(tag.clone(), ti);
		}
	    }
	    
	    new.data.insert(entry);
	}
	new
    }
}

impl From<Store> for Freeze
{
    #[inline] fn from(from: Store) -> Self
    {
	Self::new_moved(from)
    }
}

impl From<Freeze> for Store
{
    #[inline] fn from(from: Freeze) -> Self
    {
	from.into_new()
    }
}