#!/usr/bin/env python3


def multiplication(Model):
    prods = []

    # TODO: switch operands so less steps are needed
    # switch_mul = Model.productionstring(
    #     name="switch_mul",
    #     string="""
    #     =g>
    #     =imaginal>
    #     ==>
    #     =imaginal>
    # """,
    # )
    # prods.append(switch_mul)

    mul_start = Model.productionstring(
        name="mul_start",
        string="""
        =g>
        isa         math_goal
        op          mul
        arg1        ~0
        arg1        ~1
        arg2        ~0
        arg1        ~1
        arg1        =mul
        arg2        =arg
        ones2       =ones
        tens2       =tens
        hundreds2   =huns
        mul_counter None
        ?retrieval>
        state       free
        ==>
        =g>
        isa         math_goal
        mul_counter 1
        result      =arg
        +retrieval>
        isa         math_op
        op          add
        arg1        =arg
        arg2        =arg
    """,
    )
    prods.append(mul_start)

    mul_step_success = Model.productionstring(
        name="mul_step_success",
        string="""
        =g>
        isa         math_goal
        op          mul
        arg1        =mul
        arg2        =arg
        ones2       =ones
        tens2       =tens
        hundreds2   =huns
        mul_counter =mul_counter
        result      =result
        =retrieval>
        isa         math_op
        op          add
        arg1        =arg
        arg2        =result
        result      =sum
        ==>
        =g>
        isa         math_goal
        result        =sum
        +retrieval>
        isa         math_op
        op          add
        arg1        =mul_counter
        arg2        1
    """,
    )
    prods.append(mul_step_success)

    mul_done = Model.productionstring(
        name="mul_done",
        string="""
        =g>
        isa         math_goal
        op          mul
        arg1        =arg1
        arg2        =arg2
        mul_counter =mul_counter
        =retrieval>
        isa         math_op
        op          add
        arg1        =mul_counter
        arg2        1
        result      =arg1
        ==>
        =g>
        isa         math_goal
        op          done
        """,
    )

    mul_continue = Model.productionstring(
        name="mul_continue",
        string="""
        =g>
        isa         math_goal
        op          mul
        arg1        =arg1
        arg2        =arg2
        mul_counter =mul_counter
        result      =result
        =retrieval>
        isa         math_op
        op          add
        arg1        =mul_counter
        arg2        1
        result      ~=arg1
        result      =counted
        ==>
        =g>
        isa         math_goal
        mul_counter =counted
        ~retrieval>
        +retrieval>
        isa         math_op
        op          add
        arg1        =arg2
        arg2        =result
        """,
    )

    mul_step_failure = Model.productionstring(
        name="mul_step_failure",
        string="""
        =g>
        isa         math_goal
        op          mul
        arg1        =mul
        arg2        =arg
        ones2       =ones
        tens2       =tens
        hundreds2   =huns
        mul_counter =mul_counter
        result      =result
        ?retrieval>
        state       error
        ==>
        =g>
        isa         math_goal
        nextop      mul_fail
        op          add
        arg1        =arg
        arg2        =result
        mem_arg1    =mul
        mem_arg2    =arg
        ones1       None
        tens1       None
        hundreds1   None
        ones2       None
        tens2       None
        hundreds2   None
        ones_ans    None
        tens_ans    None
        hundreds_ans    None
        result      None
        ~retrieval>
    """,
    )

    # instead of remembering original mult args, maybe should
    # start from the beginning, with the addition results now
    # retrievable
    mul_step_addition_return = Model.productionstring(
        name="mul_step_addition_return",
        string="""
        =g>
        isa         math_goal
        op          mul_fail
        mul_counter =mul_counter
        result      =result
        mem_arg1    =mem_arg1
        mem_arg2    =mem_arg2
        ==>
        =g>
        isa         math_goal
        op          mul
        arg1        =mem_arg1
        arg2        =mem_arg2
        +retrieval>
        isa         math_op
        op          add
        arg1        =mul_counter
        arg2        1
    """,
    )
    prods.append(mul_start)

    return prods