#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "arg.h"
#include "file.h"
#include "util.h"

#define INVERT_T "\x1b[7m"
#define UINVERT_T "\x1b[27m"
#define GREY "\x1b[90m"
#define RESET "\x1b[0m"

void run(FILE *fp, char *filename, bool tty) {
  const char *invert_t = conf.color ? INVERT_T : "";
  const char *uinvert_t = conf.color ? UINVERT_T : "";
  const char *grey = conf.color ? GREY : "";
  const char *reset = conf.color ? RESET : "";

  struct filedata f;
  f = readfile(fp);

  if (tty) {
    char *addon = f.binary ? "<binary>" : "";
    fprintf(stderr, "\r\x1b[2K%s%s%s%s\r\n", invert_t, basename(filename),
            addon, uinvert_t);
  }

  int lcpad = intlen(f.lc);

  f.lc = 0;
  char pc = '\0';
  char c;
  for (size_t i = 0; i < f.len; i++) {
    c = f.buf[i];

    if ((conf.lines && tty && !f.binary) && (pc == '\n' || i == 0)) {
      f.lc++;

      int padlen = lcpad - intlen(f.lc);
      char padding[padlen];

      if (padlen)
        memset(padding, ' ', padlen);

      fprintf(stderr, "\r%s%s%d:%s ", grey, padlen > 0 ? padding : "", f.lc,
              reset); // padlen  < 1 causes undefined
    }

    pc = c;
    printf("%c", c);
  }

  fflush(stdout); // prevent timing inconsistencies between stdout and stderr

  if (tty) {
    float rounded;
    char *format = formatbytes(f.len, &rounded);

    char *cnewline = c == '\n' ? "" : "\n";
    fprintf(stderr, "\r%s%s%.2f %s%s\r\n", cnewline, invert_t, rounded, format,
            uinvert_t);
  }
}

void initconf(void) {
  conf.color = true;
  conf.lines = true;
  conf.has_read_stdin = false;
}

void clearstdin() {
  // from
  // https://stackoverflow.com/questions/7898215/how-to-clear-input-buffer-in-c
  fseek(stdin, 0, SEEK_END);
}

int main(int argc, char *argv[]) {
  initconf();

  // init no_color first so that args take priority
  char *no_color = getenv("NO_COLOR");

  if (no_color != NULL && no_color[0] != '\0') {
    conf.color = false;
  }

  bool tty = isatty(STDOUT_FILENO);
  if (argc > 1) {
    int offset = parseargs(argc, argv);
    for (int i = offset; i < argc; i++) {
      if (*argv[i] == '-') {
        if (conf.has_read_stdin)
          clearstdin();
        conf.has_read_stdin = true;
        run(stdin, "stdin", tty);
        continue;
      }

      FILE *fp = fopen(argv[i], "rb");
      if (fp == NULL)
        die(argv[i]);
      run(fp, argv[i], tty);
      fclose(fp);

      if (tty && (i + 1 != argc)) {
        fprintf(stderr, "\r\n"); // separate concurrent files in tty
      }
    }

    if (offset == argc) {
      run(stdin, "stdin", tty);
    }
  } else {
    run(stdin, "stdin", tty); // for piped-input or repl-like behavior
  }

  return EXIT_SUCCESS;
}