dlmm_swap.rs

use anchor_lang::prelude::*;

#[derive(Accounts)]
pub struct DlmmSwap<'info> {
    #[account(mut)]
    /// CHECK: The pool account
    pub lb_pair: UncheckedAccount<'info>,

    /// CHECK: Bin array extension account of the pool
    pub bin_array_bitmap_extension: Option<UncheckedAccount<'info>>,

    #[account(mut)]
    /// CHECK: Reserve account of token X
    pub reserve_x: UncheckedAccount<'info>,
    #[account(mut)]
    /// CHECK: Reserve account of token Y
    pub reserve_y: UncheckedAccount<'info>,

    #[account(mut)]
    /// CHECK: User token account to sell token
    pub user_token_in: UncheckedAccount<'info>,
    #[account(mut)]
    /// CHECK: User token account to buy token
    pub user_token_out: UncheckedAccount<'info>,

    /// CHECK: Mint account of token X
    pub token_x_mint: UncheckedAccount<'info>,
    /// CHECK: Mint account of token Y
    pub token_y_mint: UncheckedAccount<'info>,

    #[account(mut)]
    /// CHECK: Oracle account of the pool
    pub oracle: UncheckedAccount<'info>,

    #[account(mut)]
    /// CHECK: Referral fee account
    pub host_fee_in: Option<UncheckedAccount<'info>>,

    /// CHECK: User who's executing the swap
    pub user: Signer<'info>,

    #[account(address = dlmm::ID)]
    /// CHECK: DLMM program
    pub dlmm_program: UncheckedAccount<'info>,

    /// CHECK: DLMM program event authority for event CPI
    pub event_authority: UncheckedAccount<'info>,

    /// CHECK: Token program of mint X
    pub token_x_program: UncheckedAccount<'info>,
    /// CHECK: Token program of mint Y
    pub token_y_program: UncheckedAccount<'info>,
    // Bin arrays need to be passed using remaining accounts
}

/// Executes a DLMM swap
///
/// # Arguments
///
/// * `ctx` - The context containing accounts and programs.
/// * `amount_in` - The amount of input tokens to be swapped.
/// * `min_amount_out` - The minimum amount of output tokens expected a.k.a slippage
///
/// # Returns
///
/// Returns a `Result` indicating success or failure.
pub fn handle_dlmm_swap<'a, 'b, 'c, 'info>(
    ctx: Context<'a, 'b, 'c, 'info, DlmmSwap<'info>>,
    amount_in: u64,
    min_amount_out: u64,
) -> Result<()> {
    let accounts = dlmm::cpi::accounts::Swap {
        lb_pair: ctx.accounts.lb_pair.to_account_info(),
        bin_array_bitmap_extension: ctx
            .accounts
            .bin_array_bitmap_extension
            .as_ref()
            .map(|account| account.to_account_info()),
        reserve_x: ctx.accounts.reserve_x.to_account_info(),
        reserve_y: ctx.accounts.reserve_y.to_account_info(),
        user_token_in: ctx.accounts.user_token_in.to_account_info(),
        user_token_out: ctx.accounts.user_token_out.to_account_info(),
        token_x_mint: ctx.accounts.token_x_mint.to_account_info(),
        token_y_mint: ctx.accounts.token_y_mint.to_account_info(),
        oracle: ctx.accounts.oracle.to_account_info(),
        host_fee_in: ctx
            .accounts
            .host_fee_in
            .as_ref()
            .map(|account| account.to_account_info()),
        user: ctx.accounts.user.to_account_info(),
        token_x_program: ctx.accounts.token_x_program.to_account_info(),
        token_y_program: ctx.accounts.token_y_program.to_account_info(),
        event_authority: ctx.accounts.event_authority.to_account_info(),
        program: ctx.accounts.dlmm_program.to_account_info(),
    };

    let cpi_context = CpiContext::new(ctx.accounts.dlmm_program.to_account_info(), accounts)
        .with_remaining_accounts(ctx.remaining_accounts.to_vec());
    dlmm::cpi::swap(cpi_context, amount_in, min_amount_out)
}