#include "arena_alloc.h"
#include "context.h"
#include "gapbuffer.h"
#include "interp.h"
#include "mprintf.h"
#include "self.h"
#include "strbuf.h"
#include <arena.h>
#include <kb.h>
#include <list.h>
#include <printf.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <system.h>
#include <tcursor.h>
#include <tscreen.h>

#define LINE_INIT_MAX 2
#define PROMPT        "$ "

struct edit_line {
  struct gapbuffer gb;
  size_t cursor;
};

static void exec_line (const char* line) {
  struct list_node_link* tokens = NULL;

  tokenize (&tokens, line);

  if (tokens != NULL)
    parse_and_execute (tokens);
}

void app_main (void) {
  e_pid = get_exec_pid ();
  e_pgid = get_procgroup (e_pid);

  struct edit_line edit_line;

  const char* render = NULL;

  while (interp_is_running ()) {
    gapbuffer_init (&edit_line.gb, LINE_INIT_MAX);
    edit_line.cursor = 0;

    mprintf (PROMPT);

    uint8_t ch = 0;
    for (;;) {
      mail_receive (&ch, 1);

      if (ch == '\n')
        break;

      switch (ch) {
      case '\b':
        if (edit_line.cursor > 0) {
          gapbuffer_backspace (&edit_line.gb);
          edit_line.cursor--;

          mprintf ("\b");

          char* tail = gapbuffer_string_at (&edit_line.gb, edit_line.cursor);
          mprintf ("%s" ANSIQ_SCR_CLR2END, tail);

          int move_back = (int)strlen (tail);
          if (move_back > 0)
            mprintf (ANSIQ_DYN_CUR_LEFT, move_back);
        }
        break;
      case KB_LEFT:
        if (edit_line.cursor > 0) {
          edit_line.cursor--;
          mprintf (ANSIQ_CUR_LEFT (1));
        }
        break;
      case KB_RIGHT:
        if (edit_line.cursor < gapbuffer_length (&edit_line.gb)) {
          edit_line.cursor++;
          mprintf (ANSIQ_CUR_RIGHT (1));
        }
        break;
      default:
        if (isascii (ch)) {
          gapbuffer_insert (&edit_line.gb, ch);
          edit_line.cursor++;

          char* tail = gapbuffer_string_at (&edit_line.gb, edit_line.cursor - 1);
          mprintf ("%s" ANSIQ_SCR_CLR2LEND, tail);

          int move_back = (int)strlen (tail) - 1;
          if (move_back > 0)
            mprintf (ANSIQ_DYN_CUR_LEFT, move_back);
        }
        break;
      }

      gapbuffer_move (&edit_line.gb, edit_line.cursor);
    }

    mprintf ("\n");

    render = gapbuffer_get_string (&edit_line.gb);

    if (render != NULL)
      exec_line (render);

    gapbuffer_fini (&edit_line.gb);
    arena_reset (&arena);
  }

  arena_destroy (&arena);
}