ligo/contracts/coase.ligo
2019-05-12 20:57:30 +00:00

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// Copyright Coase, Inc 2019
type card_pattern_id is nat
type card_pattern is record [
coefficient : tez ;
quantity : nat ;
]
type card_patterns is map(card_pattern_id , card_pattern)
type card_id is nat
type card is record [
card_owner : address ;
card_pattern : card_pattern_id ;
]
type cards is map(card_id , card)
type storage_type is record [
cards : cards ;
card_patterns : card_patterns ;
next_id : nat ;
]
type action_buy_single is record [
card_to_buy : card_pattern_id ;
]
type action_sell_single is record [
card_to_sell : card_id ;
]
type action_transfer_single is record [
card_to_transfer : card_id ;
destination : address ;
]
type action is
| Buy_single of action_buy_single
| Sell_single of action_sell_single
| Transfer_single of action_transfer_single
function transfer_single(const action : action_transfer_single ; const s : storage_type) : (list(operation) * storage_type) is
begin
const cards : cards = s.cards ;
const card : card = get_force(action.card_to_transfer , cards) ;
if (card.card_owner =/= source) then fail "This card doesn't belong to you" else skip ;
card.card_owner := action.destination ;
cards[action.card_to_transfer] := card ;
s.cards := cards ;
const operations : list(operation) = nil ;
end with (operations , s) ;
function sell_single(const action : action_sell_single ; const s : storage_type) : (list(operation) * storage_type) is
begin
const card : card = get_force(action.card_to_sell , s.cards) ;
if (card.card_owner =/= source) then fail "This card doesn't belong to you" else skip ;
const card_pattern : card_pattern = get_force(card.card_pattern , s.card_patterns) ;
card_pattern.quantity := abs(card_pattern.quantity - 1n);
const card_patterns : card_patterns = s.card_patterns ;
card_patterns[card.card_pattern] := card_pattern ;
s.card_patterns := card_patterns ;
const cards : cards = s.cards ;
remove action.card_to_sell from map cards ;
s.cards := cards ;
const price : tez = card_pattern.coefficient * card_pattern.quantity ;
const receiver : contract(unit) = get_contract(source) ;
const op : operation = transaction(unit , price , receiver) ;
const operations : list(operation) = list op end ;
end with (operations , s)
function buy_single(const action : action_buy_single ; const s : storage_type) : (list(operation) * storage_type) is
begin
// Check funds
const card_pattern : card_pattern = get_force(action.card_to_buy , s.card_patterns) ;
const price : tez = card_pattern.coefficient * (card_pattern.quantity + 1n) ;
if (price > amount) then fail "Not enough money" else skip ;
// Administrative procedure
const operations : list(operation) = nil ;
// Increase quantity
card_pattern.quantity := card_pattern.quantity + 1n ;
const card_patterns : card_patterns = s.card_patterns ;
card_patterns[action.card_to_buy] := card_pattern ;
s.card_patterns := card_patterns ;
// Add card
const cards : cards = s.cards ;
cards[s.next_id] := record
card_owner = source ;
card_pattern = action.card_to_buy ;
end ;
s.cards := cards ;
s.next_id := s.next_id + 1n ;
end with (operations , s)
function main(const action : action ; const s : storage_type) : (list(operation) * storage_type) is
block {skip} with
case action of
| Buy_single bs -> buy_single (bs , s)
| Sell_single as -> sell_single (as , s)
| Transfer_single at -> transfer_single (at , s)
end