/*           Intermediate Code           */
/*     The Translators - Spring 2025     */

#include "intermediate_code.h"

// TODO: this is here to bring your attention to the comment bellow.
// check if start is NULL if it is assign it to the start globle variable
// otherwise make it next of current and set cur to your instruction.
TNodeOrConst* getOperand1(Instruction* i) {
    return i->operand1;
}

TNodeOrConst* getOperand2(Instruction* i) {
    return i->operand2;
}

TableNode* getResult(Instruction* i) {
    return i->result;
}

Op getOp(Instruction* i) {
    return i->opcode;
}

int getLabel(Instruction* i) {
    return i->label;
}

int get_index(Instruction* i) {
    return i->index;
}

void set_label(Instruction* i, int label) {
    i->label = label;
}

bool isConst(TNodeOrConst* tnc) {
    return tnc->d != NODE;
}

TNodeOrConst* tn_or_const(Discriminant d, void* tnc) {
    TNodeOrConst* count = calloc(1, sizeof(*count));
    count->d = d;
    count->tnc_union = calloc(1, sizeof(*count->tnc_union));
    switch (d) {
        case NODE:
            count->tnc_union->node = tnc;
            break;
        case ADDRESS:
            count->tnc_union->address = tnc;
            break;
        case STRING:
            count->tnc_union->string = tnc;
            break;
        case INTEGER:
            count->tnc_union->integer = *(int*)tnc;
            break;
        case CHARACTER:
            count->tnc_union->character = *(char*)tnc;
            break;
        case BOOLEAN:
            count->tnc_union->Boolean = *(uint_least8_t*)tnc;
            break;
    }
    return count;
}

static void emit_helper(void) {
    Instruction* inst = calloc(1, sizeof(*inst));
    if (begin == NULL) {
        begin = current = inst;
        current->index = 1;
    } else {
        current->next = inst;
        inst->prev = current;
        inst->index = current->index + 1;
        current = inst;
    }
}

void emit_binary_op(Op op, TableNode* result, TNodeOrConst* arg1, TNodeOrConst* arg2) {
    emit_helper();
    current->opcode = op;
    // TODO: create temp and remove result from param list
    current->result = result;
    current->operand1 = arg1;
    current->operand2 = arg2;
}

void emit_unary_op(Op op, TableNode* result, TNodeOrConst* arg) {
    emit_helper();
    current->opcode = op;
    current->result = result;
    current->operand1 = arg;
}

void emit_assignment(TableNode* target, TNodeOrConst* source) {
    emit_helper();
    current->opcode = E_ASSIGN;
    current->result = target;
    current->operand1 = source;
}

char* get_string(TNodeOrConst* tc) {
    char* s;
    switch (tc->d) {
        case NODE:
            return getName(tc->tnc_union->node);
        case ADDRESS:
            return strdup("null");
        case STRING:
            return tc->tnc_union->string;
        case INTEGER:
            s = calloc(10, sizeof(char));
            sprintf(s, "%d", tc->tnc_union->integer);
            return s;
        case CHARACTER:
            s = calloc(2, sizeof(char));
            sprintf(s, "%c", tc->tnc_union->character);
            return s;
        case BOOLEAN:
            if (tc->tnc_union->Boolean) {
                return strdup("true");
            }
            return strdup("false");
    }
}

void emit_as_file(FILE* out_file, Instruction* i) {
    if (i == NULL) {
        return;
    }
    switch (i->opcode) {
        case E_LABEL:
            break;
            // this is a terrible one to start with
            // fprintf(out_file, "%04.d:  %d ", i->index, i->label);
        case E_ADD:
            fprintf(out_file, "%4.d:  %s = %s + %s\n",
                    i->index, getName(i->result),
                    get_string(i->operand1),
                    get_string(i->operand2));
            break;
        case E_SUB:
            fprintf(out_file, "%4.d:  %s = %s - %s\n",
                    i->index, getName(i->result),
                    get_string(i->operand1),
                    get_string(i->operand2));
            break;
        case E_MUL:
            fprintf(out_file, "%4.d:  %s = %s * %s\n",
                    i->index, getName(i->result),
                    get_string(i->operand1),
                    get_string(i->operand2));
            break;
        case E_DIV:
            fprintf(out_file, "%4.d:  %s = %s / %s\n",
                    i->index, getName(i->result),
                    get_string(i->operand1),
                    get_string(i->operand2));
            break;
        case E_MOD:
            fprintf(out_file, "%4.d:  %s = %s %% %s\n",
                    i->index, getName(i->result),
                    get_string(i->operand1),
                    get_string(i->operand2));
            break;
        case E_OR:
            fprintf(out_file, "%4.d:  %s = %s | %s\n",
                    i->index, getName(i->result),
                    get_string(i->operand1),
                    get_string(i->operand2));
            break;
        case E_AND:
            fprintf(out_file, "%4.d:  %s = %s & %s\n",
                    i->index, getName(i->result),
                    get_string(i->operand1),
                    get_string(i->operand2));
            break;
        case E_NEG:
            fprintf(out_file, "%4.d:  %s = -%s\n",
                    i->index, getName(i->result),
                    get_string(i->operand1));
            break;
        case E_NOT:
            fprintf(out_file, "%4.d:  %s = !%s\n",
                    i->index, getName(i->result),
                    get_string(i->operand1));
            break;
        case E_ASSIGN:
            fprintf(out_file, "%4.d:  %s = %s\n",
                    i->index, getName(i->result),
                    get_string(i->operand1));
            break;
        case E_GOTO:
            // are we ever going to use this?
            // yes we do look at bounds checking
        case E_IF_X_TRUE:
            fprintf(out_file, "%4.d:  if %s goto %d\n",
                    i->index, get_string(i->operand1),
                    i->label);
            break;
        case E_IF_X_FALSE:
            fprintf(out_file, "%4.d:  if %s false goto %d\n",
                    i->index, get_string(i->operand1),
                    i->label);
            break;
        case E_LESS_THAN:
            fprintf(out_file, "%4.d:  if %s < %s goto %d\n",
                    i->index, get_string(i->operand1),
                    get_string(i->operand2), i->label);
            break;
        case E_EQUAL_TO:
            fprintf(out_file, "%4.d:  if %s = %s goto %d\n",
                    i->index, get_string(i->operand1),
                    get_string(i->operand2), i->label);
            break;
        case E_CALL:
            fprintf(out_file, "%4.d:  call %s %s\n",
                    i->index, get_string(i->operand1),
                    get_string(i->operand2));
            break;

        case E_PARAM:
            fprintf(out_file, "%4.d:  param %s \n",
                    i->index, get_string(i->operand1));
            break;
        case E_RETURN:

        case E_INDEX_COPY_RIGHT:
        case E_INDEX_COPY_LEFT:

        case E_ADDRESS_OF:

        case E_DEREF_RIGHT:
        case E_DEREF_LEFT:
    }

    emit_as_file(out_file, i->next);
}

void emit_label(int label) {
    emit_helper();
    current->opcode = E_LABEL;
    current->label = label;
}

void emit_jump(int label) {
    emit_helper();
    current->opcode = E_GOTO;
    current->label = label;
}

void emit_conditional_jump(Op condition, int label, ...) {
    // when this instruction is a conditional jump then the imput looks like (Op, int, TNodeOrConst *).
    // when the inst is a cond with a Relational operation then the input looks like (Op, int, TNodeOrConst *, TNodeOrConst *)
    emit_helper();
    va_list argptr;
    va_start(argptr, label);
    current->opcode = condition;
    current->label = label;
    TNodeOrConst* n1;
    TNodeOrConst* n2;
    switch (condition) {
        case E_IF_X_TRUE:
        case E_IF_X_FALSE:
            n1 = va_arg(argptr, TNodeOrConst*);
            current->operand1 = n1;
            break;
        case E_LESS_THAN:
        case E_EQUAL_TO:
            n1 = va_arg(argptr, TNodeOrConst*);
            n2 = va_arg(argptr, TNodeOrConst*);
            current->operand1 = n1;
            current->operand2 = n2;
            break;
    }
    va_end(argptr);
}

void emit_function_start(int name) {
    emit_helper();
    current->opcode = E_LABEL;  // I think this is right TODO: ask
    current->label = name;
    // this is probabaly a func decleration
}

void emit_parameter(TNodeOrConst* param) {
    emit_helper();
    current->opcode = E_PARAM;
    current->operand1 = param;
}

void emit_function_call(TableNode* result, int param_count, TNodeOrConst* name) {
    emit_helper();
    current->opcode = E_CALL;
    current->operand1 = tn_or_const(INTEGER, &param_count);
    current->operand2 = name;
    current->result = result;
}

void emit_return(TNodeOrConst* value) {
    emit_helper();
    current->opcode = E_RETURN;
    current->operand1 = value;
}

void emit_reserve(TableNode* result, TNodeOrConst* size) {
    emit_parameter(size);
    emit_function_call(result, 1, tn_or_const(NODE, look_up(cur, "reserve")));
}

void emit_release(TableNode* pointer) {
    emit_parameter(tn_or_const(NODE, pointer));
    emit_function_call(pointer, 1, tn_or_const(NODE, look_up(cur, "release")));
}

void emit_deref_right() {
    return;
}

void emit_deref_left() {
    return;
}

void emit_field_access(char* result, char* record, char* field) {
    emit_helper();
}

void emit_array_access(Op op, TableNode* result, TNodeOrConst* array, TNodeOrConst* index) {
    emit_helper();
    current->opcode;
    current->result = result;
    current->operand1 = array;
    current->operand2 = index;
    // TODO: Still don't know what to do with the dimentions
}

void emit_bounds_check(TNodeOrConst* index, TNodeOrConst* arr) {
    /*
       {[string: 5]
            .
            .
        s:= reserve s(5);
        s(0) := 'H';
        s(1) := 'e';
            .
            .
        s._0 num of dims Known at compile time
        s._1 size Known at run time
        s._1 int | 1 byte
        +-------+---+---+---+---+---+
        |   5   | H | e | l | l | o |
        +-------+---+---+---+---+---+
          size
        ^
        |
        p
        s._0        ok
        s._1        ok
        s._2        not ok
        t_0 is index
        t_1 = *(int *)p = s._1
        if t_0 < 0 GOTO ERROR
        if t_0 < s._1 GOTO access array
        GOTO ERROR
       */
    //emit_conditional_jump(E_LESS_THAN, );
    //emit_conditional_jump(E_LESS_THAN, );
    //emit_jump();
    /* We need a label ERROR to jump to
    */
}

/*// * Implement temp variable generator function that produces unique names (t1, t2, etc.)
char * temp_var_gen(){
    char * ret = calloc(9, sizeof(*ret));
    sprintf(ret, "$t%d", temp_count);
    temp_count++;
    return ret;
}
*/
char* label_gen() {
    char* ret = calloc(9, sizeof(*ret));
    sprintf(ret, "L_%d", label_count);
    label_count++;
    return ret;
}

TableNode* getTN(TNodeOrConst* tnc) {
    if (tnc->d == NODE) {
        return tnc->tnc_union->node;
    }
    return NULL;
}
//we must fix this
int getConst(TNodeOrConst* tnc) {
    if (tnc->d == INTEGER) {
        return tnc->tnc_union->integer;
    }
    return -1;
}