#include "common.h"
#include "ppu.c"
#include "uxn-fast.c"
#include "rom.c"

static Uxn u;
static Ppu ppu;
static Device *devscreen;
static Device *devctrl;
static Device *devmouse;
static Device *devaudio;

void
nil_talk(Device *d, u8 b0, u8 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; uart_puts(stmp); break;
        // TODO: implement printf for the uart to be able to format
        // numbers.
        // 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;
    }
}

static void
docolors(Device *d) {
    for(size_t i = 0; i < 4; ++i) {
        u8 r = ((d->dat[0x8 + i / 2] >> (!(i % 2) << 2)) & 0x0f) * 0x11;
        u8 g = ((d->dat[0xa + i / 2] >> (!(i % 2) << 2)) & 0x0f) * 0x11;
        u8 b = ((d->dat[0xc + i / 2] >> (!(i % 2) << 2)) & 0x0f) * 0x11;

        if (rgb_order) {
            palette[i] = (b << 16) | (g << 8) | r;
        } else {
            palette[i] = (r << 16) | (g << 8) | b;
        }
    }
    for(size_t i = 4; i < 16; ++i) {
        palette[i] = palette[i / 4];
    }

    // Redraw the screen if we change the color palette.
    reqdraw = 1;
    redraw_screen();
}

void
system_talk(Device *d, u8 b0, u8 w) {
    if(!w) { /* read */
        switch(b0) {
        case 0x2: d->dat[0x2] = d->u->wst.ptr; break;
        case 0x3: d->dat[0x3] = d->u->rst.ptr; break;
        }
    } else { /* write */
        switch(b0) {
        case 0x2: d->u->wst.ptr = d->dat[0x2]; break;
        case 0x3: d->u->rst.ptr = d->dat[0x3]; break;
        case 0xf: d->u->ram.ptr = 0x0000; break;
        }
        if(b0 > 0x7 && b0 < 0xe) {
            docolors(d);
        }
    }
    (void)b0;
}

void
screen_talk(Device *d, u8 b0, u8 w) {
    // uart_puts("screen_talk\n");
    if(w && b0 == 0xe) {
        Uint16 x = mempeek16(d->dat, 0x8);
        Uint16 y = mempeek16(d->dat, 0xa);
        Uint8 layer = d->dat[0xe] >> 4 & 0x1;
        ppu_pixel(&ppu, layer, x, y, d->dat[0xe] & 0x3);
        reqdraw = 1;
    } else if(w && b0 == 0xf) {
        Uint16 x = mempeek16(d->dat, 0x8);
        Uint16 y = mempeek16(d->dat, 0xa);
        Uint8 layer = d->dat[0xf] >> 0x6 & 0x1;
        Uint8 *addr = &d->mem[mempeek16(d->dat, 0xc)];
        if(d->dat[0xf] >> 0x7 & 0x1)
            ppu_2bpp(&ppu, layer, x, y, addr, d->dat[0xf] & 0xf, d->dat[0xf] >> 0x4 & 0x1, d->dat[0xf] >> 0x5 & 0x1);
        else
            ppu_1bpp(&ppu, layer, x, y, addr, d->dat[0xf] & 0xf, d->dat[0xf] >> 0x4 & 0x1, d->dat[0xf] >> 0x5 & 0x1);
        reqdraw = 1;
    }
}

static void
audio_talk(Device *d, u8 b0, u8 w) {
    // TODO: Implement...
    // uart_puts("audio_talk\n");
    (void)d;
    (void)b0;
    (void)w;
}

void
datetime_talk(Device *d, u8 b0, u8 w) {
    // TODO: Implement...
    // uart_puts("datetime_talk\n");
    (void)d;
    (void)b0;
    (void)w;
}

void
file_talk(Device *d, u8 b0, u8 w) {
    // TODO: Implement...
    // uart_puts("file_talk\n");
    (void)d;
    (void)b0;
    (void)w;
}

void
init_uxn() {
    uart_puts("Initializing UXN.\n");

    // Clear UXN memory.
    memzero8(&u, sizeof(Uxn));

    ppu_init(&ppu, SCREEN_WIDTH / 8,  SCREEN_HEIGHT / 8);

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

    // Prepare devices.
    uxn_port(&u, 0x0, "system", system_talk);
    uxn_port(&u, 0x1, "console", console_talk);
    devscreen = uxn_port(&u, 0x2, "screen", screen_talk);
    devaudio = uxn_port(&u, 0x3, "audio0", audio_talk);
    uxn_port(&u, 0x4, "audio1", audio_talk);
    uxn_port(&u, 0x5, "audio2", audio_talk);
    uxn_port(&u, 0x6, "audio3", audio_talk);
    uxn_port(&u, 0x7, "---", nil_talk);
    devctrl = uxn_port(&u, 0x8, "controller", nil_talk);
    devmouse = uxn_port(&u, 0x9, "mouse", nil_talk);
    uxn_port(&u, 0xa, "file", file_talk);
    uxn_port(&u, 0xb, "datetime", datetime_talk);
    uxn_port(&u, 0xc, "---", nil_talk);
    uxn_port(&u, 0xd, "---", nil_talk);
    uxn_port(&u, 0xe, "---", nil_talk);
    uxn_port(&u, 0xf, "---", nil_talk);
    mempoke16(devscreen->dat, 2, ppu.width);
    mempoke16(devscreen->dat, 4, ppu.height);
}

void
clear_bss(void) {
    extern u64 __bss_start;
    extern u64 __bss_end;
    u64 bss_size = &__bss_end - &__bss_start;
    memzero64(&__bss_start, bss_size);
}

void
main(void) {
    // Initialization.
    clear_bss();
    uart_init();
    init_uxn();

    uxn_eval(&u, 0x0100);
    u64 current_ticks = timer_get_ticks();
    while (true) {
        // Echo input to standard output.
        uxn_eval(&u, mempeek16(devscreen->dat, 0));

        // Blit ppu.pixels to the framebuffer.
        blit_framebuffer(&ppu);

        // Sync at 60 Hz.
        if ((timer_get_ticks() - current_ticks) < 16666) {
            wait(16666 - (timer_get_ticks() - current_ticks));
        }
        current_ticks = timer_get_ticks();
    }
}