//! Translates the calldata instructions.

use crate::polkavm::context::address_space::AddressSpace;
use crate::polkavm::context::pointer::Pointer;
use crate::polkavm::context::Context;
use crate::polkavm::Dependency;
use inkwell::types::BasicType;

/// Translates the calldata load.
pub fn load<'ctx, D>(
    context: &mut Context<'ctx, D>,
    offset: inkwell::values::IntValue<'ctx>,
) -> anyhow::Result<inkwell::values::BasicValueEnum<'ctx>>
where
    D: Dependency + Clone,
{
    let calldata_pointer = context
        .get_global(crate::polkavm::GLOBAL_CALLDATA_POINTER)?
        .value
        .as_pointer_value();
    let offset = context.build_gep(
        Pointer::new(context.byte_type(), AddressSpace::Stack, calldata_pointer),
        &[offset],
        context.word_type().as_basic_type_enum(),
        "calldata_pointer_with_offset",
    );
    context
        .build_load(offset, "calldata_value")
        .and_then(|value| context.build_byte_swap(value))
}

/// Translates the calldata size.
pub fn size<'ctx, D>(
    context: &mut Context<'ctx, D>,
) -> anyhow::Result<inkwell::values::BasicValueEnum<'ctx>>
where
    D: Dependency + Clone,
{
    let value = context.get_global_value(crate::polkavm::GLOBAL_CALLDATA_SIZE)?;

    Ok(value)
}

/// Translates the calldata copy.
pub fn copy<'ctx, D>(
    context: &mut Context<'ctx, D>,
    destination_offset: inkwell::values::IntValue<'ctx>,
    source_offset: inkwell::values::IntValue<'ctx>,
    size: inkwell::values::IntValue<'ctx>,
) -> anyhow::Result<()>
where
    D: Dependency + Clone,
{
    let offset = context.safe_truncate_int_to_xlen(destination_offset)?;
    let size = context.safe_truncate_int_to_xlen(size)?;
    let destination = context.build_heap_gep(offset, size)?;

    let calldata_pointer = context
        .get_global(crate::polkavm::GLOBAL_CALLDATA_POINTER)?
        .value
        .as_pointer_value();
    let source = context.build_gep(
        Pointer::new(context.byte_type(), AddressSpace::Stack, calldata_pointer),
        &[context.safe_truncate_int_to_xlen(source_offset)?],
        context.byte_type(),
        "calldata_pointer_with_offset",
    );

    context.build_memcpy(destination, source, size, "calldata_copy_memcpy_from_child")
}