#include <compiler/fzl_debug.h>
#include <compiler/fzl_parser.h>
#include <compiler/fzl_reader.h>
#include <compiler/fzl_walker.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Build arguments setup descriptor
typedef struct
{
  char *filepath;
  bool verbose;
  bool help;
} build_args_t;

// Print command usage hint
void print_usage()
{
  printf("Usage: fzc [flags] <file path>\n");
  printf("Flags:\n");
  printf("\t-v\t--verbose\tdisplay debug information\n");
  printf("\t-h\t--help\t\tprint usage hint (which you're looking at)\n");
}

// Read the arguments and build `build_args_t` struct
build_args_t *getargs(int argc, char **argv)
{
  build_args_t *args = malloc(sizeof(build_args_t));
  if (!args)
    return NULL;

  args->filepath = NULL;
  args->verbose = false;
  args->help = false;

  size_t args_total = 0;
  if (argc > 2)
  {
    for (int i = 1; i < argc; i++)
    {
      if (argv[i][0] != '-')
        continue;

      args_total++;

      if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--help") == 0)
      {
        args->help = true;
      }
      else if (strcmp(argv[i], "-v") == 0 || strcmp(argv[i], "--verbose") == 0)
      {
        args->verbose = true;
      }
      else
      {
        printf("Error: unknown argument '%s'\n", argv[i]);
        return NULL;
      }
    }
  }

  if (argc - 1 - args_total < 1)
  {
    printf("Error: source code file is not specified.\n");
    print_usage();
    return NULL;
  }

  if (argv[argc - 1][0] == '-')
  {
    printf("Error: last argument MUST be a path to file.\n");
    printf("Write 'fzc --help' to read help\n");
    return NULL;
  }

  args->filepath = argv[argc - 1];
  return args;
}

int main(int argc, char **argv)
{
  build_args_t *args = getargs(argc, argv);
  if (args == NULL)
    return -1;
  else if (args->help)
    return 0;

  if (args->verbose)
    printf("> analyze\n-> reading file...");

  char source[8192];
  FILE *fd = fopen(args->filepath, "r");
  if (!fd)
  {
    printf("Error: failed to open file '%s'\n", args->filepath);
    return -1;
  }

  fseek(fd, 0L, SEEK_END);
  size_t fsz = ftell(fd);
  rewind(fd);

  fread(source, fsz, 1, fd);
  fclose(fd);
  if (args->verbose)
  {
    printf("ok!\n");
    printf("-> tokenizing...");
  }

  fzl_reader_t *rd = fzl_mkreader(source);
  int result = fzl_read(rd);
  if (result != 0)
  {
    printf("error: %s\n", fzl_reader_geterror());
    return -1;
  }

  if (args->verbose)
    printf("ok!\n");

  fzl_reader_ll_t *entry = rd->first;

  if (args->verbose)
  {
    printf("--> structure: ");
    while (entry)
    {
      if (entry->token)
      {
        if (entry->token->store_value)
          printf("<TOK:%d:%s>", entry->token->type,
                 (char *)entry->token->value);
        else
          printf("<TOK:%d>", entry->token->type);
      }

      entry = entry->next;
    }

    printf("\n");
    printf("-> parsing...");
  }

  fzl_parser_t *parser = fzl_mkparser(rd->first);
  result = fzl_parse(parser);
  if (result != 0)
  {
    printf("Error: %s\n", fzl_parser_geterror());
    return -1;
  }

  if (args->verbose)
  {
    printf("ok!\n");
    fzl_debug_print_ast(parser->root);
    printf("-> walking AST...");
  }

  fzl_walker_t *walker = fzl_mkwalker(parser->root);
  result = fzl_walk(walker);
  if (result != 0)
  {
    printf("Error: %s\n", fzl_walker_geterror());
    return -1;
  }

  if (args->verbose)
  {
    printf("ok!\n");

    printf("--> Constants table:\n");
    for (size_t i = 0; i < walker->consts->size; i++)
      printf("---> %s\n", walker->consts->array[i].as.string.chars);

    printf("--> Ops:\n");
    for (size_t i = 0; i < walker->op_count; i++)
      printf("---> %lu\n", walker->ops[i]);
  }

  free(args);
  fzl_freereader(rd);
  fzl_freeparser(parser);
  fzl_freeast(parser->root);
  fzl_freewalker(walker);

  printf("done.\n");
  return 0;
}