#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "args.h"
#include "config.h"
#include "logs.h"
#include "string.h"
#include "types.h"

static void print_help(int status_code) {
  puts(PACKAGE
       " " VERSION "\n\n"
       "usage: " PACKAGE " "
       "[-h] "
       "[-v] "
       "[-hr] "
       "[-s=SCREEN] "
       "[-f=DIR_PATH] "
       "[-fc=CFG_PATH] "
       "[-is=SIZE] "
       "[-t=TEMPO] "
       "[--monitor] "
       "[--demo] "
       "\n\n"
       "Fusion Of Real-time Generative Effects.\n\n"
       "options:\n"
       "  -h, --help            show this help message and exit\n"
       "  -v, --version         print version\n"
       "  -hr, --hot-reload     hot reload of shaders scripts\n"
       "  -s, --screen          output screen number (default: primary)\n"
       "  -f, --frag            fragment shaders directory (default: TODO)\n"
       "  -fc, --frag-config    fragment shaders config file (default: TODO)\n"
       "  -is, --internal-size  internal texture height (default: 720)\n"
       "  -t, --tempo           base tempo (default: 60)\n"
       "  -m, --monitor             output monitor\n"
       "  --demo                demonstration mode\n");
  exit(status_code);
}

static void invalid_arg(char *arg) {
  log_error("invalid argument: '%s'", arg);
  print_help(EXIT_FAILURE);
}

static void invalid_value(char *arg, char *value) {
  log_error("invalid value for argument '%s': '%s'", arg, value);
  print_help(EXIT_FAILURE);
}

static bool is_arg(char *arg, char *ref) { return strcoll(arg, ref) == 0; }

static char *split_arg_value(char *arg) {
  strtok(arg, "=");
  return strtok(NULL, "=");
}

static unsigned int parse_uint(char *arg, char *value) {
  if (!string_is_number(value)) {
    invalid_value(arg, value);
  }
  unsigned long long tmp_value = (unsigned long long)atoll(value);
  if (tmp_value >= UINT_MAX) {
    invalid_value(arg, value);
  }
  return (unsigned int)tmp_value;
}

Parameters args_parse(int argc, char **argv) {
  Parameters params;
  int i;
  char *arg;
  char *value;

  params.hot_reload = false;
  params.screen = 0;
  params.frag_path = 0;
  params.frag_config_path = 0;
  params.internal_size = 720;
  params.base_tempo = 60.0f;
  params.monitor = false;
  params.demo = false;

  for (i = 1; i < argc; i++) {
    arg = argv[i];
    value = split_arg_value(arg);
    if (is_arg(arg, "-h") || is_arg(arg, "--help")) {
      print_help(EXIT_SUCCESS);
    } else if (is_arg(arg, "-v") || is_arg(arg, "--version")) {
      puts(PACKAGE " " VERSION);
      exit(EXIT_SUCCESS);
    } else if (is_arg(arg, "-hr") || is_arg(arg, "--hot-reload")) {
      params.hot_reload = true;
    } else if (is_arg(arg, "-s") || is_arg(arg, "--screen")) {
      params.screen = parse_uint(arg, value);
    } else if (is_arg(arg, "-f") || is_arg(arg, "--frag")) {
      params.frag_path = value;
    } else if (is_arg(arg, "-fc") || is_arg(arg, "--frag-config")) {
      params.frag_config_path = value;
    } else if (is_arg(arg, "-t") || is_arg(arg, "--tempo")) {
      params.base_tempo = (float)parse_uint(arg, value);
    } else if (is_arg(arg, "-is") || is_arg(arg, "--internal-size")) {
      params.internal_size = (float)parse_uint(arg, value);
    } else if (is_arg(arg, "--monitor")) {
      params.monitor = true;
    } else if (is_arg(arg, "--demo")) {
      params.demo = true;
    } else {
      invalid_arg(arg);
    }
  }

  if (params.frag_path == 0) {
    log_error("required argument -f/--frag");
    exit(EXIT_FAILURE);
  }

  if (params.frag_path == 0) {
    log_error("required argument -fc/--frag-config");
    exit(EXIT_FAILURE);
  }

  return params;
}