#include <ctype.h>     // for iscntrl
#include <stdio.h>     // for NULL
#include <stdlib.h>    // for free
#include <unistd.h>    // for STDOUT_FILENO

#include "input.h"
#include "file.h"      // for editorSave
#include "fn.h"        // for E, editorConfig, erow, CTRL_KEY, editorKey::AR...
#include "output.h"    // for editorSetStatusMessage, editorDelChar, editorI...
#include "search.h"    // for editorSearch
#include "terminal.h"  // for editorReadKey


char *editorPrompt(char *prompt, void (*callback)(char *, int)) {
  size_t bufsize = 128;
  char *buf = malloc(bufsize);

  size_t buflen = 0;
  buf[0] = '\0';

  while (1) {
    editorSetStatusMessage(prompt, buf);
    editorRefreshScreen();

    int c = editorReadKey();
    if (c == DEL_KEY || c == CTRL_KEY('h') || c == BACKSPACE) {
      if (buflen != 0) buf[--buflen] = '\0';
    } else if (c == '\x1b') {
      editorSetStatusMessage("");
      if (callback) callback(buf, c);
      free(buf);
      return NULL;
    } else if (c == '\r') {
      if (buflen != 0) {
        editorSetStatusMessage("");
        if (callback) callback(buf, c);
        return buf;
      }
    } else if (!iscntrl(c) && c < 128) {
      if (buflen == bufsize -1) {
        bufsize *= 2;
        buf = realloc(buf, bufsize);
      }
      buf[buflen++] = c;
      buf[buflen] = '\0';
    }
    
    if (callback) callback(buf, c);
  }
}

void editorMoveCursor(int key) {
  erow *row = (E.cy >= E.numrows) ? NULL : &E.row[E.cy];

  switch (key) {
    case ARROW_LEFT:
      if (E.cx != 0) {
        E.cx--;
      } else if (E.cy > 0) {
        E.cy--;
        E.cx = E.row[E.cy].size;
      }
      break;
    case ARROW_RIGHT:
      if (row && E.cx < row->size) {
        E.cx++;
      } else if (row && E.cx == row->size) {
        E.cy++;
        E.cx = 0;
      }
      break;
    case ARROW_UP:
      if (E.cy != 0) {
        E.cy--;
      }
      break;
    case ARROW_DOWN:
      if (E.cy < E.numrows) {
        E.cy++;
      }
      break;
  }

  row = (E.cy >= E.numrows) ? NULL : &E.row[E.cy];
  int rowlen = row ? row->size : 0;
  if (E.cx > rowlen) {
    E.cx = rowlen;
  }
}

void editorProcessKeypress() {
  static int wantToQuit = 0;
  int c = editorReadKey(); // Blocking!

  switch (c) {
    case '\r': // ENTER
      if (wantToQuit == 0) {
        editorInsertNewLine();
      } else {
        editorSetStatusMessage("");
      }
      break;

    case CTRL_KEY('c'):
      if (E.dirty) {
        editorSetStatusMessage("WARNING: Unsaved changes. Exit anyway? [y/N]");
        wantToQuit = 1;
        return;
      }
      exitEditor();
      break;

    // Special cases if the user want to quit
    // TODO: Make a "question mode" with a callback for y and n
    case 'y':
      if (wantToQuit == 0) {
        editorInsertChar(c);
      } else {
        exitEditor();
      }
      break;

    case CTRL_KEY('s'):
      editorSave();
      break;

    case HOME_KEY:
      E.cx = 0;
      break;

    case END_KEY:
      if (E.cy < E.numrows) {
        E.cx = E.row[E.cy].size;
      }
      break;

    case CTRL_KEY('f'):
      editorSearch();
      break;

    case BACKSPACE:
    case CTRL_KEY('h'):
    case DEL_KEY:
      if (c == DEL_KEY) editorMoveCursor(ARROW_RIGHT);
      editorDelChar();
      break;

    case PAGE_UP:
    case PAGE_DOWN:
      {
        if (c == PAGE_UP) {
          E.cy = E.rowoff;
        } else if (c == PAGE_DOWN) {
          E.cy = E.rowoff + E.screenrows - 1;
          if (E.cy > E.numrows) E.cy = E.numrows;
        }
        int times = E.screenrows;
        while(times--)
          editorMoveCursor(c == PAGE_UP ? ARROW_UP : ARROW_DOWN);
      }
      break;
    case ARROW_UP:
    case ARROW_DOWN:
    case ARROW_LEFT:
    case ARROW_RIGHT:
      editorMoveCursor(c);
      break;

    case CTRL_KEY('l'):
    case '\x1b': // ESC
      break;

    default:
      if (wantToQuit == 1) {
        wantToQuit = 0;
        editorSetStatusMessage("");
      } else {
        editorInsertChar(c);
      }
      break;
  }

  wantToQuit = 0;
}