#![allow(clippy::unwrap_used)]
use crate::prelude::*;

#[test]
fn test_opcode_nop() {
    let instr = Instruction::Nop;
    assert_eq!(instr.opcode(), 0x0);
}

#[test]
fn test_opcode_data_transfer() {
    let args = RTypeArgs::new(None, None, None, None);
    assert_eq!(Instruction::Mov(args).opcode(), 0x1);
    assert_eq!(Instruction::MovSigned(args).opcode(), 0x2);

    let iargs = ITypeArgs::new(0, None, None);
    assert_eq!(Instruction::LoadByte(iargs).opcode(), 0x3);
    assert_eq!(Instruction::LoadByteSigned(iargs).opcode(), 0x4);
    assert_eq!(Instruction::LoadHalfword(iargs).opcode(), 0x5);
    assert_eq!(Instruction::LoadHalfwordSigned(iargs).opcode(), 0x6);
    assert_eq!(Instruction::LoadWord(iargs).opcode(), 0x7);
    assert_eq!(Instruction::StoreByte(iargs).opcode(), 0x8);
    assert_eq!(Instruction::StoreHalfword(iargs).opcode(), 0x9);
    assert_eq!(Instruction::StoreWord(iargs).opcode(), 0xA);
    assert_eq!(Instruction::LoadLowerImmediate(iargs).opcode(), 0xB);
    assert_eq!(Instruction::LoadUpperImmediate(iargs).opcode(), 0xC);
}

#[test]
fn test_opcode_jump_instructions() {
    let args = ITypeArgs::new(0, None, None);
    assert_eq!(Instruction::Jump(args).opcode(), 0xD);
    assert_eq!(Instruction::JumpEq(args).opcode(), 0xE);
    assert_eq!(Instruction::JumpNeq(args).opcode(), 0xF);
    assert_eq!(Instruction::JumpGt(args).opcode(), 0x10);
    assert_eq!(Instruction::JumpGe(args).opcode(), 0x11);
    assert_eq!(Instruction::JumpLt(args).opcode(), 0x12);
    assert_eq!(Instruction::JumpLe(args).opcode(), 0x13);
}

#[test]
fn test_opcode_arithmetic() {
    let args = RTypeArgs::new(None, None, None, None);
    assert_eq!(Instruction::Compare(args).opcode(), 0x14);
    assert_eq!(Instruction::Increment(args).opcode(), 0x15);
    assert_eq!(Instruction::Decrement(args).opcode(), 0x16);
    assert_eq!(Instruction::ShiftLeft(args).opcode(), 0x17);
    assert_eq!(Instruction::ShiftRight(args).opcode(), 0x18);
    assert_eq!(Instruction::Add(args).opcode(), 0x19);
    assert_eq!(Instruction::Sub(args).opcode(), 0x1A);
}

#[test]
fn test_opcode_logical() {
    let args = RTypeArgs::new(None, None, None, None);
    assert_eq!(Instruction::And(args).opcode(), 0x1B);
    assert_eq!(Instruction::Or(args).opcode(), 0x1C);
    assert_eq!(Instruction::Not(args).opcode(), 0x1D);
    assert_eq!(Instruction::Xor(args).opcode(), 0x1E);
    assert_eq!(Instruction::Nand(args).opcode(), 0x1F);
    assert_eq!(Instruction::Nor(args).opcode(), 0x20);
    assert_eq!(Instruction::Xnor(args).opcode(), 0x21);
}

#[test]
fn test_opcode_misc() {
    let interrupt = Interrupt::Software(5);
    assert_eq!(Instruction::Interrupt(interrupt).opcode(), 0x22);
    assert_eq!(Instruction::IntReturn.opcode(), 0x23);
    assert_eq!(Instruction::Halt.opcode(), 0x24);
}

#[test]
fn test_opcode_with_different_args() {
    let args1 = RTypeArgs::new(
        Some(Register::Rg0),
        Some(Register::Rg1),
        Some(Register::Rg2),
        Some(5),
    );
    let args2 = RTypeArgs::new(
        Some(Register::Acc),
        Some(Register::Spr),
        Some(Register::Bpr),
        Some(31),
    );

    // Opcode should be the same regardless of arguments
    assert_eq!(
        Instruction::Add(args1).opcode(),
        Instruction::Add(args2).opcode()
    );
    assert_eq!(
        Instruction::Sub(args1).opcode(),
        Instruction::Sub(args2).opcode()
    );
}

#[test]
fn test_opcode_boundary_values() {
    // Test highest opcode value
    assert_eq!(Instruction::Halt.opcode(), 0x24);

    // Test lowest opcode value
    assert_eq!(Instruction::Nop.opcode(), 0x0);
}

#[test]
fn test_instruction_decode_nop() {
    let instr = Instruction::Nop;
    let encoded = instr.encode();
    let decoded = Instruction::decode(encoded).unwrap();
    assert_eq!(instr, decoded);
}

#[test]
fn test_instruction_decode_data_transfer() {
    let args = RTypeArgs::new(
        Some(Register::Rg0),
        Some(Register::Rg1),
        Some(Register::Rg2),
        Some(5),
    );
    let instr = Instruction::Mov(args);
    let encoded = instr.encode();
    let decoded = Instruction::decode(encoded).unwrap();
    assert_eq!(instr, decoded);

    let iargs = ITypeArgs::new(100, Some(Register::Rg3), Some(Register::Rg4));
    let instr = Instruction::LoadWord(iargs);
    let encoded = instr.encode();
    let decoded = Instruction::decode(encoded).unwrap();
    assert_eq!(instr, decoded);
}

#[test]
fn test_instruction_decode_jump() {
    let args = ITypeArgs::new(200, Some(Register::Acc), Some(Register::Spr));
    let instr = Instruction::Jump(args);
    let encoded = instr.encode();
    let decoded = Instruction::decode(encoded).unwrap();
    assert_eq!(instr, decoded);

    let instr = Instruction::JumpEq(args);
    let encoded = instr.encode();
    let decoded = Instruction::decode(encoded).unwrap();
    assert_eq!(instr, decoded);
}

#[test]
fn test_instruction_decode_arithmetic() {
    let args = RTypeArgs::new(
        Some(Register::Bpr),
        Some(Register::Rg7),
        Some(Register::Rgf),
        Some(31),
    );
    let instr = Instruction::Add(args);
    let encoded = instr.encode();
    let decoded = Instruction::decode(encoded).unwrap();
    assert_eq!(instr, decoded);

    let instr = Instruction::Compare(args);
    let encoded = instr.encode();
    let decoded = Instruction::decode(encoded).unwrap();
    assert_eq!(instr, decoded);
}

#[test]
fn test_instruction_decode_logical() {
    let args = RTypeArgs::new(
        Some(Register::Rg8),
        Some(Register::Rg9),
        Some(Register::Rga),
        Some(15),
    );
    let instr = Instruction::And(args);
    let encoded = instr.encode();
    let decoded = Instruction::decode(encoded).unwrap();
    assert_eq!(instr, decoded);

    let instr = Instruction::Xor(args);
    let encoded = instr.encode();
    let decoded = Instruction::decode(encoded).unwrap();
    assert_eq!(instr, decoded);
}

#[test]
fn test_instruction_decode_misc() {
    let instr = Instruction::Halt;
    let encoded = instr.encode();
    let decoded = Instruction::decode(encoded).unwrap();
    assert_eq!(instr, decoded);
}

#[test]
fn test_instruction_decode_invalid() {
    // Test with invalid opcode.
    let invalid_encoded = 0xF500_0000;
    let decode = Instruction::decode(invalid_encoded);

    dbg!(&decode);

    assert!(decode.is_err());
}

// TODO: Get interrupts working.
// #[test]
// fn test_instruction_decode_interrupt() {
//     let interrupt = Interrupt::Software(10);
//     let instr = Instruction::Interrupt(interrupt);
//     let encoded = instr.encode();
//     let decoded = Instruction::decode(encoded).unwrap();
//     assert_eq!(instr, decoded);
// }
