#include "ansi_lib.h"
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>

#include "hydroforth/hydroforth.h"

void free_word_def_value(void *x) {
  struct hf__interpreter__word *word = x;

  for (size_t i = 0; i < word->body_len; i++) {
    // TODO: free nodes
  }

  free(word->body);
  free(word);
}

const hf__hashmap__free_value_t hf__interpreter__word_free =
    free_word_def_value;

void hf__interpreter__free(struct hf__interpreter *interpreter) {
  free(interpreter->call_stack);
  hf__hashmap__free(&interpreter->words, hf__interpreter__word_free);
  free(interpreter->stack);
}

struct hf__result words__number(struct hf__interpreter *const interpreter,
                                const struct hf__node *const node) {
  hf__interpreter__stack_push(&interpreter->stack, &interpreter->stack_len,
                              &interpreter->stack_size, node->value.number);

  return HF__OK;
}

struct hf__result words__char(struct hf__interpreter *const interpreter,
                              const struct hf__node *const node) {
  hf__interpreter__stack_push(&interpreter->stack, &interpreter->stack_len,
                              &interpreter->stack_size, node->value.ch);

  return HF__OK;
}

struct hf__result words__word(struct hf__interpreter *const interpreter,
                              const struct hf__node *const node) {
  // printf("word = \"%s\"\n", node->value.word.value);

  const struct hf__interpreter__word *const *const word =
      (const struct hf__interpreter__word *const *const)hf__hashmap__get(
          &interpreter->words, node->value.word.hash);
  if (word == NULL) {
    char *msg = hf__quote(node->value.word.value, true);
    free(node->value.word.value);

    return HF__ERR_CUSTOM(HF__ERROR__INTERPRETER__UNKNOWN_WORD, msg, true);
  }

  for (size_t i = (*word)->body_len - 1; i != 0 - 1; i--) {
    hf__parser__node_array_push(&interpreter->call_stack,
                                &interpreter->call_stack_len,
                                &interpreter->call_stack_cap, (*word)->body[i]);
    interpreter->call_stack[interpreter->call_stack_len - 1].is_owner = false;
  }

  if (node->is_owner) {
    free(node->value.word.value);
  }

  return HF__OK;
}

struct hf__result words__word_def(struct hf__interpreter *const interpreter,
                                  const struct hf__node *const node) {
  if (hf__hashmap__get(&interpreter->words, node->value.word_def->name.hash)) {
    char *msg = hf__quote(node->value.word_def->name.value, true);

    free(node->value.word_def->name.value);
    free(node->value.word_def->body);
    free(node->value.word_def);

    return HF__ERR_CUSTOM(HF__ERROR__INTERPRETER__WORD_ALREADY_DEF, msg, true);
  }

  struct hf__interpreter__word *word =
      malloc(sizeof(struct hf__interpreter__word));
  (*word) = (struct hf__interpreter__word){
      .body = node->value.word_def->body,
      .body_len = node->value.word_def->body_len,
  };

  hf__hashmap__insert(&interpreter->words, node->value.word_def->name.hash,
                      word);

  free(node->value.word_def->name.value);
  free(node->value.word_def);

  return HF__OK;
}

struct hf__result words__comment(struct hf__interpreter *const interpreter,
                                 const struct hf__node *const node) {
  // printf("comment = \"%s\"\n", node->value.comment);

  free(node->value.comment);

  return HF__OK;
}

struct hf__result words__dup(struct hf__interpreter *const interpreter,
                             const struct hf__node *const node) {
  if (interpreter->stack_len < 1) {
    return (struct hf__result){
        .ok = false,
        .error = HF__ERROR__INTERPRETER__STACK_UNDERFLOW,
    };
  }

  const int top = interpreter->stack[interpreter->stack_len - 1];
  hf__interpreter__stack_push(&interpreter->stack, &interpreter->stack_len,
                              &interpreter->stack_size, top);

  return HF__OK;
}

struct hf__result words__drop(struct hf__interpreter *const interpreter,
                              const struct hf__node *const node) {
  if (interpreter->stack_len < 1) {
    return (struct hf__result){
        .ok = false,
        .error = HF__ERROR__INTERPRETER__STACK_UNDERFLOW,
    };
  }

  interpreter->stack_len--;

  return HF__OK;
}

struct hf__result words__swap(struct hf__interpreter *const interpreter,
                              const struct hf__node *const node) {
  if (interpreter->stack_len < 2) {
    return (struct hf__result){
        .ok = false,
        .error = HF__ERROR__INTERPRETER__STACK_UNDERFLOW,
    };
  }

  const int tmp = interpreter->stack[interpreter->stack_len - 1];
  interpreter->stack[interpreter->stack_len - 1] =
      interpreter->stack[interpreter->stack_len - 2];
  interpreter->stack[interpreter->stack_len - 2] = tmp;

  return HF__OK;
}

struct hf__result words__over(struct hf__interpreter *const interpreter,
                              const struct hf__node *const node) {
  if (interpreter->stack_len < 2) {
    return (struct hf__result){
        .ok = false,
        .error = HF__ERROR__INTERPRETER__STACK_UNDERFLOW,
    };
  }

  hf__interpreter__stack_push(&interpreter->stack, &interpreter->stack_len,
                              &interpreter->stack_size,
                              interpreter->stack[interpreter->stack_len - 2]);

  return HF__OK;
}

struct hf__result words__rot(struct hf__interpreter *const interpreter,
                             const struct hf__node *const node) {
  if (interpreter->stack_len < 1) {
    return (struct hf__result){
        .ok = false,
        .error = HF__ERROR__INTERPRETER__STACK_UNDERFLOW,
    };
  }

  interpreter->stack_len--;

  return HF__OK;
}

struct hf__result words__add(struct hf__interpreter *const interpreter,
                             const struct hf__node *const node) {
  if (interpreter->stack_len < 2) {
    return (struct hf__result){
        .ok = false,
        .error = HF__ERROR__INTERPRETER__STACK_UNDERFLOW,
    };
  }

  interpreter->stack[interpreter->stack_len - 2] +=
      interpreter->stack[interpreter->stack_len - 1];
  interpreter->stack_len--;

  return HF__OK;
}

struct hf__result words__sub(struct hf__interpreter *const interpreter,
                             const struct hf__node *const node) {
  if (interpreter->stack_len < 2) {
    return (struct hf__result){
        .ok = false,
        .error = HF__ERROR__INTERPRETER__STACK_UNDERFLOW,
    };
  }

  interpreter->stack[interpreter->stack_len - 2] -=
      interpreter->stack[interpreter->stack_len - 1];
  interpreter->stack_len--;

  return HF__OK;
}

struct hf__result words__dot(struct hf__interpreter *const interpreter,
                             const struct hf__node *const node) {
  if (interpreter->stack_len < 1) {
    return HF__ERR(HF__ERROR__INTERPRETER__STACK_UNDERFLOW);
  }

  printf("%i", interpreter->stack[--interpreter->stack_len]);

  return HF__OK;
}

struct hf__result words__emit(struct hf__interpreter *const interpreter,
                              const struct hf__node *const node) {
  if (interpreter->stack_len < 1) {
    return HF__ERR(HF__ERROR__INTERPRETER__STACK_UNDERFLOW);
  }

  putchar(interpreter->stack[--interpreter->stack_len]);

  return HF__OK;
}

struct hf__result words__space(struct hf__interpreter *const interpreter,
                               const struct hf__node *const node) {
  putchar(' ');

  return HF__OK;
}

struct hf__result words__spaces(struct hf__interpreter *const interpreter,
                                const struct hf__node *const node) {
  if (interpreter->stack_len < 1) {
    return HF__ERR(HF__ERROR__INTERPRETER__STACK_UNDERFLOW);
  }

  const int max = interpreter->stack[--interpreter->stack_len];
  for (int i = 0; i < max; i++) {
    putchar(' ');
  }

  return HF__OK;
}

struct hf__result words__cr(struct hf__interpreter *const interpreter,
                            const struct hf__node *const node) {
  putchar('\n');

  return HF__OK;
}

struct hf__result words__crs(struct hf__interpreter *const interpreter,
                             const struct hf__node *const node) {
  if (interpreter->stack_len < 1) {
    return HF__ERR(HF__ERROR__INTERPRETER__STACK_UNDERFLOW);
  }

  const int max = interpreter->stack[--interpreter->stack_len];
  for (int i = 0; i < max; i++) {
    putchar('\n');
  }

  return HF__OK;
}

struct hf__result words__debug(struct hf__interpreter *const interpreter,
                               const struct hf__node *const node) {
  SET_8_VALUE_COLOUR(TXT_CYAN);
  puts("\n===\nDEBUG:");
  for (size_t i = interpreter->stack_len - 1; i != 0 - 1; i--) {
    printf("%lu : %i\n", i, interpreter->stack[i]);
  }
  puts("===");
  SET_8_VALUE_COLOUR(TXT_DEFAULT);

  return HF__OK;
}

struct hf__result words__exit(struct hf__interpreter *const interpreter,
                              const struct hf__node *const node) {
  if (interpreter->stack_len < 1) {
    return HF__ERR(HF__ERROR__INTERPRETER__STACK_UNDERFLOW);
  }

  interpreter->is_running = false;
  interpreter->exit_code = interpreter->stack[--interpreter->stack_len];

  return HF__OK;
}

struct hf__result words__abort(struct hf__interpreter *const interpreter,
                               const struct hf__node *const node) {
  abort();

  return HF__OK;
}

const hf__interpreter__word_func_t
    HF__INTERPRETER__WORD_FUNCTION[__HF__NODE_TYPE__N] = {
        [HF__NODE_TYPE__NUMBER] = words__number,
        [HF__NODE_TYPE__CHAR] = words__char,
        [HF__NODE_TYPE__WORD] = words__word,
        [HF__NODE_TYPE__WORD_DEF] = words__word_def,

        [HF__NODE_TYPE__DASH_COMMENT] = words__comment,
        [HF__NODE_TYPE__PAREN_COMMENT] = words__comment,

        [HF__NODE_TYPE__DUP] = words__dup,
        [HF__NODE_TYPE__DROP] = words__drop,
        [HF__NODE_TYPE__SWAP] = words__swap,
        [HF__NODE_TYPE__OVER] = words__over,
        [HF__NODE_TYPE__ROT] = words__rot,

        [HF__NODE_TYPE__ADD] = words__add,
        [HF__NODE_TYPE__SUB] = words__sub,

        [HF__NODE_TYPE__DOT] = words__dot,
        [HF__NODE_TYPE__EMIT] = words__emit,
        [HF__NODE_TYPE__SPACE] = words__space,
        [HF__NODE_TYPE__SPACES] = words__spaces,
        [HF__NODE_TYPE__CR] = words__cr,
        [HF__NODE_TYPE__CRS] = words__crs,
        [HF__NODE_TYPE__DEBUG] = words__debug,

        [HF__NODE_TYPE__ABORT] = words__abort,
        [HF__NODE_TYPE__EXIT] = words__exit,
};

void hf__interpreter__stack_push(int **arr, size_t *const len,
                                 size_t *const cap, int item) {
  if (*len > *cap) {
    return;
  } else if (*len == *cap) {
    *cap += 1 + (*cap / 2);
    *arr = realloc(*arr, sizeof(int) * (*cap));
  }

  (*arr)[*len] = item;
  (*len)++;
}

struct hf__result
hf__interpreter__run(struct hf__interpreter *const interpreter) {
  if (interpreter->call_stack_len == 0) {
    return HF__OK;
  }

  const struct hf__node *const top =
      interpreter->call_stack + --interpreter->call_stack_len;
  const hf__interpreter__word_func_t func =
      HF__INTERPRETER__WORD_FUNCTION[top->type];

  if (func) {
    struct hf__result res = func(interpreter, top);

    if (res.ok && interpreter->call_stack_cap_max != 0 &&
        interpreter->call_stack_cap >= interpreter->call_stack_cap_max) {
      const size_t required_size =
          snprintf(NULL, 0, "%lu >= %lu", interpreter->call_stack_cap,
                   interpreter->call_stack_cap_max);
      char *msg = malloc(sizeof(char) * (required_size + 1));
      snprintf(msg, required_size + 1, "%lu >= %lu",
               interpreter->call_stack_cap, interpreter->call_stack_cap_max);

      return HF__ERR_CUSTOM(HF__ERROR__INTERPRETER__CALL_STACK_TOO_BIG, msg,
                            true);
    } else {
      return res;
    }
  } else {
    return HF__OK;
  }
}