/* File ast.c
   Implementation of DISM ASTs for sim-dism
*/

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "ast.h"

void printError(char *reason) {
  printf("Error: %s\n", reason);
  exit(-1);
}

/* Create a new AST node of type t */
ASTree *newAST(ASTNodeType t, ASTree *child1,
       ASTree *child2, ASTree *child3, char *attribute) {
  ASTree *toReturn = malloc(sizeof(ASTree));
  if(toReturn==NULL) printError("malloc in newAST()");
  toReturn->typ = t;
  // create a linked list of children
  ASTList *childList = malloc(sizeof(ASTList));
  if(childList==NULL) printError("malloc in newAST()");
  childList->data = child3;
  childList->next = NULL;
  toReturn->childrenHead = childList;
  if(child2!=NULL) prependAST(child2, toReturn);
  if(child1!=NULL) prependAST(child1, toReturn);
  // finally set this node's attribute
  if(attribute==NULL) toReturn->text=NULL;
  else {
    char *copyStr = malloc(strlen(attribute)+1);
    if(copyStr==NULL) printError("malloc in newAST()");
    strcpy(copyStr, attribute);
    toReturn->text = copyStr;
  }
  return toReturn;
}

/* Prepend an AST node to a parent's list of children */
ASTree *prependAST(ASTree *newChild, ASTree *parent) {
  if(parent==NULL) printError("prepend called with bad parent");
  if(newChild==NULL) printError("NULL childToPrepend");
  ASTList *newList = malloc(sizeof(ASTList));
  if(newList==NULL) printError("malloc in prependToChildrenList()");
  newList->data = newChild;
  if(parent->childrenHead!=NULL && parent->childrenHead->data==NULL)
    newList->next = NULL; //cut out empty child node from list
  else newList->next = parent->childrenHead;
  parent->childrenHead = newList;
  return parent;
}

/* Print the type of this node and any node attributes */
void printNodeTypeAndAttribute(ASTree *t) {
  if(t==NULL) return;
  switch(t->typ) {
    case INSTR_LIST: printf("INSTR_LIST"); break;
    case LABELED_INSTR: printf("LABELED_INSTR"); break;
    case ADD_AST: printf("ADD_AST"); break;
    case SUB_AST: printf("SUB_AST"); break;
    case MUL_AST: printf("MUL_AST"); break;
    case MOV_AST: printf("MOV_AST"); break;
    case LOD_AST: printf("LOD_AST"); break;
    case STR_AST: printf("STR_AST"); break;
    case JMP_AST: printf("JMP_AST"); break;
    case BEQ_AST: printf("BEQ_AST"); break;
    case BLT_AST: printf("BLT_AST"); break;
    case RDN_AST: printf("RDN_AST"); break;
    case PTN_AST: printf("PTN_AST"); break;
    case HLT_AST: printf("HLT_AST"); break;
    case LABEL_AST: printf("LABEL_AST(%s)",t->text); break;
    case INT_AST: printf("INT_AST(%s)",t->text); break;
    default: printf("unknown node type!");
  }  
}

/* print tree in preorder */
void printASTree(ASTree *t, int depth) {
  if(t==NULL) return;
  printf("%d:",depth);
  int i=0;
  for(; i<depth; i++) printf("  ");
  printNodeTypeAndAttribute(t);
  printf("\n");
  //recursively print all children
  ASTList *childListIterator = t->childrenHead;
  while(childListIterator!=NULL) {
    printASTree(childListIterator->data, depth+1);
    childListIterator = childListIterator->next;
  }
}

/* Print the AST to stdout with indentations marking tree depth. */
void printAST(ASTree *t) { printASTree(t, 0); }