#include "shell.h"

char** s_completion(const char* text, int start, int end) {
  rl_attempted_completion_over = 1;
  return rl_completion_matches(text, s_names);
}

void s_die(const char* msg) {
  fprintf(stderr, "s: %s\n", msg);
  exit(1);
}

int s_do(char **args) {
  pid_t pid, wpid;
  int s;

  pid = fork();
  if (!pid) {
    if (execvp(args[0], args) == -1) perror(args[0]);
    exit(EXIT_FAILURE);
  } else if (pid < 0) {
    // Error forking
    perror(args[0]);
  } else {
    do {
      wpid = waitpid(pid, &s, WUNTRACED);
    } while (!WIFEXITED(s) && !WIFSIGNALED(s));
  }

  return 1;
}


char** s_prompt() {
  char* line = readline("> ");
  int bs = 64;
  int pos = 0;
  char **tokens = malloc(bs * sizeof(char*));
  char *token;


  if (!line) return NULL;

  add_history(line);

  if (!tokens) s_die("allocation error");

  token = strtok(line, " \t\r\n\a");

  while (token) {
    tokens[pos++] = token;

    if (pos >= bs) {
      bs += 64;
      tokens = realloc(tokens, bs * sizeof(char*));
      if (!tokens) s_die("allocation error");
    }

    token = strtok(NULL, " \t\r\n\a");
  }
  tokens[pos] = NULL;

  free(line);
  return tokens;
}

int s_exec(char** args) {
  int i;

  if (!args[0]) return 1;

  for (i = 0; i < s_builtins_count(); i++) {
    if (!strcmp(args[0], s_builtin_names[i])) return (*s_builtins[i])(args);
  }

  return s_do(args);
}

void s_loop() {
  rl_attempted_completion_function = s_completion;

  char** cmd;
  int s;

  do {
    cmd = s_prompt();
    if(!cmd) return;
    s = s_exec(cmd);
    free(cmd);
  } while(s);
}