#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <malloc.h>
#include <string.h>
#include <errno.h>
#include "stack.h"

void allocate_stack(struct stack **stack) {
  if (!(*stack = malloc(sizeof(**stack)))) {
    fprintf(stderr, "%s: %s (%s:%d)\n", program_name, strerror(errno), __FILE__, __LINE__ - 1);
    exit(errno);
  }

  allocate_card(&((*stack)->card));

  return;
}

void initialize_stack(struct stack *stack) {
  initialize_card(stack->card);
  stack->next = NULL;

  return;
}

void free_stack(struct stack *stack) {
  struct stack *tmp_stack;

  while (stack) {
    tmp_stack = stack->next;
    free_card(stack->card);
    free(stack);
    stack = tmp_stack;
  }

  return;
}

bool empty(struct stack *stack) {
  return(stack->card->value == NO_VALUE &&
         stack->card->suit == NO_SUIT &&
         stack->card->face == NO_FACE &&
         !stack->next);
}

int length(struct stack *stack) {
  int length;

  if (!empty(stack)) {
    for (length = 1; stack->next; stack = stack->next, length++)
      ;
  } else {
    length = 0;
  }

  return(length);
}

void push(struct stack **stack, struct card *card) {
  struct stack *new_stack = NULL;

  if (card) {
    if (empty(*stack)) {
      (*stack)->card = card;
    } else {
      allocate_stack(&new_stack);
      new_stack->card = card;
      new_stack->next = (*stack);
      *stack = new_stack;
    }
  }
}

struct stack *pop(struct stack **stack) {
  struct stack *popped_entry = NULL;

  if(!empty(*stack)) {
    popped_entry = *stack;
    /* As what's considered an empty stack is an allocated and initialized
     * stack structure, we make sure pop doesn't make '*stack' point to NULL
     * when popping a stack with only 1 element. */
    if (length(*stack) == 1) {
      allocate_stack(stack);
      initialize_stack(*stack);
      set_frame((*stack)->card->frame,
                (*stack)->card->frame->start_y,
                (*stack)->card->frame->start_x);
    } else {
      *stack = (*stack)->next;
    }
    popped_entry->next = NULL;
  }

  return(popped_entry);
}

struct stack *reverse(struct stack *stack) {
  if (length(stack) > 1) {
    struct stack *tmp_stack;

    allocate_stack(&tmp_stack);
    initialize_stack(tmp_stack);
    while (!empty(stack)) {
      push(&tmp_stack, pop((&stack))->card);
    }
    return(tmp_stack);
  } else {
    return(stack);
  }
}