Item prices

[anhthang]

Add ItemPrice model and exposes per-version item pricing data

• Populate item prices from a new CSV source: ‎data/v2/csv/item_prices.csv
• Remove the old ‎Item.cost field in favor of the new structured pricing model.

Closes #1406 and #1397, #1398

Example REST API response

GET /api/v2/item/305/

{
    "id": 305,
    "name": "some-item-name",
    "fling_power": null,
    "fling_effect": null,
    "category": {
        "name": "held-items"
    },
    "prices": [
        {
            "is_purchasable": true,
            "purchase_price": 3000,
            "sell_price": 1500,
            "version_group": {
                "name": "red-blue",
                "url": "https://pokeapi.co/api/v2/version-group/1/"
            }
        },
        {
            "is_purchasable": false,
            "purchase_price": null,
            "sell_price": 1500,
            "version_group": {
                "name": "ruby-sapphire",
                "url": "https://pokeapi.co/api/v2/version-group/3/"
            }
        }
    ]
}

Example GraphQL queries

v1beta: item with prices

query ItemWithPrices {
  pokemon_v2_item_by_pk(id: 305) {
    id
    name
    pokemon_v2_itemprices {
      is_purchasable
      purchase_price
      sell_price
      pokemon_v2_versiongroup {
        id
        name
      }
    }
  }
}

v1beta2: item with itemprice relation

query ItemWithItemprice {
  pokemon_v2_item_by_pk(id: 305) {
    id
    name
    itemprices {
      is_purchasable
      purchase_price
      sell_price
      versiongroup {
        id
        name
      }
    }
  }
}

{
    "data": {
        "item": [
            {
                "id": 305,
                "name": "tm01",
                "cost": null,
                "itemnames": [
                    {
                        "name": "TM01"
                    }
                ],
                "itemprices": [
                    {
                        "is_purchasable": true,
                        "purchase_price": 3000,
                        "sell_price": 1500,
                        "versiongroup": {
                            "id": 1,
                            "name": "red-blue",
                        }
                    },
                    {
                        "is_purchasable": false,
                        "purchase_price": null,
                        "sell_price": 1500,
                        "versiongroup": {
                            "id": 5,
                            "name": "ruby-sapphire",
                        }
                    }
                ]
            }
        ]
    }
}

[anhthang]

Hi @Naramsim! Could you share your thoughts on the new ItemPrice model and the prices API shape? I'd like to confirm this is the right direction.

[Naramsim]

Hi! Thanks for the implementation. Would it be fine to remove the is_purchasable property?

By looking at the value of purchase_price we can understand whether we can buy it or not? If it's null we cannot, if it's an integer we can. What do you think?

[Naramsim]

In regard to this issue #1404, RamType0 could you review this PR?

[Naramsim]

We shouldn't touch old migration files.

[anhthang]

Should we remove the cost field in a new migration since it's no longer used?

[anhthang]

Hi! Thanks for the implementation. Would it be fine to remove the is_purchasable property?

By looking at the value of purchase_price we can understand whether we can buy it or not? If it's null we cannot, if it's an integer we can. What do you think?

I think it's fine to remove is_purchasable and rely on purchase_price instead.

I'm also wondering how we should handle items that can be obtained via other “currencies” instead of Poké Dollars, like candies or similar resources (for example, TM001). Do you have any ideas on how we could represent that in the pricing model?

I'm also unsure. We would first need a list of all available methods and then discuss the best solution.

[anhthang]

Add script to scrape Poké Ball prices from Bulbapedia. If this works well, I'll handle other item categories in separate PRs

[Naramsim]

Hi! I posted a reply but it doesn't show up. Maybe I lost my connection while I submitted it. Anyways, regarding all the possible way for obtaining items in the game and all possible currencies that can be used, I'd say: let's understand all possible ways for obtaining items. There are surely many ways, for TM100 I see Spheres, League Points, Berry points, Candies... So it's a mess.

We could either have the cost property expose a list of prices, and in the price we define the unit as well. Now the price is an integer, we could tranform it in a string, so that we can do things like:

{
    "id": 305,
    "name": "some-item-name",
    "fling_power": null,
    "fling_effect": null,
    "category": {
        "name": "held-items"
    },
    "prices": [
        {
            "purchase_price": "$3000",
            "sell_price": "$1500",
            "version_group": {
                "name": "red-blue",
                "url": "https://pokeapi.co/api/v2/version-group/1/"
            }
        },
        {
            "purchase_price": "5 Spheres",
            "sell_price": "3 candies",
            "version_group": {
                "name": "red-blue",
                "url": "https://pokeapi.co/api/v2/version-group/1/"
            }
        },
        ...
    ]
}

or

{
    "id": 305,
    "name": "some-item-name",
    "fling_power": null,
    "fling_effect": null,
    "category": {
        "name": "held-items"
    },
    "prices": [
        {
            "purchase_price": ["$3000","2 Battle exp point"],
            "sell_price": ["$1500","3 Candies"],
            "version_group": {
                "name": "red-blue",
                "url": "https://pokeapi.co/api/v2/version-group/1/"
            }
        },
        ...
    ]
}

This way doesn't account for conditions though. More over the price maybe changes based on the location where it's purchased. I'm not that knowledgable.

[anhthang]

"purchase_price": ["$3000","2 Battle exp point"],
"sell_price": ["$1500","3 Candies"]

This might be difficult for users to parse and work with.

Could we add a new currencies.csv model for this? I think it would be easier to extend in the future.

id,identifier,name
1,poke-dollar,Poké Dollar
2,battle-point,Battle Point
3,sphere,Sphere
4,candy,Candy
5,berry-point,Berry Point

{
  "purchase_price": 3000,
  "sell_price": 1500,
  "currency_id": 1,
  "version_group": {
    "name": "red-blue",
    "url": "https://pokeapi.co/api/v2/version-group/1/"
  }
}