#include "config.h"
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include "tty.h"
#include "sys/ttysize.h"
#include "export.h"
#include "charsets.h"
#include "wcwidth.h"

struct vtvt_data
{
    FILE *f;
    int sx,sy;

    uint64_t attr;
    int cx,cy;
};

#define DATA ((struct vtvt_data*)(vt->l_data))
#define SX      DATA->sx
#define SY      DATA->sy
#define CX      DATA->cx
#define CY      DATA->cy

static void print_color(FILE *f, uint32_t c, int bg)
{
    switch (c&VT100_ATTR_COLOR_TYPE)
    {
    case 1<<24:
        if (c&8)
            fprintf(f, ";%d%u", 9+bg, c&7);
        else
            fprintf(f, ";%d%u", 3+bg, c&7);
        break;
    case 2<<24:
        fprintf(f, ";%d8;5;%u", 3+bg, c&0xff);
        break;
    case 3<<24:
        fprintf(f, ";%d8;2;%u;%u;%u", 3+bg, (c>>16)&0xff, (c>>8)&0xff, c&0xff);
    }
}

static void setattr(tty vt, uint64_t attr)
{
    if (DATA->attr==attr)
        return;

    DATA->attr=attr;
    fprintf(DATA->f, "\e[0");
    if (attr&VT100_ATTR_BOLD)
        fprintf(DATA->f, ";1");
    if (attr&VT100_ATTR_DIM)
        fprintf(DATA->f, ";2");
    if (attr&VT100_ATTR_ITALIC)
        fprintf(DATA->f, ";3");
    if (attr&VT100_ATTR_UNDERLINE)
        fprintf(DATA->f, ";4");
    if (attr&VT100_ATTR_BLINK)
        fprintf(DATA->f, ";5");
    if (attr&VT100_ATTR_INVERSE)
        fprintf(DATA->f, ";7");
    if (attr&VT100_ATTR_STRIKE)
        fprintf(DATA->f, ";9");
    print_color(DATA->f, attr, 0);
    print_color(DATA->f, attr>>32, 1);
    fprintf(DATA->f, "m");
}

static void vtvt_cursor(tty vt, int x, int y)
{
    if (x==CX && y==CY)
        return;
    fprintf(DATA->f, "\e[%d;%df", y+1, x+1);
    CX=x;
    CY=y;
}

#define MAXVT100GRAPH 0x2666 // biggest codepoint is U+2666 BLACK DIAMOND
static char *vt100graph = 0;
static void build_vt100graph(void)
{
    int i;

    /* the reverse mapping Unicode->tty_graphic takes a chunk of memory, so
       build it only on demand.  This won't happen most of the time. */
    if (!(vt100graph=malloc(MAXVT100GRAPH+1)))
        abort();
    memset(vt100graph, 0, MAXVT100GRAPH+1);
    for (i=32; i<127; i++)
        if (charset_vt100[i]<=MAXVT100GRAPH)
            vt100graph[charset_vt100[i]]=i;
}

static void vtvt_char(tty vt, int x, int y, ucs ch, uint64_t attr, int width)
{
    if (x>=SX || y>SY)
        return;
    if (x!=CX || y!=CY)
        vtvt_cursor(vt, x, y);
    setattr(vt, attr);
    if (fprintf(DATA->f, "%lc", ch)<0)
    {
        clearerr(DATA->f); // required on BSD
        if (width==2)
            fprintf(DATA->f, "??"); // nothing is wide in cp437
        else if (vt->cp437)
        {
            if (!vt100graph)
                build_vt100graph();
            if (ch<=MAXVT100GRAPH && vt100graph[ch])
                fprintf(DATA->f, "\016%c\017", vt100graph[ch]);
            else
                fprintf(DATA->f, "?");
        }
        else
            fprintf(DATA->f, "?");
    }
    CX++;
}

static void vtvt_comb(tty vt, int x, int y, ucs ch, uint64_t attr)
{
    if (x>=SX || y>SY)
        return;
    if (x+1!=CX || y!=CY) // cursor should be _after_ the glyph
        vtvt_cursor(vt, x+1, y);
    setattr(vt, attr);
    if (fprintf(DATA->f, "%lc", ch)<0)
        clearerr(DATA->f); // No fallback, just ignore.
}

export void vtvt_dump(tty vt)
{
    int x,y;
    attrchar *ch;

    ch=vt->scr;
    for (y=0; y<vt->sy; y++)
    {
        for (x=0; x<vt->sx; x++)
        {
            if (ch->ch != VT100_CJK_RIGHT)
                vtvt_char(vt, x, y, ch->ch, ch->attr, mk_wcwidth(ch->ch));
            ch++;
        }
    }
    vtvt_cursor(vt, vt->cx, vt->cy);
}

static void vtvt_clear(tty vt, int x, int y, int len)
{
    int c;

    setattr(vt, vt->attr);
    if (x==0 && y==0 && len==SX*SY)
        fprintf(DATA->f, "\e[2J");
    else if (x==0 && y==0 && len==CY*SX+CX)
        fprintf(DATA->f, "\e[1J");
    else if (x==CX && y==CY && len==SX*SY-CY*SX-CX)
        fprintf(DATA->f, "\e[0J");
    else if (x==0 && y==CY && len==SX)
        fprintf(DATA->f, "\e[2K");
    else if (x==0 && y==CY && len==CX)
        fprintf(DATA->f, "\e[1K");
    else if (x==CX && y==CY && len==SX-CX)
        fprintf(DATA->f, "\e[0K");
    else
        while (len)
        {
            vtvt_cursor(vt, x, y);
            c=(len>SX-x)? SX-x : len;
            fprintf(DATA->f, "\e[%dX", c);
            len-=c;
            x=0;
            y++;
        }
    vtvt_cursor(vt, vt->cx, vt->cy);
}

static void vtvt_scroll(tty vt, int nl)
{
    if (nl>0)
        fprintf(DATA->f, "\e[0m\e[%d;%dr\e[%d;1f\e[%dM\e[r", vt->s1+1, vt->s2, vt->s1+1, nl);
    else if (nl<0)
        fprintf(DATA->f, "\e[0m\e[%d;%dr\e[%d;1f\e[%dL\e[r", vt->s1+1, vt->s2, vt->s1+1, -nl);
    CX=CY=-1;
    DATA->attr=0;

//  vtvt_dump(vt);
}

static void vtvt_flag(tty vt, int f, int v)
{
    // TODO: invisible cursor
}

static void vtvt_osc(tty vt, int cmd, const char *str)
{
    // don't passthrough unknown commands
    if (cmd==0) // set window title
        fprintf(DATA->f, "\e]0;%s\e\\", str);
}

static void vtvt_resized(tty vt, int sx, int sy)
{
    fprintf(DATA->f, "\e[8;%u;%ut", sy, sx);
}

static void vtvt_flush(tty vt)
{
    fflush(DATA->f);
}

static void vtvt_bell(tty vt)
{
    putc('\a', DATA->f);
}

static void vtvt_free(tty vt)
{
    free(vt->l_data);
}

export void vtvt_resize(tty vt, int sx, int sy)
{
    SX=sx; SY=sy;
}

export void vtvt_attach(tty vt, FILE *f, int dump)
{
    vt->l_data=malloc(sizeof(struct vtvt_data));
    CX=CY=-1;
    DATA->attr=-1;
    DATA->f=f;

    SX=80; SY=25;
    get_tty_size(fileno(f), &SX, &SY);

    vt->l_char=vtvt_char;
    vt->l_comb=vtvt_comb;
    vt->l_cursor=vtvt_cursor;
    vt->l_clear=vtvt_clear;
    vt->l_scroll=vtvt_scroll;
    vt->l_flag=vtvt_flag;
    vt->l_osc=vtvt_osc;
    vt->l_resize=vtvt_resized;
    vt->l_flush=vtvt_flush;
    vt->l_bell=vtvt_bell;
    vt->l_free=vtvt_free;

    if (dump)
    {
        fprintf(DATA->f, "\ec");
        vtvt_dump(vt);
        fflush(stdout);
    }
}