34 lines
1.1 KiB
Plaintext
34 lines
1.1 KiB
Plaintext
type taco_supply is
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record [
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current_stock : nat;
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max_price : tez
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]
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type taco_shop_storage is map (nat, taco_supply)
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type return is list (operation) * taco_shop_storage
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function buy_taco (const taco_kind_index : nat ; var taco_shop_storage : taco_shop_storage) : return is
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block {
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// Retrieve the taco_kind from the contract's storage or fail
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const taco_kind : taco_supply =
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case taco_shop_storage[taco_kind_index] of
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Some (kind) -> kind
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| None -> (failwith ("Unknown kind of taco.") : taco_supply)
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end;
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const current_purchase_price : tez =
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taco_kind.max_price / taco_kind.current_stock;
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if amount =/= current_purchase_price then
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// We won't sell tacos if the amount is not correct
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failwith ("Sorry, the taco you are trying to purchase has a different price");
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else skip;
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// Decrease the stock by 1n, because we have just sold one
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taco_kind.current_stock := abs (taco_kind.current_stock - 1n);
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// Update the storage with the refreshed taco_kind
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taco_shop_storage[taco_kind_index] := taco_kind
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} with ((nil : list (operation)), taco_shop_storage)
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