#include <compiler/fzl_gen.h>
#include <compiler/fzl_writer.h>
#include <compiler/internals/writer.h>
#include <compiler/utils/fzl_const_pool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char wrlast_err[256];

fzl_writer_t *fzl_mkwriter(const char *filepath)
{
  if (strlen(filepath) < 1)
    return nullptr;

  fzl_writer_t *writer = malloc(sizeof(fzl_writer_t));
  if (!writer)
    return nullptr;

  writer->filepath = filepath;

  return writer;
}

int fzl_write(fzl_writer_t *writer, fzl_gen_t *gen)
{
  if (!writer || !gen)
    return -1;

  FILE *fd = fopen(writer->filepath, "wb");
  if (!fd)
  {
    snprintf(wrlast_err, sizeof(wrlast_err), "failed to open '%s' to write",
             writer->filepath);
    return -1;
  }

  constexpr char hdr[5] = {'F', 'Z', 'L', 0x0, 0x2};
  fwrite(hdr, sizeof(char), 5, fd);
  fwrite(&gen->consts->size, sizeof(uint16_t), 1, fd);
  fwrite(&gen->extern_libs_count, sizeof(uint16_t), 1, fd);
  fwrite(&gen->extern_types_count, sizeof(uint16_t), 1, fd);
  fwrite(&gen->extern_fns_count, sizeof(uint16_t), 1, fd);
  fwrite(&gen->ops_count, sizeof(size_t), 1, fd);

  bool result = wr_consts(fd, gen->consts);
  if (!result)
  {
    snprintf(wrlast_err, sizeof(wrlast_err), "failed to write constants table");
    fclose(fd);
    return -1;
  }

  result = wr_extern_libs(fd, gen->extern_libs, gen->extern_libs_count);
  if (!result)
  {
    snprintf(wrlast_err, sizeof(wrlast_err),
             "failed to write external lib names");
    fclose(fd);
    return -1;
  }

  result = wr_extern_types(fd, gen->extern_types, gen->extern_types_count);
  if (!result)
  {
    snprintf(wrlast_err, sizeof(wrlast_err),
             "failed to write extern lib types");
    fclose(fd);
    return -1;
  }

  result = wr_extern_fns(fd, gen->extern_fns, gen->extern_fns_count);
  if (!result)
  {
    snprintf(wrlast_err, sizeof(wrlast_err),
             "failed to write extern lib functions");
    fclose(fd);
    return -1;
  }

  result = wr_ops(fd, gen->ops, gen->ops_count);
  if (!result)
  {
    snprintf(wrlast_err, sizeof(wrlast_err), "failed to write opcodes");
    fclose(fd);
    return -1;
  }

  fclose(fd);

  return 0;
}

char *fzl_writer_geterror() { return wrlast_err; }

void fzl_freewriter(fzl_writer_t *writer)
{
  if (!writer)
    return;

  free(writer);
}