#include <fcntl.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

#define PIPE_PATH "/tmp/tsarc.pipe"
#define STACK_LEN(arr) (sizeof(arr)/sizeof(arr[0]))

const char help_text[] =
  "usage: tsarc [command] ...\n"
  "commands:\n"
  "\tconfig - configure tsarbar settings\n"
  "\tset - set component data and options\n"
  "\tlayout - define the layout of the bar\n"
  "\n"
  "config:\n"
  "usage: tsarc config (-[property] [value] ...)\n"
  "\t-height - height of the bar, in pixels\n"
  "\t-font - font to use\n"
  "\t-gap - gap between components, in pixels\n"
  "\t-foreground, -fg - foreground color, as a hex code (e.g. #FFAA44)\n"
  "\t-background, -bg - background color, as a hex code (e.g. #FFAA44)\n"
  "\n"
  "set:\n"
  "usage: tsarc set [variable] (-[property] [value] ...)\n"
  "\t-text - text of the component\n"
  "\t-fg - foreground color, as a hex code (e.g. #FFAA44)\n"
  "\t-bg - background color, as a hex code (e.g. #FFAA44)\n"
  "\t-margin-left - margin to the left, in pixels\n"
  "\t-margin-right - margin to the right, in pixels\n"
  "\t-margin - sets both -margin-left and -margin-right\n"
  "\n"
  "layout:\n"
  "usage: tsarc layout (-[side] [component list] ...)\n"
  "\t-left, -center, -right - valid sides\n"
;

const char *valid_config_properties[] = {
  "-height",
  "-font",
  "-gap",
  "-fg",
  "-bg",
  "-foreground",
  "-background",
};

const char *valid_set_properties[] = {
  "-text",
  "-fg",
  "-bg",
  "-margin-left",
  "-margin-right",
  "-margin",
};

void show_help(FILE* file) {
  fputs(help_text, file);
}

bool verify_argument_spelling(const char* arg, const char** valid, int validc) {
  for (int i = 0; i < validc; i++) {
    if (strcmp(arg, valid[i]) == 0) {
      return true;
    }
  }
  return false;
}

void die(const char* fmt, ...) {
  va_list args;
  va_start(args, fmt);
  vfprintf(stderr, fmt, args);
  va_end(args);

  putc('\n', stderr);

  show_help(stderr);

  exit(1);
}

int main(int argc, const char* argv[]) {
  if (argc < 2) {
    die("error: missing a command");
  }

  const char* cmd = argv[1];

  if (strcmp(cmd, "-h") == 0 || strcmp(cmd, "--help") == 0) {
    show_help(stdout);
    return 0;
  }

  if (strcmp(cmd, "config") == 0) {
    if (argc < 3) {
      die("error: missing a config property");
    }

    verify_argument_spelling(
      argv[2],
      valid_config_properties,
      STACK_LEN(valid_config_properties)
    );
  }
  if (strcmp(cmd, "set") == 0) {
    if (argc < 3) {
      die("error: missing a component name");
    }
    if (argc < 4) {
      die("error: missing a component property");
    }

    verify_argument_spelling(
      argv[3],
      valid_set_properties,
      STACK_LEN(valid_set_properties)
    );
  }

  int cmd_len = 0;
  for (int i = 1; i < argc; i++) {
    cmd_len += strlen(argv[i]);
  }
  
  cmd_len += argc;
  char* cmd_str = (char*)malloc(sizeof(char) * (cmd_len + 1));

  int start = 0;
  for (int i = 1; i < argc; i++) {
    size_t arg_len = strlen(argv[i]);
    memcpy(cmd_str + start, argv[i], arg_len);
    cmd_str[start + arg_len] = '\201';
    start += arg_len + 1;
  }

  cmd_str[cmd_len-1] = '\n';
  cmd_str[cmd_len] = '\0';
  
  mkfifo(PIPE_PATH, 0666);
  FILE* named_pipe = fopen(PIPE_PATH, "w");

  fwrite(cmd_str, sizeof(char), cmd_len, named_pipe);

  fclose(named_pipe);

  return 0;
}