1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105

use cosmwasm_schema::cw_serde;
use cosmwasm_std::{
    to_json_binary, Addr, CosmosMsg, CustomQuery, QuerierWrapper, QueryRequest, StdResult, Uint128,
    WasmMsg, WasmQuery,
};

use crate::{
    AllowanceResponse, BalanceResponse, Cw20ExecuteMsg, Cw20QueryMsg, MinterResponse,
    TokenInfoResponse,
};

/// Cw20Contract is a wrapper around Addr that provides a lot of helpers
/// for working with this.
///
/// If you wish to persist this, convert to Cw20CanonicalContract via .canonical()
#[cw_serde]
pub struct Cw20Contract(pub Addr);

impl Cw20Contract {
    pub fn addr(&self) -> Addr {
        self.0.clone()
    }

    pub fn call<T: Into<Cw20ExecuteMsg>>(&self, msg: T) -> StdResult<CosmosMsg> {
        let msg = to_json_binary(&msg.into())?;
        Ok(WasmMsg::Execute {
            contract_addr: self.addr().into(),
            msg,
            funds: vec![],
        }
        .into())
    }

    fn encode_smart_query<CQ: CustomQuery>(
        &self,
        msg: Cw20QueryMsg,
    ) -> StdResult<QueryRequest<CQ>> {
        Ok(WasmQuery::Smart {
            contract_addr: self.addr().into(),
            msg: to_json_binary(&msg)?,
        }
        .into())
    }

    /// Get token balance for the given address
    pub fn balance<T, CQ>(&self, querier: &QuerierWrapper<CQ>, address: T) -> StdResult<Uint128>
    where
        T: Into<String>,
        CQ: CustomQuery,
    {
        let query = self.encode_smart_query(Cw20QueryMsg::Balance {
            address: address.into(),
        })?;
        let res: BalanceResponse = querier.query(&query)?;
        Ok(res.balance)
    }

    /// Get metadata from the contract. This is a good check that the address
    /// is a valid Cw20 contract.
    pub fn meta<CQ: CustomQuery>(
        &self,
        querier: &QuerierWrapper<CQ>,
    ) -> StdResult<TokenInfoResponse> {
        let query = self.encode_smart_query(Cw20QueryMsg::TokenInfo {})?;
        querier.query(&query)
    }

    /// Get allowance of spender to use owner's account
    pub fn allowance<T, U, CQ>(
        &self,
        querier: &QuerierWrapper<CQ>,
        owner: T,
        spender: U,
    ) -> StdResult<AllowanceResponse>
    where
        T: Into<String>,
        U: Into<String>,
        CQ: CustomQuery,
    {
        let query = self.encode_smart_query(Cw20QueryMsg::Allowance {
            owner: owner.into(),
            spender: spender.into(),
        })?;
        querier.query(&query)
    }

    /// Find info on who can mint, and how much
    pub fn minter<CQ: CustomQuery>(
        &self,
        querier: &QuerierWrapper<CQ>,
    ) -> StdResult<Option<MinterResponse>> {
        let query = self.encode_smart_query(Cw20QueryMsg::Minter {})?;
        querier.query(&query)
    }

    /// returns true if the contract supports the allowance extension
    pub fn has_allowance<CQ: CustomQuery>(&self, querier: &QuerierWrapper<CQ>) -> bool {
        self.allowance(querier, self.addr(), self.addr()).is_ok()
    }

    /// returns true if the contract supports the mintable extension
    pub fn is_mintable<CQ: CustomQuery>(&self, querier: &QuerierWrapper<CQ>) -> bool {
        self.minter(querier).is_ok()
    }
}