// Copyright 2000-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.

#include "fsnotifier.h"

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


#define REALLOC_FACTOR 2

struct __array {
  void** data;
  int size;
  int capacity;
};

static bool array_realloc(array* a) {
  if (a->size == a->capacity) {
    int new_cap = a->capacity * REALLOC_FACTOR;
    void* new_ptr = realloc(a->data, sizeof(void*) * new_cap);
    if (new_ptr == NULL) {
      return false;
    }
    a->capacity = new_cap;
    a->data = new_ptr;
  }
  return true;
}

array* array_create(int initial_capacity) {
  array* a = calloc(1, sizeof(array));
  if (a == NULL) {
    return NULL;
  }

  a->data = calloc(initial_capacity, sizeof(void*));
  if (a->data == NULL) {
    free(a);
    return NULL;
  }

  a->capacity = initial_capacity;
  a->size = 0;

  return a;
}

inline int array_size(array* a) {
  return (a != NULL ? a->size : 0);
}

void* array_push(array* a, void* element) {
  if (a == NULL || !array_realloc(a)) {
    return NULL;
  }
  a->data[a->size++] = element;
  return element;
}

void* array_pop(array* a) {
  if (a != NULL && a->size > 0) {
    return a->data[--a->size];
  }
  else {
    return NULL;
  }
}

void array_put(array* a, int index, void* element) {
  if (a != NULL && index >=0 && index < a->capacity) {
    a->data[index] = element;
    if (a->size <= index) {
      a->size = index + 1;
    }
  }
}

void* array_get(array* a, int index) {
  if (a != NULL && index >= 0 && index < a->size) {
    return a->data[index];
  }
  else {
    return NULL;
  }
}

void array_delete(array* a) {
  if (a != NULL) {
    free(a->data);
    free(a);
  }
}

void array_delete_vs_data(array* a) {
  if (a != NULL) {
    array_delete_data(a);
    array_delete(a);
  }
}

void array_delete_data(array* a) {
  if (a != NULL) {
    for (int i=0; i<a->size; i++) {
      if (a->data[i] != NULL) {
        free(a->data[i]);
      }
    }
    a->size = 0;
  }
}


struct __table {
  void** data;
  int capacity;
};

table* table_create(int capacity) {
  table* t = calloc(1, sizeof(table));
  if (t == NULL) {
    return NULL;
  }

  t->data = calloc(capacity, sizeof(void*));
  if (t->data == NULL) {
    free(t);
    return NULL;
  }

  t->capacity = capacity;

  return t;
}

static inline int wrap(int key, table* t) {
  return (t != NULL ? key % t->capacity : -1);
}

// todo: resolve collisions (?)
void* table_put(table* t, int key, void* value) {
  int k = wrap(key, t);
  if (k < 0 || (value != NULL && t->data[k] != NULL)) {
    return NULL;
  }
  else {
    return t->data[k] = value;
  }
}

void* table_get(table* t, int key) {
  int k = wrap(key, t);
  if (k < 0) {
    return NULL;
  }
  else {
    return t->data[k];
  }
}

void table_delete(table* t) {
  if (t != NULL) {
    free(t->data);
    free(t);
  }
}


#define INPUT_BUF_LEN 2048
static char input_buf[INPUT_BUF_LEN];

char* read_line(FILE* stream) {
  char* retval = fgets(input_buf, INPUT_BUF_LEN, stream);
  if (retval == NULL || feof(stream)) {
    return NULL;
  }
  int pos = strlen(input_buf) - 1;
  if (input_buf[pos] == '\n') {
    input_buf[pos] = '\0';
  }
  return input_buf;
}


bool is_parent_path(const char* parent_path, const char* child_path) {
  size_t parent_len = strlen(parent_path);
  return strncmp(parent_path, child_path, parent_len) == 0 &&
         (parent_len == strlen(child_path) || child_path[parent_len] == '/');
}