/*
 * This file is the general header file for all parts of the MicroEMACS
 * display editor. It contains definitions used by everyone, and it contains
 * the stuff you have to edit to create a version of the editor for a specific
 * operating system and terminal.
 */

/* #define AMIGA   1                       /* AmigaDOS, Lattice            */
/* #define ST520   0                       /* ST520, TOS                   */
/* #define MWC86   0
/* #define V7      0                       /* V7 UN*X or Coherent          */
/* #define VMS     0                       /* VAX/VMS                      */
/* #define CPM     0                       /* CP/M-86                      */
/* #define OS9     1                       /* os9/6809 level 1 (coco)      */
/* #define OSK     1                       /* os9/68000 predefined         */
/* #define MSDOS   0                       /* MS-DOS predefined            */

/* #define ANSI    1                       /* ANSI terminal (Vt100)        */
/* #define VT52    1                       /* VT52 terminal (Zenith).      */
/* #define VT100   0                       /* Handle VT100 style keypad.   */
/* #define LK201   0                       /* Handle LK201 style keypad.   */
/* #define RAINBOW 0                       /* Use Rainbow fast video.      */
/* #define TERMCAP 0                       /* Use TERMCAP                  */

#define CVMVAS  1                       /* C-V, M-V arg. in screens.    */

#define NFILEN  80                      /* # of bytes, file name        */
#define NBUFN   16                      /* # of bytes, buffer name      */
#define NLINE   256                     /* # of bytes, line             */
#define NKBDM   256                     /* # of strokes, keyboard macro */
#define NPAT    80                      /* # of bytes, pattern          */
#define HUGE    1000                    /* Huge number                  */

#define AGRAVE  0x60                    /* M- prefix,   Grave (LK201)   */
#define METACH  0x1B                    /* M- prefix,   Control-[, ESC  */
#define CTMECH  0x1C                    /* C-M- prefix, Control-\       */
#define EXITCH  0x1D                    /* Exit level,  Control-]       */
#define CTRLCH  0x1E                    /* C- prefix,   Control-^       */
#define HELPCH  0x1F                    /* Help key,    Control-_       */

#define CTRL    0x0100                  /* Control flag, or'ed in       */
#define META    0x0200                  /* Meta flag, or'ed in          */
#define CTLX    0x0400                  /* ^X flag, or'ed in            */

#define FALSE   0                       /* False, no, bad, etc.         */
#define TRUE    1                       /* True, yes, good, etc.        */
#define ABORT   2                       /* Death, ^G, abort, etc.       */

#define FIOSUC  0                       /* File I/O, success.           */
#define FIOFNF  1                       /* File I/O, file not found.    */
#define FIOEOF  2                       /* File I/O, end of file.       */
#define FIOERR  3                       /* File I/O, error.             */

#define CFCPCN  0x0001                  /* Last command was C-P, C-N    */
#define CFKILL  0x0002                  /* Last command was a kill      */

/*
 * There is a window structure allocated for every active display window. The
 * windows are kept in a big list, in top to bottom screen order, with the
 * listhead at "wheadp". Each window contains its own values of dot and mark.
 * The flag field contains some bits that are set by commands to guide
 * redisplay; although this is a bit of a compromise in terms of decoupling,
 * the full blown redisplay is just too expensive to run for every input
 * character. 
 */
typedef struct  WINDOW {
        struct  WINDOW *w_wndp;         /* Next window                  */
        struct  BUFFER *w_bufp;         /* Buffer displayed in window   */
        struct  LINE *w_linep;          /* Top line in the window       */
        struct  LINE *w_dotp;           /* Line containing "."          */
        short   w_doto;                 /* Byte offset for "."          */
        struct  LINE *w_markp;          /* Line containing "mark"       */
        short   w_marko;                /* Byte offset for "mark"       */
        char    w_toprow;               /* Origin 0 top row of window   */
        char    w_ntrows;               /* # of rows of text in window  */
        char    w_force;                /* If NZ, forcing row.          */
        char    w_flag;                 /* Flags.                       */
}       WINDOW;

#define WFFORCE 0x01                    /* Window needs forced reframe  */
#define WFMOVE  0x02                    /* Movement from line to line   */
#define WFEDIT  0x04                    /* Editing within a line        */
#define WFHARD  0x08                    /* Better to a full display     */
#define WFMODE  0x10                    /* Update mode line.            */

/*
 * Text is kept in buffers. A buffer header, described below, exists for every
 * buffer in the system. The buffers are kept in a big list, so that commands
 * that search for a buffer by name can find the buffer header. There is a
 * safe store for the dot and mark in the header, but this is only valid if
 * the buffer is not being displayed (that is, if "b_nwnd" is 0). The text for
 * the buffer is kept in a circularly linked list of lines, with a pointer to
 * the header line in "b_linep".
 */
typedef struct  BUFFER {
        struct  BUFFER *b_bufp;         /* Link to next BUFFER          */
        struct  LINE *b_dotp;           /* Link to "." LINE structure   */
        short   b_doto;                 /* Offset of "." in above LINE  */
        struct  LINE *b_markp;          /* The same as the above two,   */
        short   b_marko;                /* but for the "mark"           */
        struct  LINE *b_linep;          /* Link to the header LINE      */
        char    b_nwnd;                 /* Count of windows on buffer   */
        char    b_flag;                 /* Flags                        */
        char    b_fname[NFILEN];        /* File name                    */
        char    b_bname[NBUFN];         /* Buffer name                  */
}       BUFFER;

#define BFTEMP  0x01                    /* Internal temporary buffer    */
#define BFCHG   0x02                    /* Changed since last write     */

/*
 * The starting position of a region, and the size of the region in
 * characters, is kept in a region structure.  Used by the region commands.
 */
typedef struct  {
        struct  LINE *r_linep;          /* Origin LINE address.         */
        short   r_offset;               /* Origin LINE offset.          */
        short   r_size;                 /* Length in characters.        */
}       REGION;

/*
 * All text is kept in circularly linked lists of "LINE" structures. These
 * begin at the header line (which is the blank line beyond the end of the
 * buffer). This line is pointed to by the "BUFFER". Each line contains a the
 * number of bytes in the line (the "used" size), the size of the text array,
 * and the text. The end of line is not stored as a byte; it's implied. Future
 * additions will include update hints, and a list of marks into the line.
 */
typedef struct  LINE {
        struct  LINE *l_fp;             /* Link to the next line        */
        struct  LINE *l_bp;             /* Link to the previous line    */
        short   l_size;                 /* Allocated size               */
        short   l_used;                 /* Used size                    */
        char    l_text[1];              /* A bunch of characters.       */
}       LINE;

#define lforw(lp)       ((lp)->l_fp)
#define lback(lp)       ((lp)->l_bp)
#define lgetc(lp, n)    ((lp)->l_text[(n)]&0xFF)
#define lputc(lp, n, c) ((lp)->l_text[(n)]=(c))
#define llength(lp)     ((lp)->l_used)

/*
 * The editor communicates with the display using a high level interface. A
 * "TERM" structure holds useful variables, and indirect pointers to routines
 * that do useful operations. The low level get and put routines are here too.
 * This lets a terminal, in addition to having non standard commands, have
 * funny get and put character code too. The calls might get changed to
 * "termp->t_field" style in the future, to make it possible to run more than
 * one terminal type.
 */  
typedef struct  {
        short   t_nrow;                 /* Number of rows.              */
        short   t_ncol;                 /* Number of columns.           */
        int     (*t_open)();            /* Open terminal at the start.  */
        int     (*t_close)();           /* Close terminal at end.       */
        int     (*t_getchar)();         /* Get character from keyboard. */
        int     (*t_putchar)();         /* Put character to display.    */
        int     (*t_flush)();           /* Flush output buffers.        */
        int     (*t_move)();            /* Move the cursor, origin 0.   */
        int     (*t_eeol)();            /* Erase to end of line.        */
        int     (*t_eeop)();            /* Erase to end of page.        */
        int     (*t_beep)();            /* Beep.                        */
}       TERM;

extern  int     fillcol;                /* Fill column                  */
extern  int     currow;                 /* Cursor row                   */
extern  int     curcol;                 /* Cursor column                */
extern  int     thisflag;               /* Flags, this command          */
extern  int     lastflag;               /* Flags, last command          */
extern  int     curgoal;                /* Goal for C-P, C-N            */
extern  int     mpresf;                 /* Stuff in message line        */
extern  int     sgarbf;                 /* State of screen unknown      */
extern  WINDOW  *curwp;                 /* Current window               */
extern  BUFFER  *curbp;                 /* Current buffer               */
extern  WINDOW  *wheadp;                /* Head of list of windows      */
extern  BUFFER  *bheadp;                /* Head of list of buffers      */
extern  BUFFER  *blistp;                /* Buffer for C-X C-B           */
extern  short   kbdm[];                 /* Holds kayboard macro data    */
extern  short   *kbdmip;                /* Input pointer for above      */
extern  short   *kbdmop;                /* Output pointer for above     */
extern  char    pat[];                  /* Search pattern               */
extern  TERM    term;                   /*(Terminal information.        */

extern  BUFFER  *bfind();               /* Lookup a buffer by name      */
extern  WINDOW  *wpopup();              /* Pop up window creation       */
extern  LINE    *lalloc();              /* Allocate a line              */