#include "virtterm.h"
#include "boot/cmdline.h"
#include "boot/initrd.h"
#include "hal/obj.h"
#include "init.h"
#include "jove.h"
#include "hal/framebuffer.h"
#include "lib/printf.h"
#include "lib/psf.h"
#include "lib/string.h"

struct psf1_header *s_font = NULL;

struct virtterm s_init_vtty = { 0 };

static void
vt_blit(struct virtterm *vtty, jove_owned_obj_t *fb, const uint8_t *glyph)
{
    uint32_t buffer[s_font->char_height << 3];
    size_t cursor_x = vtty->cursor_col * 9;
    size_t cursor_y = vtty->cursor_row * s_font->char_height;

    for(size_t y = 0; y < s_font->char_height; y++) {
        uint8_t mask = 1 << 7;
        for(size_t x = 0; x < 8; x++) {
            buffer[x + (y << 3)] = glyph[y] & mask ? vtty->cursor_fg : vtty->cursor_bg;
            mask >>=1;
        }
    }
    fb_blit(fb, buffer, cursor_x, cursor_y, 8, s_font->char_height);
    vtty->cursor_col++;
}

static void
vt_putc(struct virtterm *vtty, jove_owned_obj_t *fb, char c)
{
    const uint8_t *glyph = &s_font->bitmap[(size_t)c * s_font->char_height];
    
    switch(c) {
        case '\n':
            vtty->cursor_col = 0;
            vtty->cursor_row++;
        break;
        default:
            vt_blit(vtty, fb, glyph);
        break;
    }

    if(vtty->cursor_col >= vtty->width) {
        vtty->cursor_col = 0;
        vtty->cursor_row++;
    }
    if(vtty->cursor_row >= vtty->height) {
        vtty->cursor_row = 0;
    }
}

int
vt_write(jove_owned_obj_t *obj, const char *s, size_t n)
{
    if(obj_gettype(obj) != JOVE_OBJ_VIRTTERM) {
        reterr(EBADOBJ);
    }

    struct virtterm *vtty = obj_deref(obj);
    jove_owned_obj_t *fb_obj = objdir_getlocal(_rootdir_obj, vtty->fb_obj);
    if(obj_gettype(fb_obj) != JOVE_OBJ_FRAMEBUFFER) {
        obj_release(fb_obj);
        reterr(EBADOBJ);
    }

    for(size_t i = 0; i < n; i++) {
        vt_putc(vtty, fb_obj, s[i]);
    }

    obj_release(fb_obj);
    return 0;
}

void
vt_init()
{
    const char *font_path = cmdline_getarg("font");
    if(font_path == NULL) {
        kprintf("Kernel commandline is missing 'font' argument. VTT is disabled.");
        return;
    }

    jove_owned_obj_t *initrd_obj = objdir_getlocal(_rootdir_obj, ROOTDIR_INITRD_I);
    if(obj_gettype(initrd_obj) != JOVE_OBJ_OBJDIR) {
        kprintf("Initrd is not present. VTT is disabled.\n");
        obj_release(initrd_obj);
        return;
    }

    jove_owned_obj_t *file_obj = initrd_seek(initrd_obj, font_path);
    if(file_obj != NULL) {
        s_font = initrd_file_data(file_obj);
        obj_release(file_obj);
    }

    obj_release(initrd_obj);

    if(s_font == NULL) {
        kprintf("Could not find file %s in initrd. VTT is disabled.\n", font_path);
        return;
    }
    if(s_font->magic != PSF1_FONT_MAGIC) {
        kprintf("Font '%s' does not match magic number! VTT is disabled.\n", font_path);
        return;
    }

    s_init_vtty.fb_obj = ROOTDIR_FRAMEBUFFER_I;
    s_init_vtty.cursor_fg = 0x00FFFFFF;

    {
        jove_owned_obj_t *fb_obj = objdir_getlocal(_rootdir_obj, ROOTDIR_FRAMEBUFFER_I);
        s_init_vtty.width = fb_width(fb_obj) / 9;
        s_init_vtty.height = fb_height(fb_obj) / s_font->char_height;
        obj_release(fb_obj);

        jove_owned_obj_t *vt_obj = objdir_getlocal(_rootdir_obj, ROOTDIR_VIRTTERM_I);
        obj_settype(vt_obj, JOVE_OBJ_VIRTTERM);
        obj_setvalue(vt_obj, (uintmax_t)&s_init_vtty);
        obj_release(vt_obj);
    }
}