#include "declaration.h"
#include "../../lexer/token.h"
#include "../../memory.h"
#include "../literals/literals.h"
#include "../parser.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

ParsedValue *parse_declaration(char *file, DArray *tokens, size_t *index) {
  (*index)++;
  error_if_finished(file, tokens, index);
  Token *token = darray_get(tokens, *index);

  ParsedValue *parsedValue = checked_malloc(sizeof(ParsedValue));
  parsedValue->type = AST_DECLARATION;
  DArray *declarations = checked_malloc(sizeof(DArray));
  darray_init(declarations, sizeof(ParsedSingleDeclaration));
  parsedValue->data = declarations;
  while (true) {
    ParsedSingleDeclaration _declaration = {};
    darray_push(declarations, &_declaration);
    ParsedSingleDeclaration *declaration =
        darray_get(declarations, declarations->size - 1);
    declaration->is_function = false;
    declaration->from = parse_null();

    if (token->type != TOKEN_IDENTIFIER) {
      fprintf(stderr, "%s:%zu:%zu error: declaration requires an identifier\n",
              file, token->line, token->column);
      exit(EXIT_FAILURE);
    }
    declaration->name =
        strcpy(checked_malloc(strlen(token->value) + 1), token->value);

    (*index)++;
    if ((*index) >= tokens->size)
      return parsedValue;
    token = darray_get(tokens, *index);
    if (token->type == TOKEN_LPAREN) {
      declaration->is_function = true;
      declaration->parameters = checked_malloc(sizeof(DArray));
      darray_init(declaration->parameters, sizeof(char *));
      (*index)++;
      error_if_finished(file, tokens, index);
      token = darray_get(tokens, *index);
      if (token->type == TOKEN_RPAREN) {
        (*index)++;
        if ((*index) >= tokens->size)
          return parsedValue;
        token = darray_get(tokens, *index);
      } else {
        while ((*index) < tokens->size) {
          token = darray_get(tokens, *index);
          if (token->type != TOKEN_IDENTIFIER) {
            fprintf(stderr,
                    "%s:%zu:%zu error: parameter names need to start with a "
                    "letter or _, only use letters, digits, or _, and can't be "
                    "keywords.\n",
                    file, token->line, token->column);
            exit(EXIT_FAILURE);
          }
          char *parameter_name =
              strcpy(checked_malloc(strlen(token->value) + 1), token->value);
          darray_push(declaration->parameters, &parameter_name);
          (*index)++;
          error_if_finished(file, tokens, index);
          skip_newlines_and_indents(tokens, index);
          error_if_finished(file, tokens, index);
          token = darray_get(tokens, *index);
          if (token->type == TOKEN_RPAREN) {
            (*index)++;
            if ((*index) >= tokens->size)
              return parsedValue;
            token = darray_get(tokens, *index);
            break;
          } else if (token->type != TOKEN_COMMA) {
            fprintf(stderr, "%s:%zu:%zu error: expected comma\n", file,
                    token->line, token->column);
            exit(EXIT_FAILURE);
          }
          (*index)++;
          error_if_finished(file, tokens, index);
        }
      }
    }
    if (token->type == TOKEN_ASSIGN) {
      (*index)++;
      error_if_finished(file, tokens, index);

      free(declaration->from);

      declaration->from = parse_token(file, tokens, index, true);
      if (!declaration->from) {
        fprintf(stderr, "%s:%zu:%zu error: syntax error\n", file, token->line,
                token->column);
        exit(EXIT_FAILURE);
      }
      if ((*index) >= tokens->size)
        break;
      token = darray_get(tokens, *index);
    }
    size_t count = skip_newlines_and_indents(tokens, index);
    if ((*index) >= tokens->size)
      break;
    token = darray_get(tokens, *index);
    if (token->type != TOKEN_COMMA) {
      (*index)-=count;
      break;
    }
    (*index)++;
    error_if_finished(file, tokens, index);
    skip_newlines_and_indents(tokens, index);
    error_if_finished(file, tokens, index);
    token = darray_get(tokens, *index);
  }
  return parsedValue;
}

void free_string(void *ptr) {
  // `ptr` is a pointer to a char*
  char *str = *(char **)ptr;
  free(str);
}

void free_single_declaration(void *ptr) {
  ParsedSingleDeclaration *declaration = ptr;
  free(declaration->name);
  if (declaration->is_function)
    darray_free(declaration->parameters, free_string);
  free_parsed(declaration->from);
  free(declaration->from);
}

void free_declaration(void *ptr) {
  ParsedValue *parsedValue = ptr;
  DArray *declaration = parsedValue->data;
  darray_free(declaration, free_single_declaration);
  free(declaration);
}