//! # Implementation of address conversions and generators

use crate::error::AnyResult;
use crate::{MockApiBech32, MockApiBech32m};
use cosmwasm_std::testing::MockApi;
use cosmwasm_std::{instantiate2_address, Addr, Api, CanonicalAddr, Storage};
use sha2::digest::Update;
use sha2::{Digest, Sha256};

const DEFAULT_PREFIX: &str = "cosmwasm";

/// Defines conversions to [Addr], this conversion is format agnostic
/// and should be aligned with the format generated by [MockApi].
///
/// [MockApi]: https://github.com/CosmWasm/cosmwasm/blob/9a239838baba50f4f47230da306f39a8bb4ea697/packages/std/src/testing/mock.rs#L251-L257
pub trait IntoAddr {
    /// Converts into [Addr].
    fn into_addr(self) -> Addr;

    /// Converts into [Addr] with custom prefix.
    fn into_addr_with_prefix(self, prefix: &'static str) -> Addr;
}

impl IntoAddr for &str {
    /// Converts [&str] into [Addr].
    fn into_addr(self) -> Addr {
        MockApi::default().addr_make(self)
    }

    /// Converts [&str] into [Addr] with custom prefix.
    fn into_addr_with_prefix(self, prefix: &'static str) -> Addr {
        MockApi::default().with_prefix(prefix).addr_make(self)
    }
}

/// Defines conversions to `Bech32` compatible addresses.
pub trait IntoBech32 {
    /// Converts into [Addr] containing a string compatible with `Bech32` format with default prefix.
    fn into_bech32(self) -> Addr;

    /// Converts into [Addr] containing a string compatible with `Bech32` format with custom prefix.
    fn into_bech32_with_prefix(self, prefix: &'static str) -> Addr;
}

impl IntoBech32 for &str {
    /// Converts [&str] into [Addr] containing a string compatible with `Bech32` format with default prefix.
    fn into_bech32(self) -> Addr {
        MockApiBech32::new(DEFAULT_PREFIX).addr_make(self)
    }

    /// Converts [&str] into [Addr] containing a string compatible with `Bech32` format with custom prefix.
    fn into_bech32_with_prefix(self, prefix: &'static str) -> Addr {
        MockApiBech32::new(prefix).addr_make(self)
    }
}

/// Defines conversions to `Bech32m` compatible addresses.
pub trait IntoBech32m {
    /// Converts into [Addr] containing a string compatible with `Bech32m` format with default prefix.
    fn into_bech32m(self) -> Addr;
    /// Converts into [Addr] containing a string compatible with `Bech32m` format with custom prefix.
    fn into_bech32m_with_prefix(self, prefix: &'static str) -> Addr;
}

impl IntoBech32m for &str {
    /// Converts [&str] into [Addr] containing a string compatible with `Bech32m` format with default prefix.
    fn into_bech32m(self) -> Addr {
        MockApiBech32m::new(DEFAULT_PREFIX).addr_make(self)
    }

    /// Converts [&str] into [Addr] containing a string compatible with `Bech32m` format with custom prefix.
    fn into_bech32m_with_prefix(self, prefix: &'static str) -> Addr {
        MockApiBech32m::new(prefix).addr_make(self)
    }
}

/// Common address generator interface.
///
/// The default implementation of this trait generates fully predictable
/// addresses, no matter if [contract_address](AddressGenerator::contract_address)
/// or [predictable_contract_address](AddressGenerator::predictable_contract_address) is used,
/// but users should not make any assumptions about the value of the generated address.
pub trait AddressGenerator {
    /// Generates a _non-predictable_ contract address, just like the real-life chain
    /// returns contract address after its instantiation.
    /// Address generated by this function is returned as a result of processing
    /// `WasmMsg::Instantiate` message.
    ///
    /// The default implementation generates a contract address based
    /// on contract's code and instance identifier.
    ///
    /// # Example
    ///
    /// ```
    /// # use cosmwasm_std::testing::{MockApi, MockStorage};
    /// # use cw_multi_test::{AddressGenerator, SimpleAddressGenerator};
    /// # let api = MockApi::default();
    /// # let mut storage = MockStorage::default();
    /// struct MyAddressGenerator;
    ///
    /// impl AddressGenerator for MyAddressGenerator {}
    ///
    /// let my_address_generator = MyAddressGenerator{};
    ///
    /// let addr = my_address_generator.contract_address(&api, &mut storage, 100, 1).unwrap();
    /// assert!(addr.as_str().starts_with("cosmwasm1"));
    /// ```
    fn contract_address(
        &self,
        api: &dyn Api,
        _storage: &mut dyn Storage,
        code_id: u64,
        instance_id: u64,
    ) -> AnyResult<Addr> {
        let canonical_addr = instantiate_address(code_id, instance_id);
        Ok(api.addr_humanize(&canonical_addr)?)
    }

    /// Generates a _predictable_ contract address, just like the real-life chain
    /// returns contract address after its instantiation using `MsgInstantiateContract2` message.
    /// Address generated by this function is returned as a result of processing
    /// `WasmMsg::Instantiate2` message.
    ///
    /// The default implementation generates a contract address based on provided
    /// creator address and salt.
    ///
    /// # Example
    ///
    /// ```
    /// # use cosmwasm_std::{Api, Checksum};
    /// # use cosmwasm_std::testing::{MockApi, MockStorage};
    /// # use cw_multi_test::{AddressGenerator, SimpleAddressGenerator};
    /// # let api = MockApi::default();
    /// # let mut storage = MockStorage::default();
    /// struct MyAddressGenerator;
    ///
    /// impl AddressGenerator for MyAddressGenerator {}
    ///
    /// let my_address_generator = MyAddressGenerator{};
    ///
    /// let creator1 = api.addr_canonicalize(&api.addr_make("creator1").to_string()).unwrap();
    /// let creator2 = api.addr_canonicalize(&api.addr_make("creator2").to_string()).unwrap();
    /// let salt1 = [0xc0,0xff,0xee];
    /// let salt2 = [0xbe,0xef];
    /// let chs = Checksum::generate(&[1]);
    ///
    /// let addr11 = my_address_generator.predictable_contract_address(&api, &mut storage, 1, 0, chs.as_slice(), &creator1, &salt1).unwrap();
    /// let addr12 = my_address_generator.predictable_contract_address(&api, &mut storage, 1, 0, chs.as_slice(), &creator1, &salt2).unwrap();
    /// let addr21 = my_address_generator.predictable_contract_address(&api, &mut storage, 1, 0, chs.as_slice(), &creator2, &salt1).unwrap();
    /// let addr22 = my_address_generator.predictable_contract_address(&api, &mut storage, 1, 0, chs.as_slice(), &creator2, &salt2).unwrap();
    ///
    /// assert_ne!(addr11, addr12);
    /// assert_ne!(addr11, addr21);
    /// assert_ne!(addr11, addr22);
    /// assert_ne!(addr12, addr21);
    /// assert_ne!(addr12, addr22);
    /// assert_ne!(addr21, addr22);
    /// ```
    fn predictable_contract_address(
        &self,
        api: &dyn Api,
        _storage: &mut dyn Storage,
        _code_id: u64,
        _instance_id: u64,
        checksum: &[u8],
        creator: &CanonicalAddr,
        salt: &[u8],
    ) -> AnyResult<Addr> {
        let canonical_addr = instantiate2_address(checksum, creator, salt)?;
        Ok(api.addr_humanize(&canonical_addr)?)
    }
}

/// Returns non-predictable contract address.
///
/// Address is generated using the same algorithm as [`BuildContractAddressClassic`]
/// implementation in `wasmd`.
///
/// [`BuildContractAddressClassic`]:https://github.com/CosmWasm/wasmd/blob/3b6512c9f154995188ead84ab3bd9e034b49a0f3/x/wasm/keeper/addresses.go#L35-L41
fn instantiate_address(code_id: u64, instance_id: u64) -> CanonicalAddr {
    let mut key = Vec::<u8>::new();
    key.extend_from_slice(b"wasm\0");
    key.extend_from_slice(&code_id.to_be_bytes());
    key.extend_from_slice(&instance_id.to_be_bytes());
    let module = Sha256::digest("module".as_bytes());
    Sha256::new()
        .chain(module)
        .chain(key)
        .finalize()
        .to_vec()
        .into()
}

/// Default contract address generator used in [WasmKeeper](crate::WasmKeeper).
pub struct SimpleAddressGenerator;

impl AddressGenerator for SimpleAddressGenerator {}