use crate::core::srs::{FADE_PER_DAY, MAX_SCORE, WordOpenMode};
use crate::data::{INVALID_ID, Id};
use crate::data_provider::history::HistoryRepositoryInner;
use chrono::{DateTime, Local, NaiveDate, Utc};
use fsrs::MemoryState;
use litemap::LiteMap;
use log::info;
use rhai::Engine;
use std::cmp::Ordering;
use std::hash::{Hash, Hasher};
use std::marker::PhantomData;
use std::sync::Arc;
use std::time::Instant;

#[derive(Clone, Debug)]
pub struct WordData {
    pub id: Id,
    pub group_id: Id,
    pub key: String,
    pub value: String,
    pub tags: String,
    pub additional: LiteMap<Id, String>,
}

impl EntityData for WordData {
    fn id(&self) -> Id {
        self.id
    }

    fn set_id(&mut self, id: Id) {
        self.id = id;
    }
}

#[derive(Clone)]
pub struct WordGroup {
    pub id: Id,
    pub name: String,
}

impl EntityData for WordGroup {
    fn id(&self) -> Id {
        self.id
    }

    fn set_id(&mut self, id: Id) {
        self.id = id;
    }
}

impl WordData {
    pub fn new() -> Self {
        Self {
            id: INVALID_ID,
            key: String::new(),
            value: String::new(),
            tags: String::new(),
            additional: Default::default(),
            group_id: 1.into(),
        }
    }
}

#[derive(Clone)]
pub struct HistoryNote {
    pub id: Id,
    pub timestamp: DateTime<Utc>,
    pub deck_id: Id,
    pub word_id: Id,
    pub answer: WordOpenMode,
    pub before: u8,
    pub after: u8,
    pub fsrs: bool,
}

impl EntityData for HistoryNote {
    fn id(&self) -> Id {
        self.id
    }

    fn set_id(&mut self, id: Id) {
        self.id = id;
    }
}

impl HistoryRepositoryInner {
    pub fn activity_of_deck(&self, id: Id) -> Vec<(NaiveDate, u32)> {
        let mut query = self.query(Arc::new(move |note| note.deck_id == id));
        let values = query.iter(self).collect::<Vec<_>>();
        let mut counts = vec![];
        if !values.is_empty() {
            let mut date = values[0].timestamp.with_timezone(&Local).date_naive();
            let mut count = 0;
            for note in values {
                let current_date = note.timestamp.with_timezone(&Local).date_naive();
                if date == current_date {
                    count += 1;
                } else {
                    counts.push((date, count));
                    date = current_date;
                    count = 0;
                }
            }
            if count != 0 {
                counts.push((date, count));
            }
        }
        counts
    }
}

#[derive(Clone)]
pub struct DeckSettings {
    pub id: Id,
    pub name: String,
    pub forward: String,
    pub backward: String,
    pub filter: String,
}

impl EntityData for DeckSettings {
    fn id(&self) -> Id {
        self.id
    }

    fn set_id(&mut self, id: Id) {
        self.id = id;
    }
}

impl DeckSettings {
    pub(crate) fn with_name(name: String) -> DeckSettings {
        DeckSettings {
            id: 0.into(),
            name,
            forward: String::new(),
            backward: String::new(),
            filter: "true".to_string(),
        }
    }
    pub fn check_filter(&self) -> bool {
        let time = Instant::now();
        let engine = Engine::new();
        let ast = engine.compile(&self.filter);
        info!("Compile time is {:?}", time.elapsed());
        ast.is_ok()
    }
    pub fn require_speech(&self) -> bool {
        self.forward.contains("speech") || self.backward.contains("speech")
    }
}

#[derive(Clone, PartialEq)]
pub struct CardState {
    pub id: Id,
    pub word_id: Id,
    pub deck_id: Id,
    pub last_open: DateTime<Utc>,
    pub score: u8,
    pub fsrs_opened: NaiveDate,
    pub fsrs_memory: Option<MemoryState>,
    pub fsrs_open_day: NaiveDate,
}

impl EntityData for CardState {
    fn id(&self) -> Id {
        self.id
    }

    fn set_id(&mut self, id: Id) {
        self.id = id;
    }
}

impl CardState {
    pub fn update(&mut self, status: WordOpenMode) {
        match status {
            WordOpenMode::Easy => {
                self.score = (self.calculated_score() + 5.0).round() as u8;
            }
            WordOpenMode::Ok => self.score = (self.calculated_score() + 2.0).round() as u8,
            WordOpenMode::Hard => {
                self.score = (self.calculated_score() * 0.75).round() as u8;
            }
            WordOpenMode::None => {
                self.score = (self.calculated_score() * 0.4) as u8;
            }
        }

        self.score = self.score.clamp(1, MAX_SCORE);
        self.last_open = Utc::now();
    }

    pub fn calculated_score(&self) -> f32 {
        let time = Utc::now() - self.last_open;
        let days = time.num_days();
        let multiplier = FADE_PER_DAY.powi(days as i32);
        (self.score as f32 * multiplier).max(1.0)
    }
}

#[derive(Clone)]
pub struct CustomField {
    pub id: Id,
    pub name: String,
    pub identifier: String,
}

impl EntityData for CustomField {
    fn id(&self) -> Id {
        self.id
    }

    fn set_id(&mut self, id: Id) {
        self.id = id;
    }
}

#[derive(Clone)]
pub struct Exam {
    pub id: Id,
    pub timestamp: DateTime<Utc>,
    pub deck_id: Id,
}

impl EntityData for Exam {
    fn id(&self) -> Id {
        self.id
    }
    fn set_id(&mut self, id: Id) {
        self.id = id;
    }
}

#[derive(Clone)]
pub struct ExamEntry{
    pub id: Id,
    pub exam_id: Id,
    pub word_id: Id,
    pub status: Option<bool>
}

impl EntityData for ExamEntry {
    fn id(&self) -> Id {
        self.id
    }
    
    fn set_id(&mut self, id: Id) {
        self.id = id;
    }
}

pub struct EntityHandle<E> {
    pub(crate) id: Id,
    index: u32,
    pub(crate) _phantom: PhantomData<E>,
}

impl<T> Clone for EntityHandle<T> {
    fn clone(&self) -> Self {
        *self
    }
}

impl<T> Copy for EntityHandle<T> {}
impl<T> EntityHandle<T> {
    pub fn new(id: Id, index: usize, real: bool) -> Self {
        Self {
            id,
            index: ((index as u32) << 1 >> 1) | (!real as u32) << 31,
            _phantom: Default::default(),
        }
    }

    pub fn from_id(id: Id) -> Self {
        Self::new(id, id.0 as usize, true)
    }

    pub fn index(&self) -> usize {
        (self.index << 1 >> 1) as usize
    }

    pub fn set_index(&mut self, index: usize) {
        self.index = (self.index >> 31 << 31) | ((index as u32) << 1 >> 1);
    }

    pub fn real(&self) -> bool {
        (self.index >> 31) == 0
    }

    pub fn set_real(&mut self, value: bool) {
        self.index = self.index << 1 >> 1 | (!value as u32) << 31;
    }
}
impl<T> Eq for EntityHandle<T> {}

impl<T> PartialEq<Self> for EntityHandle<T> {
    fn eq(&self, other: &Self) -> bool {
        self.real() == other.real() && self.id == other.id
    }
}
impl<T> PartialOrd<Self> for EntityHandle<T> {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}

impl<T> Ord for EntityHandle<T> {
    fn cmp(&self, other: &Self) -> Ordering {
        if self.real() && !other.real() {
            return Ordering::Less;
        }

        if !self.real() && other.real() {
            return Ordering::Greater;
        }

        self.id.cmp(&other.id)
    }
}

impl<T> Hash for EntityHandle<T> {
    fn hash<H: Hasher>(&self, state: &mut H) {
        self.id.hash(state);
        self.real().hash(state);
    }
}

pub trait EntityData {
    fn id(&self) -> Id;
    fn set_id(&mut self, id: Id);
}