use crate::{
    expression::{BuiltinSelectionFn, ResultTransform, SearchModifier},
    selection::Selection,
    selection_functions::{
        function_character::selection_function_character,
        function_end::selection_function_end,
        result_transformation::{complement_transform, conditional_transform},
        types::SFArguments,
    },
    state::EditorState,
};

mod function_character;
mod function_empty;
mod function_end;
mod result_transformation;
mod types;

pub use crate::selection_functions::types::{SFError, SFResult};

pub fn evaluate_selection_function(
    es: &EditorState,
    sf: BuiltinSelectionFn,
    search_mod: Option<SearchModifier>,
    result_transform: Option<ResultTransform>,
    left: Option<Selection>,
    right: Option<Selection>,
) -> SFResult {
    let sf_args = match (left, right) {
        (None, None) => Ok(SFArguments::Niladic { es }),
        (Some(left), None) => Ok(SFArguments::Monadic { es, left }),
        (Some(left), Some(right)) => Ok(SFArguments::Dyadic { es, left, right }),
        _ => Err(SFError::NoLeftArgument),
    }?;
    let res = match sf {
        BuiltinSelectionFn::CharOffset(off) => {
            selection_function_character(off, &sf_args, search_mod)
        }
        BuiltinSelectionFn::EndOfBuffer => selection_function_end((), &sf_args, search_mod),
        x => Err(SFError::NotImplemented(x).into()),
    }?;

    if let Some(result_transform) = result_transform {
        match result_transform {
            ResultTransform::Complement => complement_transform(es, res),
            ResultTransform::Conditional => conditional_transform(res, &sf_args),
            ResultTransform::ConditionalComplement => {
                let res = complement_transform(es, res)?;
                conditional_transform(res, &sf_args)
            }
            ResultTransform::ComplementConditional => {
                let res = conditional_transform(res, &sf_args)?;
                complement_transform(es, res)
            }
        }
    } else {
        Ok(res)
    }
}