# Full list of instructions
"""
U lui
U auipc
J jal
I jalr
B beq
B bne
B blt
B bge
B bltu
B bgeu
I lb
I lh
I lw
I lbu
I lhu
S sb
S sh
S sw
I addi
I slti
I sltiu
I xori
I ori
I andi
I slli
I srli
I srai
R add
R sub
R sll
R slt
R sltu
R xor
R srl
R sra
R or
R and
I fence
I fence.i
I ecall
I ebreak
I csrrw
I csrrs
I csrrc
I csrrwi
I csrrsi
I csrrci
"""


from ctypes import c_uint32

class Instruction:

    self.memory = None
    self.regs   = None

    def __init__(self):
        pass

    def compile(self):
        # return the binstream of the instruction in a c_uint32
        pass

    def execute(self):
        # executes the instruction and returns the next program counter
        return

class R(Instruction):
    funct3  = None
    funct7  = None
    opcode = None
    def __init__(self, rd, rs1, rs2):
        self.rd  = rd
        self.rs1 = rs1
        self.rs2 = rs2

    def compile(self):
        # TODO: ensure sizes and convert register names to number...
        return c_uint32(
            (self.funct7  << 25) +\
            (self.rs2    << 20) +\
            (self.rs1    << 15) +\
            (self.funct3  << 12) +\
            (self.rd     <<  7) +\
            self.opcode
        )

class I(Instruction):
    funct3 = None
    opcode = None

    def __init__(self, rd, rs, imm):
        self.rd = rd
        self.rs = rs
        self.imm = imm

    def compile(self):
        return c_uint32(
            (self.imm   << 20) +\
            (self.rs    << 15) +\
            (self.funct3 << 12) +\
            (self.rd    <<  7) +\
            self.opcode
        )

class S(Instruction):
    pass

class B(Instruction):
    pass

class U(Instruction):
    pass

class J(Instruction):
    pass



class add(R):
    name   = "add"
    opcode = 0b0110011
    funct3  = 0b000
    funct7  = 0b0000000

    def execute(self):
        pass


class addi(I):
    name   = "addi"
    opcode = 0b0010011
    funct3  = 0b000

    def execute(self):
        pass

if __name__ == "__main__":
    r = Regs()
    # This is the interface i'd love to have
    addins = add("x5","x2","zero")
    j("labelName")