lzf1/src/main.rs

//
// When inserting a new Order into the royalties tree, we must make sure the existing
// royalties don't get shared with that new node. To do this, we must "shave" down
// the tree, pushing royalties from the root down to all nodes to the left of the
// new node.
//
// Case to think about:
//   Selling 140000 USD to buy 2 BTC. Weight is ===140k USD
//   Selling  50000 GBP to buy 1 BTC. Weight is === 50k GBP 
//

// Quick & Dirty Documentation
//
// Running lzf1 from a command line:
//     lzf1                                           # --Interactive is the default mode, no need to 
//     lzf1 --log tuesday.log                         # Same as above, but log all commands to file tuesday.log
//     lzf1 --replay tuesday.log                      # Replay tuesday.log, then go into interactive mode
//     lzf1 --replay tuesday.log --log wednesday.log  # Replay tuesday.log, then go interactive logging additional commands to wednesday.log
//     lzf1 --replay tuesday.log --log tuesday.log    # Replay tuesday.log, then go interactive, then append additional commands to tuesday.log
// Commands in Interactive Mode:
//     addasset USD                         # Case sensitive, no spaces
//     setroyalty USD 0.01 0.00 0.03 0.02   # Sets 1% royalty when order selling USD is placed, but no commission.
//                                          # Then additional 3% royalty when order executes, plus 2% commission 
//     addtrader Teppy                      # Case sensitive, no spaces
//     addfunds Teppy 20000 USD             # Create funds from thin air. Do this when we receive a wire transfer, for instance.
//     subfunds Teppy 0.5 BTC               # Remove funds. Do this when we process a withdrawal.
//     balances Teppy                       # Show all of Teppy's funds (but not what has been moved to the market)
//     login Teppy                          # Some commands take an implicit Trader parameter. This sets that parameter
//     whoami                               # Shows logged in name for this Interactive session
//     wallet                               # Show all of the logged-in trader's funds (but not what is on the market)
//     order 0.5 BTC 30000 USD              # Create an order selling 0.5 BTC to buy 30000 USD. Uses logged in Trader's balance.
//     quit                                 # Clean exit
//     
//     


#![allow(unsafe_code)]
#![allow(unused_variables)]
#![allow(dead_code)]

use std::fs::File;
use std::fs::OpenOptions;
use std::path::Path;
use std::io::{self, BufRead, Write};
use std::env;
use std::collections::HashMap;
use std::cmp::Ordering;
use std::rc::Rc;
use std::cell::RefCell;
use rand::prelude::*;
use rand::rngs::StdRng;
mod finum;
use finum::FiNum;

#[derive(Debug, Clone)]
struct Trader {
    name: String,
    password: String,              // hash(name..salt..password)
    id: usize,    
    balances: HashMap<usize,FiNum>, // Maps Currency to Amount
    }

#[derive(Clone)]
struct Asset {
    name: String,
    royalty0_rate: FiNum,	// Traders get this when entered
    royalty1_rate: FiNum,	// Traders get this when executed
    commission0_rate: FiNum,    // House gets this when entered
    commission1_rate: FiNum,    // House gets this when executed
    }

impl Asset {
    fn new(name: &str) -> Self {
        Asset {
	    name: String::from(name),
	    royalty0_rate:FiNum::zero(),
	    royalty1_rate:FiNum::zero(),
	    commission0_rate:FiNum::zero(),
	    commission1_rate:FiNum::zero(),
	    }
	}
    }

impl Trader {
    fn new(name:&str,id:usize) -> Self {
        Trader {
            name: String::from(name),
            password: String::from(""),
            id: id,
            balances: HashMap::new()
            }
        }
    fn add_balance(&mut self, cur:usize, delta:FiNum) {
        self.balances.entry(cur).and_modify(|ent| *ent+=delta ).or_insert_with(|| delta);
        }
    fn sub_balance(&mut self, cur:usize, delta:FiNum) {
        self.balances.entry(cur).and_modify(|ent| *ent-=delta );
        }
    fn get_balance(&self, cur:usize) -> FiNum {
        *self.balances.get(&cur).map(|bal| bal).unwrap_or(&FiNum::new(0u64))
        }
    }

#[derive(Debug, Clone)]
struct Order {
    sell_qty: FiNum,
    sell_remain: FiNum,
    buy_qty: FiNum,
    royalty_remain: FiNum,     // Based on royalty1
    commission_remain: FiNum,  // Based on commission1
    owner: usize,
    rt_loc: usize,      // Location in the Royalty Tree
    }

struct RoyaltyTree {
    tree: Vec<Royalty>,
    next_entry: usize,
    spare_change: FiNum, // Waiting to be distributed
    }

struct Royalty {
    weight: FiNum,      // Here and below
    lazy: FiNum,        // To be distributed to here and to below based on weights
    acc: FiNum,         // Accumulated here
    }

impl Royalty {
    fn new() -> Self {
        Royalty { weight:FiNum::zero(), lazy:FiNum::zero(), acc:FiNum::zero() }
        }
    }

impl RoyaltyTree {
    fn new() -> Self {
        RoyaltyTree { tree:Vec::new(), next_entry:0, spare_change:FiNum::zero() }
        }
    fn acc_total(&self) -> FiNum {
        let mut rval=FiNum::zero();
	for r in &self.tree { rval+= r.acc; }
	rval
	}
    fn weight_here_below(&self, index:usize) -> FiNum {
        self.tree[index].weight
        }
    fn weight_below(&self, index: usize) -> FiNum {
        if index&1==0 {
            FiNum::zero()
        } else {
            let w0=self.weight_here_below(wt_left (index).unwrap());
            let w1=self.weight_here_below(wt_right(index).unwrap());
            w0+w1
            }
        }
    fn weight_here(&self, index:usize) -> FiNum {
        if index&1==0 {
            self.weight_here_below(index)
        } else {
            let w0=self.weight_here_below(index);
            let w1=self.weight_below(index);
            w0-w1
            }
        }
    fn expand_to(&mut self, index: usize) -> &mut Self {
        for _ in self.tree.len()..=index { self.tree.push(Royalty::new()) }
        self
        }
    fn capture0(&mut self, index: usize) -> &mut Self {
        if index&1==0 {
            let lazy=self.tree[index].lazy;
            self.tree[index].acc+=lazy;
            self.tree[index].lazy=FiNum::zero();
        } else {
            let lazy=self.tree[index].lazy;
            let d1=if lazy>0.into() { lazy*self.weight_here(index)/self.weight_here_below(index) } else { FiNum::zero() };
            let d02=lazy-d1;
            let index_left =wt_left (index).unwrap();
            let index_right=wt_right(index).unwrap();
            let d0=if d02>0.into() { d02*self.weight_here_below(index_left)/self.weight_below(index) } else { FiNum::zero() };
            let d2=d02-d0;
            assert!(lazy==d0+d1+d2,"Distributing amounts that don't add up.");
            self.tree[index_left ].lazy+=d0;
            self.tree[index_right].lazy+=d2;
            self.tree[index].acc+=d1;
            self.tree[index].lazy=FiNum::zero();
            }
        self
        }
    fn get_royalty(&mut self, index: usize) -> FiNum {
        let mut f=self.forefather();
        while f!=index {
            self.capture0(f);
            f=if f>index { wt_left(f).unwrap() } else { wt_right(f).unwrap() }
            }
        self.capture0(f);
        self.tree[index].acc
        }
    fn add_royalty(&mut self, amount: FiNum) {
        if self.next_entry==0 { self.spare_change+=amount }
        else {
            let ff=self.forefather();
            if self.weight_here_below(ff).is_zero() { self.spare_change+=amount } else { self.tree[ff].lazy+=amount };
            }
        }
    fn add_weight(&mut self, index: usize, weight: FiNum) {
	if self.tree.len()>0 {
            let mut ff0=self.forefather();
            let ff1=wt_forefather(index);
	    let w=self.tree[ff0].weight;
	    self.expand_to(ff1*2);
	    while ff0<ff1 {
	        ff0=wt_parent(ff0);
		self.tree[ff0].weight=w;
		}
            }
	else { self.expand_to(wt_forefather(index)*2); }
        self.get_royalty(index); // Just for the side effect of capturing everything to this point
        let mut index=index;
	let ff=self.forefather();
        while index!=ff {
            self.tree[index].weight+=weight;
            index=wt_parent(index);
            }
        self.tree[index].weight+=weight;
        }
    fn forefather(&self) -> usize {
        wt_forefather(self.tree.len()-1)
        }
    fn dump(&mut self) {
        for index in 0..self.tree.len() {
            let roy=self.get_royalty(index);
            println!("Index {} Weight {} Lazy {} Acc {} Royalty {}",index,self.tree[index].weight,self.tree[index].lazy,self.tree[index].acc,roy);
            }
        }
    }


trait Dumpable {
    fn dump(&self);
    }

impl Dumpable for usize {
    fn dump(&self) {
        println!("Dump Integer: {}",self);
        }
    }


impl Dumpable for Rc<RefCell<Order>> {
    fn dump(&self) {
        }
    }


impl Dumpable for Order {
    fn dump(&self) {
        println!("Giving {}/{} to get {}",self.sell_remain,self.sell_qty,self.buy_qty);
        }
    }



struct Market {
    asset_name2num: HashMap<String,usize>,
    assets: Vec<Asset>,
    money_supply: HashMap<usize,FiNum>,
    traders: Vec<Trader>,
    trader_name2num: HashMap<String,usize>,
    orders: HashMap<(usize,usize),PQueue<Rc<RefCell<Order>>>>,
    royalties: HashMap<usize,RoyaltyTree>, // Active orders that are accepting asset X. They receive royalties when someone makes an order to sell X
    royalty_rate: HashMap<usize,FiNum>,
    }

impl Market {
    fn new() -> Self {
        let mut rval=Market {
            asset_name2num: HashMap::new(),
	    assets: Vec::new(),
            money_supply: HashMap::new(),
            traders: Vec::new(),
            trader_name2num: HashMap::new(),
            orders: HashMap::new(),
            royalties: HashMap::new(),
	    royalty_rate: HashMap::new(),
            };
        rval.register_trader("*HOUSE*");
        rval
        }
    fn sanity_check(&self) {
        println!("Sanity Checking Market...");
        for (cur,amt) in self.money_supply.iter() {
            println!("Money Supply {}: {}",self.number_to_name(*cur),*amt);
            let mut acc_orders=FiNum::new(0);
            for (ac,pq) in &self.orders { if ac.0==*cur {
                for off in &*pq.v { acc_orders+=off.borrow().sell_remain; }
                } }
            let mut acc_traders=FiNum::new(0);
            for t in &self.traders { acc_traders+=t.get_balance(*cur); }
            let acc=acc_orders+acc_traders;
            println!("    {}: Orders {} Traders {} Total {} Should Be {}",self.number_to_name(*cur),acc_orders,acc_traders,acc,*amt);
            }
        }
    fn register_trader(&mut self, name:&str) -> usize { // Add error checking for inserting a trader twice
        let rval=self.traders.len();
        self.trader_name2num.insert(String::from(name),self.traders.len());
        self.traders.push(Trader::new(name,rval));
        rval
        }
    // These are the only ways to get money into or out of the market.
    fn get_trader_balance(&self, who:usize, cur:usize) -> FiNum {
        self.traders[who].get_balance(cur)
	}
    fn add_trader_balance(&mut self, who:usize, cur:usize, delta: FiNum) {
        self.traders[who].add_balance(cur,delta);
        *self.money_supply.get_mut(&cur).unwrap()+=delta;
        }
    fn sub_trader_balance(&mut self, who:usize, cur:usize, delta: FiNum) {
        self.traders[who].sub_balance(cur,delta);
        *self.money_supply.get_mut(&cur).unwrap()-=delta;
        }
    fn register_asset(&mut self, name:&str) -> Option<usize> {
        if self.asset_name2num.contains_key(name) { return None }
        self.assets.push(Asset::new(name));
        self.asset_name2num.insert(String::from(name),self.assets.len()-1);
        self.money_supply.insert(self.assets.len()-1,FiNum::new(0));
        let rval=self.assets.len()-1;
        Some(rval)
        }
    fn set_royalty(&mut self, n: usize, roy0: FiNum, com0: FiNum, roy1: FiNum, com1: FiNum) {
        self.assets[n].royalty0_rate   =roy0;
        self.assets[n].commission0_rate=com0;
        self.assets[n].royalty1_rate   =roy1;
        self.assets[n].commission1_rate=com1;
	}
    fn number_to_asset(&self, n: usize) -> Asset {
        self.assets[n].clone()
        }
    fn number_to_name(&self, n: usize) -> String {
        self.assets[n].name.clone()
	}
    fn name_to_number(&self, name:&str) -> Option<&usize> {
        self.asset_name2num.get(name)
        }
    fn dump(&self) {
        println!("Dumping Market:");
        for t in &self.traders {
            println!("    Trader {}: {}",t.id,t.name);
            for (cur,bal) in t.balances.iter() {
                println!("        {}: {}",self.number_to_name(*cur),*bal)
                }
            }
        for (ap,pq) in &self.orders {
            println!("Orders selling {} to buy {}:",self.number_to_name(ap.0),self.number_to_name(ap.1));
            let mut sorted=pq.v.clone();
            sorted.sort_by(|a,b| { let a=a.borrow(); let b=b.borrow(); (a.sell_qty/a.buy_qty).cmp(&(b.sell_qty/b.buy_qty)) });
            for off in sorted.iter() {
                let off=off.borrow();
                println!("    {} @ {} ({}), Acc: {}",
                         off.sell_remain,              // off.buy_qty*off.sell_remain/off.sell_qty,
                         off.buy_qty/off.sell_qty,
                         self.traders[off.owner as usize].name,
			 self.royalties.get(&ap.1).unwrap().tree[off.rt_loc].acc);
                }
            pq.dump();
            }
	for index in 0..self.assets.len() {
	    let tot=self.royalties.get(&index).unwrap().acc_total();
	    println!("Accumulated Royalties for {}: {}",self.number_to_asset(index).name,tot);
	    }
        }
     fn replay_file(&mut self, fname:&str) {
        println!("Replaying {}",fname);
        let f=File::open(Path::new(fname));
	let reader=io::BufReader::new(f.unwrap());
        for line in reader.lines() {
            if let Ok(line) = line {
                let cmd=Command::deserialize(line);
		if let Command::NOP(comment)=cmd { println!("{}",comment); }
		else {
  		    let res=self.execute(&cmd);
		    println!("{}",res.describe());
		    }
                }
	    }
        }        
    fn make_order(&mut self, owner:usize, sell_type:usize, buy_type:usize, sell_qty_initial:FiNum, buy_qty_initial:FiNum) -> Result { 
	let mut log:Vec<String>=Vec::new();
        let initial_balance=self.traders[owner].get_balance(sell_type);
        let asset=self.number_to_asset(sell_type);
        let mut royalty0_qty=asset.royalty0_rate*sell_qty_initial;
        let mut royalty1_qty=asset.royalty1_rate*sell_qty_initial;
        let mut commission0_qty=asset.commission0_rate*sell_qty_initial;
        let mut commission1_qty=asset.commission1_rate*sell_qty_initial;
        let sell_qty_plus=sell_qty_initial+royalty0_qty+royalty1_qty+commission0_qty+commission1_qty; // This is the maximum amount we are going to sell
        let sell_qty=sell_qty_initial;
        if initial_balance<sell_qty_plus { return Result::Error(format!("Funds not available")) }
        let mut buy_qty=buy_qty_initial;
        let ap=(buy_type,sell_type);
        let mut royalty_acc=FiNum::zero();
        let mut commission_acc=FiNum::zero();
        while buy_qty>FiNum::new(0) && self.orders.contains_key(&ap) && self.orders.get(&ap).unwrap().v.len()>0 {
            let mut elt=(*(self.orders.get(&ap).unwrap().v[0].borrow())).clone();
            if sell_qty/buy_qty_initial>=elt.buy_qty/elt.sell_qty { // Transact at ask_rate
                let qty=std::cmp::min(elt.sell_remain,buy_qty);
                elt.sell_remain-=qty;
                buy_qty-=qty;
                let pay_qty=qty*elt.buy_qty/elt.sell_qty;
                self.traders[owner    ].sub_balance(sell_type,pay_qty);
                self.traders[owner    ].add_balance(buy_type ,qty); 
                self.traders[elt.owner].add_balance(sell_type,pay_qty);
		log.push(format!("Sold {} {} ({}) to buy {} {} ({})",pay_qty,self.number_to_name(sell_type),self.traders[owner    ].name,
		                                                     qty    ,self.number_to_name(buy_type ),self.traders[elt.owner].name));
                let rq0=royalty0_qty   *pay_qty/sell_qty_initial;
                let cq0=commission0_qty*pay_qty/sell_qty_initial;
                let rq1=royalty1_qty   *pay_qty/sell_qty_initial;
                let cq1=commission1_qty*pay_qty/sell_qty_initial;
	        println!("Transact at ask rate. Qty={} elt.sell_remain={} elt.royalty_remain={} elt.commission_remain={}",qty,elt.sell_remain,elt.royalty_remain,elt.commission_remain);
                let rq2=if !elt.sell_remain.is_zero() { elt.royalty_remain   *qty/elt.sell_remain } else { FiNum::zero() };
                let cq2=if !elt.sell_remain.is_zero() { elt.commission_remain*qty/elt.sell_remain } else { FiNum::zero() };
                royalty_acc+=rq0+rq1;
                commission_acc+=cq0+cq1;
                royalty0_qty-=rq0;
                royalty1_qty-=rq1;
                commission0_qty-=cq0;
                commission1_qty-=cq1;
                self.royalties.entry(sell_type).or_insert(RoyaltyTree::new()).add_royalty(rq0+rq1);
                self.royalties.entry(buy_type) .or_insert(RoyaltyTree::new()).add_royalty(rq2);
                self.orders.get(&ap).unwrap().v[0].borrow_mut().royalty_remain-=rq2;
                self.orders.get(&ap).unwrap().v[0].borrow_mut().commission_remain-=cq2;
                self.traders[0].add_balance(buy_type,cq2);
                self.royalties.entry(buy_type).or_insert(RoyaltyTree::new()).add_royalty(rq2);
                if elt.sell_remain==0.into() { // deal with pennies stored in royalty_remain and commission_remain
                    self.traders[0].add_balance(buy_type,self.orders.get(&ap).unwrap().v[0].borrow_mut().commission_remain);
                    self.royalties.entry(buy_type).or_insert(RoyaltyTree::new()).add_royalty(self.orders.get(&ap).unwrap().v[0].borrow_mut().royalty_remain);
                    self.orders.get_mut(&ap).unwrap().pop();
                } else {
                    self.orders.get(&ap).unwrap().v[0].borrow_mut().sell_remain-=qty;
                    }
            } else { break; }
            }
        if buy_qty>0.into() {
            let ap=(sell_type,buy_type);
            if let None=self.orders.get_mut(&ap) { self.orders.insert(ap,PQueue::new()); }
            let bids=self.orders.get_mut(&ap).unwrap();
            let sell_qty_remain=sell_qty*buy_qty/buy_qty_initial;
            if sell_qty_remain>0.into() {
                self.royalties.entry(sell_type).or_insert(RoyaltyTree::new()).add_royalty(royalty0_qty);
                let rt=self.royalties.entry(buy_type).or_insert(RoyaltyTree::new());
		rt.add_weight(rt.next_entry,buy_qty); // Weight should really be the quantity you would be able to immediately transact rather than how much you wish for.
                let neworder=Rc::new(RefCell::new(
                    Order { owner:owner, sell_qty:sell_qty_remain, sell_remain:sell_qty_remain, buy_qty:buy_qty, rt_loc: rt.next_entry, royalty_remain:royalty1_qty, commission_remain:commission1_qty } ));
		rt.next_entry+=1;
                bids.insert(neworder);
                self.traders[owner].sub_balance(sell_type,sell_qty_remain);
                self.traders[0].add_balance(sell_type,commission0_qty);
		log.push(format!("Moved {} {} ({}) to market",sell_qty_remain,self.number_to_name(sell_type),self.traders[owner].name));
                }
            }
        self.traders[0].add_balance(sell_type,commission_acc);
        self.traders[owner].sub_balance(sell_type,royalty_acc+commission_acc);
	log.push(format!("Paid {} {} in royalties and {} {} ({}) in commissions",royalty_acc   ,self.number_to_name(sell_type),
	                                                                         commission_acc,self.number_to_name(sell_type),self.traders[owner].name));
        Result::PlacedOrder(0,log)
        }
    }

impl PartialOrd for Order {  
    fn partial_cmp(&self, other:&Self) -> Option<Ordering> {
        let ord0=self .sell_qty/self .buy_qty;
        let ord1=other.sell_qty/other.buy_qty;
        if      ord0<ord1 { Some(Ordering::Less) }
        else if ord0>ord1 { Some(Ordering::Greater) }
        else              { Some(Ordering::Equal) }
        }
    }

impl PartialEq for Order {
    fn eq(&self, other:&Self) -> bool {
        let ord0=self .sell_qty/self .buy_qty;
        let ord1=other.sell_qty/other.buy_qty;
        ord0==ord1
        }
    }


struct PQueue<T: Dumpable> {
  v: Vec<T>,
  }

impl<T: Dumpable + std::cmp::PartialOrd + std::fmt::Debug> PQueue<T> {
    fn new()->Self {
        PQueue {
            v: Vec::new()
            }
        }
    fn peek(&self) -> &T {
        &self.v[0]
        }
    fn bubble_up(&mut self, pos: usize) {
        if pos>0 {
            let parent=(pos-1)/2;
            if self.v[parent]<self.v[pos] {
                self.v.swap(parent,pos);
                self.bubble_up(parent);
                }
            }
        }
    fn trickle_down(&mut self, pos: usize) {
        let mut pivot=pos;
        let child0=pos*2+1;
        let child1=pos*2+2;
        if child0<self.v.len() {
            if self.v[pos]<self.v[child0] { pivot=child0; }
            if child1<self.v.len() {
                if self.v[pivot]<self.v[child1] { pivot=child1; }
                }
            if pivot!=pos {
                self.v.swap(pivot,pos);
                self.trickle_down(pivot);
                }
            }
        }
    fn insert(&mut self, item: T) {
        self.v.push(item);
        self.bubble_up(self.v.len()-1);
        }
    fn pop(&mut self) -> Option<T> {
        if self.v.len()==0 { None }
        else {
            let end=self.v.len()-1;
            self.v.swap(0,end);
            let rval=self.v.pop();
            self.trickle_down(0);
            rval
            }
        }
    fn dump(&self) {
        for index in 0..self.v.len() {
            self.v[index].dump();
            }
        }
    }

impl Market {
    fn exercise(&mut self) {
        let mut rng: StdRng=StdRng::seed_from_u64(13u64);
        let teppy=self.register_trader("Teppy");  
        let luni =self.register_trader("Luni");
        let usd  =self.register_asset("USD").unwrap();
        let btc  =self.register_asset("BTC").unwrap();
        self.add_trader_balance(teppy,btc,100000.into());
        self.add_trader_balance(luni ,usd,650000000.into());
        let mut count=0;
        let mut tries=0;
        for _i in 1..=1000000 {
            let seller=if rng.gen_bool(0.5) { teppy } else { luni };
            let (buy_type,sell_type,buy_qty,sell_qty):(usize,usize,FiNum,FiNum);
            if rng.gen_bool(0.5) {
                sell_type=btc;
                buy_type=usd;
                sell_qty=rng.gen_range(1..=5).into();
                buy_qty=sell_qty*rng.gen_range(60..=70).into();
            } else {
                sell_type=usd;
                buy_type=btc;
                buy_qty=rng.gen_range(1..=5).into();
                sell_qty=buy_qty*rng.gen_range(60..=70).into();
                }
            let mut _success=false;
            if let Result::Ok=self.make_order(seller,sell_type,buy_type,sell_qty,buy_qty) { count+=1; _success=true; };
            if count>=1000000 { break; }
            tries+=1;
            }
        println!("Tries: {} Trades: {}",tries,count);
        self.sanity_check();
        }
    }

fn wt_level(index:usize) -> usize {
    (index^(index+1)).trailing_ones() as usize-1
    }

fn wt_leaf(index:usize) -> bool {
    index&1==0
    }

fn wt_left(index:usize) -> Option<usize> {
    let level=wt_level(index);
    if level>0 { Some(index-(1<<(wt_level(index)-1))) } else { None }
    }

fn wt_right_edge(index: usize, edge: usize) -> Option<usize> { // Less than edge
    if index&1==0 { None }
    else {
        let mut r=wt_right(index).unwrap();
        if r<edge { Some(r) }
        else {
            while r&1==1 {
                if r<edge { return Some(r); }
                else { r=wt_left(r).unwrap(); }
                }
            if r<edge { Some(r) } else { None }
            }
        }
    }

fn wt_right(index:usize) -> Option<usize> {
    let level=wt_level(index);
    if level>0 { Some(index+(1<<(wt_level(index)-1))) } else { None }
    }

fn wt_parent(index:usize) -> usize {
    let lev=wt_level(index);
    let first_in_row=index%(1<<lev);
    let skip=2<<lev;
    let nth_in_row=(index-first_in_row)/skip;
    let first_in_parent_row=(2<<lev)-1;
    let skip_in_parent_row=4<<lev;
    let nth_in_parent_row=nth_in_row>>1;
    first_in_parent_row+nth_in_parent_row*skip_in_parent_row
    }

fn wt_forefather(max_index:usize) -> usize {
    let mut rval=max_index;
    rval=rval|(rval>>1);
    rval=rval|(rval>>2);
    rval=rval|(rval>>4);
    rval=rval|(rval>>8);
    rval=rval|(rval>>16);
    rval=rval|(rval>>32);
    if rval>max_index { wt_left(rval).unwrap() } else { rval }
    }


fn royalty_stuff() {
    let mut rt=RoyaltyTree::new();
    for index in 0..10 {
        rt.add_weight(index,FiNum::new_i32(10));
        rt.add_royalty(FiNum::new_i32(24))
        }
    for index in 0..rt.tree.len() {
        println!("Index: {} Weight_here {} Weight_below {} Weight_here_below {}",index,rt.weight_here(index),rt.weight_below(index),rt.weight_here_below(index));
        }
    }


enum Result {
    AddedTrader(usize),
    AddedAsset(usize),
    PlacedOrder(usize, Vec<String>),
    FundsRemaining(FiNum),
    Error(String),
    Ok
    }

enum Command {
    AddTrader { user: String },
    AddAsset { asset: String },
    SetRoyalty { asset_id: usize, roy0: FiNum, com0: FiNum, roy1: FiNum, com1: FiNum },
    AddFunds { user_id: usize, asset_id: usize, amt: FiNum },
    SubFunds { user_id: usize, asset_id: usize, amt: FiNum },
    Order { user_id: usize, sell_type: usize, sell_qty: FiNum, buy_type: usize, buy_qty: FiNum },
    Retract { order_id: usize },
    Error(String),
    NOP(String),
    None,
    }

fn clean(s: &str) -> String { s.to_string() }

impl Command {
    fn serialize(&self) -> String {
        match self {
	    Self::AddTrader { user: name }                        => format!("AT {}",name),
	    Self::AddAsset { asset: name }                        => format!("AA {}",name),
	    Self::SetRoyalty { asset_id, roy0, com0 , roy1 , com1 }
	    		       		 	                  => format!("SR {} {} {} {} {}",asset_id,roy0.serialize(),com0.serialize(),roy1.serialize(),com1.serialize()),
	    Self::AddFunds { user_id, asset_id, amt }
            		     	      	                          => format!("AF {} {} {}",user_id,asset_id,amt.serialize()),
	    Self::SubFunds { user_id, asset_id , amt }
	    		     	      	     	       	     	  => format!("SF {} {} {}",user_id,asset_id,amt.serialize()),
	    Self::Order { user_id, sell_type, sell_qty, buy_type, buy_qty }
	                                                          => format!("OR {} {} {} {} {}",user_id,sell_type,sell_qty.serialize(),buy_type,buy_qty.serialize()),
	    Self::Retract { order_id }              	  => format!("RE {}",order_id),
	    Self::Error(str)                                      => format!("NOP Error: {}",str),
	    Self::NOP(str)                                        => format!("NOP {}",clean(str)),
	    _ 						   	  => format!("NOP (This should never happen)"),
	    }
	}
    fn deserialize(line: String) -> Self {
        let tokens: Vec<&str> = line.split_whitespace().collect();
        match tokens.as_slice() {
            ["AT",name] => Self::AddTrader { user: name.to_string() },
	    ["AA",name] => Self::AddAsset { asset: name.to_string() },
	    ["SR",asset_id,roy0,com0,roy1,com1] =>
	        Self::SetRoyalty { asset_id: asset_id.parse::<usize>().unwrap(), roy0: FiNum::new_deserialize(roy0), com0: FiNum::new_deserialize(com0),
			                                                                    roy1: FiNum::new_deserialize(roy1), com1: FiNum::new_deserialize(com1) },
	    ["AF",user_id,asset_id,amt] =>
	        Self::AddFunds { user_id: user_id.parse::<usize>().unwrap(), asset_id: asset_id.parse::<usize>().unwrap(), amt: FiNum::new_deserialize(amt) },
	    ["SF",user_id,asset_id,amt] =>
	        Self::SubFunds { user_id: user_id.parse::<usize>().unwrap(), asset_id: asset_id.parse::<usize>().unwrap(), amt: FiNum::new_deserialize(amt) },
	    ["OR",user_id,sell_type,sell_qty,buy_type,buy_qty] =>
	        Self::Order { user_id: user_id.parse::<usize>().unwrap(), sell_type: sell_type.parse::<usize>().unwrap(), sell_qty: FiNum::new_deserialize(sell_qty),
		                                                          buy_type:  buy_type.parse::<usize>().unwrap(),  buy_qty:  FiNum::new_deserialize(buy_qty) },
            ["NOP", many_things @ ..] => Self::NOP(clean(&line)),
	    _ => Self::Error("Unimplemented Parse".to_string()),
	    }
        }
    }

impl Result {
    fn describe(&self) -> String {
        match self {
	    Self::PlacedOrder(order_id,vec) => format!("Placed order {}:\n    {}",order_id,vec.join("\n    ")),
	    Self::AddedTrader(id) => format!("Added Trader Id {}",id),
	    Self::AddedAsset(id) => format!("Added Asset Id {}",id),
	    Self::FundsRemaining(amt) => format!("Funds Remaining: {}",amt),
	    Self::Ok => format!("Ok"),
	    Self::Error(str) => format!("Error: {}",str),
//	    _ => "Some other result".to_string(),
	    }
	}
    fn print(&self) -> &Self {
	println!("{}",self.describe());
	self
	}
    }

impl Market {
    fn execute(&mut self, cmd: &Command) -> Result {
	match cmd {
	    Command::AddTrader { user: user_name } => {
	        let id=self.register_trader(user_name);
	        Result::AddedTrader(id)
		}
	    Command::AddAsset { asset: asset_name } => {
                if let Some(cur)=self.register_asset(asset_name) {
		    Result::AddedAsset(cur)
		} else { Result::Error(format!("Asset {} already exists.",asset_name)) }
		}
	    Command::SetRoyalty { asset_id,roy0,com0,roy1,com1 } => {
                if *roy0+*com0+*roy1+*com1<FiNum::new_i32(1) {
                    self.set_royalty(*asset_id,*roy0,*com0,*roy1,*com1);
    		    println!("Set royalty for {} to {} {} {} {}",asset_id,roy0,com0,roy1,com1);
		    Result::Ok
		    }
		else { Result::Error(format!("Sum of royalties and commissions should be less than 1.00")) }
		}
	    Command::AddFunds{ user_id, asset_id, amt } => {
                self.add_trader_balance(*user_id,*asset_id,*amt);
                println!("Added {} {} to {}",*amt,self.number_to_asset(*asset_id).name,self.traders[*user_id].name);
		Result::FundsRemaining(self.get_trader_balance(*user_id,*asset_id))
		}
	    Command::SubFunds { user_id,asset_id,amt } => {
                if *amt>self.get_trader_balance(*user_id,*asset_id) { Result::Error(format!("Not enough {} in {}",asset_id,user_id)) }
		else {
		    self.sub_trader_balance(*user_id,*asset_id,*amt);
                    println!("Subtracted {} {} from {}",*amt,self.number_to_asset(*asset_id).name,self.traders[*user_id].name);
                    Result::FundsRemaining(self.get_trader_balance(*user_id,*asset_id))
		    }
		}
	    Command::Order { user_id, sell_type, sell_qty, buy_type, buy_qty } => {
                self.make_order(*user_id,*sell_type,*buy_type,*sell_qty,*buy_qty)
		}
	    Command::Error(str) => Result::Error(format!("Command Error")),
	    Command::NOP(str) => Result::Ok,
	    _ => Result::Error(format!("Tried to execute an unimplemented Command. This is a bug because all Commands should be implemented, even NOPs and Errors.")),
	    }
        }
    }



fn erase(filename: &str) {
    // Stub function for erasing a file
    println!("Erasing file: {}", filename);
}

fn copy(source: &str, destination: &str) {
    // Stub function for copying a file
    println!("Copying file from {} to {}", source, destination);
}


fn tokens_to_command(m: &Market, logged_in: usize, tokens: Vec<&str>,line: &str) -> Command {
    let cmd:Command=match &tokens[..] {
        ["addtrader", username] => Command::AddTrader { user: username.to_string() },
        ["addasset", assetname] => Command::AddAsset { asset: assetname.to_string() },
        ["setroyalty", assetname, roy0, com0, roy1, com1] => {
            if let Some(cur)=m.name_to_number(assetname) {
                let roy0=FiNum::new_str(roy0);
                let com0=FiNum::new_str(com0);
                let roy1=FiNum::new_str(roy1);
                let com1=FiNum::new_str(com1);
                if roy0+com0+roy1+com1<FiNum::new_i32(1) {
                    Command::SetRoyalty { asset_id: *cur, roy0: roy0, com0: com0, roy1: roy1, com1: com1 }
                } else { Command::Error("Sum of royalties must be less than 1".to_string()) }
            } else {
	        Command::Error("Unknown Asset".to_string())
		}
            }
        ["addfunds", username, qty0, cur0 ] => {
            let user=m.trader_name2num.get(*username);
            let qty=FiNum::new_str(qty0);
            let cur=m.name_to_number(cur0);
            if      user.is_none() { Command::Error(format!("Could not find trader {}",username)) }
            else if qty.is_zero()  { Command::Error(format!("Could not parse quantity {}",qty0)) }
            else if cur.is_none()  { Command::Error(format!("Could not find asset {}",cur0)) }
            else {
                let user=*user.unwrap();
                let cur=*cur.unwrap();
                Command::AddFunds { user_id: user, asset_id: cur, amt: qty }
		}
            }
        ["subfunds", username, qty0, cur0 ] => {
            let user=m.trader_name2num.get(*username);
            let qty=FiNum::new_str(qty0);
            let cur=m.name_to_number(cur0);
            if      user.is_none() { Command::Error(format!("Could not find trader {}",username)) }
            else if qty.is_zero()  { Command::Error(format!("Could not parse quantity {}",qty0)) }
            else if cur.is_none()  { Command::Error(format!("Could not find asset {}",cur0)) }
            else {
                let user=*user.unwrap(); 
                let cur=*cur.unwrap();
                Command::SubFunds { user_id: user, asset_id: cur, amt: qty }
		}
            }
        ["order", qty0, cur0, qty1, cur1 ] => {
            let qty0=FiNum::new_str(qty0);
            let cur0=m.name_to_number(cur0);
            let qty1=FiNum::new_str(qty1);
            let cur1=m.name_to_number(cur1);
            if !cur0.is_some() { Command::Error("Count not find currency".to_string()) }
            else if !cur1.is_some() { Command::Error("Count not find currency".to_string()) }
            else if qty0.is_zero() { Command::Error("Qty0 is must be > 0".to_string()) }
            else if qty1.is_zero() { Command::Error("Qty1 is must be > 0".to_string()) }
            else { Command::Order { user_id: logged_in, sell_type: *cur0.unwrap(), sell_qty: qty0, buy_type: *cur1.unwrap(), buy_qty: qty1 } }
            }
        _ => { Command::Error(line.to_string()) },
	};
    cmd
    }

    
fn interactive(m: &mut Market, mut out: Option<File>) {
    println!("Trading interactively in Tuesday Markets (demo)");
    let stdin = io::stdin();
    let mut trader:usize=0;
    for line in stdin.lock().lines() {
        match line {
            Ok(input) => {
                let tokens: Vec<&str> = input.split_whitespace().collect();
                let cmd:Command=match tokens.as_slice() {
                    ["dump"] => { m.dump(); Command::None },
                    ["login", username] => {
                        if let Some(t)=m.trader_name2num.get_mut(*username) { trader=*t; println!("Logged in as {}",m.traders[trader].name) } else { println!("Trader {} not found.",username) }
			Command::None
			},
                    ["whoami" ] => { println!("Logged in as {}, id {}",m.traders[trader].name,trader ); Command::None }
		    ["wallet"] => {
                        for (key,value) in &m.traders[trader].balances { println!("    {} {}",m.number_to_name(*key),value); }
			Command::None
			}
                    ["balances", username] => {
                        if let Some(user)=m.trader_name2num.get(*username) {
                            println!("Balances for trader {}",m.traders[*user].name);
                            for (key,value) in &m.traders[*user].balances { println!("    {} {}",m.number_to_name(*key),value); }
			} else { println!("Could not find trader {}",username); }
			Command::None
                        },
                    ["quit"] => { return },
                    _ => {
		        let cmd=tokens_to_command(m,trader,tokens,&input);
			if let Some(ref mut f)=out {
    			    let ser=cmd.serialize();
			    if let Err(e)=writeln!(f,"{}",ser) { eprintln!("An error occurred while writing {}",e); }
			    else { println!("Wrote to logfile: {}",ser); }
			    }
		        let res=m.execute(&cmd);
			println!("Result: {}",res.describe());
			Command::None
			},
                    };
                }
            Err(error) => println!("Error reading input: {}", error),
            }
        }
    }

fn numbers_stuff() {
    println!("Numbers_stuff");
    let n=FiNum::new_i32(7)/FiNum::new_i32(2);
    let n_s=n.serialize();
    let n_d=FiNum::new_deserialize(&n_s);
    println!("N is {}, Serialized to {}, Deserialized to {}",n,n_s,n_d);
    }

fn paths_match(path0: &str, path1: &str) -> bool
    {
    let path0 = Path::new(path0);
    let path1 = Path::new(path1);
    path0 == path1
    }

//
// Use cases:
//   Replace logfile
//   Replay logfile and then append to it
//   Replay one logfile and then replace a different one
// Future additional use cases:
//   Replay logfile1+logfile2+... and then replace a different log file
//   Replay logfile1+logfile2+logfileN and then append to logfileN
//
fn main() {
    let args: Vec<String> = env::args().collect();
    let mut options:HashMap<&str,String>=HashMap::new();
    let mut i=1;
    enum Mode { Help, Royalty, Interactive, Exercise, Numbers, None }
    let mut mode_count=0;
    let mut mode=Mode::None;
    while i<args.len() {
        match args[i].as_str() {
	    "--help"        => { mode=Mode::Help;        mode_count+=1; i+=1; }
	    "--interactive" => { mode=Mode::Interactive; mode_count+=1; i+=1; }
	    "--royalty"     => { mode=Mode::Royalty;     mode_count+=1; i+=1; }
	    "--exercise"    => { mode=Mode::Exercise;    mode_count+=1; i+=1; }
	    "--numbers"     => { mode=Mode::Numbers;     mode_count+=1; i+=1; }
	    "--log"         => {
	        if i+1>=args.len() { println!("No log file specified."); return; }
		else { options.insert("logfile",args[i+1].clone()); i+=2; }
		}
            "--replay"      => {
	        if i+1>=args.len() { println!("No replay file specified."); return; }
		else { options.insert("replay",args[i+1].clone()); i+=2; }
		}
	    _ =>               { println!("Unknown option."); return; }
	    }
	}
    if mode_count==0 { mode=Mode::Interactive; mode_count+=1; }
    if mode_count!=1 { println!("You may only select one mode to run in."); return; }
    let mut m=Market::new(); // USD type is 1, EUR type is 2, BTC type is 10, ETH type is 11, zKN6FBdD SOL type is 12
    if      options.contains_key("replay")      { m.replay_file(options.get("replay").unwrap()); }
    match mode {
        Mode::Interactive => {  
            if options.contains_key("logfile") {
		let ap=options.contains_key("replay") && paths_match(options.get("replay").unwrap(),options.get("logfile").unwrap());
	        let f=OpenOptions::new().write(true).append(ap).truncate(!ap).create(true).open(options.get("logfile").unwrap());
	        if let Ok(f)=f { interactive(&mut m,Some(f)); }
		else { println!("Could not open logfile for writing."); }
	    } else { interactive(&mut m,None); }
	    }
	Mode::Exercise => m.exercise(),
	Mode::Numbers  => numbers_stuff(),
	Mode::Royalty  => royalty_stuff(),
	_              => println!("Unspecified mode"),
	}
    }