// Copyright (c) 2025 taitep
// SPDX-License-Identifier: MIT
//
// This file is part of TRVE (https://gitea.taitep.se/taitep/trve)
// See LICENSE file in the project root for full license text.

mod rvi;

use crate::{
    core::{Core, InstructionResult},
    decode::Instruction,
};

pub(crate) fn find_and_exec(instr: Instruction, core: &mut Core) -> Option<InstructionResult> {
    match instr.opcode_noncompressed() {
        0b01100 => match (instr.funct7(), instr.funct3()) {
            // OP
            (0b0000000, 0b000) => Some(rvi::add(core, instr)),
            _ => None,
        },
        0b00100 => match instr.funct3() {
            // OP_IMM
            0b000 => Some(rvi::addi(core, instr)),
            0b001 => (instr.funct6() == 0).then(|| rvi::slli(core, instr)),
            0b111 => Some(rvi::andi(core, instr)),
            _ => None,
        },
        0b00110 => match instr.funct3() {
            // OP_IMM_32
            0b000 => Some(rvi::addiw(core, instr)),
            _ => None,
        },
        0b01000 => match instr.funct3() {
            // STORE
            0b000 => Some(rvi::sb(core, instr)),
            0b011 => Some(rvi::sd(core, instr)),
            _ => None,
        },
        0b00000 => match instr.funct3() {
            // LOAD
            0b000 => Some(rvi::lb(core, instr)),
            0b100 => Some(rvi::lbu(core, instr)),
            0b011 => Some(rvi::ld(core, instr)),
            _ => None,
        },
        0b11000 => match instr.funct3() {
            // BRANCH
            0b000 => Some(rvi::beq(core, instr)),
            0b001 => Some(rvi::bne(core, instr)),
            _ => None,
        },
        0b01101 => Some(rvi::lui(core, instr)),
        0b00101 => Some(rvi::auipc(core, instr)),
        0b11011 => Some(rvi::jal(core, instr)),
        0b11001 => (instr.funct3() == 0).then(|| rvi::jalr(core, instr)),
        _ => None,
    }
}