Add DEX tasks and endpoints

[miksax]

Store swap from DEXes (WingRiders, MinSwap, SundaeSwap)
Store mean values from DEXes

All assets amounts are without decimal places

Add endpoints

mean price - show the mean price after each exchange.

It is only a ratio between asset amounts (without fees, etc..)

POST /dex/mean-price HTTP/1.1
Host: localhost:3000
Content-Type: application/json
Content-Length: 411

{
    "assetPairs": [
        {
            "asset2": null,
            "asset1": {
                "policyId": "c0ee29a85b13209423b10447d3c2e6a50641a15c57770e27cb9d5073",
                "assetName": "57696e67526964657273"
            }
        }
    ],
    "dexes": ["WingRiders", "MinSwap", "SundaeSwap"],
    "limit": 1,
    "untilBlock": "a4432189e2e3a75c97480e65460b76d023bc0f2fb0ee961c5caf19779bc64e18"
}

{
    "meanPrices": [
        {
            "tx_hash": "483315a7dfc225d02f9f666b96a54e04c7a44efd7a0960905ddeec76b8c95255",
            "dex": "WingRiders",
            "asset1": null,
            "asset2": {
                "policyId": "c0ee29a85b13209423b10447d3c2e6a50641a15c57770e27cb9d5073",
                "assetName": "57696e67526964657273"
            },
            "amount1": "1929381124638",
            "amount2": "5766737594563"
        }
    ]
}

swap price - show all real swap prices

POST /dex/swap-price HTTP/1.1
Host: localhost:3000
Content-Type: application/json
Content-Length: 386

{
    "assetPairs": [
        {
            "asset1": null,
            "asset2": {
                "policyId": "c0ee29a85b13209423b10447d3c2e6a50641a15c57770e27cb9d5073",
                "assetName": "57696e67526964657273"
            }
        }
    ],
    "dexes": ["WingRiders"],
    "limit": 3,
    "untilBlock": "a4432189e2e3a75c97480e65460b76d023bc0f2fb0ee961c5caf19779bc64e18"
}

{
    "swap": [
        {
            "tx_hash": "4eb8fed0bf9db2ca4b0ff42342ad8ce950c1cda7906cadaf3000d313af5c6ce5",
            "dex": "WingRiders",
            "asset1": null,
            "asset2": {
                "policyId": "c0ee29a85b13209423b10447d3c2e6a50641a15c57770e27cb9d5073",
                "assetName": "57696e67526964657273"
            },
            "amount1": "85504346",
            "amount2": "256473383",
            "direction": "sell"
        }
    ]
}

the last price - show the final price from all active DEXes

POST /dex/last-price HTTP/1.1
Host: localhost:3000
Content-Type: application/json
Content-Length: 268

{
    "assetPairs": [
        {
            "asset2": null,
            "asset1": {
                "policyId": "8e51398904a5d3fc129fbf4f1589701de23c7824d5c90fdb9490e15a",
                "assetName": "434841524c4933"
            }
        }
    ],
    "type": "buy"
}

{
    "lastPrice": [
        {
            "asset1": null,
            "asset2": {
                "policyId": "8e51398904a5d3fc129fbf4f1589701de23c7824d5c90fdb9490e15a",
                "assetName": "434841524c4933"
            },
            "amount1": "5000087662",
            "amount2": "8550230148",
            "dex": "SundaeSwap"
        },
        {
            "asset1": null,
            "asset2": {
                "policyId": "8e51398904a5d3fc129fbf4f1589701de23c7824d5c90fdb9490e15a",
                "assetName": "434841524c4933"
            },
            "amount1": "2197800000",
            "amount2": "3869564858",
            "dex": "Minswap"
        },
        {
            "asset1": null,
            "asset2": {
                "policyId": "8e51398904a5d3fc129fbf4f1589701de23c7824d5c90fdb9490e15a",
                "assetName": "434841524c4933"
            },
            "amount1": "61055009",
            "amount2": "106621898",
            "dex": "WingRiders"
        }
    ]
}

[SebastienGllmt]

What is the benefit of representing the mean price as a separate table with separate logic instead of a materialized view? Maybe there is a good reason for this, and if so we should write it down somewhere

[miksax]

We split tables because data represents different approaches. The mean price is the theoretical price for an asset, swap is the real price.
But there is no problem with merging tables

[SebastienGllmt]

Right, but why can't the theoretical price be a (maybe materialized) view instead merging tables or having separate tables? It'd be nice to outline the tradeoffs and why one is picked

[miksax]

I have merged tables and crate views for the webserver.

[miksax]

view removed. Everything is routed from joined tables

[SebastienGllmt]

be careful with using || because for example, 0 is falsy in javascript. If you're doing a null-check, it's better to use ??
I mention this here, but this applies to a few places

[miksax]

It is only because views return type or null value.
There is no option that the value will be really null.