#ifndef NVIM_UNDO_DEFS_H
#define NVIM_UNDO_DEFS_H

#include <time.h>  // for time_t

#include "nvim/extmark_defs.h"
#include "nvim/mark_defs.h"
#include "nvim/pos.h"

typedef struct u_header u_header_T;

// Structure to store info about the Visual area.
typedef struct {
  pos_T vi_start;               // start pos of last VIsual
  pos_T vi_end;                 // end position of last VIsual
  int vi_mode;                  // VIsual_mode of last VIsual
  colnr_T vi_curswant;          // MAXCOL from w_curswant
} visualinfo_T;

#include "nvim/buffer_defs.h"

typedef struct u_entry u_entry_T;
struct u_entry {
  u_entry_T *ue_next;         // pointer to next entry in list
  linenr_T ue_top;              // number of line above undo block
  linenr_T ue_bot;              // number of line below undo block
  linenr_T ue_lcount;           // linecount when u_save called
  char_u **ue_array;       // array of lines in undo block
  long ue_size;                 // number of lines in ue_array
#ifdef U_DEBUG
  int ue_magic;                 // magic number to check allocation
#endif
};

struct u_header {
  /* The following have a pointer and a number. The number is used when
   * reading the undo file in u_read_undo() */
  union {
    u_header_T *ptr;            // pointer to next undo header in list
    long seq;
  } uh_next;
  union {
    u_header_T *ptr;            // pointer to previous header in list
    long seq;
  } uh_prev;
  union {
    u_header_T *ptr;            // pointer to next header for alt. redo
    long seq;
  } uh_alt_next;
  union {
    u_header_T *ptr;            // pointer to previous header for alt. redo
    long seq;
  } uh_alt_prev;
  long uh_seq;                  // sequence number, higher == newer undo
  int uh_walk;                  // used by undo_time()
  u_entry_T *uh_entry;        // pointer to first entry
  u_entry_T *uh_getbot_entry;   // pointer to where ue_bot must be set
  pos_T uh_cursor;              // cursor position before saving
  long uh_cursor_vcol;
  int uh_flags;                 // see below
  fmark_T uh_namedm[NMARKS];    // marks before undo/after redo
  extmark_undo_vec_t uh_extmark;  // info to move extmarks
  visualinfo_T uh_visual;       // Visual areas before undo/after redo
  time_t uh_time;               // timestamp when the change was made
  long uh_save_nr;              // set when the file was saved after the
                                // changes in this block
#ifdef U_DEBUG
  int uh_magic;                 // magic number to check allocation
#endif
};

// values for uh_flags
#define UH_CHANGED  0x01        // b_changed flag before undo/after redo
#define UH_EMPTYBUF 0x02        // buffer was empty
#define UH_RELOAD   0x04        // buffer was reloaded

/// Structure passed around between undofile functions.
typedef struct {
  buf_T *bi_buf;
  FILE *bi_fp;
} bufinfo_T;

#endif // NVIM_UNDO_DEFS_H