//! The LLVM IR generator Yul data.

use std::collections::BTreeMap;

use num::Zero;

/// The LLVM IR generator Yul data.
/// Describes some data that is only relevant to Yul.
#[derive(Debug, Default)]
pub struct YulData {
    /// The list of constant arrays in the code section.
    /// It is a temporary storage used until the finalization method is called.
    const_arrays: BTreeMap<u8, Vec<num::BigUint>>,
}

impl YulData {
    /// Declares a temporary constant array representation.
    pub fn const_array_declare(&mut self, index: u8, size: u16) -> anyhow::Result<()> {
        if self.const_arrays.contains_key(&index) {
            anyhow::bail!(
                "The constant array with index {} is already declared",
                index
            );
        }

        self.const_arrays
            .insert(index, vec![num::BigUint::zero(); size as usize]);

        Ok(())
    }

    /// Sets a value in the constant array representation.
    pub fn const_array_set(
        &mut self,
        index: u8,
        offset: u16,
        value: num::BigUint,
    ) -> anyhow::Result<()> {
        let array = self.const_arrays.get_mut(&index).ok_or_else(|| {
            anyhow::anyhow!("The constant array with index {} is not declared", index)
        })?;
        if offset >= array.len() as u16 {
            anyhow::bail!(
                "The constant array with index {} has size {} but the offset is {}",
                index,
                array.len(),
                offset,
            );
        }
        array[offset as usize] = value;

        Ok(())
    }

    /// Finalizes the constant array declaration.
    pub fn const_array_take(&mut self, index: u8) -> anyhow::Result<Vec<num::BigUint>> {
        self.const_arrays.remove(&index).ok_or_else(|| {
            anyhow::anyhow!("The constant array with index {} is not declared", index)
        })
    }
}