#include <common/fzl_types.h>
#include <compiler/fzl_analyzer.h>
#include <compiler/fzl_parser.h>
#include <compiler/fzl_token.h>
#include <compiler/internals/analyzer.h>
#include <compiler/utils/fzl_symtable.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>

// Analyze external function definition
fzl_an_res_t analyze_externfn(fzl_analyzer_t *analyzer, fzl_node_t *externfn)
{
  if (!analyzer)
    return (fzl_an_res_t){.error = true};

  if (!externfn || externfn->type != FZL_NODETYPE_EXTERN_FN)
  {
    an_push_error(analyzer, NULL, "node is not an external function");
    return (fzl_an_res_t){.error = true};
  }

  an_nest_ctx(analyzer, FZL_AN_CTX_TYPE_UNNECESSARY);

  for (size_t i = 0; i < externfn->ext_fn.args_count; i++)
  {
    fzl_an_res_t res = analyze_common(analyzer, externfn->ext_fn.args[i]);
    if (res.error)
      return (fzl_an_res_t){.error = true};
  }

  if (externfn->ext_fn.type->type == FZL_TOKTYPE_NAME)
  {
    fzl_sym_t sym;
    bool found = false;
    for (ssize_t i = analyzer->symbols_top - 1; i >= 0; i--)
    {
      if ((found = fzl_symt_get(analyzer->symbols[i],
                                (char *)externfn->ext_fn.type->value, &sym)))
        break;
    }

    if (!found)
    {
      snprintf(an_problem, sizeof(an_problem),
               "cannot find '%s' used as return type",
               (char *)externfn->ext_fn.type->value);
      an_push_error(analyzer, externfn->ext_fn.type, an_problem);
      return (fzl_an_res_t){.error = true};
    }
  }

  fzl_symtable_res_t wrres =
      fzl_symt_put(analyzer->symbols[0], externfn,
                   (char *)externfn->ext_fn.name, FZL_TYPE_EXTERN_FN, 0);
  if (wrres != FZL_SYMTABLE_RESULT_OK)
  {
    if (wrres == FZL_SYMTABLE_RESULT_EXISTS)
    {
      snprintf(an_problem, sizeof(an_problem),
               "symbol '%s' already has been declared", externfn->ext_fn.name);
      an_push_error(analyzer, externfn->token, an_problem);
      return (fzl_an_res_t){.error = true};
    }
    else
    {
      snprintf(an_problem, sizeof(an_problem), "cannot store symbol '%s'",
               externfn->ext_fn.name);
    }

    an_push_error(analyzer, externfn->token, an_problem);
    return (fzl_an_res_t){.error = true};
  }

  an_fin_ctx(analyzer);

  return (fzl_an_res_t){
      .error = false, .type = FZL_TYPE_EXTERN_FN, .classname = NULL};
}