create-bid-fauna.js

create-bid-fauna.js

Query(
  Lambda(
    ["bidderRef", "auctionId", "amount"],
    Let(
      { auction: Get(Ref(Collection("auction"), Var("auctionId"))) },
      If(
        Equals(Select(["data", "isSettled"], Var("auction"), false), true),
        Abort("Cannot bid on already settled auction"),
        Let(
          {
            startingPrice: Select(
              ["data", "startingPrice"],
              Var("auction"),
              null
            )
          },
          If(
            And(
              Not(IsNull(Var("startingPrice"))),
              LT(Var("amount"), Var("startingPrice"))
            ),
            Abort(
              Concat([
                "Cannot bid lower than the starting price [",
                ToString(Var("startingPrice")),
                "]"
              ])
            ),
            Let(
              {
                highestBidAmount: Select(
                  ["data", "amount"],
                  Get(
                    Max(
                      Match(
                        Index("getBidsByAuctionId"),
                        Ref(Collection("auction"), Var("auctionId"))
                      )
                    )
                  ),
                  null
                )
              },
              If(
                And(
                  Not(IsNull(Var("highestBidAmount"))),
                  LTE(Var("amount"), Var("highestBidAmount"))
                ),
                Abort(
                  Concat([
                    "Cannot bid lower or equal than the last bid [",
                    ToString(Var("highestBidAmount")),
                    "]"
                  ])
                ),
                Let(
                  {
                    bidIncrement: Select(
                      ["data", "bidIncrement"],
                      Var("auction"),
                      null
                    )
                  },
                  If(
                    And(
                      Not(IsNull(Var("bidIncrement"))),
                      LT(
                        Subtract(Var("amount"), Var("highestBidAmount")),
                        Var("bidIncrement")
                      )
                    ),
                    Abort(
                      Concat([
                        "Cannot bid less than the bid increment [",
                        ToString(Var("bidIncrement")),
                        "]. Provided an increment of ",
                        ToString(
                          Subtract(Var("amount"), Var("highestBidAmount"))
                        ),
                        " instead"
                      ])
                    ),
                    Create(Collection("bid"), {
                      data: {
                        bidderRef: Var("bidderRef"),
                        amount: Var("amount"),
                        auction: Ref(Collection("auction"), Var("auctionId"))
                      }
                    })
                  )
                )
              )
            )
          )
        )
      )
    )
  )
)