#include <string.h>
#include <time.h>

#include "common.h"
#include "bitmap.h"
// #include "small-font.c"
#include "bd-font.c"

#include "uxn/uxn.h"
#include "uxn/uxn.c"
#include "uxn/devices/ppu.h"
#include "uxn/devices/ppu.c"
#include "uxn/roms/boot.c"
#include "text.h"

/*
Copyright (c) 2021 Bad Diode

Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE.
*/

static Ppu ppu;
u8 reqdraw = 0;
static Device *devscreen;
static Device *devctrl;
time_t time_seconds;

void
nil_talk(Device *d, Uint8 b0, Uint8 w) {
    (void)d;
    (void)b0;
    (void)w;
}

void
console_talk(Device *d, u8 b0, u8 w) {
    char stmp[2];
    if(!w) {
        return;
    }
    switch(b0) {
        case 0x8: stmp[0] = d->dat[0x8]; stmp[1] = 0; txt_printf(stmp); break;
        case 0x9: txt_printf("0x%02x", d->dat[0x9]); break;
        case 0xb: txt_printf("0x%04x", mempeek16(d->dat, 0xa)); break;
        case 0xd: txt_printf("%s", &d->mem[mempeek16(d->dat, 0xc)]); break;
    }
}

void
system_talk(Device *d, Uint8 b0, Uint8 w) {
    if(!w) {
        d->dat[0x2] = d->u->wst.ptr;
        d->dat[0x3] = d->u->rst.ptr;
    } else {
        putcolors(&ppu, &d->dat[0x8]);
    }
    (void)b0;
}

IWRAM_CODE
void
screen_talk(Device *d, Uint8 b0, Uint8 w) {
    if(w && b0 == 0xe) {
        Uint16 x = mempeek16(d->dat, 0x8);
        Uint16 y = mempeek16(d->dat, 0xa);
        Uint8 *addr = &d->mem[mempeek16(d->dat, 0xc)];
        Uint8 *layer = d->dat[0xe] >> 4 & 0x1 ? ppu.fg : ppu.bg;
        Uint8 mode = d->dat[0xe] >> 5;
        if(!mode) {
            putpixel(&ppu, layer, x, y, d->dat[0xe] & 0x3);
        } else if(mode-- & 0x1) {
            puticn(&ppu, layer, x, y, addr, d->dat[0xe] & 0xf, mode & 0x2, mode & 0x4);
        } else {
            putchr(&ppu, layer, x, y, addr, d->dat[0xe] & 0xf, mode & 0x2, mode & 0x4);
        }
        reqdraw = 1;
    }
}

void
datetime_talk(Device *d, Uint8 b0, Uint8 w) {
	struct tm *t = localtime(&time_seconds);
	t->tm_year += 1900;
	mempoke16(d->dat, 0x0, t->tm_year);
	d->dat[0x2] = t->tm_mon;
	d->dat[0x3] = t->tm_mday;
	d->dat[0x4] = t->tm_hour;
	d->dat[0x5] = t->tm_min;
	d->dat[0x6] = t->tm_sec;
	d->dat[0x7] = t->tm_wday;
	mempoke16(d->dat, 0x08, t->tm_yday);
	d->dat[0xa] = t->tm_isdst;
	(void)b0;
	(void)w;
}

void
init_uxn(Uxn *u) {
    // Initialize PPU.
    initppu(&ppu, 30, 20, 0);

    // Init clock.
    time_seconds = time(NULL);

    // Copy rom to VM.
    memcpy(u->ram.dat + PAGE_PROGRAM, uxn_rom, sizeof(uxn_rom));

    // Prepare devices.
    portuxn(u, 0x0, "system", system_talk);
    portuxn(u, 0x1, "console", console_talk);
    devscreen = portuxn(u, 0x2, "screen", screen_talk);
    portuxn(u, 0x3, "---", nil_talk);
    portuxn(u, 0x4, "---", nil_talk);
    portuxn(u, 0x5, "---", nil_talk);
    portuxn(u, 0x6, "---", nil_talk);
    portuxn(u, 0x7, "---", nil_talk);
	devctrl = portuxn(u, 0x8, "controller", nil_talk);
    portuxn(u, 0x9, "---", nil_talk);
    portuxn(u, 0xa, "---", nil_talk);
	portuxn(u, 0xb, "datetime", datetime_talk);
    portuxn(u, 0xc, "---", nil_talk);
    portuxn(u, 0xd, "---", nil_talk);
    portuxn(u, 0xe, "---", nil_talk);
    portuxn(u, 0xf, "---", nil_talk);
    mempoke16(devscreen->dat, 2, ppu.hor * 8);
    mempoke16(devscreen->dat, 4, ppu.ver * 8);
}

void
handle_input(Uxn *u) {
    poll_keys();

	// TODO: We don't need ifs if we use KEY_INPUTS directly and mayvbe just
	// swap some things if needed.
	Uint8 *flag = &devctrl->dat[2];
	if (key_pressed(KEY_A) | key_hold(KEY_A)) {
	    *flag |= 0x01;
	} else {
	    *flag &= ~0x01;
    }
	if (key_pressed(KEY_B) | key_hold(KEY_B)) {
	    *flag |= 0x02;
	} else {
	    *flag &= ~0x02;
    }
	if (key_pressed(KEY_L) | key_hold(KEY_L)) {
	    *flag |= 0x04;
	} else {
	    *flag &= ~0x04;
    }
	if (key_pressed(KEY_R) | key_hold(KEY_R)) {
	    *flag |= 0x08;
	} else {
	    *flag &= ~0x08;
    }
	if (key_pressed(KEY_UP) | key_hold(KEY_UP)) {
	    *flag |= 0x10;
	} else {
	    *flag &= ~0x10;
    }
	if (key_pressed(KEY_DOWN) | key_hold(KEY_DOWN)) {
	    *flag |= 0x20;
	} else {
	    *flag &= ~0x20;
    }
	if (key_pressed(KEY_LEFT) | key_hold(KEY_LEFT)) {
	    *flag |= 0x40;
	} else {
	    *flag &= ~0x40;
    }
	if (key_pressed(KEY_RIGHT) | key_hold(KEY_RIGHT)) {
	    *flag |= 0x80;
	} else {
	    *flag &= ~0x80;
    }

    evaluxn(u, mempeek16(devctrl->dat, 0));
    devctrl->dat[3] = 0;
}

static Uxn u;
EWRAM_BSS
static Uint8 umem[65536];

int main(void) {
    // Register interrupts.
    irq_init();
    irs_set(IRQ_VBLANK, irs_stub);


    // Initialize VM.
    memset(&u, 0, sizeof(u));
    u.ram.dat = umem;
    init_uxn(&u);

    // Initialize text engine.
    txt_init_hybrid(
            TXT_MODE_HYBRID,
            (Font){
                .data = bd_font,
                .char_height = 8,
                .char_width = 8,
            }, &ppu.fg);
    txt_position(0,0);

    // Main loop.
    int frame_counter = 0;
    evaluxn(&u, 0x0100);
    // flipbuf(&ppu);
    while(true) {
        bios_vblank_wait();
        handle_input(&u);
        profile_start();
        evaluxn(&u, mempeek16(devscreen->dat, 0));
        int eval_cycles = profile_stop();
        flipbuf(&ppu);
        txt_position(0,0);
        txt_printf("FRAME: %d\n", frame_counter);
        txt_printf("EVAL: %d\n", eval_cycles);
        time_seconds++;
        frame_counter++;
    }

    return 0;
}