use std::fmt;
use std::fmt::{Display, Formatter};
use std::hash::{Hash, Hasher};

use dyn_clone::clone_box;

use crate::connectors::Exchange;
use crate::currency::{Symbol, SymbolPair};
use crate::strategy::OrderStrategy;

/***************
* Prices
***************/

#[derive(Copy, Clone, Debug)]
pub struct PriceTicker {
    pub bid: f64,
    pub bid_size: f64,
    pub ask: f64,
    pub ask_size: f64,
    pub daily_change: f64,
    pub daily_change_perc: f64,
    pub last_price: f64,
    pub volume: f64,
    pub high: f64,
    pub low: f64,
}

/***************
* Orders
***************/

#[derive(Debug)]
pub enum OrderBookEntry {
    Trading {
        price: f64,
        count: u64,
        amount: f64,
    },
    Funding {
        rate: f64,
        period: u64,
        count: u64,
        amount: f64,
    },
}

#[derive(Debug)]
pub struct OrderBook {
    pair: SymbolPair,
    entries: Vec<OrderBookEntry>,
}

impl OrderBook {
    pub fn new(pair: SymbolPair) -> Self {
        OrderBook {
            pair,
            entries: Vec::new(),
        }
    }

    pub fn with_entries(mut self, entries: Vec<OrderBookEntry>) -> Self {
        self.entries = entries;
        self
    }

    // TODO: distinguish between trading and funding
    pub fn bids(&self) -> Vec<&OrderBookEntry> {
        self.entries
            .iter()
            .filter(|x| match x {
                OrderBookEntry::Trading { amount, .. } => amount > &0.0,
                OrderBookEntry::Funding { amount, .. } => amount < &0.0,
            })
            .collect()
    }

    // TODO: distinguish between trading and funding
    pub fn asks(&self) -> Vec<&OrderBookEntry> {
        self.entries
            .iter()
            .filter(|x| match x {
                OrderBookEntry::Trading { amount, .. } => amount < &0.0,
                OrderBookEntry::Funding { amount, .. } => amount > &0.0,
            })
            .collect()
    }

    pub fn highest_bid(&self) -> f64 {
        self.bids()
            .iter()
            .map(|x| match x {
                OrderBookEntry::Trading { price, .. } => price,
                OrderBookEntry::Funding { rate, .. } => rate,
            })
            .fold(f64::NEG_INFINITY, |a, &b| a.max(b))
    }

    pub fn lowest_ask(&self) -> f64 {
        self.asks()
            .iter()
            .map(|x| match x {
                OrderBookEntry::Trading { price, .. } => price,
                OrderBookEntry::Funding { rate, .. } => rate,
            })
            .fold(f64::INFINITY, |a, &b| a.min(b))
    }
}

#[derive(Debug)]
pub enum OrderFee {
    Maker(f64),
    Taker(f64),
}

#[derive(Debug)]
pub struct OrderDetails {
    exchange: Exchange,
    pair: SymbolPair,
    platform: TradingPlatform,
    kind: OrderKind,
    execution_timestamp: u64,
    id: u64,
}

impl OrderDetails {
    pub fn new(
        exchange: Exchange,
        id: u64,
        pair: SymbolPair,
        platform: TradingPlatform,
        kind: OrderKind,
        execution_timestamp: u64,
    ) -> Self {
        OrderDetails {
            exchange,
            pair,
            platform,
            kind,
            execution_timestamp,
            id,
        }
    }

    pub fn id(&self) -> u64 {
        self.id
    }

    pub fn pair(&self) -> &SymbolPair {
        &self.pair
    }
}

#[derive(Debug)]
pub struct ActiveOrder {
    exchange: Exchange,
    id: u64,
    group_id: Option<u64>,
    client_id: Option<u64>,
    pair: SymbolPair,
    order_form: OrderForm,
    creation_timestamp: u64,
    update_timestamp: u64,
    strategy: Option<Box<dyn OrderStrategy>>,
}

impl ActiveOrder {
    pub fn new(
        exchange: Exchange,
        id: u64,
        pair: SymbolPair,
        order_form: OrderForm,
        creation_timestamp: u64,
        update_timestamp: u64,
    ) -> Self {
        Self {
            exchange,
            id,
            group_id: None,
            client_id: None,
            pair,
            order_form,
            creation_timestamp,
            update_timestamp,
            strategy: None,
        }
    }

    pub fn with_group_id(mut self, group_id: Option<u64>) -> Self {
        self.group_id = group_id;
        self
    }

    pub fn with_client_id(mut self, client_id: Option<u64>) -> Self {
        self.client_id = client_id;
        self
    }

    pub fn with_strategy(mut self, strategy: Option<Box<dyn OrderStrategy>>) -> Self {
        self.strategy = strategy;
        self
    }

    pub fn with_leverage(mut self, leverage: Option<f64>) -> Self {
        self.order_form = self.order_form.with_leverage(leverage);
        self
    }

    pub fn exchange(&self) -> Exchange {
        self.exchange
    }
    pub fn id(&self) -> u64 {
        self.id
    }
    pub fn group_id(&self) -> Option<u64> {
        self.group_id
    }
    pub fn client_id(&self) -> Option<u64> {
        self.client_id
    }
    pub fn pair(&self) -> &SymbolPair {
        &self.pair
    }
    pub fn order_form(&self) -> &OrderForm {
        &self.order_form
    }
    pub fn creation_timestamp(&self) -> u64 {
        self.creation_timestamp
    }
    pub fn update_timestamp(&self) -> u64 {
        self.update_timestamp
    }
    pub fn strategy(&self) -> &Option<Box<dyn OrderStrategy>> {
        &self.strategy
    }
}

impl Hash for ActiveOrder {
    fn hash<H: Hasher>(&self, state: &mut H) {
        state.write(&self.id.to_le_bytes());
    }
}

impl PartialEq for ActiveOrder {
    fn eq(&self, other: &Self) -> bool {
        self.id == other.id && self.client_id == other.client_id && self.group_id == other.group_id
    }
}

impl Eq for ActiveOrder {}

impl Clone for ActiveOrder {
    fn clone(&self) -> Self {
        Self {
            exchange: self.exchange,
            id: self.id,
            group_id: self.group_id,
            client_id: self.client_id,
            pair: self.pair.clone(),
            order_form: self.order_form.clone(),
            creation_timestamp: self.creation_timestamp,
            update_timestamp: self.update_timestamp,
            strategy: self.strategy.as_ref().map(|x| clone_box(&**x))
        }
    }
}

#[derive(Debug, Clone, Copy, Eq, PartialEq)]
pub enum TradingPlatform {
    Exchange,
    Derivative,
    Funding,
    Margin,
}

impl TradingPlatform {
    pub fn as_str(&self) -> &'static str {
        match self {
            TradingPlatform::Exchange => "Exchange",
            TradingPlatform::Derivative => "Derivative",
            TradingPlatform::Funding => "Funding",
            TradingPlatform::Margin => "Margin",
        }
    }
}

impl Display for TradingPlatform {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        write!(f, "{}", self.as_str())
    }
}

#[derive(Copy, Clone, Debug)]
pub enum OrderKind {
    Limit { price: f64 },
    Market,
    Stop { price: f64 },
    StopLimit { stop_price: f64, limit_price: f64 },
    TrailingStop { distance: f64 },
    FillOrKill { price: f64 },
    ImmediateOrCancel { price: f64 },
}

impl OrderKind {
    pub fn as_str(&self) -> &'static str {
        match self {
            OrderKind::Limit { .. } => "Limit",
            OrderKind::Market { .. } => "Market",
            OrderKind::Stop { .. } => "Stop",
            OrderKind::StopLimit { .. } => "Stop Limit",
            OrderKind::TrailingStop { .. } => "Trailing Stop",
            OrderKind::FillOrKill { .. } => "Fill or Kill",
            OrderKind::ImmediateOrCancel { .. } => "Immediate or Cancel",
        }
    }
}

impl Display for OrderKind {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        match self {
            OrderKind::Limit { price } => {
                write!(f, "[{} | Price: {:0.5}]", self.as_str(), price, )
            }
            OrderKind::Market => {
                write!(f, "[{}]", self.as_str())
            }
            OrderKind::Stop { price } => {
                write!(f, "[{} | Price: {:0.5}]", self.as_str(), price, )
            }
            OrderKind::StopLimit { stop_price, limit_price } => {
                write!(
                    f,
                    "[{} | Stop: {:0.5}, Limit: {:0.5}]",
                    self.as_str(),
                    stop_price,
                    limit_price
                )
            }
            OrderKind::TrailingStop { distance } => {
                write!(f, "[{} | Distance: {:0.5}]", self.as_str(), distance, )
            }
            OrderKind::FillOrKill { price } => {
                write!(f, "[{} | Price: {:0.5}]", self.as_str(), price, )
            }
            OrderKind::ImmediateOrCancel { price } => {
                write!(f, "[{} | Price: {:0.5}]", self.as_str(), price, )
            }
        }
    }
}

#[derive(Debug, Clone)]
pub struct OrderForm {
    pair: SymbolPair,
    kind: OrderKind,
    platform: TradingPlatform,
    amount: f64,
    leverage: Option<f64>,
    metadata: Option<OrderMetadata>,
}

impl OrderForm {
    pub fn new(
        pair: SymbolPair,
        order_kind: OrderKind,
        platform: TradingPlatform,
        amount: f64,
    ) -> Self {
        Self {
            pair,
            kind: order_kind,
            platform,
            amount,
            leverage: None,
            metadata: None,
        }
    }

    pub fn with_leverage(mut self, leverage: Option<f64>) -> Self {
        self.leverage = leverage;
        self
    }

    pub fn with_metadata(mut self, metadata: Option<OrderMetadata>) -> Self {
        self.metadata = metadata;
        self
    }

    pub fn pair(&self) -> &SymbolPair {
        &self.pair
    }

    pub fn kind(&self) -> OrderKind {
        self.kind
    }

    pub fn platform(&self) -> &TradingPlatform {
        &self.platform
    }

    pub fn amount(&self) -> f64 {
        self.amount
    }

    pub fn price(&self) -> Option<f64> {
        match self.kind {
            OrderKind::Limit { price, .. } => Some(price),
            OrderKind::Market { .. } => None,
            OrderKind::Stop { price, .. } => Some(price),
            OrderKind::StopLimit { stop_price: price, .. } => Some(price),
            OrderKind::TrailingStop { .. } => None,
            OrderKind::FillOrKill { price, .. } => Some(price),
            OrderKind::ImmediateOrCancel { price, .. } => Some(price),
        }
    }

    pub fn leverage(&self) -> Option<f64> {
        self.leverage
    }

    pub fn metadata(&self) -> &Option<OrderMetadata> {
        &self.metadata
    }
}

#[derive(Debug)]
pub struct OrderMetadata {
    position_id: Option<u64>,
    strategy: Option<Box<dyn OrderStrategy>>,
}

impl Clone for OrderMetadata {
    fn clone(&self) -> Self {
        Self {
            position_id: self.position_id.clone(),
            strategy: self.strategy.as_ref().map(|x| clone_box(&**x)),
        }
    }
}

impl OrderMetadata {
    pub fn new() -> Self {
        Self {
            position_id: None,
            strategy: None,
        }
    }

    pub fn with_position_id(mut self, position_id: Option<u64>) -> Self {
        self.position_id = position_id;
        self
    }

    pub fn with_strategy(mut self, strategy: Option<Box<dyn OrderStrategy>>) -> Self {
        self.strategy = strategy;
        self
    }

    pub fn position_id(&self) -> Option<u64> {
        self.position_id
    }
    pub fn cloned_strategy(&self) -> Option<Box<dyn OrderStrategy>> {
        match &self.strategy {
            None => { None }
            Some(strategy) => {
                Some(clone_box(&**strategy))
            }
        }
    }
}

/***************
* Positions
***************/

#[derive(Clone, Debug)]
pub struct Position {
    pair: SymbolPair,
    state: PositionState,
    profit_state: Option<PositionProfitState>,
    amount: f64,
    base_price: f64,
    pl: f64,
    pl_perc: f64,
    price_liq: f64,
    position_id: u64,
    creation_date: Option<u64>,
    creation_update: Option<u64>,
    platform: TradingPlatform,
    leverage: f64,
}

impl Position {
    pub fn new(
        pair: SymbolPair,
        state: PositionState,
        amount: f64,
        base_price: f64,
        pl: f64,
        pl_perc: f64,
        price_liq: f64,
        position_id: u64,
        platform: TradingPlatform,
        leverage: f64,
    ) -> Self {
        Position {
            pair,
            state,
            amount,
            base_price,
            pl,
            pl_perc,
            price_liq,
            position_id,
            creation_date: None,
            creation_update: None,
            profit_state: None,
            platform,
            leverage,
        }
    }

    pub fn with_creation_date(mut self, creation_date: Option<u64>) -> Self {
        self.creation_date = creation_date;
        self
    }

    pub fn with_creation_update(mut self, creation_update: Option<u64>) -> Self {
        self.creation_update = creation_update;
        self
    }

    pub fn with_profit_state(mut self, profit_state: Option<PositionProfitState>) -> Self {
        self.profit_state = profit_state;
        self
    }

    pub fn update_profit_loss(&mut self, best_offer: f64, fee_perc: f64) {
        let (base_price, delta) = {
            if self.is_short() {
                let base_price = self.base_price * (1.0 - fee_perc / 100.0);
                let delta = base_price - best_offer;

                (base_price, delta)
            } else {
                let base_price = self.base_price * (1.0 + fee_perc / 100.0);
                let delta = best_offer - base_price;

                (base_price, delta)
            }
        };

        let profit_loss = delta * self.amount.abs();
        let profit_loss_percentage = delta / base_price * 100.0;

        self.pl = profit_loss;
        self.pl_perc = profit_loss_percentage;
    }

    pub fn with_profit_loss(mut self, profit_loss: f64) -> Self {
        self.pl = profit_loss;
        self
    }

    pub fn pair(&self) -> &SymbolPair {
        &self.pair
    }
    pub fn state(&self) -> PositionState {
        self.state
    }
    pub fn amount(&self) -> f64 {
        self.amount
    }
    pub fn base_price(&self) -> f64 {
        self.base_price
    }
    pub fn pl(&self) -> f64 {
        self.pl
    }
    pub fn pl_perc(&self) -> f64 {
        self.pl_perc
    }
    pub fn price_liq(&self) -> f64 {
        self.price_liq
    }
    pub fn id(&self) -> u64 {
        self.position_id
    }
    pub fn profit_state(&self) -> Option<PositionProfitState> {
        self.profit_state
    }
    pub fn creation_date(&self) -> Option<u64> {
        self.creation_date
    }
    pub fn creation_update(&self) -> Option<u64> {
        self.creation_update
    }
    pub fn is_short(&self) -> bool {
        self.amount.is_sign_negative()
    }
    pub fn is_long(&self) -> bool {
        self.amount.is_sign_positive()
    }
    pub fn platform(&self) -> TradingPlatform {
        self.platform
    }
    pub fn leverage(&self) -> f64 {
        self.leverage
    }
}

impl Hash for Position {
    fn hash<H: Hasher>(&self, state: &mut H) {
        state.write(&self.id().to_le_bytes())
    }
}

impl PartialEq for Position {
    fn eq(&self, other: &Self) -> bool {
        self.id() == other.id()
    }
}

impl Eq for Position {}

#[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
pub enum PositionProfitState {
    Critical,
    Loss,
    BreakEven,
    MinimumProfit,
    Profit,
}

#[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
pub enum PositionState {
    Closed,
    Open,
}

pub enum WalletKind {
    Exchange,
    Margin,
    Funding,
}

#[derive(Debug)]
pub struct Trade {
    pub trade_id: u64,
    pub pair: SymbolPair,
    pub execution_timestamp: u64,
    pub price: f64,
    pub amount: f64,
    pub fee: OrderFee,
    pub fee_currency: Symbol,
}

#[derive(Debug)]
pub enum TradingFees {
    Maker {
        platform: TradingPlatform,
        percentage: f64,
    },
    Taker {
        platform: TradingPlatform,
        percentage: f64,
    },
}