/**
 * SPDX-License-Identifier: MIT
 * SPDX-FileCopyrightText: 2015-2016 Johan Van den Brande
 *
 * @file	variables.c
 */

#define _GNU_SOURCE
#include <array.h>
#include <dictionary.h>
#include <error.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <variables.h>

typedef union {
  float num;
  char* string;
} variable_value;

struct variable {
  char* name;
  variable_type type;
  variable_value value;
  bool is_array;
  size_t nr_dimensions;
  size_t dimensions[5];
  array* array;
};

dictionary* _dictionary = NULL;

const char* E_INDEX_OUT_OF_BOUNDS = "INDEX OUT OF BOUNDS";
const char* E_VAR_NOT_FOUND = "VAR NOT FOUND";

static void vector_print(size_t* vector, size_t dimensions);

bool variables_init(void) {
  _dictionary = dictionary_new();
  return _dictionary != NULL;
}

static void cb(char* name, void* value, void* context) {
  variable* var = (variable*)value;
  if (var->type == variable_type_string) {
    if (var->value.string != NULL) free(var->value.string);
  }
  if (var->is_array) {
    array_destroy(var->array);
  }
  if (var->name != NULL) free(var->name);
  free(var);
}

void variables_destroy(void) { dictionary_destroy(_dictionary, cb); }

variable* variable_get(char* name) { return dictionary_get(_dictionary, name); }

char* variable_get_string(char* name) {
  variable* var = dictionary_get(_dictionary, name);
  if (!var) {
    var = variable_set_string(name, "");
  }
  return var->value.string;
}

float variable_get_numeric(char* name) {
  variable* var = dictionary_get(_dictionary, name);
  if (!var) {
    var = variable_set_numeric(name, 0);
  }
  return var->value.num;
}

variable* variable_set_string(char* name, char* value) {
  variable* var = dictionary_get(_dictionary, name);
  if (var == NULL) {
    var = (variable*)malloc(sizeof(variable));
    var->name = strdup(name);
    var->type = variable_type_string;
    var->is_array = false;
  } else {
    if (var->value.string != NULL) {
      free(var->value.string);
    }
  }
  var->value.string = strdup(value);
  dictionary_put(_dictionary, name, var);
  return var;
}

variable* variable_set_numeric(char* name, float value) {
  variable* var = dictionary_get(_dictionary, name);
  if (var == NULL) {
    var = (variable*)malloc(sizeof(variable));
    var->name = strdup(name);
    var->type = variable_type_numeric;
    var->is_array = false;
  }
  var->value.num = value;
  dictionary_put(_dictionary, name, var);
  return var;
}

variable_type variable_get_type(char* name) {
  variable* var = dictionary_get(_dictionary, name);
  return var->type;
}

static size_t calc_size(variable* var) {
  size_t size = 1;
  for (size_t i = 0; i < var->nr_dimensions; ++i) {
    size *= var->dimensions[i];
  }
  return size;
}

static bool check_in_bounds(variable* var, size_t* vector) {
  for (size_t i = 0; i < var->nr_dimensions; i++) {
    size_t vector_i = vector[i];
    if (vector_i > var->dimensions[i]) {
      return false;
    }
  }

  return true;
}

/*

  DIM A(2,3)
    w h
    x y
  A(1,1) 0
  A(1,2) 1
  A(1,3) 2
  A(2,1) 3
  A(2,2) 4
  A(2,3) 5

  (x*ySize*zSize + y*zSize + z)

  v[0] = x
  v[1] = y
  v[2] = z

  v[0] * d[1] * ... d[n] + v[1] * d[2] ... d[n] + ... + v[n]


 */

static size_t calc_index(variable* var, size_t* vector) {
  size_t index = 0;
  for (size_t i = 0; i < var->nr_dimensions; ++i) {
    // size_t product = vector[i] - 1;
    size_t product = vector[i];
    for (size_t j = i + 1; j < var->nr_dimensions; ++j) {
      product *= var->dimensions[j];
    }
    index += product;
  }
  return index;
}

variable* variable_array_init(char* name, variable_type type, size_t dimensions, size_t* vector) {
  variable* var = (variable*)malloc(sizeof(variable));
  var->name = strdup(name);
  var->is_array = true;
  var->value.string = NULL;
  var->value.num = 0;
  var->type = type;
  var->nr_dimensions = dimensions;
  var->dimensions[0] = vector[0] + 1;
  var->dimensions[1] = vector[1] + 1;
  var->dimensions[2] = vector[2] + 1;
  var->dimensions[3] = vector[3] + 1;
  var->dimensions[4] = vector[4] + 1;
  var->array = array_new(sizeof(variable_value));
  array_alloc(var->array, calc_size(var));
  dictionary_put(_dictionary, name, var);
  return var;
}

variable* variable_array_set_string(char* name, char* value, size_t* vector) {
  variable* var = dictionary_get(_dictionary, name);
  if (var == NULL) {
    error(E_VAR_NOT_FOUND);
    return NULL;
  }

  if (!check_in_bounds(var, vector)) {
    error(E_INDEX_OUT_OF_BOUNDS);
    return NULL;
  }

  size_t index = calc_index(var, vector);
  variable_value val;
  val.string = strdup(value);
  array_set(var->array, index, &val);

  return var;
}

char* variable_array_get_string(char* name, size_t* vector) {
  variable* var = dictionary_get(_dictionary, name);
  if (var == NULL) {
    error(E_VAR_NOT_FOUND);
    return NULL;
  }

  if (!check_in_bounds(var, vector)) {
    error(E_INDEX_OUT_OF_BOUNDS);
    return NULL;
  }

  size_t index = calc_index(var, vector);
  variable_value* val = array_get(var->array, index);

  return val->string;
}

variable* variable_array_set_numeric(char* name, float value, size_t* vector) {
  variable* var = dictionary_get(_dictionary, name);
  if (var == NULL) {
    error(E_VAR_NOT_FOUND);
    return NULL;
  }

  if (!check_in_bounds(var, vector)) {
    error(E_INDEX_OUT_OF_BOUNDS);
    return NULL;
  }

  // variable_dump(var);
  size_t index = calc_index(var, vector);
  // printf("index = %ld\n", index);
  variable_value val;
  val.num = value;
  array_set(var->array, index, &val);
  // variable_dump(var);

  return var;
}

float variable_array_get_numeric(char* name, size_t* vector) {
  variable* var = dictionary_get(_dictionary, name);
  if (var == NULL) {
    error(E_VAR_NOT_FOUND);
    return 0;
  }

  if (!check_in_bounds(var, vector)) {
    error(E_INDEX_OUT_OF_BOUNDS);
    return 0;
  }

  size_t index = calc_index(var, vector);
  variable_value* val = array_get(var->array, index);

  return val->num;
}

struct each_v_ctx {
  variables_each_cb cb;
  void* context;
};

void each_v(char* name, void* value, void* context) {
  struct each_v_ctx* ctx = (struct each_v_ctx*)context;
  variable* var = (variable*)value;
  ctx->cb(var, ctx->context);
}

void variables_each(variables_each_cb each, void* context) {
  struct each_v_ctx ctx = {.cb = each, .context = context};
  dictionary_each(_dictionary, each_v, &ctx);
}

static void calc_vector(variable* var, size_t index, size_t* vector) {
  size_t product = 1;
  for (size_t i = 1; i < var->nr_dimensions; ++i) {
    product *= var->dimensions[i];
  }

  for (int i = 0; i < var->nr_dimensions; ++i) {
    vector[i] = index / product;
    index %= product;
    if ((i + 1) < var->nr_dimensions) {
      product /= var->dimensions[i + 1];
    }
  }
}

static void vector_print(size_t* vector, size_t dimensions) {
  for (size_t j = 0; j < dimensions; j++) {
    printf("%ld", vector[j]);
    if (j < dimensions - 1) {
      printf(",");
    }
  }
}

void variable_dump(variable* var) {
  printf(
      "-- variable\n"
      "\tname:'%s'\n"
      "\ttype: %s\n",
      var->name, (var->type == variable_type_numeric) ? "number" : "string");

  if (var->is_array) {
    printf("\tdimensions: %ld\n", var->nr_dimensions);
    for (size_t d = 0; d < var->nr_dimensions; d++) {
      printf("\tdim %ld size = %ld\n", d, var->dimensions[d]);
    }
    printf("\tarray size: %ld\n", array_size(var->array));
    for (size_t i = 0; i < array_size(var->array); i++) {
      size_t vector[5];
      calc_vector(var, i, vector);
      printf("\t%3ld %s", i, var->name);
      vector_print(vector, var->nr_dimensions);
      printf(") = ");
      variable_value* val = array_get(var->array, i);
      if (var->type == variable_type_string) {
        printf("%s\n", (val->string) ? val->string : "");
      } else {
        printf("%f\n", val->num);
      }
    }
  } else {
    if (var->type == variable_type_numeric) {
      printf("\tvalue: %f\n", var->value.num);
    } else {
      printf("\tvalue: '%s'\n", var->value.string);
    }
  }
}