#include "search.h"
#include <stdio.h>   // for NULL
#include <stdlib.h>  // for free, malloc
#include <string.h>  // for memcpy, memset, strlen, strstr
#include "fn.h"      // for E, editorConfig, erow, editorPrompt, editorHighl...
#include "row.h"     // for editorRowRxToCx
#include "hl.h"      // for editorSelectSyntaxHighlight


void editorSearchCallback(char *query, int key) {
  static int last_match = -1;
  static int direction = 1;

  static int saved_hl_line;
  static char *saved_hl = NULL;

  if (saved_hl) {
    memcpy(E.row[saved_hl_line].hl, saved_hl, E.row[saved_hl_line].rsize);
    free(saved_hl);
    saved_hl = NULL;
  }
  
  if (key == '\r' || key == '\x1b') {
    last_match = -1;
    direction = 1;
    // Clean up the syntax highlighting
    editorSelectSyntaxHighlight();
    return;
  } else if (key == ARROW_RIGHT || key == ARROW_DOWN) {
    direction = 1;
  } else if (key == ARROW_LEFT || key == ARROW_UP) {
    direction = -1;
  } else {
    last_match = -1;
    direction = 1;
  }

  if (last_match == -1) direction = 1;
  int current = last_match;

  int i;
  for (i=0; i < E.numrows; i++) {
    current += direction;
    if (current == -1) current = E.numrows -1;
    else if (current == E.numrows) current = 0;

    erow *row = &E.row[current];
    char *match = strstr(row->render, query);
    if (match) {
      last_match = current;
      E.cy = current;
      E.cx = editorRowRxToCx(row, match - row->render); // Substract pointers here
      // Reposition the cursor if needed
      if (E.cy < E.rowoff) {
        E.rowoff = E.cy;
      }
      if (E.cy >= E.rowoff + E.screenrows) {
        E.rowoff = E.cy - E.screenrows + 1;
      }

      saved_hl_line = current;
      saved_hl = malloc(row->rsize);
      memcpy(saved_hl, row->hl, row->rsize);
      memset(&row->hl[match - row->render], HL_MATCH, strlen(query));
      break;
    }
  }
}

void editorSearch() {
  int saved_cx = E.cx;
  int saved_cy = E.cy;
  int saved_coloff = E.coloff;
  int saved_rowoff = E.rowoff;

  char *query = editorPrompt("Search (Use Arrows/ESC/Enter): %s", editorSearchCallback);
  if (query) {
    free(query);
  } else {
    E.cx = saved_cx;
    E.cy = saved_cy;
    E.coloff = saved_coloff;
    E.rowoff = saved_rowoff;
  }
}