use std::collections::binary_heap::Iter;
use std::collections::HashMap;
use std::iter::Map;
use std::sync::{Arc, Mutex};
use ciborium::Value as CborValue;
use log::trace;

use crate::id::MizeId;
use crate::instance::store::Store;
use crate::error::{MizeError, MizeResult, IntoMizeResult};
use crate::item::{Item, ItemData};

#[derive(Clone, Debug)]
pub struct MemStore {
    inner: Arc<Mutex<MemStoreInner>>,
}

pub type MemStoreId = u64;

#[derive(Debug)]
struct MemStoreInner {
    map: HashMap<u64, ItemData>,
    next_id: u64,
}

impl Store for MemStore {
    fn set<T: Into<ItemData>>(&mut self, id: MizeId, data: T) -> MizeResult<()> {
        let mut inner = self.inner.lock()?;


        inner.map.insert(id_to_u64(id)?, data.into());
        return Ok(())
    }
    fn get_links(&self, item: Item<Self>) -> MizeResult<Vec<MizeId>> {
        let inner = self.inner.lock()?;

        Ok(Vec::new())
    }
    fn get_backlinks(&self, item: Item<Self>) -> MizeResult<Vec<MizeId>> {
        let inner = self.inner.lock()?;

        Ok(Vec::new())
    }
    fn new_id(&self) -> MizeResult<String> {
        let mut inner = self.inner.lock()?;

        let id_string = format!("{}", inner.next_id);
        inner.next_id += 1;
        return Ok(id_string);
    }
    fn get_value_raw(&self, id: MizeId) -> MizeResult<Vec<u8>> {
        let inner = self.inner.lock()?;

        let cbor_val = inner.map.get(&id_to_u64(id.clone())?)
            .ok_or(MizeError::new()
            .msg(format!("Item with store_part: {}, id: {} does not exist in MemStore", id_to_u64(id.clone())?, id)))?;

        let path = id.path();
        let mut id_iter = path.iter();
        id_iter.next();
        let id_without_first = id_iter.collect();

        Ok(get_raw_from_cbor(&cbor_val.0, id_without_first)?.to_owned())
    }

    fn get_value_data_full(&self, id: MizeId) -> MizeResult<ItemData> {
        let inner = self.inner.lock()?;
        inner.map.get(&id_to_u64(id.clone())?)
            .ok_or(MizeError::new().msg(format!("Item wich id '{}' has not data stored in this MemStore", id.clone()))).cloned()
    }
}

impl MemStore {
    pub fn new() -> MemStore {
        let inner = MemStoreInner { map: HashMap::new(), next_id: 0 };
        return MemStore { inner: Arc::new(Mutex::new(inner)) };
    }
}

fn id_to_u64(id: MizeId) -> MizeResult<u64> {
    id.store_part()
        .parse()
        .mize_result_msg(format!("Could not parse the store_part of mizeid {} into a u64 for the MemStore", id))
}

fn get_raw_from_cbor<'a>(value: &'a CborValue, path: Vec<&String>) -> MizeResult<&'a [u8]> {
    match value {
        CborValue::Bytes(vec) => Ok(&vec[..]),
        CborValue::Text(string) => Ok(string.as_bytes()),
        CborValue::Map(map) => {
            let mut inner_val: &CborValue = &CborValue::Null;
            for (key, val) in map.into_iter() {
                let first_path_string = *path.iter().nth(0)
                    .ok_or(MizeError::new()
                    .msg("get_raw_from_cbor: path is empty"))?;

                if let CborValue::Text(key_text) = key {
                    if key_text == first_path_string {
                        inner_val = val
                    }
                }
            }
            if inner_val == &CborValue::Null {
                return Err(MizeError::new()
                    // jesus christ, this is a pfusch...
                    .msg(format!("get_raw_from_cbor: Path {} not Found", path.clone().into_iter().map(|v| v.to_owned()).collect::<Vec<String>>().join("/"))))
            }
            let mut path_iter = path.into_iter();
            path_iter.next();
            let inner_path = path_iter.collect();
            get_raw_from_cbor(inner_val, inner_path)
        },
        _ => Err(MizeError::new().msg("get_raw_from_cbor: value is not Bytes, Text or Map")),
    }
}