#include <stdlib.h>
#include <termios.h>
#include <unistd.h>
#include <sys/ioctl.h>

#include "framebuffer.h"

size_t term_width = 0,
       term_height = 0;
struct termios initial_terminal_state = {0};

Framebuffer fb_new(size_t width, size_t height) {
    Framebuffer fb;

    /* In case malloc() fails and we return early */
    fb.width = 0;
    fb.height = 0;

    fb.fb = malloc(sizeof(Pixel *) * height);
    if (fb.fb == NULL) return fb;

    for (size_t i = 0; i < height; i++) {
        fb.fb[i] = malloc(sizeof(Pixel) * width);
        if (fb.fb[i] == NULL) {
            /* FIXME: Memory leak; should free all prev. malloced rows */
            fb.fb = NULL;
            return fb;
        }
    }

    fb.width = width;
    fb.height = height;
    return fb;
}

void fb_free(Framebuffer *fb) {
    if (fb->fb == NULL) goto ret;

    for (size_t i = 0; i < fb->height; i++) {
        free(fb->fb[i]);
    }
    free(fb->fb);

ret:
    fb->width = 0;
    fb->height = 0;
    return;
}

void fb_fill(Framebuffer fb, Pixel pixel) {
    for (size_t row = 0; row < fb.height; row++) {
        for (size_t col = 0; col < fb.width; col++) {
            fb_put(fb, row, col, pixel);
        }
    }
}

void inline fb_put(Framebuffer fb, size_t row, size_t col, Pixel pixel) {
    fb.fb[row][col] = pixel;
}

void term_init(void) {
    tcgetattr(0, &initial_terminal_state);

    struct termios new = initial_terminal_state;

    new.c_lflag &= ~ICANON;   /* Turn off canonical mode */
    new.c_lflag &= ~ECHO;     /* Turn off echoing */
    new.c_cc[VMIN] = 1;       /* One char at a time */
    new.c_cc[VTIME] = 0;      /* No input timeout */
    tcsetattr(0, TCSANOW, &new);

    write(STDOUT_FILENO, "\x1b[?1049h", 8); /* Alternative screen buffer */
    write(STDOUT_FILENO, "\x1b[H", 3); /* Move cursor to top-left */
    write(STDOUT_FILENO, "\x1b[?25l", 6); /* Hide the cursor */

    term_update_size();
}

void term_cleanup(void) {
    tcsetattr(0, TCSANOW, &initial_terminal_state);

    write(STDOUT_FILENO, "\x1b[?25h", 6); /* Show the cursor */
    write(STDOUT_FILENO, "\x1b[?1049l", 8); /* Alternative screen buffer */
}

void term_update_size(void) {
#if defined(TIOCGWINSZ)
    struct winsize ws;

    if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == 0) {
        term_height = ws.ws_row;
        term_width  = ws.ws_col;
        return;
    }
#elif defined(TIOCGSIZE)
    struct ttysize ts;

    if (ioctl(STDOUT_FILENO, TIOCGSIZE, &ts) == 0) {
        term_height = ts.ts_row;
        term_width  = ts.ts_col;
        return;
    }
#else
    #error "Neither TIOCGWINSZ or TIOCGSIZE are defined, can't proceed"
#endif
}

void fb_print(Framebuffer fb) {
    write(STDOUT_FILENO, "\x1b[H", 3); /* Move cursor to top-left */

    /* TODO: finish me */
}